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phi instruction retains stack ptr hint

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This commit is contained in:
Andrew Kelley 2017-04-27 23:40:43 -04:00
parent 2e512a0e6e
commit 458afb0ef9
2 changed files with 25 additions and 2 deletions
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15
src/ir.cpp
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@ -9226,6 +9226,8 @@ static TypeTableEntry *ir_analyze_instruction_phi(IrAnalyze *ira, IrInstructionP
return ira->codegen->builtin_types.entry_invalid;
}
bool all_stack_ptrs = (resolved_type->id == TypeTableEntryIdPointer);
// cast all values to the resolved type. however we can't put cast instructions in front of the phi instruction.
// so we go back and insert the casts as the last instruction in the corresponding predecessor blocks, and
// then make sure the branch instruction is preserved.
@ -9238,12 +9240,23 @@ static TypeTableEntry *ir_analyze_instruction_phi(IrAnalyze *ira, IrInstructionP
IrInstruction *casted_value = ir_implicit_cast(ira, new_value, resolved_type);
new_incoming_values.items[i] = casted_value;
predecessor->instruction_list.append(branch_instruction);
if (all_stack_ptrs && (casted_value->value.special != ConstValSpecialRuntime ||
casted_value->value.data.rh_ptr != RuntimeHintPtrStack))
{
all_stack_ptrs = false;
}
}
ir_set_cursor_at_end(&ira->new_irb, cur_bb);
ir_build_phi_from(&ira->new_irb, &phi_instruction->base, new_incoming_blocks.length,
IrInstruction *result = ir_build_phi_from(&ira->new_irb, &phi_instruction->base, new_incoming_blocks.length,
new_incoming_blocks.items, new_incoming_values.items);
if (all_stack_ptrs) {
assert(result->value.special == ConstValSpecialRuntime);
result->value.data.rh_ptr = RuntimeHintPtrStack;
}
return resolved_type;
}

12
test/compile_errors.zig
View File

@ -1611,11 +1611,21 @@ pub fn addCases(cases: &tests.CompileErrorContext) {
".tmp_source.zig:3:5: error: cannot set section of external function 'foo'",
".tmp_source.zig:1:8: note: declared here");
cases.add("returning address of local variable",
cases.add("returning address of local variable - simple",
\\export fn foo() -> &i32 {
\\ var a: i32 = undefined;
\\ return &a;
\\}
,
".tmp_source.zig:3:13: error: function returns address of local variable");
cases.add("returning address of local variable - phi",
\\export fn foo(c: bool) -> &i32 {
\\ var a: i32 = undefined;
\\ var b: i32 = undefined;
\\ return if (c) &a else &b;
\\}
,
".tmp_source.zig:4:12: error: function returns address of local variable");
}