mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-01-21 06:45:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

fix implicit cast from zero sized array ptr to slice

Browse Source 
closes #1850
This commit is contained in:
Andrew Kelley 2019-08-28 12:16:52 -04:00
parent d5b3d97c23
commit af90da1531
No known key found for this signature in database
GPG Key ID: 7C5F548F728501A9
2 changed files with 24 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
src/codegen.cpp
View File

@ -3052,8 +3052,10 @@ static LLVMValueRef ir_render_ptr_of_array_to_slice(CodeGen *g, IrExecutable *ex
IrInstructionPtrOfArrayToSlice *instruction)
{
ZigType *actual_type = instruction->operand->value.type;
LLVMValueRef expr_val = ir_llvm_value(g, instruction->operand);
assert(expr_val);
ZigType *slice_type = instruction->base.value.type;
ZigType *slice_ptr_type = slice_type->data.structure.fields[slice_ptr_index].type_entry;
size_t ptr_index = slice_type->data.structure.fields[slice_ptr_index].gen_index;
size_t len_index = slice_type->data.structure.fields[slice_len_index].gen_index;
LLVMValueRef result_loc = ir_llvm_value(g, instruction->result_loc);
@ -3061,15 +3063,21 @@ static LLVMValueRef ir_render_ptr_of_array_to_slice(CodeGen *g, IrExecutable *ex
ZigType *array_type = actual_type->data.pointer.child_type;
assert(array_type->id == ZigTypeIdArray);
LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, result_loc, slice_ptr_index, "");
LLVMValueRef indices[] = {
LLVMConstNull(g->builtin_types.entry_usize->llvm_type),
LLVMConstInt(g->builtin_types.entry_usize->llvm_type, 0, false),
};
LLVMValueRef slice_start_ptr = LLVMBuildInBoundsGEP(g->builder, expr_val, indices, 2, "");
gen_store_untyped(g, slice_start_ptr, ptr_field_ptr, 0, false);
if (type_has_bits(actual_type)) {
LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, result_loc, ptr_index, "");
LLVMValueRef indices[] = {
LLVMConstNull(g->builtin_types.entry_usize->llvm_type),
LLVMConstInt(g->builtin_types.entry_usize->llvm_type, 0, false),
};
LLVMValueRef expr_val = ir_llvm_value(g, instruction->operand);
LLVMValueRef slice_start_ptr = LLVMBuildInBoundsGEP(g->builder, expr_val, indices, 2, "");
gen_store_untyped(g, slice_start_ptr, ptr_field_ptr, 0, false);
} else if (ir_want_runtime_safety(g, &instruction->base)) {
LLVMValueRef ptr_field_ptr = LLVMBuildStructGEP(g->builder, result_loc, ptr_index, "");
gen_undef_init(g, slice_ptr_type->abi_align, slice_ptr_type, ptr_field_ptr);
}
LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, result_loc, slice_len_index, "");
LLVMValueRef len_field_ptr = LLVMBuildStructGEP(g->builder, result_loc, len_index, "");
LLVMValueRef len_value = LLVMConstInt(g->builtin_types.entry_usize->llvm_type,
array_type->data.array.len, false);
gen_store_untyped(g, len_value, len_field_ptr, 0, false);

6
test/stage1/behavior/array.zig
View File

@ -292,3 +292,9 @@ test "read/write through global variable array of struct fields initialized via
};
S.doTheTest();
}
test "implicit cast zero sized array ptr to slice" {
var b = "";
const c: []const u8 = &b;
expect(c.len == 0);
}