disallow duplicate fields

2 files changed, 13 insertions, 0 deletions

diff --git a/src/parse.cff b/src/parse.cff
index 96ffaea..f7dc651 100644
--- a/src/parse.cff
+++ b/src/parse.cff
@@ -780,6 +780,11 @@ fn parseagg(P *Parser, loc Loc, kind AggKind, name *const u8, retdecl **Decl) *c
             size = kind == :Struct ? off + type.size
                                    : MAX(size, type.size);
          }
+         vec_each (fld, _, flds) {
+            if fld.name == name {
+               err(P, tok.loc, "duplicate field %qT", &tok);
+            }
+         }
          flds->push({ name, type, off });
 
          if !lexmatch(P, #null, ',') {
@@ -879,6 +884,12 @@ fn parsebitfield(P *Parser, name *const u8) *const Type {
       let off = 0u, size = 0u;
       let ty = bitf.intty;
 
+      vec_each (fld, _, flds) {
+         if fld.name == name {
+            err(P, tok.loc, "duplicate field %qT", &tok);
+         }
+      }
+
       if lexmatch(P, &tok, '(') {
          // `(offset, size)`
          let off_ex = parseexpr(P);
diff --git a/test/3.cff b/test/3.cff
index 7d73db6..cafed6a 100644
--- a/test/3.cff
+++ b/test/3.cff
@@ -6,6 +6,7 @@ bitfield ColorMaskFlags : u32 {
    blue 1 bool,
    alpha 1 bool,
    id (8,3),
+   // red 1,
 };
 
 struct Foo {
@@ -13,6 +14,7 @@ struct Foo {
    y f32,
    z union { p *void, i int },
    h enum union { fa, ga *void },
+   // x *void,
 }
 static foo Foo = { .z: { .i: 42 }, .h: :ga(&stderr) };