Merge remote-tracking branch 'origin/master' into llvm6

CMakeLists.txt

@@ -339,7 +339,7 @@ set(ZIG_SOURCES
     "${CMAKE_SOURCE_DIR}/src/target.cpp"
     "${CMAKE_SOURCE_DIR}/src/tokenizer.cpp"
     "${CMAKE_SOURCE_DIR}/src/util.cpp"
-    "${CMAKE_SOURCE_DIR}/src/parsec.cpp"
+    "${CMAKE_SOURCE_DIR}/src/translate_c.cpp"
     "${CMAKE_SOURCE_DIR}/src/zig_llvm.cpp"
 )
 

build.zig

@@ -58,5 +58,5 @@ pub fn build(b: &Builder) {
     test_step.dependOn(tests.addCompileErrorTests(b, test_filter));
     test_step.dependOn(tests.addAssembleAndLinkTests(b, test_filter));
     test_step.dependOn(tests.addDebugSafetyTests(b, test_filter));
-    test_step.dependOn(tests.addParseCTests(b, test_filter));
+    test_step.dependOn(tests.addTranslateCTests(b, test_filter));
 }

ci/travis_osx_script

@@ -22,4 +22,4 @@ make install
 ./zig build --build-file ../build.zig test-compile-errors --verbose
 ./zig build --build-file ../build.zig test-asm-link --verbose
 ./zig build --build-file ../build.zig test-debug-safety --verbose
-./zig build --build-file ../build.zig test-parsec --verbose
+./zig build --build-file ../build.zig test-translate-c --verbose

doc/home.html.in

@@ -70,10 +70,14 @@
       <li><a href="#mersenne">Mersenne Twister Random Number Generator</a></li>
     </ul>
     <h3 id="hello">Hello World</h3>
-    <pre><code class="zig">const io = @import("std").io;
+    <pre><code class="zig">const std = @import("std");
 
 pub fn main() -&gt; %void {
-    %return io.stdout.printf("Hello, world!\n");
+    // If this program is run without stdout attached, exit with an error.
+    var stdout_file = %return std.io.getStdOut();
+    // If this program encounters pipe failure when printing to stdout, exit
+    // with an error.
+    %return stdout_file.write("Hello, world!\n");
 }</code></pre>
     <p>Build this with:</p>
     <pre>zig build-exe hello.zig</pre>

doc/langref.html.in

@@ -75,6 +75,7 @@
         <li><a href="#slices">Slices</a></li>
         <li><a href="#struct">struct</a></li>
         <li><a href="#enum">enum</a></li>
+        <li><a href="#union">union</a></li>
         <li><a href="#switch">switch</a></li>
         <li><a href="#while">while</a></li>
         <li><a href="#for">for</a></li>
@@ -209,6 +210,7 @@
             <li><a href="#undef-invalid-error-code">Invalid Error Code</a></li>
             <li><a href="#undef-invalid-enum-cast">Invalid Enum Cast</a></li>
             <li><a href="#undef-incorrect-pointer-alignment">Incorrect Pointer Alignment</a></li>
+            <li><a href="#undef-bad-union-field">Wrong Union Field Access</a></li>
           </ul>
         </li>
         <li><a href="#memory">Memory</a></li>
@@ -2189,6 +2191,8 @@ Test 4/4 enum builtins...OK</code></pre>
         <li><a href="#builtin-enumTagName">@enumTagName</a></li>
         <li><a href="#builtin-memberCount">@memberCount</a></li>
       </ul>
+      <h2 id="union">union</h2>
+      <p>TODO union documentation</p>
       <h2 id="switch">switch</h2>
       <pre><code class="zig">const assert = @import("std").debug.assert;
 const builtin = @import("builtin");
@@ -5117,6 +5121,9 @@ comptime {
       <h3 id="undef-incorrect-pointer-alignment">Incorrect Pointer Alignment</h3>
       <p>TODO</p>
 
+      <h3 id="undef-bad-union-field">Wrong Union Field Access</h3>
+      <p>TODO</p>
+
       <h2 id="memory">Memory</h2>
       <p>TODO: explain no default allocator in zig</p>
       <p>TODO: show how to use the allocator interface</p>
@@ -5405,10 +5412,14 @@ const c = @cImport({
 export fn decode_base_64(dest_ptr: &amp;u8, dest_len: usize,
     source_ptr: &amp;const u8, source_len: usize) -&gt; usize
 {
-    const src = source_ptr[0...source_len];
+    const src = source_ptr[0..source_len];
-    const dest = dest_ptr[0...dest_len];
+    const dest = dest_ptr[0..dest_len];
-    return base64.decode(dest, src).len;
+    const base64_decoder = base64.standard_decoder_unsafe;
-}</code></pre>
+    const decoded_size = base64_decoder.calcSize(src);
+    base64_decoder.decode(dest[0..decoded_size], src);
+    return decoded_size;
+}
+</code></pre>
       <h4>test.c</h4>
       <pre><code class="c">// This header is generated by zig from base64.zig
 #include "base64.h"

example/mix_o_files/base64.zig

@@ -3,5 +3,8 @@ const base64 = @import("std").base64;
 export fn decode_base_64(dest_ptr: &u8, dest_len: usize, source_ptr: &const u8, source_len: usize) -> usize {
     const src = source_ptr[0..source_len];
     const dest = dest_ptr[0..dest_len];
-    return base64.decode(dest, src).len;
+    const base64_decoder = base64.standard_decoder_unsafe;
+    const decoded_size = base64_decoder.calcSize(src);
+    base64_decoder.decode(dest[0..decoded_size], src);
+    return decoded_size;
 }

src-self-hosted/main.zig

@@ -208,7 +208,7 @@ fn printUsage(outstream: &io.OutStream) -> %void {
         \\  build-exe [source]           create executable from source or object files
         \\  build-lib [source]           create library from source or object files
         \\  build-obj [source]           create object from source or assembly
-        \\  parsec [source]              convert c code to zig code
+        \\  translate-c [source]         convert c code to zig code
         \\  targets                      list available compilation targets
         \\  test [source]                create and run a test build
         \\  version                      print version number and exit

src/all_types.hpp

@@ -36,6 +36,7 @@ struct IrInstructionCast;
 struct IrBasicBlock;
 struct ScopeDecls;
 struct ZigWindowsSDK;
+struct Tld;
 
 struct IrGotoItem {
     AstNode *source_node;
@@ -59,7 +60,9 @@ struct IrExecutable {
     Buf *c_import_buf;
     AstNode *source_node;
     IrExecutable *parent_exec;
+    IrExecutable *source_exec;
     Scope *begin_scope;
+    ZigList<Tld *> tld_list;
 };
 
 enum OutType {
@@ -73,6 +76,7 @@ enum ConstParentId {
     ConstParentIdNone,
     ConstParentIdStruct,
     ConstParentIdArray,
+    ConstParentIdUnion,
 };
 
 struct ConstParent {
@@ -87,6 +91,9 @@ struct ConstParent {
             ConstExprValue *struct_val;
             size_t field_index;
         } p_struct;
+        struct {
+            ConstExprValue *union_val;
+        } p_union;
     } data;
 };
 
@@ -100,6 +107,12 @@ struct ConstStructValue {
     ConstParent parent;
 };
 
+struct ConstUnionValue {
+    uint64_t tag;
+    ConstExprValue *payload;
+    ConstParent parent;
+};
+
 enum ConstArraySpecial {
     ConstArraySpecialNone,
     ConstArraySpecialUndef,
@@ -238,6 +251,7 @@ struct ConstExprValue {
         ErrorTableEntry *x_pure_err;
         ConstEnumValue x_enum;
         ConstStructValue x_struct;
+        ConstUnionValue x_union;
         ConstArrayValue x_array;
         ConstPtrValue x_ptr;
         ImportTableEntry *x_import;
@@ -336,6 +350,13 @@ struct TypeEnumField {
     uint32_t gen_index;
 };
 
+struct TypeUnionField {
+    Buf *name;
+    TypeTableEntry *type_entry;
+    uint32_t value;
+    uint32_t gen_index;
+};
+
 enum NodeType {
     NodeTypeRoot,
     NodeTypeFnProto,
@@ -1021,14 +1042,19 @@ struct TypeTableEntryEnumTag {
     LLVMValueRef name_table;
 };
 
+uint32_t type_ptr_hash(const TypeTableEntry *ptr);
+bool type_ptr_eql(const TypeTableEntry *a, const TypeTableEntry *b);
+
 struct TypeTableEntryUnion {
     AstNode *decl_node;
     ContainerLayout layout;
     uint32_t src_field_count;
     uint32_t gen_field_count;
-    TypeStructField *fields;
+    TypeUnionField *fields;
-    uint64_t size_bytes;
     bool is_invalid; // true if any fields are invalid
+    TypeTableEntry *tag_type;
+    LLVMTypeRef union_type_ref;
+
     ScopeDecls *decls_scope;
 
     // set this flag temporarily to detect infinite loops
@@ -1039,6 +1065,13 @@ struct TypeTableEntryUnion {
 
     bool zero_bits_loop_flag;
     bool zero_bits_known;
+    uint32_t abi_alignment; // also figured out with zero_bits pass
+
+    size_t gen_union_index;
+    size_t gen_tag_index;
+
+    uint32_t union_size_bytes;
+    TypeTableEntry *most_aligned_union_member;
 };
 
 struct FnGenParamInfo {
@@ -1287,6 +1320,7 @@ enum PanicMsgId {
     PanicMsgIdUnwrapMaybeFail,
     PanicMsgIdInvalidErrorCode,
     PanicMsgIdIncorrectAlignment,
+    PanicMsgIdBadUnionField,
 
     PanicMsgIdCount,
 };
@@ -1796,6 +1830,7 @@ enum IrInstructionId {
     IrInstructionIdFieldPtr,
     IrInstructionIdStructFieldPtr,
     IrInstructionIdEnumFieldPtr,
+    IrInstructionIdUnionFieldPtr,
     IrInstructionIdElemPtr,
     IrInstructionIdVarPtr,
     IrInstructionIdCall,
@@ -1805,6 +1840,7 @@ enum IrInstructionId {
     IrInstructionIdContainerInitList,
     IrInstructionIdContainerInitFields,
     IrInstructionIdStructInit,
+    IrInstructionIdUnionInit,
     IrInstructionIdUnreachable,
     IrInstructionIdTypeOf,
     IrInstructionIdToPtrType,
@@ -2060,6 +2096,14 @@ struct IrInstructionEnumFieldPtr {
     bool is_const;
 };
 
+struct IrInstructionUnionFieldPtr {
+    IrInstruction base;
+
+    IrInstruction *union_ptr;
+    TypeUnionField *field;
+    bool is_const;
+};
+
 struct IrInstructionElemPtr {
     IrInstruction base;
 
@@ -2150,6 +2194,15 @@ struct IrInstructionStructInit {
     LLVMValueRef tmp_ptr;
 };
 
+struct IrInstructionUnionInit {
+    IrInstruction base;
+
+    TypeTableEntry *union_type;
+    TypeUnionField *field;
+    IrInstruction *init_value;
+    LLVMValueRef tmp_ptr;
+};
+
 struct IrInstructionUnreachable {
     IrInstruction base;
 };

src/analyze.cpp

@@ -28,7 +28,7 @@ static void resolve_union_zero_bits(CodeGen *g, TypeTableEntry *union_type);
 
 ErrorMsg *add_node_error(CodeGen *g, AstNode *node, Buf *msg) {
     if (node->owner->c_import_node != nullptr) {
-        // if this happens, then parsec generated code that
+        // if this happens, then translate_c generated code that
         // failed semantic analysis, which isn't supposed to happen
         ErrorMsg *err = add_node_error(g, node->owner->c_import_node,
             buf_sprintf("compiler bug: @cImport generated invalid zig code"));
@@ -48,7 +48,7 @@ ErrorMsg *add_node_error(CodeGen *g, AstNode *node, Buf *msg) {
 
 ErrorMsg *add_error_note(CodeGen *g, ErrorMsg *parent_msg, AstNode *node, Buf *msg) {
     if (node->owner->c_import_node != nullptr) {
-        // if this happens, then parsec generated code that
+        // if this happens, then translate_c generated code that
         // failed semantic analysis, which isn't supposed to happen
 
         Buf *note_path = buf_create_from_str("?.c");
@@ -338,7 +338,7 @@ TypeTableEntry *get_smallest_unsigned_int_type(CodeGen *g, uint64_t x) {
 TypeTableEntry *get_pointer_to_type_extra(CodeGen *g, TypeTableEntry *child_type, bool is_const,
         bool is_volatile, uint32_t byte_alignment, uint32_t bit_offset, uint32_t unaligned_bit_count)
 {
-    assert(child_type->id != TypeTableEntryIdInvalid);
+    assert(!type_is_invalid(child_type));
 
     TypeId type_id = {};
     TypeTableEntry **parent_pointer = nullptr;
@@ -1008,11 +1008,12 @@ TypeTableEntry *get_partial_container_type(CodeGen *g, Scope *scope, ContainerKi
     }
 
     size_t line = decl_node ? decl_node->line : 0;
+    unsigned dwarf_kind = ZigLLVMTag_DW_structure_type();
 
     ImportTableEntry *import = get_scope_import(scope);
     entry->type_ref = LLVMStructCreateNamed(LLVMGetGlobalContext(), name);
     entry->di_type = ZigLLVMCreateReplaceableCompositeType(g->dbuilder,
-        ZigLLVMTag_DW_structure_type(), name,
+        dwarf_kind, name,
         ZigLLVMFileToScope(import->di_file), import->di_file, (unsigned)(line + 1));
 
     buf_init_from_str(&entry->name, name);
@@ -1285,7 +1286,7 @@ static void resolve_enum_type(CodeGen *g, TypeTableEntry *enum_type) {
         return;
 
     resolve_enum_zero_bits(g, enum_type);
-    if (enum_type->data.enumeration.is_invalid)
+    if (type_is_invalid(enum_type))
         return;
 
     AstNode *decl_node = enum_type->data.enumeration.decl_node;
@@ -1834,7 +1835,246 @@ static void resolve_struct_type(CodeGen *g, TypeTableEntry *struct_type) {
 }
 
