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support switching on error union type 

closes #23
master
Andrew Kelley 2016-04-25 21:51:04 -07:00
parent d1b65c6f46
commit d0378057d1
5 changed files with 143 additions and 15 deletions
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1
src/all_types.hpp
View File

@ -691,6 +691,7 @@ struct AstNodeSymbolExpr {
// set this to instead of analyzing the node, pretend it's a type entry and it's this one.
TypeTableEntry *override_type_entry;
TypeEnumField *enum_field;
uint32_t err_value;
};
struct AstNodeBoolLiteral {

65
src/analyze.cpp
View File

@ -5116,8 +5116,11 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
int *field_use_counts = nullptr;
HashMap<int, AstNode *, int_hash, int_eq> err_use_nodes;
if (expr_type->id == TypeTableEntryIdEnum) {
field_use_counts = allocate<int>(expr_type->data.enumeration.field_count);
} else if (expr_type->id == TypeTableEntryIdErrorUnion) {
err_use_nodes.init(10);
}
int *const_chosen_prong_index = &node->data.switch_expr.const_chosen_prong_index;
@ -5186,8 +5189,54 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
add_node_error(g, item_node, buf_sprintf("expected enum tag name"));
any_errors = true;
}
} else if (expr_type->id == TypeTableEntryIdErrorUnion) {
if (item_node->type == NodeTypeSymbol) {
Buf *err_name = &item_node->data.symbol_expr.symbol;
bool is_ok_case = buf_eql_str(err_name, "Ok");
auto err_table_entry = is_ok_case ? nullptr: g->error_table.maybe_get(err_name);
if (is_ok_case || err_table_entry) {
uint32_t err_value = is_ok_case ? 0 : err_table_entry->value->value;
item_node->data.symbol_expr.err_value = err_value;
TypeTableEntry *this_var_type;
if (is_ok_case) {
this_var_type = expr_type->data.error.child_type;
} else {
this_var_type = g->builtin_types.entry_pure_error;
}
if (!var_type) {
var_type = this_var_type;
}
if (this_var_type != var_type) {
all_agree_on_var_type = false;
}
// detect duplicate switch values
auto existing_entry = err_use_nodes.maybe_get(err_value);
if (existing_entry) {
add_node_error(g, existing_entry->value,
buf_sprintf("duplicate switch value: '%s'", buf_ptr(err_name)));
any_errors = true;
} else {
err_use_nodes.put(err_value, item_node);
}
if (!any_errors && expr_val->ok) {
if (expr_val->data.x_err.err->value == err_value) {
*const_chosen_prong_index = prong_i;
}
}
} else {
add_node_error(g, item_node,
buf_sprintf("use of undeclared error value '%s'", buf_ptr(err_name)));
any_errors = true;
}
} else {
add_node_error(g, item_node, buf_sprintf("expected error value name"));
any_errors = true;
}
} else {
if (!any_errors && expr_val->ok) {
// note: there is now a function in eval.cpp for doing const expr comparison
zig_panic("TODO determine if const exprs are equal");
}
TypeTableEntry *item_type = analyze_expression(g, import, context, expr_type, item_node);
@ -5252,17 +5301,25 @@ static TypeTableEntry *analyze_switch_expr(CodeGen *g, ImportTableEntry *import,
return g->builtin_types.entry_invalid;
}
TypeTableEntry *result_type = resolve_peer_type_compatibility(g, import, context, node,
peer_nodes, peer_types, prong_count);
if (expr_val->ok) {
assert(*const_chosen_prong_index != -1);
*const_val = get_resolved_expr(peer_nodes[*const_chosen_prong_index])->const_val;
// the target expr depends on a compile var,
// so the entire if statement does too
// the target expr depends on a compile var because we have an error on unnecessary
// switch statement, so the entire switch statement does too
const_val->depends_on_compile_var = true;
if (!const_val->ok) {
return add_error_if_type_is_num_lit(g, result_type, node);
}
} else {
return add_error_if_type_is_num_lit(g, result_type, node);
}
return resolve_peer_type_compatibility(g, import, context, node, peer_nodes, peer_types, prong_count);
return result_type;
}
static TypeTableEntry *analyze_return_expr(CodeGen *g, ImportTableEntry *import, BlockContext *context,

