Commit 39567e8b50e9026288bb1323d84f481740bd0de7 | zig

author	kristopher tate <kris.tate+github@gmail.com> 2018-12-20 22:47:44+09:00
committer	kristopher tate <kris.tate+github@gmail.com> 2018-12-20 22:53:54+09:00
log	39567e8b50e9026288bb1323d84f481740bd0de7
tree	212cab92b7aa7d0b586dc8363a7a3547b0f05d70
parent	8768816d69ddf3253d2598923643f390cc18082c
signature	Commit is signed but in an unrecognized format.

src/analyze.cpp: support alignOf(struct T) aligned member inside struct T;

ref: ziglang/zig#1832

1 files changed, 21 insertions(+), 4 deletions(-)

src
- analyze.cpp

src/analyze.cpp+21-4

 @@ -2686,13 +2686,22 @@ static Error resolve_struct_alignment(CodeGen *g, ZigType *struct_type) {
     }
     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) {
         TypeStructField *field = &struct_type->data.structure.fields[i];
-        // If this assertion trips, look up the call stack. Probably something is
+        // If we have no type_entry for the field, assume that we are in the
-        // calling type_resolve with ResolveStatusAlignmentKnown when it should only
+        // midst of resolving this struct. We further assume that since the
-        // be resolving ResolveStatusZeroBitsKnown
+        // resolved alignment of the other fields of this struct is ultimately
-        assert(field->type_entry != nullptr);
+        // 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;
+        }
         if (type_is_invalid(field->type_entry)) {
             struct_type->data.structure.resolve_status = ResolveStatusInvalid;
 @@ -2723,6 +2732,14 @@ 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;
 }