 static void resolve_union_type(CodeGen *g, TypeTableEntry *union_type) {
-    zig_panic("TODO");
+    assert(union_type->id == TypeTableEntryIdUnion);
+
+    if (union_type->data.unionation.complete)
+        return;
+
+    resolve_union_zero_bits(g, union_type);
+    if (type_is_invalid(union_type))
+        return;
+
+    AstNode *decl_node = union_type->data.unionation.decl_node;
+
+    if (union_type->data.unionation.embedded_in_current) {
+        if (!union_type->data.unionation.reported_infinite_err) {
+            union_type->data.unionation.reported_infinite_err = true;
+            add_node_error(g, decl_node, buf_sprintf("union '%s' contains itself", buf_ptr(&union_type->name)));
+        }
+        return;
+    }
+
+    assert(!union_type->data.unionation.zero_bits_loop_flag);
+    assert(decl_node->type == NodeTypeContainerDecl);
+    assert(union_type->di_type);
+
+    uint32_t field_count = union_type->data.unionation.src_field_count;
+
+    assert(union_type->data.unionation.fields);
+
+    uint32_t gen_field_count = union_type->data.unionation.gen_field_count;
+    ZigLLVMDIType **union_inner_di_types = allocate<ZigLLVMDIType*>(gen_field_count);
+
+    TypeTableEntry *most_aligned_union_member = nullptr;
+    uint64_t size_of_most_aligned_member_in_bits = 0;
+    uint64_t biggest_align_in_bits = 0;
+    uint64_t biggest_size_in_bits = 0;
+
+    bool auto_layout = (union_type->data.unionation.layout == ContainerLayoutAuto);
+    ZigLLVMDIEnumerator **di_enumerators = allocate<ZigLLVMDIEnumerator*>(field_count);
+
+    Scope *scope = &union_type->data.unionation.decls_scope->base;
+    ImportTableEntry *import = get_scope_import(scope);
+
+    // set temporary flag
+    union_type->data.unionation.embedded_in_current = true;
+
+    for (uint32_t i = 0; i < field_count; i += 1) {
+        AstNode *field_node = decl_node->data.container_decl.fields.at(i);
+        TypeUnionField *type_union_field = &union_type->data.unionation.fields[i];
+        TypeTableEntry *field_type = type_union_field->type_entry;
+
+        ensure_complete_type(g, field_type);
+        if (type_is_invalid(field_type)) {
+            union_type->data.unionation.is_invalid = true;
+            continue;
+        }
+
+        if (!type_has_bits(field_type))
+            continue;
+
+        di_enumerators[i] = ZigLLVMCreateDebugEnumerator(g->dbuilder, buf_ptr(type_union_field->name), i);
+
+        uint64_t store_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, field_type->type_ref);
+        uint64_t abi_align_in_bits = 8*LLVMABIAlignmentOfType(g->target_data_ref, field_type->type_ref);
+
+        assert(store_size_in_bits > 0);
+        assert(abi_align_in_bits > 0);
+
+        union_inner_di_types[type_union_field->gen_index] = ZigLLVMCreateDebugMemberType(g->dbuilder,
+                ZigLLVMTypeToScope(union_type->di_type), buf_ptr(type_union_field->name),
+                import->di_file, (unsigned)(field_node->line + 1),
+                store_size_in_bits,
+                abi_align_in_bits,
+                0,
+                0, field_type->di_type);
+
+        biggest_size_in_bits = max(biggest_size_in_bits, store_size_in_bits);
+
+        if (!most_aligned_union_member || abi_align_in_bits > biggest_align_in_bits) {
+            most_aligned_union_member = field_type;
+            biggest_align_in_bits = abi_align_in_bits;
+            size_of_most_aligned_member_in_bits = store_size_in_bits;
+        }
+    }
+
+    // unset temporary flag
+    union_type->data.unionation.embedded_in_current = false;
+    union_type->data.unionation.complete = true;
+    union_type->data.unionation.union_size_bytes = biggest_size_in_bits / 8;
+    union_type->data.unionation.most_aligned_union_member = most_aligned_union_member;
+
+    if (union_type->data.unionation.is_invalid)
+        return;
+
+    if (union_type->zero_bits) {
+        union_type->type_ref = LLVMVoidType();
+
+        uint64_t debug_size_in_bits = 0;
+        uint64_t debug_align_in_bits = 0;
+        ZigLLVMDIType **di_root_members = nullptr;
+        size_t debug_member_count = 0;
+        ZigLLVMDIType *replacement_di_type = ZigLLVMCreateDebugUnionType(g->dbuilder,
+                ZigLLVMFileToScope(import->di_file),
+                buf_ptr(&union_type->name),
+                import->di_file, (unsigned)(decl_node->line + 1),
+                debug_size_in_bits,
+                debug_align_in_bits,
+                0, di_root_members, (int)debug_member_count, 0, "");
+
+        ZigLLVMReplaceTemporary(g->dbuilder, union_type->di_type, replacement_di_type);
+        union_type->di_type = replacement_di_type;
+        return;
+    }
+
+    assert(most_aligned_union_member != nullptr);
+
+    bool want_safety = auto_layout && (field_count >= 2);
+    uint64_t padding_in_bits = biggest_size_in_bits - size_of_most_aligned_member_in_bits;
+
+
+    if (!want_safety) {
+        if (padding_in_bits > 0) {
+            TypeTableEntry *u8_type = get_int_type(g, false, 8);
+            TypeTableEntry *padding_array = get_array_type(g, u8_type, padding_in_bits / 8);
+            LLVMTypeRef union_element_types[] = {
+                most_aligned_union_member->type_ref,
+                padding_array->type_ref,
+            };
+            LLVMStructSetBody(union_type->type_ref, union_element_types, 2, false);
+        } else {
+            LLVMStructSetBody(union_type->type_ref, &most_aligned_union_member->type_ref, 1, false);
+        }
+        union_type->data.unionation.union_type_ref = union_type->type_ref;
+        union_type->data.unionation.gen_tag_index = SIZE_MAX;
+        union_type->data.unionation.gen_union_index = SIZE_MAX;
+
+        assert(8*LLVMABIAlignmentOfType(g->target_data_ref, union_type->type_ref) >= biggest_align_in_bits);
+        assert(8*LLVMStoreSizeOfType(g->target_data_ref, union_type->type_ref) >= biggest_size_in_bits);
+
+        // create debug type for union
+        ZigLLVMDIType *replacement_di_type = ZigLLVMCreateDebugUnionType(g->dbuilder,
+            ZigLLVMFileToScope(import->di_file), buf_ptr(&union_type->name),
+            import->di_file, (unsigned)(decl_node->line + 1),
+            biggest_size_in_bits, biggest_align_in_bits, 0, union_inner_di_types,
+            gen_field_count, 0, "");
+
+        ZigLLVMReplaceTemporary(g->dbuilder, union_type->di_type, replacement_di_type);
+        union_type->di_type = replacement_di_type;
+        return;
+    }
+
+    LLVMTypeRef union_type_ref;
+    if (padding_in_bits > 0) {
+        TypeTableEntry *u8_type = get_int_type(g, false, 8);
+        TypeTableEntry *padding_array = get_array_type(g, u8_type, padding_in_bits / 8);
+        LLVMTypeRef union_element_types[] = {
+            most_aligned_union_member->type_ref,
+            padding_array->type_ref,
+        };
+        union_type_ref = LLVMStructType(union_element_types, 2, false);
+    } else {
+        union_type_ref = most_aligned_union_member->type_ref;
+    }
+    union_type->data.unionation.union_type_ref = union_type_ref;
+
+    assert(8*LLVMABIAlignmentOfType(g->target_data_ref, union_type_ref) >= biggest_align_in_bits);
+    assert(8*LLVMStoreSizeOfType(g->target_data_ref, union_type_ref) >= biggest_size_in_bits);
+
+    // create llvm type for root struct
+    TypeTableEntry *tag_int_type = get_smallest_unsigned_int_type(g, field_count - 1);
+    TypeTableEntry *tag_type_entry = tag_int_type;
+    union_type->data.unionation.tag_type = tag_type_entry;
+    uint64_t align_of_tag_in_bits = 8*LLVMABIAlignmentOfType(g->target_data_ref, tag_int_type->type_ref);
+
+    if (align_of_tag_in_bits >= biggest_align_in_bits) {
+        union_type->data.unionation.gen_tag_index = 0;
+        union_type->data.unionation.gen_union_index = 1;
+    } else {
+        union_type->data.unionation.gen_union_index = 0;
+        union_type->data.unionation.gen_tag_index = 1;
+    }
+
+    LLVMTypeRef root_struct_element_types[2];
+    root_struct_element_types[union_type->data.unionation.gen_tag_index] = tag_type_entry->type_ref;
+    root_struct_element_types[union_type->data.unionation.gen_union_index] = union_type_ref;
+    LLVMStructSetBody(union_type->type_ref, root_struct_element_types, 2, false);
+
+
+    // create debug type for root struct
+
+    // create debug type for tag
+    uint64_t tag_debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, tag_type_entry->type_ref);
+    uint64_t tag_debug_align_in_bits = 8*LLVMABIAlignmentOfType(g->target_data_ref, tag_type_entry->type_ref);
+    ZigLLVMDIType *tag_di_type = ZigLLVMCreateDebugEnumerationType(g->dbuilder,
+            ZigLLVMTypeToScope(union_type->di_type), "AnonEnum",
+            import->di_file, (unsigned)(decl_node->line + 1),
+            tag_debug_size_in_bits, tag_debug_align_in_bits, di_enumerators, field_count,
+            tag_type_entry->di_type, "");
+
+    // create debug type for union
+    ZigLLVMDIType *union_di_type = ZigLLVMCreateDebugUnionType(g->dbuilder,
+            ZigLLVMTypeToScope(union_type->di_type), "AnonUnion",
+            import->di_file, (unsigned)(decl_node->line + 1),
+            biggest_size_in_bits, biggest_align_in_bits, 0, union_inner_di_types,
+            gen_field_count, 0, "");
+
+    uint64_t union_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, union_type->type_ref,
+            union_type->data.unionation.gen_union_index);
+    uint64_t tag_offset_in_bits = 8*LLVMOffsetOfElement(g->target_data_ref, union_type->type_ref,
+            union_type->data.unionation.gen_tag_index);
+
+    ZigLLVMDIType *union_member_di_type = ZigLLVMCreateDebugMemberType(g->dbuilder,
+            ZigLLVMTypeToScope(union_type->di_type), "union_field",
+            import->di_file, (unsigned)(decl_node->line + 1),
+            biggest_size_in_bits,
+            biggest_align_in_bits,
+            union_offset_in_bits,
+            0, union_di_type);
+    ZigLLVMDIType *tag_member_di_type = ZigLLVMCreateDebugMemberType(g->dbuilder,
+            ZigLLVMTypeToScope(union_type->di_type), "tag_field",
+            import->di_file, (unsigned)(decl_node->line + 1),
+            tag_debug_size_in_bits,
+            tag_debug_align_in_bits,
+            tag_offset_in_bits,
+            0, tag_di_type);
+
+    ZigLLVMDIType *di_root_members[2];
+    di_root_members[union_type->data.unionation.gen_tag_index] = tag_member_di_type;
+    di_root_members[union_type->data.unionation.gen_union_index] = union_member_di_type;
+
+    uint64_t debug_size_in_bits = 8*LLVMStoreSizeOfType(g->target_data_ref, union_type->type_ref);
+    uint64_t debug_align_in_bits = 8*LLVMABISizeOfType(g->target_data_ref, union_type->type_ref);
+    ZigLLVMDIType *replacement_di_type = ZigLLVMCreateDebugStructType(g->dbuilder,
+            ZigLLVMFileToScope(import->di_file),
+            buf_ptr(&union_type->name),
+            import->di_file, (unsigned)(decl_node->line + 1),
+            debug_size_in_bits,
+            debug_align_in_bits,
+            0, nullptr, di_root_members, 2, 0, nullptr, "");
+
+    ZigLLVMReplaceTemporary(g->dbuilder, union_type->di_type, replacement_di_type);
+    union_type->di_type = replacement_di_type;
 }
 
 static void resolve_enum_zero_bits(CodeGen *g, TypeTableEntry *enum_type) {
@@ -1873,7 +2113,7 @@ static void resolve_enum_zero_bits(CodeGen *g, TypeTableEntry *enum_type) {
         type_enum_field->value = i;
 
         type_ensure_zero_bits_known(g, field_type);
-        if (field_type->id == TypeTableEntryIdInvalid) {
+        if (type_is_invalid(field_type)) {
             enum_type->data.enumeration.is_invalid = true;
             continue;
         }
@@ -1980,7 +2220,69 @@ static void resolve_struct_zero_bits(CodeGen *g, TypeTableEntry *struct_type) {
 }
 
 static void resolve_union_zero_bits(CodeGen *g, TypeTableEntry *union_type) {
-    zig_panic("TODO resolve_union_zero_bits");
+    assert(union_type->id == TypeTableEntryIdUnion);
+
+    if (union_type->data.unionation.zero_bits_known)
+        return;
+
+    if (union_type->data.unionation.zero_bits_loop_flag) {
+        union_type->data.unionation.zero_bits_known = true;
+        return;
+    }
+
+    union_type->data.unionation.zero_bits_loop_flag = true;
+
+    AstNode *decl_node = union_type->data.unionation.decl_node;
+    assert(decl_node->type == NodeTypeContainerDecl);
+    assert(union_type->di_type);
+
+    assert(!union_type->data.unionation.fields);
+    uint32_t field_count = (uint32_t)decl_node->data.container_decl.fields.length;
+    union_type->data.unionation.src_field_count = field_count;
+    union_type->data.unionation.fields = allocate<TypeUnionField>(field_count);
+
+    uint32_t biggest_align_bytes = 0;
+
+    Scope *scope = &union_type->data.unionation.decls_scope->base;
+
+    uint32_t gen_field_index = 0;
+    for (uint32_t i = 0; i < field_count; i += 1) {
+        AstNode *field_node = decl_node->data.container_decl.fields.at(i);
+        TypeUnionField *type_union_field = &union_type->data.unionation.fields[i];
+        type_union_field->name = field_node->data.struct_field.name;
+        TypeTableEntry *field_type = analyze_type_expr(g, scope, field_node->data.struct_field.type);
+        type_union_field->type_entry = field_type;
+        type_union_field->value = i;
+
+        type_ensure_zero_bits_known(g, field_type);
+        if (type_is_invalid(field_type)) {
+            union_type->data.unionation.is_invalid = true;
+            continue;
+        }
+
+        if (!type_has_bits(field_type))
+            continue;
+
+        type_union_field->gen_index = gen_field_index;
+        gen_field_index += 1;
+
+        uint32_t field_align_bytes = get_abi_alignment(g, field_type);
+        if (field_align_bytes > biggest_align_bytes) {
+            biggest_align_bytes = field_align_bytes;
+        }
+    }
+
+    bool auto_layout = (union_type->data.unionation.layout == ContainerLayoutAuto);
+
+    union_type->data.unionation.zero_bits_loop_flag = false;
+    union_type->data.unionation.gen_field_count = gen_field_index;
+    union_type->zero_bits = (gen_field_index == 0 && (field_count < 2 || !auto_layout));
+    union_type->data.unionation.zero_bits_known = true;
+
+    // also compute abi_alignment
+    if (!union_type->zero_bits) {
+        union_type->data.unionation.abi_alignment = biggest_align_bytes;
+    }
 }
 
 static void get_fully_qualified_decl_name_internal(Buf *buf, Scope *scope, uint8_t sep) {
@@ -2851,6 +3153,18 @@ TypeStructField *find_struct_type_field(TypeTableEntry *type_entry, Buf *name) {
     return nullptr;
 }
 
+TypeUnionField *find_union_type_field(TypeTableEntry *type_entry, Buf *name) {
+    assert(type_entry->id == TypeTableEntryIdUnion);
+    assert(type_entry->data.unionation.complete);
+    for (uint32_t i = 0; i < type_entry->data.unionation.src_field_count; i += 1) {
+        TypeUnionField *field = &type_entry->data.unionation.fields[i];
+        if (buf_eql_buf(field->name, name)) {
+            return field;
+        }
+    }
+    return nullptr;
+}
+
 static bool is_container(TypeTableEntry *type_entry) {
     switch (type_entry->id) {
         case TypeTableEntryIdInvalid:
@@ -4703,6 +5017,8 @@ ConstParent *get_const_val_parent(CodeGen *g, ConstExprValue *value) {
         return &value->data.x_array.s_none.parent;
     } else if (type_entry->id == TypeTableEntryIdStruct) {
         return &value->data.x_struct.parent;
+    } else if (type_entry->id == TypeTableEntryIdUnion) {
+        return &value->data.x_union.parent;
     }
     return nullptr;
 }
@@ -4914,7 +5230,8 @@ uint32_t get_abi_alignment(CodeGen *g, TypeTableEntry *type_entry) {
         assert(type_entry->data.enumeration.abi_alignment != 0);
         return type_entry->data.enumeration.abi_alignment;
     } else if (type_entry->id == TypeTableEntryIdUnion) {
-        zig_panic("TODO");
+        assert(type_entry->data.unionation.abi_alignment != 0);
+        return type_entry->data.unionation.abi_alignment;
     } else if (type_entry->id == TypeTableEntryIdOpaque) {
         return 1;
     } else {
@@ -4929,3 +5246,11 @@ TypeTableEntry *get_align_amt_type(CodeGen *g) {
     }
     return g->align_amt_type;
 }
+
+uint32_t type_ptr_hash(const TypeTableEntry *ptr) {
+    return hash_ptr((void*)ptr);
+}
+
+bool type_ptr_eql(const TypeTableEntry *a, const TypeTableEntry *b) {
+    return a == b;
+}

src/analyze.hpp

@@ -63,6 +63,7 @@ void resolve_container_type(CodeGen *g, TypeTableEntry *type_entry);
 TypeStructField *find_struct_type_field(TypeTableEntry *type_entry, Buf *name);
 ScopeDecls *get_container_scope(TypeTableEntry *type_entry);
 TypeEnumField *find_enum_type_field(TypeTableEntry *enum_type, Buf *name);
+TypeUnionField *find_union_type_field(TypeTableEntry *type_entry, Buf *name);
 bool is_container_ref(TypeTableEntry *type_entry);
 void scan_decls(CodeGen *g, ScopeDecls *decls_scope, AstNode *node);
 void scan_import(CodeGen *g, ImportTableEntry *import);

src/c_tokenizer.cpp

@@ -120,6 +120,7 @@ static void begin_token(CTokenize *ctok, CTokId id) {
         case CTokIdLParen:
         case CTokIdRParen:
         case CTokIdEOF:
+        case CTokIdDot:
             break;
     }
 }
@@ -216,9 +217,8 @@ void tokenize_c_macro(CTokenize *ctok, const uint8_t *c) {
                         buf_append_char(&ctok->buf, '0');
                         break;
                     case '.':
-                        begin_token(ctok, CTokIdNumLitFloat);
+                        begin_token(ctok, CTokIdDot);
-                        ctok->state = CTokStateFloat;
+                        end_token(ctok);
-                        buf_init_from_str(&ctok->buf, "0.");
                         break;
                     case '(':
                         begin_token(ctok, CTokIdLParen);
@@ -238,6 +238,8 @@ void tokenize_c_macro(CTokenize *ctok, const uint8_t *c) {
                 break;
             case CTokStateFloat:
                 switch (*c) {
+                    case '.':
+                        break;
                     case 'e':
                     case 'E':
                         buf_append_char(&ctok->buf, 'e');

src/c_tokenizer.hpp

@@ -21,6 +21,7 @@ enum CTokId {
     CTokIdLParen,
     CTokIdRParen,
     CTokIdEOF,
+    CTokIdDot,
 };
 
 enum CNumLitSuffix {

src/codegen.cpp

@@ -15,7 +15,7 @@
 #include "ir.hpp"
 #include "link.hpp"
 #include "os.hpp"
-#include "parsec.hpp"
+#include "translate_c.hpp"
 #include "target.hpp"
 #include "zig_llvm.hpp"
 
