[PATCH] D27279: Store decls in prototypes on the declarator instead of in the AST

[Reid Kleckner via Phabricator via cfe-commits]

rnk marked an inline comment as done.
rnk added inline comments.


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Comment at: include/clang/Sema/DeclSpec.h:1240
+    /// in the prototype. These are generally tag types or enumerators.
+    unsigned NumDeclsInPrototype : 8;
+
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rsmith wrote:
> It seems plausible that generated code could have more than 256 such declarations. This class has a pointer, a set of bit-fields, 12 `unsigned`s, and another pointer, so we could give this a full 32 bits without increasing the size of the class. Alternatively we could share the storage with `NumExceptions`, since this can only be non-zero in C and that can only be non-zero in C++.
I did it as a union with the EH machinery initially, but it changes our behavior on this test case:
  void f(struct Foo {} o) {} // error in C++
  struct Foo {}; // follow on error for redefining type Foo

We actually have test cases for this at clang/test/SemaCXX/type-definition-in-specifier.cpp. I don't think it's important to preserve that exact behavior, though, so performance may be more important. I just did it this way to avoid premature optimization.


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Comment at: test/Misc/ast-dump-decl.c:109-110
 // CHECK:      FunctionDecl{{.*}} TestFunctionDecl 'int (int, enum {{.*}})'
-// CHECK-NEXT:   EnumDecl
-// CHECK-NEXT:     EnumConstantDecl{{.*}} e
 // CHECK-NEXT:   ParmVarDecl{{.*}} x
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rsmith wrote:
> Why is this not here any more? Looks like SemaDecl.cpp:8255 should have added it to this `DeclContext`. It'd be nice for `-ast-dump` to still dump these declarations somewhere.
I changed things to dump non-parameter decls in the function now, but we only move NamedDecls into the function DeclContext, so the output is a little different. Think it matters?


https://reviews.llvm.org/D27279