Parser: canonicalize record type in offsetofMemberDesignator

Closes #342
Vexu · Jul 25, 2022 · dde0bbb · dde0bbb
1 parent 365d3b5
commit dde0bbb
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/src/Parser.zig b/src/Parser.zig
@@ -5565,7 +5565,8 @@ fn offsetofMemberDesignator(p: *Parser, base_ty: Type) Error!Result {
     const base_node = try p.addNode(.{ .tag = .default_init_expr, .ty = base_ty, .data = undefined });
 
     var bit_offset = Value.int(0);
-    var lhs = try p.fieldAccessExtra(base_node, base_ty, base_field_name, false);
+    const base_record_ty = base_ty.canonicalize(.standard);
+    var lhs = try p.fieldAccessExtra(base_node, base_record_ty, base_field_name, false);
 
     while (true) switch (p.tok_ids[p.tok_i]) {
         .period => {
@@ -5578,7 +5579,8 @@ fn offsetofMemberDesignator(p: *Parser, base_ty: Type) Error!Result {
                 return error.ParsingFailed;
             }
             try p.validateFieldAccess(lhs.ty, lhs.ty, field_name_tok, field_name);
-            lhs = try p.fieldAccessExtra(lhs.node, lhs.ty, field_name, false);
+            const record_ty = lhs.ty.canonicalize(.standard);
+            lhs = try p.fieldAccessExtra(lhs.node, record_ty, field_name, false);
         },
         .l_bracket => {
             const l_bracket_tok = p.tok_i;

diff --git a/test/cases/offsetof.c b/test/cases/offsetof.c
@@ -7,6 +7,11 @@ struct A{
 int b = __builtin_offsetof(struct A, b);
 int b = __builtin_offsetof(struct A, a[1]);
 
+struct Foo {
+  char a;
+} __attribute__((packed));
+_Static_assert(__builtin_offsetof(struct Foo, a) == 0, "field Foo.a wrong bit offset");
+
 #define EXPECTED_ERRORS "offsetof.c:1:28: error: offsetof requires struct or union type, 'int' invalid" \
     "offsetof.c:3:28: error: offsetof of incomplete type 'struct A'" \
     "offsetof.c:7:38: error: no member named 'b' in 'struct A'" \