provide std.zig and add it to import paths

CMakeLists.txt

@@ -117,6 +117,7 @@ set(C_HEADERS
 
 set(ZIG_STD_SRC
     "${CMAKE_SOURCE_DIR}/std/bootstrap.zig"
+    "${CMAKE_SOURCE_DIR}/std/std.zig"
 )
 
 set(C_HEADERS_DEST "lib/zig/include")

example/hello_world/hello2.zig

@@ -1,11 +1,8 @@
 export executable "hello";
 
-#link("c")
-extern {
-    fn printf(__format: *const u8, ...) -> i32;
-}
+use "std.zig";
 
 export fn main(argc : isize, argv : *mut *mut u8, env : *mut *mut u8) -> i32 {
-    printf("argc = %zu\n", argc);
+    print_str("Hello, world!", 13);
     return 0;
 }

src/analyze.hpp

@@ -108,6 +108,8 @@ struct CodeGen {
     LLVMZigDIBuilder *dbuilder;
     LLVMZigDICompileUnit *compile_unit;
 
+    ZigList<Buf *> lib_search_paths;
+
     // reminder: hash tables must be initialized before use
     HashMap<Buf *, FnTableEntry *, buf_hash, buf_eql_buf> fn_table;
     HashMap<Buf *, LLVMValueRef, buf_hash, buf_eql_buf> str_table;

src/codegen.cpp

@@ -26,6 +26,7 @@ CodeGen *codegen_create(Buf *root_source_dir) {
     g->import_table.init(32);
     g->build_type = CodeGenBuildTypeDebug;
     g->root_source_dir = root_source_dir;
+
     return g;
 }
 
@@ -1066,6 +1067,9 @@ static void define_primitive_types(CodeGen *g) {
 
 
 static void init(CodeGen *g, Buf *source_path) {
+    g->lib_search_paths.append(g->root_source_dir);
+    g->lib_search_paths.append(buf_create_from_str(ZIG_STD_DIR));
+
     LLVMInitializeAllTargets();
     LLVMInitializeAllTargetMCs();
     LLVMInitializeAllAsmPrinters();
@@ -1188,17 +1192,34 @@ static ImportTableEntry *codegen_add_code(CodeGen *g, Buf *source_path, Buf *sou
         AstNode *top_level_decl = import_entry->root->data.root.top_level_decls.at(decl_i);
 
         if (top_level_decl->type == NodeTypeUse) {
-            auto entry = g->import_table.maybe_get(&top_level_decl->data.use.path);
+            Buf *import_target_path = &top_level_decl->data.use.path;
+            auto entry = g->import_table.maybe_get(import_target_path);
             if (!entry) {
                 Buf full_path = BUF_INIT;
-                os_path_join(g->root_source_dir, &top_level_decl->data.use.path, &full_path);
                 Buf *import_code = buf_alloc();
-                if ((err = os_fetch_file_path(&full_path, import_code))) {
-                    add_node_error(g, top_level_decl,
-                            buf_sprintf("unable to open '%s': %s", buf_ptr(&full_path), err_str(err)));
+                bool found_it = false;
+
+                for (int path_i = 0; path_i < g->lib_search_paths.length; path_i += 1) {
+                    Buf *search_path = g->lib_search_paths.at(path_i);
+                    os_path_join(search_path, import_target_path, &full_path);
+
+                    if ((err = os_fetch_file_path(&full_path, import_code))) {
+                        if (err == ErrorFileNotFound) {
+                            continue;
+                        } else {
+                            add_node_error(g, top_level_decl,
+                                    buf_sprintf("unable to open '%s': %s", buf_ptr(&full_path), err_str(err)));
+                            goto done_looking_at_imports;
+                        }
+                    }
+                    codegen_add_code(g, &top_level_decl->data.use.path, import_code);
+                    found_it = true;
                     break;
                 }
-                codegen_add_code(g, &top_level_decl->data.use.path, import_code);
+                if (!found_it) {
+                    add_node_error(g, top_level_decl,
+                            buf_sprintf("unable to find '%s'", buf_ptr(import_target_path)));
+                }
             }
         } else if (top_level_decl->type == NodeTypeFnDef) {
             AstNode *proto_node = top_level_decl->data.fn_def.fn_proto;
@@ -1213,6 +1234,8 @@ static ImportTableEntry *codegen_add_code(CodeGen *g, Buf *source_path, Buf *sou
         }
     }
 
+done_looking_at_imports:
+
     return import_entry;
 }
 

std/std.zig

@@ -0,0 +1,23 @@
+fn syscall3(number: isize, arg1: isize, arg2: isize, arg3: isize) -> isize {
+    let mut result : isize;
+    asm volatile (
+        "mov %[number], %%rax\n"
+        "mov %[arg1], %%rdi\n"
+        "mov %[arg2], %%rsi\n"
+        "mov %[arg3], %%rdx\n"
+        "syscall\n"
+        "mov %%rax, %[ret]\n"
+        : [ret] "=r" (result)
+        : [number] "r" (number), [arg1] "r" (arg1), [arg2] "r" (arg2), [arg3] "r" (arg3)
+        : "rcx", "r11", "rax", "rdi", "rsi", "rdx");
+    return result;
+}
+
+// TODO error handling
+// TODO zig strings instead of C strings
+// TODO handle buffering and flushing
+pub print_str(str : *const u8, len: isize) {
+    let SYS_write = 1;
+    let stdout_fileno = 1;
+    syscall3(SYS_write, stdout_fileno, str as isize, str_len);
+}

test/run_tests.cpp

@@ -461,7 +461,7 @@ export executable "test";
 
     add_compile_fail_case("bad import", R"SOURCE(
 use "bogus-does-not-exist.zig";
-    )SOURCE", 1, ".tmp_source.zig:2:1: error: unable to open './bogus-does-not-exist.zig': file not found");
+    )SOURCE", 1, ".tmp_source.zig:2:1: error: unable to find 'bogus-does-not-exist.zig'");
 
     add_compile_fail_case("undeclared identifier", R"SOURCE(
 fn a() {