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fixups

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This commit is contained in:
Andrew Kelley 2018-12-20 12:36:15 -05:00
parent fb81b1978b
commit 0f54194e6a
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GPG Key ID: 7C5F548F728501A9
1 changed files with 32 additions and 38 deletions
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70
src/analyze.cpp
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@ -2681,48 +2681,50 @@ static Error resolve_struct_alignment(CodeGen *g, ZigType *struct_type) {
assert(decl_node->type == NodeTypeContainerDecl);
assert(struct_type->di_type);
size_t field_count = struct_type->data.structure.src_field_count;
if (struct_type->data.structure.layout == ContainerLayoutPacked) {
struct_type->data.structure.abi_alignment = 1;
}
size_t field_count = struct_type->data.structure.src_field_count;
bool self_resolving = false;
for (size_t i = 0; i < field_count; i += 1) {
for (size_t i = 0; i < field_count; i += 1) {
TypeStructField *field = &struct_type->data.structure.fields[i];
if (field->type_entry != nullptr && type_is_invalid(field->type_entry)) {
struct_type->data.structure.resolve_status = ResolveStatusInvalid;
break;
}
}
} else for (size_t i = 0; i < field_count; i += 1) {
TypeStructField *field = &struct_type->data.structure.fields[i];
uint32_t this_field_align;
// If we have no type_entry for the field, assume that we are in the
// midst of resolving this struct. We further assume that since the
// resolved alignment of the other fields of this struct is ultimately
// equal to the resolved alignment of this struct, we can safely ignore.
//
// If this struct is used down-stream in aligning a sub-struct, ignoring
// this struct in the context of a sub struct has the same effect since
// the other fields will be calculated and bubble-up.
if (nullptr == field->type_entry) {
self_resolving = true;
continue;
}
// TODO If we have no type_entry for the field, we've already failed to
// compile the program correctly. This stage1 compiler needs a deeper
// reworking to make this correct, or we can ignore the problem
// and make sure it is fixed in stage2. This workaround is for when
// there is a false positive of a dependency loop, of alignment depending
// on itself. When this false positive happens we assume a pointer-aligned
// field, which is usually fine but could be incorrectly over-aligned or
// even under-aligned. See https://github.com/ziglang/zig/issues/1512
if (field->type_entry == nullptr) {
this_field_align = LLVMABIAlignmentOfType(g->target_data_ref, LLVMPointerType(LLVMInt8Type(), 0));
} else {
if (type_is_invalid(field->type_entry)) {
struct_type->data.structure.resolve_status = ResolveStatusInvalid;
break;
}
if (type_is_invalid(field->type_entry)) {
struct_type->data.structure.resolve_status = ResolveStatusInvalid;
break;
}
if (!type_has_bits(field->type_entry))
continue;
if (!type_has_bits(field->type_entry))
continue;
// alignment of structs is the alignment of the most-aligned field
if (struct_type->data.structure.layout != ContainerLayoutPacked) {
if ((err = type_resolve(g, field->type_entry, ResolveStatusAlignmentKnown))) {
struct_type->data.structure.resolve_status = ResolveStatusInvalid;
break;
}
uint32_t this_field_align = get_abi_alignment(g, field->type_entry);
this_field_align = get_abi_alignment(g, field->type_entry);
assert(this_field_align != 0);
if (this_field_align > struct_type->data.structure.abi_alignment) {
struct_type->data.structure.abi_alignment = this_field_align;
}
}
// alignment of structs is the alignment of the most-aligned field
if (this_field_align > struct_type->data.structure.abi_alignment) {
struct_type->data.structure.abi_alignment = this_field_align;
}
}
@ -2732,14 +2734,6 @@ static Error resolve_struct_alignment(CodeGen *g, ZigType *struct_type) {
return ErrorSemanticAnalyzeFail;
}
if ( self_resolving
&& field_count > 0
) {
// If we get here it's due to self-referencing this struct before it has been fully resolved.
// In this case, set alignment to target pointer default.
struct_type->data.structure.abi_alignment = LLVMABIAlignmentOfType(g->target_data_ref,
LLVMPointerType(LLVMInt8Type(), 0));
}
struct_type->data.structure.resolve_status = ResolveStatusAlignmentKnown;
return ErrorNone;
}