@@ -810,6 +810,8 @@ static Buf *panic_msg_buf(PanicMsgId msg_id) {
             return buf_create_from_str("invalid error code");
         case PanicMsgIdIncorrectAlignment:
             return buf_create_from_str("incorrect alignment");
+        case PanicMsgIdBadUnionField:
+            return buf_create_from_str("access of inactive union field");
     }
     zig_unreachable();
 }
@@ -2393,6 +2395,50 @@ static LLVMValueRef ir_render_enum_field_ptr(CodeGen *g, IrExecutable *executabl
     return bitcasted_union_field_ptr;
 }
 
+static LLVMValueRef ir_render_union_field_ptr(CodeGen *g, IrExecutable *executable,
+    IrInstructionUnionFieldPtr *instruction)
+{
+    TypeTableEntry *union_ptr_type = instruction->union_ptr->value.type;
+    assert(union_ptr_type->id == TypeTableEntryIdPointer);
+    TypeTableEntry *union_type = union_ptr_type->data.pointer.child_type;
+    assert(union_type->id == TypeTableEntryIdUnion);
+
+    TypeUnionField *field = instruction->field;
+
+    if (!type_has_bits(field->type_entry))
+        return nullptr;
+
+    LLVMValueRef union_ptr = ir_llvm_value(g, instruction->union_ptr);
+    LLVMTypeRef field_type_ref = LLVMPointerType(field->type_entry->type_ref, 0);
+
+    if (union_type->data.unionation.gen_tag_index == SIZE_MAX) {
+        LLVMValueRef union_field_ptr = LLVMBuildStructGEP(g->builder, union_ptr, 0, "");
+        LLVMValueRef bitcasted_union_field_ptr = LLVMBuildBitCast(g->builder, union_field_ptr, field_type_ref, "");
+        return bitcasted_union_field_ptr;
+    }
+
+    if (ir_want_debug_safety(g, &instruction->base)) {
+        LLVMValueRef tag_field_ptr = LLVMBuildStructGEP(g->builder, union_ptr, union_type->data.unionation.gen_tag_index, "");
+        LLVMValueRef tag_value = gen_load_untyped(g, tag_field_ptr, 0, false, "");
+        LLVMValueRef expected_tag_value = LLVMConstInt(union_type->data.unionation.tag_type->type_ref,
+                field->value, false);
+
+        LLVMBasicBlockRef ok_block = LLVMAppendBasicBlock(g->cur_fn_val, "UnionCheckOk");
+        LLVMBasicBlockRef bad_block = LLVMAppendBasicBlock(g->cur_fn_val, "UnionCheckFail");
+        LLVMValueRef ok_val = LLVMBuildICmp(g->builder, LLVMIntEQ, tag_value, expected_tag_value, "");
+        LLVMBuildCondBr(g->builder, ok_val, ok_block, bad_block);
+
+        LLVMPositionBuilderAtEnd(g->builder, bad_block);
+        gen_debug_safety_crash(g, PanicMsgIdBadUnionField);
+
+        LLVMPositionBuilderAtEnd(g->builder, ok_block);
+    }
+
+    LLVMValueRef union_field_ptr = LLVMBuildStructGEP(g->builder, union_ptr, union_type->data.unionation.gen_union_index, "");
+    LLVMValueRef bitcasted_union_field_ptr = LLVMBuildBitCast(g->builder, union_field_ptr, field_type_ref, "");
+    return bitcasted_union_field_ptr;
+}
+
 static size_t find_asm_index(CodeGen *g, AstNode *node, AsmToken *tok) {
     const char *ptr = buf_ptr(node->data.asm_expr.asm_template) + tok->start + 2;
     size_t len = tok->end - tok->start - 2;
@@ -3365,6 +3411,42 @@ static LLVMValueRef ir_render_struct_init(CodeGen *g, IrExecutable *executable,
     return instruction->tmp_ptr;
 }
 
+static LLVMValueRef ir_render_union_init(CodeGen *g, IrExecutable *executable, IrInstructionUnionInit *instruction) {
+    TypeUnionField *type_union_field = instruction->field;
+
+    if (!type_has_bits(type_union_field->type_entry))
+        return nullptr;
+
+    uint32_t field_align_bytes = get_abi_alignment(g, type_union_field->type_entry);
+    TypeTableEntry *ptr_type = get_pointer_to_type_extra(g, type_union_field->type_entry,
+            false, false, field_align_bytes,
+            0, 0);
+
+    LLVMValueRef uncasted_union_ptr;
+    // Even if safety is off in this block, if the union type has the safety field, we have to populate it
+    // correctly. Otherwise safety code somewhere other than here could fail.
+    TypeTableEntry *union_type = instruction->union_type;
+    if (union_type->data.unionation.gen_tag_index != SIZE_MAX) {
+        LLVMValueRef tag_field_ptr = LLVMBuildStructGEP(g->builder, instruction->tmp_ptr,
+                union_type->data.unionation.gen_tag_index, "");
+        LLVMValueRef tag_value = LLVMConstInt(union_type->data.unionation.tag_type->type_ref,
+                type_union_field->value, false);
+        gen_store_untyped(g, tag_value, tag_field_ptr, 0, false);
+
+        uncasted_union_ptr = LLVMBuildStructGEP(g->builder, instruction->tmp_ptr,
+                (unsigned)union_type->data.unionation.gen_union_index, "");
+    } else {
+        uncasted_union_ptr = LLVMBuildStructGEP(g->builder, instruction->tmp_ptr, (unsigned)0, "");
+    }
+
+    LLVMValueRef field_ptr = LLVMBuildBitCast(g->builder, uncasted_union_ptr, ptr_type->type_ref, "");
+    LLVMValueRef value = ir_llvm_value(g, instruction->init_value);
+
+    gen_assign_raw(g, field_ptr, ptr_type, value);
+
+    return instruction->tmp_ptr;
+}
+
 static LLVMValueRef ir_render_container_init_list(CodeGen *g, IrExecutable *executable,
         IrInstructionContainerInitList *instruction)
 {
@@ -3486,6 +3568,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
             return ir_render_struct_field_ptr(g, executable, (IrInstructionStructFieldPtr *)instruction);
         case IrInstructionIdEnumFieldPtr:
             return ir_render_enum_field_ptr(g, executable, (IrInstructionEnumFieldPtr *)instruction);
+        case IrInstructionIdUnionFieldPtr:
+            return ir_render_union_field_ptr(g, executable, (IrInstructionUnionFieldPtr *)instruction);
         case IrInstructionIdAsm:
             return ir_render_asm(g, executable, (IrInstructionAsm *)instruction);
         case IrInstructionIdTestNonNull:
@@ -3544,6 +3628,8 @@ static LLVMValueRef ir_render_instruction(CodeGen *g, IrExecutable *executable,
             return ir_render_init_enum(g, executable, (IrInstructionInitEnum *)instruction);
         case IrInstructionIdStructInit:
             return ir_render_struct_init(g, executable, (IrInstructionStructInit *)instruction);
+        case IrInstructionIdUnionInit:
+            return ir_render_union_init(g, executable, (IrInstructionUnionInit *)instruction);
         case IrInstructionIdPtrCast:
             return ir_render_ptr_cast(g, executable, (IrInstructionPtrCast *)instruction);
         case IrInstructionIdBitCast:
@@ -3595,6 +3681,7 @@ static void ir_render(CodeGen *g, FnTableEntry *fn_entry) {
 
 static LLVMValueRef gen_const_ptr_struct_recursive(CodeGen *g, ConstExprValue *struct_const_val, size_t field_index);
 static LLVMValueRef gen_const_ptr_array_recursive(CodeGen *g, ConstExprValue *array_const_val, size_t index);
+static LLVMValueRef gen_const_ptr_union_recursive(CodeGen *g, ConstExprValue *array_const_val);
 
 static LLVMValueRef gen_parent_ptr(CodeGen *g, ConstExprValue *val, ConstParent *parent) {
     switch (parent->id) {
@@ -3608,6 +3695,8 @@ static LLVMValueRef gen_parent_ptr(CodeGen *g, ConstExprValue *val, ConstParent
         case ConstParentIdArray:
             return gen_const_ptr_array_recursive(g, parent->data.p_array.array_val,
                     parent->data.p_array.elem_index);
+        case ConstParentIdUnion:
+            return gen_const_ptr_union_recursive(g, parent->data.p_union.union_val);
     }
     zig_unreachable();
 }
@@ -3637,6 +3726,18 @@ static LLVMValueRef gen_const_ptr_struct_recursive(CodeGen *g, ConstExprValue *s
     return LLVMConstInBoundsGEP(base_ptr, indices, 2);
 }
 
+static LLVMValueRef gen_const_ptr_union_recursive(CodeGen *g, ConstExprValue *union_const_val) {
+    ConstParent *parent = &union_const_val->data.x_union.parent;
+    LLVMValueRef base_ptr = gen_parent_ptr(g, union_const_val, parent);
+
+    TypeTableEntry *u32 = g->builtin_types.entry_u32;
+    LLVMValueRef indices[] = {
+        LLVMConstNull(u32->type_ref),
+        LLVMConstInt(u32->type_ref, 0, false),
+    };
+    return LLVMConstInBoundsGEP(base_ptr, indices, 2);
+}
+
 static LLVMValueRef pack_const_int(CodeGen *g, LLVMTypeRef big_int_type_ref, ConstExprValue *const_val) {
     switch (const_val->special) {
         case ConstValSpecialRuntime:
@@ -3872,10 +3973,6 @@ static LLVMValueRef gen_const_val(CodeGen *g, ConstExprValue *const_val) {
                     return LLVMConstNamedStruct(type_entry->type_ref, fields, type_entry->data.structure.gen_field_count);
                 }
             }
-        case TypeTableEntryIdUnion:
-            {
-                zig_panic("TODO");
-            }
         case TypeTableEntryIdArray:
             {
                 uint64_t len = type_entry->data.array.len;
@@ -3898,6 +3995,55 @@ static LLVMValueRef gen_const_val(CodeGen *g, ConstExprValue *const_val) {
                     return LLVMConstArray(element_type_ref, values, (unsigned)len);
                 }
             }
+        case TypeTableEntryIdUnion:
+            {
+                LLVMTypeRef union_type_ref = type_entry->data.unionation.union_type_ref;
+                ConstExprValue *payload_value = const_val->data.x_union.payload;
+                assert(payload_value != nullptr);
+
+                if (!type_has_bits(payload_value->type)) {
+                    return LLVMGetUndef(union_type_ref);
+                }
+
+                uint64_t field_type_bytes = LLVMStoreSizeOfType(g->target_data_ref, payload_value->type->type_ref);
+                uint64_t pad_bytes = type_entry->data.unionation.union_size_bytes - field_type_bytes;
+                LLVMValueRef correctly_typed_value = gen_const_val(g, payload_value);
+                bool make_unnamed_struct = is_llvm_value_unnamed_type(payload_value->type, correctly_typed_value) ||
+                    payload_value->type != type_entry->data.unionation.most_aligned_union_member;
+
+                LLVMValueRef union_value_ref;
+                {
+                    if (pad_bytes == 0) {
+                        union_value_ref = correctly_typed_value;
+                    } else {
+                        LLVMValueRef fields[2];
+                        fields[0] = correctly_typed_value;
+                        fields[1] = LLVMGetUndef(LLVMArrayType(LLVMInt8Type(), (unsigned)pad_bytes));
+                        if (make_unnamed_struct || type_entry->data.unionation.gen_tag_index != SIZE_MAX) {
+                            union_value_ref = LLVMConstStruct(fields, 2, false);
+                        } else {
+                            union_value_ref = LLVMConstNamedStruct(union_type_ref, fields, 2);
+                        }
+                    }
+                }
+
+                if (type_entry->data.unionation.gen_tag_index == SIZE_MAX) {
+                    return union_value_ref;
+                }
+
+                LLVMValueRef tag_value = LLVMConstInt(type_entry->data.unionation.tag_type->type_ref, const_val->data.x_union.tag, false);
+
+                LLVMValueRef fields[2];
+                fields[type_entry->data.unionation.gen_union_index] = union_value_ref;
+                fields[type_entry->data.unionation.gen_tag_index] = tag_value;
+
+                if (make_unnamed_struct) {
+                    return LLVMConstStruct(fields, 2, false);
+                } else {
+                    return LLVMConstNamedStruct(type_entry->type_ref, fields, 2);
+                }
+
+            }
         case TypeTableEntryIdEnum:
             {
                 LLVMTypeRef tag_type_ref = type_entry->data.enumeration.tag_type->type_ref;
@@ -4376,6 +4522,9 @@ static void do_code_gen(CodeGen *g) {
             } else if (instruction->id == IrInstructionIdStructInit) {
                 IrInstructionStructInit *struct_init_instruction = (IrInstructionStructInit *)instruction;
                 slot = &struct_init_instruction->tmp_ptr;
+            } else if (instruction->id == IrInstructionIdUnionInit) {
+                IrInstructionUnionInit *union_init_instruction = (IrInstructionUnionInit *)instruction;
+                slot = &union_init_instruction->tmp_ptr;
             } else if (instruction->id == IrInstructionIdCall) {
                 IrInstructionCall *call_instruction = (IrInstructionCall *)instruction;
                 slot = &call_instruction->tmp_ptr;
@@ -5204,7 +5353,7 @@ static void init(CodeGen *g) {
     define_builtin_compile_vars(g);
 }
 
-void codegen_parsec(CodeGen *g, Buf *full_path) {
+void codegen_translate_c(CodeGen *g, Buf *full_path) {
     find_libc_include_path(g);
 
     Buf *src_basename = buf_alloc();

src/codegen.hpp

@@ -56,7 +56,7 @@ PackageTableEntry *codegen_create_package(CodeGen *g, const char *root_src_dir,
 void codegen_add_assembly(CodeGen *g, Buf *path);
 void codegen_add_object(CodeGen *g, Buf *object_path);
 
-void codegen_parsec(CodeGen *g, Buf *path);
+void codegen_translate_c(CodeGen *g, Buf *path);
 
 
 #endif

src/ir.cpp

@@ -11,7 +11,7 @@
 #include "ir.hpp"
 #include "ir_print.hpp"
 #include "os.hpp"
-#include "parsec.hpp"
+#include "translate_c.hpp"
 #include "range_set.hpp"
 #include "softfloat.hpp"
 
@@ -227,6 +227,10 @@ static constexpr IrInstructionId ir_instruction_id(IrInstructionEnumFieldPtr *)
     return IrInstructionIdEnumFieldPtr;
 }
 
+static constexpr IrInstructionId ir_instruction_id(IrInstructionUnionFieldPtr *) {
+    return IrInstructionIdUnionFieldPtr;
+}
+
 static constexpr IrInstructionId ir_instruction_id(IrInstructionElemPtr *) {
     return IrInstructionIdElemPtr;
 }
@@ -351,6 +355,10 @@ static constexpr IrInstructionId ir_instruction_id(IrInstructionStructInit *) {
     return IrInstructionIdStructInit;
 }
 
+static constexpr IrInstructionId ir_instruction_id(IrInstructionUnionInit *) {
+    return IrInstructionIdUnionInit;
+}
+
 static constexpr IrInstructionId ir_instruction_id(IrInstructionMinValue *) {
     return IrInstructionIdMinValue;
 }
@@ -922,6 +930,27 @@ static IrInstruction *ir_build_enum_field_ptr_from(IrBuilder *irb, IrInstruction
     return new_instruction;
 }
 
+static IrInstruction *ir_build_union_field_ptr(IrBuilder *irb, Scope *scope, AstNode *source_node,
+    IrInstruction *union_ptr, TypeUnionField *field)
+{
+    IrInstructionUnionFieldPtr *instruction = ir_build_instruction<IrInstructionUnionFieldPtr>(irb, scope, source_node);
+    instruction->union_ptr = union_ptr;
+    instruction->field = field;
+
+    ir_ref_instruction(union_ptr, irb->current_basic_block);
+
+    return &instruction->base;
+}
+
+static IrInstruction *ir_build_union_field_ptr_from(IrBuilder *irb, IrInstruction *old_instruction,
+    IrInstruction *union_ptr, TypeUnionField *type_union_field)
+{
+    IrInstruction *new_instruction = ir_build_union_field_ptr(irb, old_instruction->scope,
+            old_instruction->source_node, union_ptr, type_union_field);
+    ir_link_new_instruction(new_instruction, old_instruction);
+    return new_instruction;
+}
+
 static IrInstruction *ir_build_call(IrBuilder *irb, Scope *scope, AstNode *source_node,
         FnTableEntry *fn_entry, IrInstruction *fn_ref, size_t arg_count, IrInstruction **args,
         bool is_comptime, bool is_inline)
@@ -1112,6 +1141,28 @@ static IrInstruction *ir_build_struct_init_from(IrBuilder *irb, IrInstruction *o
     return new_instruction;
 }
 
