Handle the obvious case for diagnosing redeclarations of extern "C" functions.
Fixes PR7859.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@110906 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index 339a793..047a5d9 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -573,6 +573,11 @@
bool Sema::IsOverload(FunctionDecl *New, FunctionDecl *Old,
bool UseUsingDeclRules) {
+ // If both of the functions are extern "C", then they are not
+ // overloads.
+ if (Old->isExternC() && New->isExternC())
+ return false;
+
FunctionTemplateDecl *OldTemplate = Old->getDescribedFunctionTemplate();
FunctionTemplateDecl *NewTemplate = New->getDescribedFunctionTemplate();
diff --git a/test/SemaCXX/linkage-spec.cpp b/test/SemaCXX/linkage-spec.cpp
index 0d1c166..fdb642c 100644
--- a/test/SemaCXX/linkage-spec.cpp
+++ b/test/SemaCXX/linkage-spec.cpp
@@ -57,3 +57,14 @@
// PR6991
extern "C" typedef int (*PutcFunc_t)(int);
+
+
+// PR7859
+extern "C" void pr7859_a(int) {} // expected-note {{previous definition}}
+extern "C" void pr7859_a(int) {} // expected-error {{redefinition}}
+
+extern "C" void pr7859_b() {} // expected-note {{previous definition}}
+extern "C" void pr7859_b(int) {} // expected-error {{conflicting}}
+
+extern "C" void pr7859_c(short) {} // expected-note {{previous definition}}
+extern "C" void pr7859_c(int) {} // expected-error {{conflicting}}