51
src/codegen.cpp
View File

@ -2627,12 +2627,6 @@ static LLVMValueRef gen_symbol(CodeGen *g, AstNode *node) {
}
zig_unreachable();
/* TODO delete
FnTableEntry *fn_entry = node->data.symbol_expr.fn_entry;
assert(fn_entry);
return fn_entry->fn_value;
*/
}
static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
@ -2653,6 +2647,10 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
add_debug_source_node(g, node);
LLVMValueRef tag_field_ptr = LLVMBuildStructGEP(g->builder, target_value_handle, 0, "");
target_value = LLVMBuildLoad(g->builder, tag_field_ptr, "");
} else if (target_type->id == TypeTableEntryIdErrorUnion) {
add_debug_source_node(g, node);
LLVMValueRef tag_field_ptr = LLVMBuildStructGEP(g->builder, target_value_handle, 0, "");
target_value = LLVMBuildLoad(g->builder, tag_field_ptr, "");
} else {
zig_unreachable();
}
@ -2696,12 +2694,23 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
assert(item_node->type != NodeTypeSwitchRange);
LLVMValueRef val;
if (target_type->id == TypeTableEntryIdEnum) {
if (target_type->id == TypeTableEntryIdEnum ||
target_type->id == TypeTableEntryIdErrorUnion)
{
assert(item_node->type == NodeTypeSymbol);
TypeEnumField *enum_field = item_node->data.symbol_expr.enum_field;
assert(enum_field);
val = LLVMConstInt(target_type->data.enumeration.tag_type->type_ref,
enum_field->value, false);
TypeEnumField *enum_field = nullptr;
uint32_t err_value = 0;
if (target_type->id == TypeTableEntryIdEnum) {
enum_field = item_node->data.symbol_expr.enum_field;
assert(enum_field);
val = LLVMConstInt(target_type->data.enumeration.tag_type->type_ref,
enum_field->value, false);
} else if (target_type->id == TypeTableEntryIdErrorUnion) {
err_value = item_node->data.symbol_expr.err_value;
val = LLVMConstInt(g->err_tag_type->type_ref, err_value, false);
} else {
zig_unreachable();
}
if (prong_var && type_has_bits(prong_var->type)) {
LLVMBasicBlockRef item_block;
@ -2721,6 +2730,7 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, target_value, prong_var->type, target_type);
} else if (target_type->id == TypeTableEntryIdEnum) {
assert(enum_field);
assert(type_has_bits(enum_field->type_entry));
LLVMValueRef union_field_ptr = LLVMBuildStructGEP(g->builder, target_value_handle,
1, "");
@ -2731,6 +2741,25 @@ static LLVMValueRef gen_switch_expr(CodeGen *g, AstNode *node) {
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, handle_val, prong_var->type, enum_field->type_entry);
} else if (target_type->id == TypeTableEntryIdErrorUnion) {
if (err_value == 0) {
// variable is the payload
LLVMValueRef err_payload_ptr = LLVMBuildStructGEP(g->builder,
target_value_handle, 1, "");
LLVMValueRef handle_val = get_handle_value(g, var_node,
err_payload_ptr, prong_var->type);
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, handle_val, prong_var->type, prong_var->type);
} else {
// variable is the pure error value
LLVMValueRef err_tag_ptr = LLVMBuildStructGEP(g->builder,
target_value_handle, 0, "");
LLVMValueRef handle_val = LLVMBuildLoad(g->builder, err_tag_ptr, "");
gen_assign_raw(g, var_node, BinOpTypeAssign,
prong_var->value_ref, handle_val, prong_var->type, g->err_tag_type);
}
} else {
zig_unreachable();
}
if (make_item_blocks) {
LLVMBuildBr(g->builder, prong_block);

12
test/run_tests.cpp
View File

@ -1233,6 +1233,18 @@ fn bad_eql_2(a: EnumWithData, b: EnumWithData) -> bool {
)SOURCE", 2,
".tmp_source.zig:3:7: error: operator not allowed for type '[]u8'",
".tmp_source.zig:10:7: error: operator not allowed for type 'EnumWithData'");
add_compile_fail_case("non-const switch number literal", R"SOURCE(
fn foo() {
const x = switch (bar()) {
1, 2 => 1,
3, 4 => 2,
else => 3,
};
}
#static_eval_enable(false)
fn bar() -> i32 { 2 }
)SOURCE", 1, ".tmp_source.zig:3:15: error: unable to infer expression type");
}
//////////////////////////////////////////////////////////////////////////////

29
test/self_hosted.zig
View File

@ -1339,3 +1339,32 @@ fn character_literals() {
assert('\'' == single_quote);
}
const single_quote = '\'';
#attribute("test")
fn switch_with_multiple_expressions() {
const x: i32 = switch (returns_five()) {
1, 2, 3 => 1,
4, 5, 6 => 2,
else => 3,
};
assert(x == 2);
}
#static_eval_enable(false)
fn returns_five() -> i32 { 5 }
#attribute("test")
fn switch_on_error_union() {
const x = switch (returns_ten()) {
Ok => |val| val + 1,
ItBroke, NoMem => 1,
CrappedOut => 2,
};
assert(x == 11);
}
error ItBroke;
error NoMem;
error CrappedOut;
#static_eval_enable(false)
fn returns_ten() -> %i32 { 10 }