+static IrInstruction *ir_build_union_init(IrBuilder *irb, Scope *scope, AstNode *source_node,
+        TypeTableEntry *union_type, TypeUnionField *field, IrInstruction *init_value)
+{
+    IrInstructionUnionInit *union_init_instruction = ir_build_instruction<IrInstructionUnionInit>(irb, scope, source_node);
+    union_init_instruction->union_type = union_type;
+    union_init_instruction->field = field;
+    union_init_instruction->init_value = init_value;
+
+    ir_ref_instruction(init_value, irb->current_basic_block);
+
+    return &union_init_instruction->base;
+}
+
+static IrInstruction *ir_build_union_init_from(IrBuilder *irb, IrInstruction *old_instruction,
+        TypeTableEntry *union_type, TypeUnionField *field, IrInstruction *init_value)
+{
+    IrInstruction *new_instruction = ir_build_union_init(irb, old_instruction->scope,
+            old_instruction->source_node, union_type, field, init_value);
+    ir_link_new_instruction(new_instruction, old_instruction);
+    return new_instruction;
+}
+
 static IrInstruction *ir_build_unreachable(IrBuilder *irb, Scope *scope, AstNode *source_node) {
     IrInstructionUnreachable *unreachable_instruction =
         ir_build_instruction<IrInstructionUnreachable>(irb, scope, source_node);
@@ -2422,6 +2473,13 @@ static IrInstruction *ir_instruction_enumfieldptr_get_dep(IrInstructionEnumField
     }
 }
 
+static IrInstruction *ir_instruction_unionfieldptr_get_dep(IrInstructionUnionFieldPtr *instruction, size_t index) {
+    switch (index) {
+        case 0: return instruction->union_ptr;
+        default: return nullptr;
+    }
+}
+
 static IrInstruction *ir_instruction_elemptr_get_dep(IrInstructionElemPtr *instruction, size_t index) {
     switch (index) {
         case 0: return instruction->array_ptr;
@@ -2485,6 +2543,13 @@ static IrInstruction *ir_instruction_structinit_get_dep(IrInstructionStructInit
     return nullptr;
 }
 
+static IrInstruction *ir_instruction_unioninit_get_dep(IrInstructionUnionInit *instruction, size_t index) {
+    switch (index) {
+        case 0: return instruction->init_value;
+        default: return nullptr;
+    }
+}
+
 static IrInstruction *ir_instruction_unreachable_get_dep(IrInstructionUnreachable *instruction, size_t index) {
     return nullptr;
 }
@@ -3099,6 +3164,8 @@ static IrInstruction *ir_instruction_get_dep(IrInstruction *instruction, size_t
             return ir_instruction_structfieldptr_get_dep((IrInstructionStructFieldPtr *) instruction, index);
         case IrInstructionIdEnumFieldPtr:
             return ir_instruction_enumfieldptr_get_dep((IrInstructionEnumFieldPtr *) instruction, index);
+        case IrInstructionIdUnionFieldPtr:
+            return ir_instruction_unionfieldptr_get_dep((IrInstructionUnionFieldPtr *) instruction, index);
         case IrInstructionIdElemPtr:
             return ir_instruction_elemptr_get_dep((IrInstructionElemPtr *) instruction, index);
         case IrInstructionIdVarPtr:
@@ -3117,6 +3184,8 @@ static IrInstruction *ir_instruction_get_dep(IrInstruction *instruction, size_t
             return ir_instruction_containerinitfields_get_dep((IrInstructionContainerInitFields *) instruction, index);
         case IrInstructionIdStructInit:
             return ir_instruction_structinit_get_dep((IrInstructionStructInit *) instruction, index);
+        case IrInstructionIdUnionInit:
+            return ir_instruction_unioninit_get_dep((IrInstructionUnionInit *) instruction, index);
         case IrInstructionIdUnreachable:
             return ir_instruction_unreachable_get_dep((IrInstructionUnreachable *) instruction, index);
         case IrInstructionIdTypeOf:
@@ -6233,8 +6302,9 @@ static Buf *get_anon_type_name(CodeGen *codegen, IrExecutable *exec, const char
             buf_appendf(name, ")");
             return name;
         } else {
+            //Note: C-imports do not have valid location information
             return buf_sprintf("(anonymous %s at %s:%" ZIG_PRI_usize ":%" ZIG_PRI_usize ")", kind_name,
-                buf_ptr(source_node->owner->path), source_node->line + 1, source_node->column + 1);
+                (source_node->owner->path != nullptr) ? buf_ptr(source_node->owner->path) : "(null)", source_node->line + 1, source_node->column + 1);
         }
     }
 }
@@ -6263,6 +6333,9 @@ static IrInstruction *ir_gen_container_decl(IrBuilder *irb, Scope *parent_scope,
     }
     irb->codegen->resolve_queue.append(&tld_container->base);
 
+    // Add this to the list to mark as invalid if analyzing this exec fails.
+    irb->exec->tld_list.append(&tld_container->base);
+
     return ir_build_const_type(irb, parent_scope, node, container_type);
 }
 
@@ -6485,6 +6558,20 @@ static bool ir_goto_pass2(IrBuilder *irb) {
     return true;
 }
 
+static void invalidate_exec(IrExecutable *exec) {
+    if (exec->invalid)
+        return;
+
+    exec->invalid = true;
+
+    for (size_t i = 0; i < exec->tld_list.length; i += 1) {
+        exec->tld_list.items[i]->resolution = TldResolutionInvalid;
+    }
+
+    if (exec->source_exec != nullptr)
+        invalidate_exec(exec->source_exec);
+}
+
 bool ir_gen(CodeGen *codegen, AstNode *node, Scope *scope, IrExecutable *ir_executable) {
     assert(node->owner);
 
@@ -6508,7 +6595,7 @@ bool ir_gen(CodeGen *codegen, AstNode *node, Scope *scope, IrExecutable *ir_exec
     }
 
     if (!ir_goto_pass2(irb)) {
-        irb->exec->invalid = true;
+        invalidate_exec(ir_executable);
         return false;
     }
 
@@ -6534,7 +6621,7 @@ static void add_call_stack_errors(CodeGen *codegen, IrExecutable *exec, ErrorMsg
 }
 
 static ErrorMsg *exec_add_error_node(CodeGen *codegen, IrExecutable *exec, AstNode *source_node, Buf *msg) {
-    exec->invalid = true;
+    invalidate_exec(exec);
     ErrorMsg *err_msg = add_node_error(codegen, source_node, msg);
     if (exec->parent_exec) {
         add_call_stack_errors(codegen, exec, err_msg, 10);
@@ -7897,6 +7984,9 @@ static IrInstruction *ir_get_const_ptr(IrAnalyze *ira, IrInstruction *instructio
         ConstExprValue *const_val = &const_instr->value;
         const_val->type = pointee_type;
         type_ensure_zero_bits_known(ira->codegen, type_entry);
+        if (type_is_invalid(type_entry)) {
+            return ira->codegen->invalid_instruction;
+        }
         const_val->data.x_type = get_pointer_to_type_extra(ira->codegen, type_entry,
                 ptr_is_const, ptr_is_volatile, get_abi_alignment(ira->codegen, type_entry), 0, 0);
         return const_instr;
@@ -7984,6 +8074,7 @@ IrInstruction *ir_eval_const_value(CodeGen *codegen, Scope *scope, AstNode *node
     IrExecutable analyzed_executable = {0};
     analyzed_executable.source_node = source_node;
     analyzed_executable.parent_exec = parent_exec;
+    analyzed_executable.source_exec = &ir_executable;
     analyzed_executable.name = exec_name;
     analyzed_executable.is_inline = true;
     analyzed_executable.fn_entry = fn_entry;
@@ -10279,30 +10370,40 @@ static IrInstruction *ir_get_var_ptr(IrAnalyze *ira, IrInstruction *instruction,
 
     bool is_const = (var->value->type->id == TypeTableEntryIdMetaType) ? is_const_ptr : var->src_is_const;
     bool is_volatile = (var->value->type->id == TypeTableEntryIdMetaType) ? is_volatile_ptr : false;
-    if (mem_slot && mem_slot->special != ConstValSpecialRuntime) {
+    if (mem_slot != nullptr) {
-        ConstPtrMut ptr_mut;
+        switch (mem_slot->special) {
-        if (comptime_var_mem) {
+            case ConstValSpecialRuntime:
-            ptr_mut = ConstPtrMutComptimeVar;
+                goto no_mem_slot;
-        } else if (var->gen_is_const) {
+            case ConstValSpecialStatic: // fallthrough
-            ptr_mut = ConstPtrMutComptimeConst;
+            case ConstValSpecialUndef: {
-        } else {
+                ConstPtrMut ptr_mut;
-            assert(!comptime_var_mem);
+                if (comptime_var_mem) {
-            ptr_mut = ConstPtrMutRuntimeVar;
+                    ptr_mut = ConstPtrMutComptimeVar;
+                } else if (var->gen_is_const) {
+                    ptr_mut = ConstPtrMutComptimeConst;
+                } else {
+                    assert(!comptime_var_mem);
+                    ptr_mut = ConstPtrMutRuntimeVar;
+                }
+                return ir_get_const_ptr(ira, instruction, mem_slot, var->value->type,
+                        ptr_mut, is_const, is_volatile, var->align_bytes);
+            }
         }
-        return ir_get_const_ptr(ira, instruction, mem_slot, var->value->type,
+        zig_unreachable();
-                ptr_mut, is_const, is_volatile, var->align_bytes);
-    } else {
-        IrInstruction *var_ptr_instruction = ir_build_var_ptr(&ira->new_irb,
-                instruction->scope, instruction->source_node, var, is_const, is_volatile);
-        var_ptr_instruction->value.type = get_pointer_to_type_extra(ira->codegen, var->value->type,
-                var->src_is_const, is_volatile, var->align_bytes, 0, 0);
-        type_ensure_zero_bits_known(ira->codegen, var->value->type);
-
-        bool in_fn_scope = (scope_fn_entry(var->parent_scope) != nullptr);
-        var_ptr_instruction->value.data.rh_ptr = in_fn_scope ? RuntimeHintPtrStack : RuntimeHintPtrNonStack;
-
-        return var_ptr_instruction;
     }
+
+no_mem_slot:
+
+    IrInstruction *var_ptr_instruction = ir_build_var_ptr(&ira->new_irb,
+            instruction->scope, instruction->source_node, var, is_const, is_volatile);
+    var_ptr_instruction->value.type = get_pointer_to_type_extra(ira->codegen, var->value->type,
+            var->src_is_const, is_volatile, var->align_bytes, 0, 0);
+    type_ensure_zero_bits_known(ira->codegen, var->value->type);
+
+    bool in_fn_scope = (scope_fn_entry(var->parent_scope) != nullptr);
+    var_ptr_instruction->value.data.rh_ptr = in_fn_scope ? RuntimeHintPtrStack : RuntimeHintPtrNonStack;
+
+    return var_ptr_instruction;
 }
 
 static TypeTableEntry *ir_analyze_fn_call(IrAnalyze *ira, IrInstructionCall *call_instruction,
@@ -10408,10 +10509,11 @@ static TypeTableEntry *ir_analyze_fn_call(IrAnalyze *ira, IrInstructionCall *cal
             result = ir_eval_const_value(ira->codegen, exec_scope, body_node, return_type,
                 ira->new_irb.exec->backward_branch_count, ira->new_irb.exec->backward_branch_quota, fn_entry,
                 nullptr, call_instruction->base.source_node, nullptr, ira->new_irb.exec);
-            if (type_is_invalid(result->value.type))
-                return ira->codegen->builtin_types.entry_invalid;
 
             ira->codegen->memoized_fn_eval_table.put(exec_scope, result);
+
+            if (type_is_invalid(result->value.type))
+                return ira->codegen->builtin_types.entry_invalid;
         }
 
         ConstExprValue *out_val = ir_build_const_from(ira, &call_instruction->base);
@@ -11417,8 +11519,20 @@ static TypeTableEntry *ir_analyze_container_member_access_inner(IrAnalyze *ira,
             return ir_analyze_ref(ira, &field_ptr_instruction->base, bound_fn_value, true, false);
         }
     }
+    const char *prefix_name;
+    if (is_slice(bare_struct_type)) {
+        prefix_name = "";
+    } else if (bare_struct_type->id == TypeTableEntryIdStruct) {
+        prefix_name = "struct ";
+    } else if (bare_struct_type->id == TypeTableEntryIdEnum) {
+        prefix_name = "enum ";
+    } else if (bare_struct_type->id == TypeTableEntryIdUnion) {
+        prefix_name = "union ";
+    } else {
+        prefix_name = "";
+    }
     ir_add_error_node(ira, field_ptr_instruction->base.source_node,
-        buf_sprintf("no member named '%s' in '%s'", buf_ptr(field_name), buf_ptr(&bare_struct_type->name)));
+        buf_sprintf("no member named '%s' in %s'%s'", buf_ptr(field_name), prefix_name, buf_ptr(&bare_struct_type->name)));
     return ira->codegen->builtin_types.entry_invalid;
 }
 
@@ -11428,14 +11542,13 @@ static TypeTableEntry *ir_analyze_container_field_ptr(IrAnalyze *ira, Buf *field
 {
     TypeTableEntry *bare_type = container_ref_type(container_type);
     ensure_complete_type(ira->codegen, bare_type);
+    if (type_is_invalid(bare_type))
+        return ira->codegen->builtin_types.entry_invalid;
 
     assert(container_ptr->value.type->id == TypeTableEntryIdPointer);
     bool is_const = container_ptr->value.type->data.pointer.is_const;
     bool is_volatile = container_ptr->value.type->data.pointer.is_volatile;
     if (bare_type->id == TypeTableEntryIdStruct) {
-        if (bare_type->data.structure.is_invalid)
-            return ira->codegen->builtin_types.entry_invalid;
-
         TypeStructField *field = find_struct_type_field(bare_type, field_name);
         if (field) {
             bool is_packed = (bare_type->data.structure.layout == ContainerLayoutPacked);
@@ -11476,9 +11589,6 @@ static TypeTableEntry *ir_analyze_container_field_ptr(IrAnalyze *ira, Buf *field
                 field_ptr_instruction, container_ptr, container_type);
         }
     } else if (bare_type->id == TypeTableEntryIdEnum) {
-        if (bare_type->data.enumeration.is_invalid)
-            return ira->codegen->builtin_types.entry_invalid;
-
         TypeEnumField *field = find_enum_type_field(bare_type, field_name);
         if (field) {
             ir_build_enum_field_ptr_from(&ira->new_irb, &field_ptr_instruction->base, container_ptr, field);
@@ -11489,7 +11599,15 @@ static TypeTableEntry *ir_analyze_container_field_ptr(IrAnalyze *ira, Buf *field
                 field_ptr_instruction, container_ptr, container_type);
         }
     } else if (bare_type->id == TypeTableEntryIdUnion) {
-        zig_panic("TODO");
+        TypeUnionField *field = find_union_type_field(bare_type, field_name);
+        if (field) {
+            ir_build_union_field_ptr_from(&ira->new_irb, &field_ptr_instruction->base, container_ptr, field);
+            return get_pointer_to_type_extra(ira->codegen, field->type_entry, is_const, is_volatile,
+                    get_abi_alignment(ira->codegen, field->type_entry), 0, 0);
+        } else {
+            return ir_analyze_container_member_access_inner(ira, bare_type, field_name,
+                field_ptr_instruction, container_ptr, container_type);
+        }
     } else {
         zig_unreachable();
     }
@@ -13033,9 +13151,71 @@ static TypeTableEntry *ir_analyze_instruction_ref(IrAnalyze *ira, IrInstructionR
     return ir_analyze_ref(ira, &ref_instruction->base, value, ref_instruction->is_const, ref_instruction->is_volatile);
 }
 
