Author: vvassilev
Date: Thu Sep 8 15:34:41 2016
New Revision: 280984
URL: http://llvm.org/viewvc/llvm-project?rev=280984&view=rev
Log:
[modules] Apply ODR merging for function scoped tags only in C++ mode.
In C mode, if we have a visible declaration but not a visible definition, a tag
defined in the declaration should be have a visible definition. In C++ we rely
on the ODR merging, whereas in C we cannot because each declaration of a
function gets its own set of declarations in its prototype scope.
Patch developed in collaboration with Richard Smith!
Added:
cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/
cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/a.h
cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/b.h
cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/c.h
cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/module.modulemap
cfe/trunk/test/Modules/merge-fn-prototype-tags.c
Modified:
cfe/trunk/lib/Sema/SemaLookup.cpp
Modified: cfe/trunk/lib/Sema/SemaLookup.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaLookup.cpp?rev=280984&r1=280983&r2=280984&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaLookup.cpp (original)
+++ cfe/trunk/lib/Sema/SemaLookup.cpp Thu Sep 8 15:34:41 2016
@@ -1543,7 +1543,12 @@ bool LookupResult::isVisibleSlow(Sema &S
// For a parameter, check whether our current template declaration's
// lexical context is visible, not whether there's some other visible
// definition of it, because parameters aren't "within" the definition.
- if ((D->isTemplateParameter() || isa<ParmVarDecl>(D))
+ //
+ // In C++ we need to check for a visible definition due to ODR merging,
+ // and in C we must not because each declaration of a function gets its own
+ // set of declarations for tags in prototype scope.
+ if ((D->isTemplateParameter() || isa<ParmVarDecl>(D)
+ || (isa<FunctionDecl>(DC) && !SemaRef.getLangOpts().CPlusPlus))
? isVisible(SemaRef, cast<NamedDecl>(DC))
: SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC))) {
if (SemaRef.ActiveTemplateInstantiations.empty() &&
Added: cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/a.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/a.h?rev=280984&view=auto
==============================================================================
--- cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/a.h (added)
+++ cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/a.h Thu Sep 8
15:34:41 2016
@@ -0,0 +1,2 @@
+#include "c.h"
+void ftw(struct stat);
Added: cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/b.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/b.h?rev=280984&view=auto
==============================================================================
--- cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/b.h (added)
+++ cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/b.h Thu Sep 8
15:34:41 2016
@@ -0,0 +1 @@
+struct stat;
Added: cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/c.h
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/c.h?rev=280984&view=auto
==============================================================================
--- cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/c.h (added)
+++ cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/c.h Thu Sep 8
15:34:41 2016
@@ -0,0 +1,4 @@
+#ifndef _STAT_H_
+#define _STAT_H_
+struct stat {};
+#endif
Added: cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/module.modulemap
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/module.modulemap?rev=280984&view=auto
==============================================================================
--- cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/module.modulemap
(added)
+++ cfe/trunk/test/Modules/Inputs/merge-fn-prototype-tags/module.modulemap Thu
Sep 8 15:34:41 2016
@@ -0,0 +1,5 @@
+module M {
+ header "a.h"
+ module mod_c { header "c.h" }
+ header "b.h"
+}
Added: cfe/trunk/test/Modules/merge-fn-prototype-tags.c
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Modules/merge-fn-prototype-tags.c?rev=280984&view=auto
==============================================================================
--- cfe/trunk/test/Modules/merge-fn-prototype-tags.c (added)
+++ cfe/trunk/test/Modules/merge-fn-prototype-tags.c Thu Sep 8 15:34:41 2016
@@ -0,0 +1,8 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -x c -I%S/Inputs/merge-fn-prototype-tags -verify %s
+// RUN: %clang_cc1 -fmodules
-fmodule-map-file=%S/Inputs/merge-fn-prototype-tags/module.modulemap
-fmodules-cache-path=%t -x c -I%S/Inputs/merge-fn-prototype-tags -verify %s
+
+#include "c.h"
+void mmalloc_attach() { struct stat sbuf; }
+
+// expected-no-diagnostics
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