+static TypeTableEntry *ir_analyze_container_init_fields_union(IrAnalyze *ira, IrInstruction *instruction,
+    TypeTableEntry *container_type, size_t instr_field_count, IrInstructionContainerInitFieldsField *fields)
+{
+    assert(container_type->id == TypeTableEntryIdUnion);
+
+    ensure_complete_type(ira->codegen, container_type);
+
+    if (instr_field_count != 1) {
+        ir_add_error(ira, instruction,
+            buf_sprintf("union initialization expects exactly one field"));
+        return ira->codegen->builtin_types.entry_invalid;
+    }
+
+    IrInstructionContainerInitFieldsField *field = &fields[0];
+    IrInstruction *field_value = field->value->other;
+    if (type_is_invalid(field_value->value.type))
+        return ira->codegen->builtin_types.entry_invalid;
+
+    TypeUnionField *type_field = find_union_type_field(container_type, field->name);
+    if (!type_field) {
+        ir_add_error_node(ira, field->source_node,
+            buf_sprintf("no member named '%s' in union '%s'",
+                buf_ptr(field->name), buf_ptr(&container_type->name)));
+        return ira->codegen->builtin_types.entry_invalid;
+    }
+
+    if (type_is_invalid(type_field->type_entry))
+        return ira->codegen->builtin_types.entry_invalid;
+
+    IrInstruction *casted_field_value = ir_implicit_cast(ira, field_value, type_field->type_entry);
+    if (casted_field_value == ira->codegen->invalid_instruction)
+        return ira->codegen->builtin_types.entry_invalid;
+
+    bool is_comptime = ir_should_inline(ira->new_irb.exec, instruction->scope);
+    if (is_comptime || casted_field_value->value.special != ConstValSpecialRuntime) {
+        ConstExprValue *field_val = ir_resolve_const(ira, casted_field_value, UndefOk);
+        if (!field_val)
+            return ira->codegen->builtin_types.entry_invalid;
+
+        ConstExprValue *out_val = ir_build_const_from(ira, instruction);
+        out_val->data.x_union.payload = field_val;
+        out_val->data.x_union.tag = type_field->value;
+
+        ConstParent *parent = get_const_val_parent(ira->codegen, field_val);
+        if (parent != nullptr) {
+            parent->id = ConstParentIdUnion;
+            parent->data.p_union.union_val = out_val;
+        }
+
+        return container_type;
+    }
+
+    IrInstruction *new_instruction = ir_build_union_init_from(&ira->new_irb, instruction,
+        container_type, type_field, casted_field_value);
+
+    ir_add_alloca(ira, new_instruction, container_type);
+    return container_type;
+}
+
 static TypeTableEntry *ir_analyze_container_init_fields(IrAnalyze *ira, IrInstruction *instruction,
     TypeTableEntry *container_type, size_t instr_field_count, IrInstructionContainerInitFieldsField *fields)
 {
+    if (container_type->id == TypeTableEntryIdUnion) {
+        return ir_analyze_container_init_fields_union(ira, instruction, container_type, instr_field_count, fields);
+    }
     if (container_type->id != TypeTableEntryIdStruct || is_slice(container_type)) {
         ir_add_error(ira, instruction,
             buf_sprintf("type '%s' does not support struct initialization syntax",
@@ -13043,8 +13223,7 @@ static TypeTableEntry *ir_analyze_container_init_fields(IrAnalyze *ira, IrInstru
         return ira->codegen->builtin_types.entry_invalid;
     }
 
-    if (!type_is_complete(container_type))
+    ensure_complete_type(ira->codegen, container_type);
-        resolve_container_type(ira->codegen, container_type);
 
     size_t actual_field_count = container_type->data.structure.src_field_count;
 
@@ -13070,7 +13249,7 @@ static TypeTableEntry *ir_analyze_container_init_fields(IrAnalyze *ira, IrInstru
         TypeStructField *type_field = find_struct_type_field(container_type, field->name);
         if (!type_field) {
             ir_add_error_node(ira, field->source_node,
-                buf_sprintf("no member named '%s' in '%s'",
+                buf_sprintf("no member named '%s' in struct '%s'",
                     buf_ptr(field->name), buf_ptr(&container_type->name)));
             return ira->codegen->builtin_types.entry_invalid;
         }
@@ -15657,8 +15836,10 @@ static TypeTableEntry *ir_analyze_instruction_nocast(IrAnalyze *ira, IrInstructi
         case IrInstructionIdIntToErr:
         case IrInstructionIdErrToInt:
         case IrInstructionIdStructInit:
+        case IrInstructionIdUnionInit:
         case IrInstructionIdStructFieldPtr:
         case IrInstructionIdEnumFieldPtr:
+        case IrInstructionIdUnionFieldPtr:
         case IrInstructionIdInitEnum:
         case IrInstructionIdMaybeWrap:
         case IrInstructionIdErrWrapCode:
@@ -15968,6 +16149,7 @@ bool ir_has_side_effects(IrInstruction *instruction) {
         case IrInstructionIdContainerInitList:
         case IrInstructionIdContainerInitFields:
         case IrInstructionIdStructInit:
+        case IrInstructionIdUnionInit:
         case IrInstructionIdFieldPtr:
         case IrInstructionIdElemPtr:
         case IrInstructionIdVarPtr:
@@ -15977,6 +16159,7 @@ bool ir_has_side_effects(IrInstruction *instruction) {
         case IrInstructionIdArrayLen:
         case IrInstructionIdStructFieldPtr:
         case IrInstructionIdEnumFieldPtr:
+        case IrInstructionIdUnionFieldPtr:
         case IrInstructionIdArrayType:
         case IrInstructionIdSliceType:
         case IrInstructionIdSizeOf:

src/ir_print.cpp

@@ -290,6 +290,15 @@ static void ir_print_struct_init(IrPrint *irp, IrInstructionStructInit *instruct
     fprintf(irp->f, "} // struct init");
 }
 
+static void ir_print_union_init(IrPrint *irp, IrInstructionUnionInit *instruction) {
+    Buf *field_name = instruction->field->name;
+
+    fprintf(irp->f, "%s {", buf_ptr(&instruction->union_type->name));
+    fprintf(irp->f, ".%s = ", buf_ptr(field_name));
+    ir_print_other_instruction(irp, instruction->init_value);
+    fprintf(irp->f, "} // union init");
+}
+
 static void ir_print_unreachable(IrPrint *irp, IrInstructionUnreachable *instruction) {
     fprintf(irp->f, "unreachable");
 }
@@ -359,6 +368,13 @@ static void ir_print_enum_field_ptr(IrPrint *irp, IrInstructionEnumFieldPtr *ins
     fprintf(irp->f, ")");
 }
 
+static void ir_print_union_field_ptr(IrPrint *irp, IrInstructionUnionFieldPtr *instruction) {
+    fprintf(irp->f, "@UnionFieldPtr(&");
+    ir_print_other_instruction(irp, instruction->union_ptr);
+    fprintf(irp->f, ".%s", buf_ptr(instruction->field->name));
+    fprintf(irp->f, ")");
+}
+
 static void ir_print_set_debug_safety(IrPrint *irp, IrInstructionSetDebugSafety *instruction) {
     fprintf(irp->f, "@setDebugSafety(");
     ir_print_other_instruction(irp, instruction->scope_value);
@@ -1023,6 +1039,9 @@ static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
         case IrInstructionIdStructInit:
             ir_print_struct_init(irp, (IrInstructionStructInit *)instruction);
             break;
+        case IrInstructionIdUnionInit:
+            ir_print_union_init(irp, (IrInstructionUnionInit *)instruction);
+            break;
         case IrInstructionIdUnreachable:
             ir_print_unreachable(irp, (IrInstructionUnreachable *)instruction);
             break;
@@ -1056,6 +1075,9 @@ static void ir_print_instruction(IrPrint *irp, IrInstruction *instruction) {
         case IrInstructionIdEnumFieldPtr:
             ir_print_enum_field_ptr(irp, (IrInstructionEnumFieldPtr *)instruction);
             break;
+        case IrInstructionIdUnionFieldPtr:
+            ir_print_union_field_ptr(irp, (IrInstructionUnionFieldPtr *)instruction);
+            break;
         case IrInstructionIdSetDebugSafety:
             ir_print_set_debug_safety(irp, (IrInstructionSetDebugSafety *)instruction);
             break;

src/main.cpp

@@ -23,7 +23,7 @@ static int usage(const char *arg0) {
         "  build-exe [source]           create executable from source or object files\n"
         "  build-lib [source]           create library from source or object files\n"
         "  build-obj [source]           create object from source or assembly\n"
-        "  parsec [source]              convert c code to zig code\n"
+        "  translate-c [source]         convert c code to zig code\n"
         "  targets                      list available compilation targets\n"
         "  test [source]                create and run a test build\n"
         "  version                      print version number and exit\n"
@@ -229,7 +229,7 @@ enum Cmd {
     CmdTest,
     CmdVersion,
     CmdZen,
-    CmdParseC,
+    CmdTranslateC,
     CmdTargets,
 };
 
@@ -632,8 +632,8 @@ int main(int argc, char **argv) {
                 cmd = CmdVersion;
             } else if (strcmp(arg, "zen") == 0) {
                 cmd = CmdZen;
-            } else if (strcmp(arg, "parsec") == 0) {
+            } else if (strcmp(arg, "translate-c") == 0) {
-                cmd = CmdParseC;
+                cmd = CmdTranslateC;
             } else if (strcmp(arg, "test") == 0) {
                 cmd = CmdTest;
                 out_type = OutTypeExe;
@@ -646,7 +646,7 @@ int main(int argc, char **argv) {
         } else {
             switch (cmd) {
                 case CmdBuild:
-                case CmdParseC:
+                case CmdTranslateC:
                 case CmdTest:
                     if (!in_file) {
                         in_file = arg;
@@ -703,13 +703,13 @@ int main(int argc, char **argv) {
 
     switch (cmd) {
     case CmdBuild:
-    case CmdParseC:
+    case CmdTranslateC:
     case CmdTest:
         {
             if (cmd == CmdBuild && !in_file && objects.length == 0 && asm_files.length == 0) {
                 fprintf(stderr, "Expected source file argument or at least one --object or --assembly argument.\n");
                 return usage(arg0);
-            } else if ((cmd == CmdParseC || cmd == CmdTest) && !in_file) {
+            } else if ((cmd == CmdTranslateC || cmd == CmdTest) && !in_file) {
                 fprintf(stderr, "Expected source file argument.\n");
                 return usage(arg0);
             } else if (cmd == CmdBuild && out_type == OutTypeObj && objects.length != 0) {
@@ -719,7 +719,7 @@ int main(int argc, char **argv) {
 
             assert(cmd != CmdBuild || out_type != OutTypeUnknown);
 
-            bool need_name = (cmd == CmdBuild || cmd == CmdParseC);
+            bool need_name = (cmd == CmdBuild || cmd == CmdTranslateC);
 
             Buf *in_file_buf = nullptr;
 
@@ -742,7 +742,7 @@ int main(int argc, char **argv) {
                 return usage(arg0);
             }
 
-            Buf *zig_root_source_file = (cmd == CmdParseC) ? nullptr : in_file_buf;
+            Buf *zig_root_source_file = (cmd == CmdTranslateC) ? nullptr : in_file_buf;
 
             Buf *full_cache_dir = buf_alloc();
             os_path_resolve(buf_create_from_str("."),
@@ -841,8 +841,8 @@ int main(int argc, char **argv) {
                 if (timing_info)
                     codegen_print_timing_report(g, stdout);
                 return EXIT_SUCCESS;
-            } else if (cmd == CmdParseC) {
+            } else if (cmd == CmdTranslateC) {
-                codegen_parsec(g, in_file_buf);
+                codegen_translate_c(g, in_file_buf);
                 ast_render(g, stdout, g->root_import->root, 4);
                 if (timing_info)
                     codegen_print_timing_report(g, stdout);

src/zig_llvm.cpp

@@ -403,6 +403,10 @@ unsigned ZigLLVMTag_DW_structure_type(void) {
     return dwarf::DW_TAG_structure_type;
 }
 
+unsigned ZigLLVMTag_DW_union_type(void) {
+    return dwarf::DW_TAG_union_type;
+}
+
 ZigLLVMDIBuilder *ZigLLVMCreateDIBuilder(LLVMModuleRef module, bool allow_unresolved) {
     DIBuilder *di_builder = new DIBuilder(*unwrap(module), allow_unresolved);
     return reinterpret_cast<ZigLLVMDIBuilder *>(di_builder);

src/zig_llvm.hpp

@@ -117,6 +117,7 @@ unsigned ZigLLVMEncoding_DW_ATE_signed_char(void);
 unsigned ZigLLVMLang_DW_LANG_C99(void);
 unsigned ZigLLVMTag_DW_variable(void);
 unsigned ZigLLVMTag_DW_structure_type(void);
+unsigned ZigLLVMTag_DW_union_type(void);
 
 ZigLLVMDIBuilder *ZigLLVMCreateDIBuilder(LLVMModuleRef module, bool allow_unresolved);
 void ZigLLVMAddModuleDebugInfoFlag(LLVMModuleRef module);

std/base64.zig

@@ -1,186 +1,485 @@
 const assert = @import("debug.zig").assert;
 const mem = @import("mem.zig");
 
-pub const standard_alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+pub const standard_alphabet_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+pub const standard_pad_char = '=';
+pub const standard_encoder = Base64Encoder.init(standard_alphabet_chars, standard_pad_char);
 
-pub fn encode(dest: []u8, source: []const u8) -> []u8 {
+pub const Base64Encoder = struct {
-    return encodeWithAlphabet(dest, source, standard_alphabet);
+    alphabet_chars: []const u8,
-}
+    pad_char: u8,
 
-/// invalid characters in source are allowed, but they cause the value of dest to be undefined.
+    /// a bunch of assertions, then simply pass the data right through.
-pub fn decode(dest: []u8, source: []const u8) -> []u8 {
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64Encoder {
-    return decodeWithAlphabet(dest, source, standard_alphabet);
+        assert(alphabet_chars.len == 64);
-}
+        var char_in_alphabet = []bool{false} ** 256;
+        for (alphabet_chars) |c| {
+            assert(!char_in_alphabet[c]);
+            assert(c != pad_char);
+            char_in_alphabet[c] = true;
+        }
 
-pub fn encodeWithAlphabet(dest: []u8, source: []const u8, alphabet: []const u8) -> []u8 {
+        return Base64Encoder{
-    assert(alphabet.len == 65);
+            .alphabet_chars = alphabet_chars,
-    assert(dest.len >= calcEncodedSize(source.len));
+            .pad_char = pad_char,
-
+        };
-    var i: usize = 0;
-    var out_index: usize = 0;
-    while (i + 2 < source.len) : (i += 3) {
-        dest[out_index] = alphabet[(source[i] >> 2) & 0x3f];
-        out_index += 1;
-
-        dest[out_index] = alphabet[((source[i] & 0x3) << 4) |
-                          ((source[i + 1] & 0xf0) >> 4)];
-        out_index += 1;
-
-        dest[out_index] = alphabet[((source[i + 1] & 0xf) << 2) |
-                          ((source[i + 2] & 0xc0) >> 6)];
-        out_index += 1;
-
-        dest[out_index] = alphabet[source[i + 2] & 0x3f];
-        out_index += 1;
     }
 
-    if (i < source.len) {
+    /// ceil(source_len * 4/3)
-        dest[out_index] = alphabet[(source[i] >> 2) & 0x3f];
+    pub fn calcSize(source_len: usize) -> usize {
-        out_index += 1;
+        return @divTrunc(source_len + 2, 3) * 4;
+    }
 
-        if (i + 1 == source.len) {
+    /// dest.len must be what you get from ::calcSize.
-            dest[out_index] = alphabet[(source[i] & 0x3) << 4];
+    pub fn encode(encoder: &const Base64Encoder, dest: []u8, source: []const u8) {
+        assert(dest.len == Base64Encoder.calcSize(source.len));
+
+        var i: usize = 0;
+        var out_index: usize = 0;
+        while (i + 2 < source.len) : (i += 3) {
+            dest[out_index] = encoder.alphabet_chars[(source[i] >> 2) & 0x3f];
             out_index += 1;
 
-            dest[out_index] = alphabet[64];
+            dest[out_index] = encoder.alphabet_chars[((source[i] & 0x3) << 4) |
-            out_index += 1;
-        } else {
-            dest[out_index] = alphabet[((source[i] & 0x3) << 4) |
                               ((source[i + 1] & 0xf0) >> 4)];
             out_index += 1;
 
-            dest[out_index] = alphabet[(source[i + 1] & 0xf) << 2];
+            dest[out_index] = encoder.alphabet_chars[((source[i + 1] & 0xf) << 2) |
+                              ((source[i + 2] & 0xc0) >> 6)];
+            out_index += 1;
+
+            dest[out_index] = encoder.alphabet_chars[source[i + 2] & 0x3f];
             out_index += 1;
         }
 
-        dest[out_index] = alphabet[64];
+        if (i < source.len) {
-        out_index += 1;
+            dest[out_index] = encoder.alphabet_chars[(source[i] >> 2) & 0x3f];
+            out_index += 1;
+
+            if (i + 1 == source.len) {
+                dest[out_index] = encoder.alphabet_chars[(source[i] & 0x3) << 4];
+                out_index += 1;
+
+                dest[out_index] = encoder.pad_char;
+                out_index += 1;
+            } else {
+                dest[out_index] = encoder.alphabet_chars[((source[i] & 0x3) << 4) |
+                                  ((source[i + 1] & 0xf0) >> 4)];
+                out_index += 1;
+
+                dest[out_index] = encoder.alphabet_chars[(source[i + 1] & 0xf) << 2];
+                out_index += 1;
+            }
+
+            dest[out_index] = encoder.pad_char;
+            out_index += 1;
+        }
+    }
+};
+
+pub const standard_decoder = Base64Decoder.init(standard_alphabet_chars, standard_pad_char);
+error InvalidPadding;
+error InvalidCharacter;
+
+pub const Base64Decoder = struct {
+    /// e.g. 'A' => 0.
+    /// undefined for any value not in the 64 alphabet chars.
+    char_to_index: [256]u8,
+    /// true only for the 64 chars in the alphabet, not the pad char.
+    char_in_alphabet: [256]bool,
+    pad_char: u8,
+
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64Decoder {
+        assert(alphabet_chars.len == 64);
+
+        var result = Base64Decoder{
+            .char_to_index = undefined,
+            .char_in_alphabet = []bool{false} ** 256,
+            .pad_char = pad_char,
+        };
+
+        for (alphabet_chars) |c, i| {
+            assert(!result.char_in_alphabet[c]);
+            assert(c != pad_char);
+
+            result.char_to_index[c] = u8(i);
+            result.char_in_alphabet[c] = true;
+        }
+
+        return result;
     }
 
-    return dest[0..out_index];
+    /// If the encoded buffer is detected to be invalid, returns error.InvalidPadding.
-}
+    pub fn calcSize(decoder: &const Base64Decoder, source: []const u8) -> %usize {
-
+        if (source.len % 4 != 0) return error.InvalidPadding;
-/// invalid characters in source are allowed, but they cause the value of dest to be undefined.
+        return calcDecodedSizeExactUnsafe(source, decoder.pad_char);
-pub fn decodeWithAlphabet(dest: []u8, source: []const u8, alphabet: []const u8) -> []u8 {
-    assert(alphabet.len == 65);
-
-    var ascii6 = []u8{64} ** 256;
-    for (alphabet) |c, i| {
-        ascii6[c] = u8(i);
     }
 
-    return decodeWithAscii6BitMap(dest, source, ascii6[0..], alphabet[64]);
+    /// dest.len must be what you get from ::calcSize.
-}
+    /// invalid characters result in error.InvalidCharacter.
+    /// invalid padding results in error.InvalidPadding.
+    pub fn decode(decoder: &const Base64Decoder, dest: []u8, source: []const u8) -> %void {
+        assert(dest.len == %%decoder.calcSize(source));
+        assert(source.len % 4 == 0);
 
-pub fn decodeWithAscii6BitMap(dest: []u8, source: []const u8, ascii6: []const u8, pad_char: u8) -> []u8 {
+        var src_cursor: usize = 0;
-    assert(ascii6.len == 256);
+        var dest_cursor: usize = 0;
-    assert(dest.len >= calcExactDecodedSizeWithPadChar(source, pad_char));
 
-    var src_index: usize = 0;
+        while (src_cursor < source.len) : (src_cursor += 4) {
-    var dest_index: usize = 0;
+            if (!decoder.char_in_alphabet[source[src_cursor + 0]]) return error.InvalidCharacter;
-    var in_buf_len: usize = source.len;
+            if (!decoder.char_in_alphabet[source[src_cursor + 1]]) return error.InvalidCharacter;
+            if (src_cursor < source.len - 4 or source[src_cursor + 3] != decoder.pad_char) {
+                // common case
+                if (!decoder.char_in_alphabet[source[src_cursor + 2]]) return error.InvalidCharacter;
+                if (!decoder.char_in_alphabet[source[src_cursor + 3]]) return error.InvalidCharacter;
+                dest[dest_cursor + 0] = decoder.char_to_index[source[src_cursor + 0]] << 2 |
+                                        decoder.char_to_index[source[src_cursor + 1]] >> 4;
+                dest[dest_cursor + 1] = decoder.char_to_index[source[src_cursor + 1]] << 4 |
+                                        decoder.char_to_index[source[src_cursor + 2]] >> 2;
+                dest[dest_cursor + 2] = decoder.char_to_index[source[src_cursor + 2]] << 6 |
+                                        decoder.char_to_index[source[src_cursor + 3]];
+                dest_cursor += 3;
+            } else if (source[src_cursor + 2] != decoder.pad_char) {
+                // one pad char
+                if (!decoder.char_in_alphabet[source[src_cursor + 2]]) return error.InvalidCharacter;
+                dest[dest_cursor + 0] = decoder.char_to_index[source[src_cursor + 0]] << 2 |
+                                        decoder.char_to_index[source[src_cursor + 1]] >> 4;
+                dest[dest_cursor + 1] = decoder.char_to_index[source[src_cursor + 1]] << 4 |
+                                        decoder.char_to_index[source[src_cursor + 2]] >> 2;
+                if (decoder.char_to_index[source[src_cursor + 2]] << 6 != 0) return error.InvalidPadding;
+                dest_cursor += 2;
+            } else {
+                // two pad chars
+                dest[dest_cursor + 0] = decoder.char_to_index[source[src_cursor + 0]] << 2 |
+                                        decoder.char_to_index[source[src_cursor + 1]] >> 4;
+                if (decoder.char_to_index[source[src_cursor + 1]] << 4 != 0) return error.InvalidPadding;
+                dest_cursor += 1;
+            }
+        }
 
-    while (in_buf_len > 0 and source[in_buf_len - 1] == pad_char) {
+        assert(src_cursor == source.len);
-        in_buf_len -= 1;
+        assert(dest_cursor == dest.len);
+    }
+};
+
+error OutputTooSmall;
+
+pub const Base64DecoderWithIgnore = struct {
+    decoder: Base64Decoder,
+    char_is_ignored: [256]bool,
+    pub fn init(alphabet_chars: []const u8, pad_char: u8, ignore_chars: []const u8) -> Base64DecoderWithIgnore {
+        var result = Base64DecoderWithIgnore {
+            .decoder = Base64Decoder.init(alphabet_chars, pad_char),
+            .char_is_ignored = []bool{false} ** 256,
+        };
+
+        for (ignore_chars) |c| {
+            assert(!result.decoder.char_in_alphabet[c]);
+            assert(!result.char_is_ignored[c]);
+            assert(result.decoder.pad_char != c);
+            result.char_is_ignored[c] = true;
+        }
+
+        return result;
     }
 
-    while (in_buf_len > 4) {
+    /// If no characters end up being ignored or padding, this will be the exact decoded size.
-        dest[dest_index] = ascii6[source[src_index + 0]] << 2 |
+    pub fn calcSizeUpperBound(encoded_len: usize) -> %usize {
-                   ascii6[source[src_index + 1]] >> 4;
+        return @divTrunc(encoded_len, 4) * 3;
-        dest_index += 1;
-
-        dest[dest_index] = ascii6[source[src_index + 1]] << 4 |
-                   ascii6[source[src_index + 2]] >> 2;
-        dest_index += 1;
-
-        dest[dest_index] = ascii6[source[src_index + 2]] << 6 |
-                   ascii6[source[src_index + 3]];
-        dest_index += 1;
-
-        src_index += 4;
-        in_buf_len -= 4;
     }
 
-    if (in_buf_len > 1) {
+    /// Invalid characters that are not ignored result in error.InvalidCharacter.
-        dest[dest_index] = ascii6[source[src_index + 0]] << 2 |
+    /// Invalid padding results in error.InvalidPadding.
-                   ascii6[source[src_index + 1]] >> 4;
+    /// Decoding more data than can fit in dest results in error.OutputTooSmall. See also ::calcSizeUpperBound.
-        dest_index += 1;
+    /// Returns the number of bytes writen to dest.
+    pub fn decode(decoder_with_ignore: &const Base64DecoderWithIgnore, dest: []u8, source: []const u8) -> %usize {
+        const decoder = &const decoder_with_ignore.decoder;
+
+        var src_cursor: usize = 0;
+        var dest_cursor: usize = 0;
+
+        while (true) {
+            // get the next 4 chars, if available
+            var next_4_chars: [4]u8 = undefined;
+            var available_chars: usize = 0;
+            var pad_char_count: usize = 0;
+            while (available_chars < 4 and src_cursor < source.len) {
+                var c = source[src_cursor];
+                src_cursor += 1;
+
+                if (decoder.char_in_alphabet[c]) {
+                    // normal char
+                    next_4_chars[available_chars] = c;
+                    available_chars += 1;
+                } else if (decoder_with_ignore.char_is_ignored[c]) {
+                    // we're told to skip this one
+                    continue;
+                } else if (c == decoder.pad_char) {
+                    // the padding has begun. count the pad chars.
+                    pad_char_count += 1;
+                    while (src_cursor < source.len) {
+                        c = source[src_cursor];
+                        src_cursor += 1;
+                        if (c == decoder.pad_char) {
+                            pad_char_count += 1;
+                            if (pad_char_count > 2) return error.InvalidCharacter;
+                        } else if (decoder_with_ignore.char_is_ignored[c]) {
+                            // we can even ignore chars during the padding
+                            continue;
+                        } else return error.InvalidCharacter;
+                    }
+                    break;
+                } else return error.InvalidCharacter;
+            }
+
+            switch (available_chars) {
+                4 => {
+                    // common case
+                    if (dest_cursor + 3 > dest.len) return error.OutputTooSmall;
+                    assert(pad_char_count == 0);
+                    dest[dest_cursor + 0] = decoder.char_to_index[next_4_chars[0]] << 2 |
+                                            decoder.char_to_index[next_4_chars[1]] >> 4;
+                    dest[dest_cursor + 1] = decoder.char_to_index[next_4_chars[1]] << 4 |
+                                            decoder.char_to_index[next_4_chars[2]] >> 2;
+                    dest[dest_cursor + 2] = decoder.char_to_index[next_4_chars[2]] << 6 |
+                                            decoder.char_to_index[next_4_chars[3]];
+                    dest_cursor += 3;
+                    continue;
+                },
+                3 => {
+                    if (dest_cursor + 2 > dest.len) return error.OutputTooSmall;
+                    if (pad_char_count != 1) return error.InvalidPadding;
+                    dest[dest_cursor + 0] = decoder.char_to_index[next_4_chars[0]] << 2 |
+                                            decoder.char_to_index[next_4_chars[1]] >> 4;
+                    dest[dest_cursor + 1] = decoder.char_to_index[next_4_chars[1]] << 4 |
+                                            decoder.char_to_index[next_4_chars[2]] >> 2;
+                    if (decoder.char_to_index[next_4_chars[2]] << 6 != 0) return error.InvalidPadding;
+                    dest_cursor += 2;
+                    break;
+                },
+                2 => {
+                    if (dest_cursor + 1 > dest.len) return error.OutputTooSmall;
+                    if (pad_char_count != 2) return error.InvalidPadding;
+                    dest[dest_cursor + 0] = decoder.char_to_index[next_4_chars[0]] << 2 |
+                                            decoder.char_to_index[next_4_chars[1]] >> 4;
+                    if (decoder.char_to_index[next_4_chars[1]] << 4 != 0) return error.InvalidPadding;
+                    dest_cursor += 1;
+                    break;
+                },
+                1 => {
+                    return error.InvalidPadding;
+                },
+                0 => {
+                    if (pad_char_count != 0) return error.InvalidPadding;
+                    break;
+                },
+                else => unreachable,
+            }
+        }
+
+        assert(src_cursor == source.len);
+
+        return dest_cursor;
     }
-    if (in_buf_len > 2) {
+};
-        dest[dest_index] = ascii6[source[src_index + 1]] << 4 |
+
-                   ascii6[source[src_index + 2]] >> 2;
+
-        dest_index += 1;
+pub const standard_decoder_unsafe = Base64DecoderUnsafe.init(standard_alphabet_chars, standard_pad_char);
-    }
+
-    if (in_buf_len > 3) {
+pub const Base64DecoderUnsafe = struct {
-        dest[dest_index] = ascii6[source[src_index + 2]] << 6 |
+    /// e.g. 'A' => 0.
-                   ascii6[source[src_index + 3]];
+    /// undefined for any value not in the 64 alphabet chars.
-        dest_index += 1;
+    char_to_index: [256]u8,
+    pad_char: u8,
+
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64DecoderUnsafe {
+        assert(alphabet_chars.len == 64);
+        var result = Base64DecoderUnsafe {
+            .char_to_index = undefined,
+            .pad_char = pad_char,
+        };
+        for (alphabet_chars) |c, i| {
+            assert(c != pad_char);
+            result.char_to_index[c] = u8(i);
+        }
+        return result;
     }
 
-    return dest[0..dest_index];
+    /// The source buffer must be valid.
-}
+    pub fn calcSize(decoder: &const Base64DecoderUnsafe, source: []const u8) -> usize {
-
+        return calcDecodedSizeExactUnsafe(source, decoder.pad_char);
-pub fn calcEncodedSize(source_len: usize) -> usize {
-    return (((source_len * 4) / 3 + 3) / 4) * 4;
-}
-
-/// Computes the upper bound of the decoded size based only on the encoded length.
-/// To compute the exact decoded size, see ::calcExactDecodedSize
-pub fn calcMaxDecodedSize(encoded_len: usize) -> usize {
-    return @divExact(encoded_len * 3,  4);
-}
-
-/// Computes the number of decoded bytes there will be. This function must
-/// be given the encoded buffer because there might be padding
-/// bytes at the end ('=' in the standard alphabet)
-pub fn calcExactDecodedSize(encoded: []const u8) -> usize {
-    return calcExactDecodedSizeWithAlphabet(encoded, standard_alphabet);
-}
-
-pub fn calcExactDecodedSizeWithAlphabet(encoded: []const u8, alphabet: []const u8) -> usize {
-    assert(alphabet.len == 65);
-    return calcExactDecodedSizeWithPadChar(encoded, alphabet[64]);
-}
-
-pub fn calcExactDecodedSizeWithPadChar(encoded: []const u8, pad_char: u8) -> usize {
-    var buf_len = encoded.len;
-
-    while (buf_len > 0 and encoded[buf_len - 1] == pad_char) {
-        buf_len -= 1;
     }
 
-    return (buf_len * 3) / 4;
+    /// dest.len must be what you get from ::calcDecodedSizeExactUnsafe.
+    /// invalid characters or padding will result in undefined values.
+    pub fn decode(decoder: &const Base64DecoderUnsafe, dest: []u8, source: []const u8) {
+        assert(dest.len == decoder.calcSize(source));
+
+        var src_index: usize = 0;
+        var dest_index: usize = 0;
+        var in_buf_len: usize = source.len;
+
+        while (in_buf_len > 0 and source[in_buf_len - 1] == decoder.pad_char) {
+            in_buf_len -= 1;
+        }
+
+        while (in_buf_len > 4) {
+            dest[dest_index] = decoder.char_to_index[source[src_index + 0]] << 2 |
+                               decoder.char_to_index[source[src_index + 1]] >> 4;
+            dest_index += 1;
+
+            dest[dest_index] = decoder.char_to_index[source[src_index + 1]] << 4 |
+                               decoder.char_to_index[source[src_index + 2]] >> 2;
+            dest_index += 1;
+
+            dest[dest_index] = decoder.char_to_index[source[src_index + 2]] << 6 |
+                               decoder.char_to_index[source[src_index + 3]];
+            dest_index += 1;
+
+            src_index += 4;
+            in_buf_len -= 4;
+        }
+
+        if (in_buf_len > 1) {
+            dest[dest_index] = decoder.char_to_index[source[src_index + 0]] << 2 |
+                               decoder.char_to_index[source[src_index + 1]] >> 4;
+            dest_index += 1;
+        }
+        if (in_buf_len > 2) {
+            dest[dest_index] = decoder.char_to_index[source[src_index + 1]] << 4 |
+                               decoder.char_to_index[source[src_index + 2]] >> 2;
+            dest_index += 1;
+        }
+        if (in_buf_len > 3) {
+            dest[dest_index] = decoder.char_to_index[source[src_index + 2]] << 6 |
+                               decoder.char_to_index[source[src_index + 3]];
+            dest_index += 1;
+        }
+    }
+};
+
+fn calcDecodedSizeExactUnsafe(source: []const u8, pad_char: u8) -> usize {
+    if (source.len == 0) return 0;
+    var result = @divExact(source.len, 4) * 3;
+    if (source[source.len - 1] == pad_char) {
+        result -= 1;
+        if (source[source.len - 2] == pad_char) {
+            result -= 1;
+        }
+    }
+    return result;
 }
 
+
 test "base64" {
-    testBase64();
+    @setEvalBranchQuota(5000);
-    comptime testBase64();
+    %%testBase64();
+    comptime %%testBase64();
 }
 
-fn testBase64() {
+fn testBase64() -> %void {
-    testBase64Case("", "");
+    %return testAllApis("",       "");
-    testBase64Case("f", "Zg==");
+    %return testAllApis("f",      "Zg==");
-    testBase64Case("fo", "Zm8=");
+    %return testAllApis("fo",     "Zm8=");
-    testBase64Case("foo", "Zm9v");
+    %return testAllApis("foo",    "Zm9v");
-    testBase64Case("foob", "Zm9vYg==");
+    %return testAllApis("foob",   "Zm9vYg==");
-    testBase64Case("fooba", "Zm9vYmE=");
+    %return testAllApis("fooba",  "Zm9vYmE=");
-    testBase64Case("foobar", "Zm9vYmFy");
+    %return testAllApis("foobar", "Zm9vYmFy");
+
+    %return testDecodeIgnoreSpace("",       " ");
+    %return testDecodeIgnoreSpace("f",      "Z g= =");
+    %return testDecodeIgnoreSpace("fo",     "    Zm8=");
+    %return testDecodeIgnoreSpace("foo",    "Zm9v    ");
+    %return testDecodeIgnoreSpace("foob",   "Zm9vYg = = ");
+    %return testDecodeIgnoreSpace("fooba",  "Zm9v YmE=");
+    %return testDecodeIgnoreSpace("foobar", " Z m 9 v Y m F y ");
+
+    // test getting some api errors
+    %return testError("A",    error.InvalidPadding);
+    %return testError("AA",   error.InvalidPadding);
+    %return testError("AAA",  error.InvalidPadding);
+    %return testError("A..A", error.InvalidCharacter);
+    %return testError("AA=A", error.InvalidCharacter);
+    %return testError("AA/=", error.InvalidPadding);
+    %return testError("A/==", error.InvalidPadding);
+    %return testError("A===", error.InvalidCharacter);
+    %return testError("====", error.InvalidCharacter);
+
+    %return testOutputTooSmallError("AA==");
+    %return testOutputTooSmallError("AAA=");
+    %return testOutputTooSmallError("AAAA");
+    %return testOutputTooSmallError("AAAAAA==");
 }
 
-fn testBase64Case(expected_decoded: []const u8, expected_encoded: []const u8) {
+fn testAllApis(expected_decoded: []const u8, expected_encoded: []const u8) -> %void {
-    const calculated_decoded_len = calcExactDecodedSize(expected_encoded);
+    // Base64Encoder
-    assert(calculated_decoded_len == expected_decoded.len);
+    {
+        var buffer: [0x100]u8 = undefined;
+        var encoded = buffer[0..Base64Encoder.calcSize(expected_decoded.len)];
+        standard_encoder.encode(encoded, expected_decoded);
+        assert(mem.eql(u8, encoded, expected_encoded));
+    }
 
-    const calculated_encoded_len = calcEncodedSize(expected_decoded.len);
+    // Base64Decoder
-    assert(calculated_encoded_len == expected_encoded.len);
+    {
+        var buffer: [0x100]u8 = undefined;
+        var decoded = buffer[0..%return standard_decoder.calcSize(expected_encoded)];
+        %return standard_decoder.decode(decoded, expected_encoded);
+        assert(mem.eql(u8, decoded, expected_decoded));
+    }
 
-    var buf: [100]u8 = undefined;
+    // Base64DecoderWithIgnore
+    {
+        const standard_decoder_ignore_nothing = Base64DecoderWithIgnore.init(
+            standard_alphabet_chars, standard_pad_char, "");
+        var buffer: [0x100]u8 = undefined;
+        var decoded = buffer[0..%return Base64DecoderWithIgnore.calcSizeUpperBound(expected_encoded.len)];
+        var written = %return standard_decoder_ignore_nothing.decode(decoded, expected_encoded);
+        assert(written <= decoded.len);
+        assert(mem.eql(u8, decoded[0..written], expected_decoded));
+    }
 
-    const actual_decoded = decode(buf[0..], expected_encoded);
+    // Base64DecoderUnsafe
-    assert(actual_decoded.len == expected_decoded.len);
+    {
-    assert(mem.eql(u8, expected_decoded, actual_decoded));
+        var buffer: [0x100]u8 = undefined;
-
+        var decoded = buffer[0..standard_decoder_unsafe.calcSize(expected_encoded)];
-    const actual_encoded = encode(buf[0..], expected_decoded);
+        standard_decoder_unsafe.decode(decoded, expected_encoded);
-    assert(actual_encoded.len == expected_encoded.len);
+        assert(mem.eql(u8, decoded, expected_decoded));
-    assert(mem.eql(u8, expected_encoded, actual_encoded));
+    }
+}
+
+fn testDecodeIgnoreSpace(expected_decoded: []const u8, encoded: []const u8) -> %void {
+    const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
+        standard_alphabet_chars, standard_pad_char, " ");
+    var buffer: [0x100]u8 = undefined;
+    var decoded = buffer[0..%return Base64DecoderWithIgnore.calcSizeUpperBound(encoded.len)];
+    var written = %return standard_decoder_ignore_space.decode(decoded, encoded);
+    assert(mem.eql(u8, decoded[0..written], expected_decoded));
+}
+
+error ExpectedError;
+fn testError(encoded: []const u8, expected_err: error) -> %void {
+    const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
+        standard_alphabet_chars, standard_pad_char, " ");
+    var buffer: [0x100]u8 = undefined;
+    if (standard_decoder.calcSize(encoded)) |decoded_size| {
+        var decoded = buffer[0..decoded_size];
+        if (standard_decoder.decode(decoded, encoded)) |_| {
+            return error.ExpectedError;
+        } else |err| if (err != expected_err) return err;
+    } else |err| if (err != expected_err) return err;
+
+    if (standard_decoder_ignore_space.decode(buffer[0..], encoded)) |_| {
+        return error.ExpectedError;
+    } else |err| if (err != expected_err) return err;
+}
+
+fn testOutputTooSmallError(encoded: []const u8) -> %void {
+    const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
+        standard_alphabet_chars, standard_pad_char, " ");
+    var buffer: [0x100]u8 = undefined;
+    var decoded = buffer[0..calcDecodedSizeExactUnsafe(encoded, standard_pad_char) - 1];
+    if (standard_decoder_ignore_space.decode(decoded, encoded)) |_| {
+        return error.ExpectedError;
+    } else |err| if (err != error.OutputTooSmall) return err;
 }

std/os/index.zig

@@ -31,6 +31,8 @@ pub const windowsWaitSingle = windows_util.windowsWaitSingle;
 pub const windowsWrite = windows_util.windowsWrite;
 pub const windowsIsCygwinPty = windows_util.windowsIsCygwinPty;
 pub const windowsOpen = windows_util.windowsOpen;
+pub const windowsLoadDll = windows_util.windowsLoadDll;
+pub const windowsUnloadDll = windows_util.windowsUnloadDll; 
 pub const createWindowsEnvBlock = windows_util.createWindowsEnvBlock;
 
 pub const FileHandle = if (is_windows) windows.HANDLE else i32;
@@ -620,7 +622,9 @@ pub fn symLinkPosix(allocator: &Allocator, existing_path: []const u8, new_path:
 }
 
 // here we replace the standard +/ with -_ so that it can be used in a file name
-const b64_fs_alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_=";
+const b64_fs_encoder = base64.Base64Encoder.init(
+    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_",
+    base64.standard_pad_char);
 
 pub fn atomicSymLink(allocator: &Allocator, existing_path: []const u8, new_path: []const u8) -> %void {
     if (symLink(allocator, existing_path, new_path)) {
@@ -632,12 +636,12 @@ pub fn atomicSymLink(allocator: &Allocator, existing_path: []const u8, new_path:
     }
 
     var rand_buf: [12]u8 = undefined;
-    const tmp_path = %return allocator.alloc(u8, new_path.len + base64.calcEncodedSize(rand_buf.len));
+    const tmp_path = %return allocator.alloc(u8, new_path.len + base64.Base64Encoder.calcSize(rand_buf.len));
     defer allocator.free(tmp_path);
     mem.copy(u8, tmp_path[0..], new_path);
     while (true) {
         %return getRandomBytes(rand_buf[0..]);
-        _ = base64.encodeWithAlphabet(tmp_path[new_path.len..], rand_buf, b64_fs_alphabet);
+        b64_fs_encoder.encode(tmp_path[new_path.len..], rand_buf);
         if (symLink(allocator, existing_path, tmp_path)) {
             return rename(allocator, tmp_path, new_path);
         } else |err| {
@@ -715,11 +719,11 @@ pub fn copyFile(allocator: &Allocator, source_path: []const u8, dest_path: []con
 /// Guaranteed to be atomic.
 pub fn copyFileMode(allocator: &Allocator, source_path: []const u8, dest_path: []const u8, mode: usize) -> %void {
     var rand_buf: [12]u8 = undefined;
-    const tmp_path = %return allocator.alloc(u8, dest_path.len + base64.calcEncodedSize(rand_buf.len));
+    const tmp_path = %return allocator.alloc(u8, dest_path.len + base64.Base64Encoder.calcSize(rand_buf.len));
     defer allocator.free(tmp_path);
     mem.copy(u8, tmp_path[0..], dest_path);
     %return getRandomBytes(rand_buf[0..]);
-    _ = base64.encodeWithAlphabet(tmp_path[dest_path.len..], rand_buf, b64_fs_alphabet);
+    b64_fs_encoder.encode(tmp_path[dest_path.len..], rand_buf);
 
     var out_file = %return io.File.openWriteMode(tmp_path, mode, allocator);
     defer out_file.close();

std/os/windows/index.zig

@@ -84,6 +84,11 @@ pub extern "kernel32" stdcallcc fn WriteFile(in_hFile: HANDLE, in_lpBuffer: &con
     in_nNumberOfBytesToWrite: DWORD, out_lpNumberOfBytesWritten: ?&DWORD,
     in_out_lpOverlapped: ?&OVERLAPPED) -> BOOL;
 
+//TODO: call unicode versions instead of relying on ANSI code page
+pub extern "kernel32" stdcallcc fn LoadLibraryA(lpLibFileName: LPCSTR) -> ?HMODULE;
+
+pub extern "kernel32" stdcallcc fn FreeLibrary(hModule: HMODULE) -> BOOL;   
+
 pub extern "user32" stdcallcc fn MessageBoxA(hWnd: ?HANDLE, lpText: ?LPCTSTR, lpCaption: ?LPCTSTR, uType: UINT) -> c_int;
 
 pub const PROV_RSA_FULL = 1;
@@ -97,6 +102,7 @@ pub const FLOAT = f32;
 pub const HANDLE = &c_void;
 pub const HCRYPTPROV = ULONG_PTR;
 pub const HINSTANCE = &@OpaqueType();
+pub const HMODULE = &@OpaqueType();
 pub const INT = c_int;
 pub const LPBYTE = &BYTE;
 pub const LPCH = &CHAR;

std/os/windows/util.zig

@@ -4,6 +4,7 @@ const windows = std.os.windows;
 const assert = std.debug.assert;
 const mem = std.mem;
 const BufMap = std.BufMap;
+const cstr = std.cstr;
 
 error WaitAbandoned;
 error WaitTimeOut;
@@ -149,3 +150,25 @@ pub fn createWindowsEnvBlock(allocator: &mem.Allocator, env_map: &const BufMap)
     result[i] = 0;
     return result;
 }
+
+error DllNotFound;
+pub fn windowsLoadDll(allocator: &mem.Allocator, dll_path: []const u8) -> %windows.HMODULE {
+    const padded_buff = %return cstr.addNullByte(allocator, dll_path);
+    defer allocator.free(padded_buff);
+    return windows.LoadLibraryA(padded_buff.ptr) ?? error.DllNotFound;
+}
+
+pub fn windowsUnloadDll(hModule: windows.HMODULE) {
+    assert(windows.FreeLibrary(hModule)!= 0);
+}
+
+
+test "InvalidDll" {
+    const DllName = "asdf.dll";
+    const allocator = std.debug.global_allocator;
+    const handle = os.windowsLoadDll(allocator, DllName) %%  |err| {
+        assert(err == error.DllNotFound);
+        return;
+    };
+}
+

test/cases/union.zig

@@ -31,3 +31,47 @@ test "unions embedded in aggregate types" {
         else => unreachable,
     }
 }
+
+
+const Foo = union {
+    float: f64,
+    int: i32,
+};
+
+test "basic unions" {
+    var foo = Foo { .int = 1 };
+    assert(foo.int == 1);
+    foo = Foo {.float = 12.34};
+    assert(foo.float == 12.34);
+}
+
+test "init union with runtime value" {
+    var foo: Foo = undefined;
+
+    setFloat(&foo, 12.34);
+    assert(foo.float == 12.34);
+
+    setInt(&foo, 42);
+    assert(foo.int == 42);
+}
+
+fn setFloat(foo: &Foo, x: f64) {
+    *foo = Foo { .float = x };
+}
+
+fn setInt(foo: &Foo, x: i32) {
+    *foo = Foo { .int = x };
+}
+
+const FooExtern = extern union {
+    float: f64,
+    int: i32,
+};
+
+test "basic extern unions" {
+    var foo = FooExtern { .int = 1 };
+    assert(foo.int == 1);
+    foo.float = 12.34;
+    assert(foo.float == 12.34);
+}
+

test/compile_errors.zig

@@ -389,8 +389,8 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
         \\    const y = a.bar;
         \\}
     ,
-            ".tmp_source.zig:4:6: error: no member named 'foo' in 'A'",
+            ".tmp_source.zig:4:6: error: no member named 'foo' in struct 'A'",
-            ".tmp_source.zig:5:16: error: no member named 'bar' in 'A'");
+            ".tmp_source.zig:5:16: error: no member named 'bar' in struct 'A'");
 
     cases.add("redefinition of struct",
         \\const A = struct { x : i32, };
@@ -454,7 +454,7 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
         \\        .foo = 42,
         \\    };
         \\}
-    , ".tmp_source.zig:10:9: error: no member named 'foo' in 'A'");
+    , ".tmp_source.zig:10:9: error: no member named 'foo' in struct 'A'");
 
     cases.add("invalid break expression",
         \\export fn f() {
@@ -2343,4 +2343,23 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
         \\pub extern fn foo(format: &const u8, ...);
     ,
         ".tmp_source.zig:2:9: error: expected type '&const u8', found '[5]u8'");
+
+    cases.add("constant inside comptime function has compile error",
+        \\const ContextAllocator = MemoryPool(usize);
+        \\
+        \\pub fn MemoryPool(comptime T: type) -> type {
+        \\    const free_list_t = @compileError("aoeu");
+        \\
+        \\    struct {
+        \\        free_list: free_list_t,
+        \\    }
+        \\}
+        \\
+        \\export fn entry() {
+        \\    var allocator: ContextAllocator = undefined;
+        \\}
+    ,
+        ".tmp_source.zig:4:25: error: aoeu",
+        ".tmp_source.zig:1:36: note: called from here",
+        ".tmp_source.zig:12:20: note: referenced here");
 }

test/debug_safety.zig

@@ -260,4 +260,24 @@ pub fn addCases(cases: &tests.CompareOutputContext) {
         \\    return int_slice[0];
         \\}
     );
+
+    cases.addDebugSafety("bad union field access",
+        \\pub fn panic(message: []const u8) -> noreturn {
+        \\    @import("std").os.exit(126);
+        \\}
+        \\
+        \\const Foo = union {
+        \\    float: f32,
+        \\    int: u32,
+        \\};
+        \\
+        \\pub fn main() -> %void {
+        \\    var f = Foo { .int = 42 };
+        \\    bar(&f);
+        \\}
+        \\
+        \\fn bar(f: &Foo) {
+        \\    f.float = 12.34;
+        \\}
+    );
 }

test/tests.zig

@@ -18,7 +18,7 @@ const build_examples = @import("build_examples.zig");
 const compile_errors = @import("compile_errors.zig");
 const assemble_and_link = @import("assemble_and_link.zig");
 const debug_safety = @import("debug_safety.zig");
-const parsec = @import("parsec.zig");
+const translate_c = @import("translate_c.zig");
 
 const TestTarget = struct {
     os: builtin.Os,
@@ -123,16 +123,16 @@ pub fn addAssembleAndLinkTests(b: &build.Builder, test_filter: ?[]const u8) -> &
     return cases.step;
 }
 
-pub fn addParseCTests(b: &build.Builder, test_filter: ?[]const u8) -> &build.Step {
+pub fn addTranslateCTests(b: &build.Builder, test_filter: ?[]const u8) -> &build.Step {
-    const cases = %%b.allocator.create(ParseCContext);
+    const cases = %%b.allocator.create(TranslateCContext);
-    *cases = ParseCContext {
+    *cases = TranslateCContext {
         .b = b,
-        .step = b.step("test-parsec", "Run the C header file parsing tests"),
+        .step = b.step("test-translate-c", "Run the C header file parsing tests"),
         .test_index = 0,
         .test_filter = test_filter,
     };
 
-    parsec.addCases(cases);
+    translate_c.addCases(cases);
 
     return cases.step;
 }
@@ -770,7 +770,7 @@ pub const BuildExamplesContext = struct {
     }
 };
 
-pub const ParseCContext = struct {
+pub const TranslateCContext = struct {
     b: &build.Builder,
     step: &build.Step,
     test_index: usize,
@@ -799,17 +799,17 @@ pub const ParseCContext = struct {
         }
     };
 
-    const ParseCCmpOutputStep = struct {
+    const TranslateCCmpOutputStep = struct {
         step: build.Step,
-        context: &ParseCContext,
+        context: &TranslateCContext,
         name: []const u8,
         test_index: usize,
         case: &const TestCase,
 
-        pub fn create(context: &ParseCContext, name: []const u8, case: &const TestCase) -> &ParseCCmpOutputStep {
+        pub fn create(context: &TranslateCContext, name: []const u8, case: &const TestCase) -> &TranslateCCmpOutputStep {
             const allocator = context.b.allocator;
-            const ptr = %%allocator.create(ParseCCmpOutputStep);
+            const ptr = %%allocator.create(TranslateCCmpOutputStep);
-            *ptr = ParseCCmpOutputStep {
+            *ptr = TranslateCCmpOutputStep {
                 .step = build.Step.init("ParseCCmpOutput", allocator, make),
                 .context = context,
                 .name = name,
@@ -821,7 +821,7 @@ pub const ParseCContext = struct {
         }
 
         fn make(step: &build.Step) -> %void {
-            const self = @fieldParentPtr(ParseCCmpOutputStep, "step", step);
+            const self = @fieldParentPtr(TranslateCCmpOutputStep, "step", step);
             const b = self.context.b;
 
             const root_src = %%os.path.join(b.allocator, b.cache_root, self.case.sources.items[0].filename);
@@ -829,7 +829,7 @@ pub const ParseCContext = struct {
             var zig_args = ArrayList([]const u8).init(b.allocator);
             %%zig_args.append(b.zig_exe);
 
-            %%zig_args.append("parsec");
+            %%zig_args.append("translate-c");
             %%zig_args.append(b.pathFromRoot(root_src));
 
             warn("Test {}/{} {}...", self.test_index+1, self.context.test_index, self.name);
@@ -882,7 +882,7 @@ pub const ParseCContext = struct {
 
             if (stderr.len != 0 and !self.case.allow_warnings) {
                 warn(
-                    \\====== parsec emitted warnings: ============
+                    \\====== translate-c emitted warnings: =======
                     \\{}
                     \\============================================
                     \\
@@ -914,7 +914,7 @@ pub const ParseCContext = struct {
         warn("\n");
     }
 
-    pub fn create(self: &ParseCContext, allow_warnings: bool, filename: []const u8, name: []const u8,
+    pub fn create(self: &TranslateCContext, allow_warnings: bool, filename: []const u8, name: []const u8,
         source: []const u8, expected_lines: ...) -> &TestCase
     {
         const tc = %%self.b.allocator.create(TestCase);
@@ -932,37 +932,37 @@ pub const ParseCContext = struct {
         return tc;
     }
 
-    pub fn add(self: &ParseCContext, name: []const u8, source: []const u8, expected_lines: ...) {
+    pub fn add(self: &TranslateCContext, name: []const u8, source: []const u8, expected_lines: ...) {
         const tc = self.create(false, "source.h", name, source, expected_lines);
         self.addCase(tc);
     }
 
-    pub fn addC(self: &ParseCContext, name: []const u8, source: []const u8, expected_lines: ...) {
+    pub fn addC(self: &TranslateCContext, name: []const u8, source: []const u8, expected_lines: ...) {
         const tc = self.create(false, "source.c", name, source, expected_lines);
         self.addCase(tc);
     }
 
-    pub fn addAllowWarnings(self: &ParseCContext, name: []const u8, source: []const u8, expected_lines: ...) {
+    pub fn addAllowWarnings(self: &TranslateCContext, name: []const u8, source: []const u8, expected_lines: ...) {
         const tc = self.create(true, "source.h", name, source, expected_lines);
         self.addCase(tc);
     }
 
-    pub fn addCase(self: &ParseCContext, case: &const TestCase) {
+    pub fn addCase(self: &TranslateCContext, case: &const TestCase) {
         const b = self.b;
 
-        const annotated_case_name = %%fmt.allocPrint(self.b.allocator, "parsec {}", case.name);
+        const annotated_case_name = %%fmt.allocPrint(self.b.allocator, "translate-c {}", case.name);
         if (self.test_filter) |filter| {
             if (mem.indexOf(u8, annotated_case_name, filter) == null)
                 return;
         }
 
-        const parsec_and_cmp = ParseCCmpOutputStep.create(self, annotated_case_name, case);
+        const translate_c_and_cmp = TranslateCCmpOutputStep.create(self, annotated_case_name, case);
-        self.step.dependOn(&parsec_and_cmp.step);
+        self.step.dependOn(&translate_c_and_cmp.step);
 
         for (case.sources.toSliceConst()) |src_file| {
             const expanded_src_path = %%os.path.join(b.allocator, b.cache_root, src_file.filename);
             const write_src = b.addWriteFile(expanded_src_path, src_file.source);
-            parsec_and_cmp.step.dependOn(&write_src.step);
+            translate_c_and_cmp.step.dependOn(&write_src.step);
         }
     }
 };

test/translate_c.zig

@@ -1,6 +1,6 @@
 const tests = @import("tests.zig");
 
-pub fn addCases(cases: &tests.ParseCContext) {
+pub fn addCases(cases: &tests.TranslateCContext) {
     cases.addAllowWarnings("simple data types",
         \\#include <stdint.h>
         \\int foo(char a, unsigned char b, signed char c);
@@ -677,12 +677,12 @@ pub fn addCases(cases: &tests.ParseCContext) {
         \\    };
         \\    a >>= @import("std").math.Log2Int(c_int)({
         \\        const _ref = &a;
-        \\        (*_ref) = c_int(c_int(*_ref) >> @import("std").math.Log2Int(c_int)(1));
+        \\        (*_ref) = ((*_ref) >> @import("std").math.Log2Int(c_int)(1));
         \\        *_ref
         \\    });
         \\    a <<= @import("std").math.Log2Int(c_int)({
         \\        const _ref = &a;
-        \\        (*_ref) = c_int(c_int(*_ref) << @import("std").math.Log2Int(c_int)(1));
+        \\        (*_ref) = ((*_ref) << @import("std").math.Log2Int(c_int)(1));
         \\        *_ref
         \\    });
         \\}
@@ -735,12 +735,12 @@ pub fn addCases(cases: &tests.ParseCContext) {
         \\    };
         \\    a >>= @import("std").math.Log2Int(c_uint)({
         \\        const _ref = &a;
-        \\        (*_ref) = c_uint(c_uint(*_ref) >> @import("std").math.Log2Int(c_uint)(1));
+        \\        (*_ref) = ((*_ref) >> @import("std").math.Log2Int(c_uint)(1));
         \\        *_ref
         \\    });
         \\    a <<= @import("std").math.Log2Int(c_uint)({
         \\        const _ref = &a;
-        \\        (*_ref) = c_uint(c_uint(*_ref) << @import("std").math.Log2Int(c_uint)(1));
+        \\        (*_ref) = ((*_ref) << @import("std").math.Log2Int(c_uint)(1));
         \\        *_ref
         \\    });
         \\}
@@ -805,6 +805,50 @@ pub fn addCases(cases: &tests.ParseCContext) {
         \\}
     );
 
+    cases.addC("pre increment/decrement",
+        \\void foo(void) {
+        \\    int i = 0;
+        \\    unsigned u = 0;
+        \\    ++i;
+        \\    --i;
+        \\    ++u;
+        \\    --u;
+        \\    i = ++i;
+        \\    i = --i;
+        \\    u = ++u;
+        \\    u = --u;
+        \\}
+    ,
+        \\export fn foo() {
+        \\    var i: c_int = 0;
+        \\    var u: c_uint = c_uint(0);
+        \\    i += 1;
+        \\    i -= 1;
+        \\    u +%= 1;
+        \\    u -%= 1;
+        \\    i = {
+        \\        const _ref = &i;
+        \\        (*_ref) += 1;
+        \\        *_ref
+        \\    };
+        \\    i = {
+        \\        const _ref = &i;
+        \\        (*_ref) -= 1;
+        \\        *_ref
+        \\    };
+        \\    u = {
+        \\        const _ref = &u;
+        \\        (*_ref) +%= 1;
+        \\        *_ref
+        \\    };
+        \\    u = {
+        \\        const _ref = &u;
+        \\        (*_ref) -%= 1;
+        \\        *_ref
+        \\    };
+        \\}
+    );
+
     cases.addC("do loop",
         \\void foo(void) {
         \\    int a = 2;
@@ -834,17 +878,21 @@ pub fn addCases(cases: &tests.ParseCContext) {
 
     cases.addC("deref function pointer",
         \\void foo(void) {}
+        \\void baz(void) {}
         \\void bar(void) {
         \\    void(*f)(void) = foo;
         \\    f();
         \\    (*(f))();
+        \\    baz();
         \\}
     ,
         \\export fn foo() {}
+        \\export fn baz() {}
         \\export fn bar() {
         \\    var f: ?extern fn() = foo;
         \\    (??f)();
         \\    (??f)();
+        \\    baz();
         \\}
     );
 
@@ -857,15 +905,277 @@ pub fn addCases(cases: &tests.ParseCContext) {
         \\    (*(??x)) = 1;
         \\}
     );
+
+    cases.add("simple union",
+        \\union Foo {
+        \\    int x;
+        \\    double y;
+        \\};
+    ,
+        \\pub const union_Foo = extern union {
+        \\    x: c_int,
+        \\    y: f64,
+        \\};
+    ,
+        \\pub const Foo = union_Foo;
+    );
+
+    cases.add("address of operator",
+        \\int foo(void) {
+        \\    int x = 1234;
+        \\    int *ptr = &x;
+        \\    return *ptr;
+        \\}
+    ,
+        \\pub fn foo() -> c_int {
+        \\    var x: c_int = 1234;
+        \\    var ptr: ?&c_int = &x;
+        \\    return *(??ptr);
+        \\}
+    );
+
+    cases.add("string literal",
+        \\const char *foo(void) {
+        \\    return "bar";
+        \\}
+    ,
+        \\pub fn foo() -> ?&const u8 {
+        \\    return c"bar";
+        \\}
+    );
+
+    cases.add("return void",
+        \\void foo(void) {
+        \\    return;
+        \\}
+    ,
+        \\pub fn foo() {
+        \\    return;
+        \\}
+    );
+
+    cases.add("for loop",
+        \\void foo(void) {
+        \\    for (int i = 0; i < 10; i += 1) { }
+        \\}
+    ,
+        \\pub fn foo() {
+        \\    {
+        \\        var i: c_int = 0;
+        \\        while (i < 10) : (i += 1) {};
+        \\    };
+        \\}
+    );
+
+    cases.add("empty for loop",
+        \\void foo(void) {
+        \\    for (;;) { }
+        \\}
+    ,
+        \\pub fn foo() {
+        \\    while (true) {};
+        \\}
+    );
+
+    cases.add("break statement",
+        \\void foo(void) {
+        \\    for (;;) {
+        \\        break;
+        \\    }
+        \\}
+    ,
+        \\pub fn foo() {
+        \\    while (true) {
+        \\        break;
+        \\    };
+        \\}
+    );
+
+    cases.add("continue statement",
+        \\void foo(void) {
+        \\    for (;;) {
+        \\        continue;
+        \\    }
+        \\}
+    ,
+        \\pub fn foo() {
+        \\    while (true) {
+        \\        continue;
+        \\    };
+        \\}
+    );
+
+    cases.add("switch statement",
+        \\int foo(int x) {
+        \\    switch (x) {
+        \\        case 1:
+        \\            x += 1;
+        \\        case 2:
+        \\            break;
+        \\        case 3:
+        \\        case 4:
+        \\            return x + 1;
+        \\        default:
+        \\            return 10;
+        \\    }
+        \\    return x + 13;
+        \\}
+    ,
+        \\fn foo(_arg_x: c_int) -> c_int {
+        \\    var x = _arg_x;
+        \\    {
+        \\        switch (x) {
+        \\            1 => goto case_0,
+        \\            2 => goto case_1,
+        \\            3 => goto case_2,
+        \\            4 => goto case_3,
+        \\            else => goto default,
+        \\        };
+        \\    case_0:
+        \\        x += 1;
+        \\    case_1:
+        \\        goto end;
+        \\    case_2:
+        \\    case_3:
+        \\        return x + 1;
+        \\    default:
+        \\        return 10;
+        \\        goto end;
+        \\    end:
+        \\    };
+        \\    return x + 13;
+        \\}
+    );
+    
+    cases.add("macros with field targets",
+        \\typedef unsigned int GLbitfield;
+        \\typedef void (*PFNGLCLEARPROC) (GLbitfield mask);
+        \\typedef void(*OpenGLProc)(void);
+        \\union OpenGLProcs {
+        \\    OpenGLProc ptr[1];
+        \\    struct {
+        \\        PFNGLCLEARPROC Clear;
+        \\    } gl;
+        \\};
+        \\extern union OpenGLProcs glProcs;
+        \\#define glClearUnion glProcs.gl.Clear
+        \\#define glClearPFN PFNGLCLEARPROC
+    ,
+        \\pub const GLbitfield = c_uint;
+    ,
+        \\pub const PFNGLCLEARPROC = ?extern fn(GLbitfield);
+    ,
+        \\pub const OpenGLProc = ?extern fn();
+    ,
+        \\pub const union_OpenGLProcs = extern union {
+        \\    ptr: [1]OpenGLProc,
+        \\    gl: extern struct {
+        \\        Clear: PFNGLCLEARPROC,
+        \\    },
+        \\};
+    ,
+        \\pub extern var glProcs: union_OpenGLProcs;
+    ,
+        \\pub const glClearPFN = PFNGLCLEARPROC;
+    ,
+        \\pub inline fn glClearUnion(arg0: GLbitfield) {
+        \\    (??glProcs.gl.Clear)(arg0)
+        \\}
+    ,
+        \\pub const OpenGLProcs = union_OpenGLProcs;
+    );
+
+    cases.add("switch statement with no default",
+        \\int foo(int x) {
+        \\    switch (x) {
+        \\        case 1:
+        \\            x += 1;
+        \\        case 2:
+        \\            break;
+        \\        case 3:
+        \\        case 4:
+        \\            return x + 1;
+        \\    }
+        \\    return x + 13;
+        \\}
+    ,
+        \\fn foo(_arg_x: c_int) -> c_int {
+        \\    var x = _arg_x;
+        \\    {
+        \\        switch (x) {
+        \\            1 => goto case_0,
+        \\            2 => goto case_1,
+        \\            3 => goto case_2,
+        \\            4 => goto case_3,
+        \\            else => goto end,
+        \\        };
+        \\    case_0:
+        \\        x += 1;
+        \\    case_1:
+        \\        goto end;
+        \\    case_2:
+        \\    case_3:
+        \\        return x + 1;
+        \\        goto end;
+        \\    end:
+        \\    };
+        \\    return x + 13;
+        \\}
+    );
+
+    cases.add("variable name shadowing",
+        \\int foo(void) {
+        \\    int x = 1;
+        \\    {
+        \\        int x = 2;
+        \\        x += 1;
+        \\    }
+        \\    return x;
+        \\}
+    ,
+        \\pub fn foo() -> c_int {
+        \\    var x: c_int = 1;
+        \\    {
+        \\        var x_0: c_int = 2;
+        \\        x_0 += 1;
+        \\    };
+        \\    return x;
+        \\}
+    );
+
+    cases.add("pointer casting",
+        \\float *ptrcast(int *a) {
+        \\    return (float *)a;
+        \\}
+    ,
+        \\fn ptrcast(a: ?&c_int) -> ?&f32 {
+        \\    return @ptrCast(?&f32, a);
+        \\}
+    );
+
+    cases.add("bin not",
+        \\int foo(int x) {
+        \\    return ~x;
+        \\}
+    ,
+        \\pub fn foo(x: c_int) -> c_int {
+        \\    return ~x;
+        \\}
+    );
+
+    cases.add("primitive types included in defined symbols",
+        \\int foo(int u32) {
+        \\    return u32;
+        \\}
+    ,
+        \\pub fn foo(u32_0: c_int) -> c_int {
+        \\    return u32_0;
+        \\}
+    );
+
+    cases.add("const ptr initializer",
+        \\static const char *v0 = "0.0.0";
+    ,
+        \\pub var v0: ?&const u8 = c"0.0.0";
+    );
 }
-
-
-
-// TODO
-//float *ptrcast(int *a) {
-//    return (float *)a;
-//}
-// should translate to
-// fn ptrcast(a: ?&c_int) -> ?&f32 {
-//     return @ptrCast(?&f32, a);
-// }