Reject typedef redefinitions when the underlying types are not identical,

even if in a system header etc.  rdar://6079937

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@54038 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/clang/Basic/DiagnosticKinds.def b/include/clang/Basic/DiagnosticKinds.def
index e0023e3667b3f58437de9d28a40f44851ff30aa0..d7698d290139391811db9d594e0bcdfa81aa235e 100644 (file)
--- a/include/clang/Basic/DiagnosticKinds.def
+++ b/include/clang/Basic/DiagnosticKinds.def
@@ -739,6 +739,8 @@ DIAG(err_non_static_static, ERROR,
      "non-static declaration of '%0' follows static declaration")
 DIAG(err_redefinition_different_kind, ERROR,
      "redefinition of '%0' as different kind of symbol")
+DIAG(err_redefinition_different_typedef, ERROR,
+     "typedef redefinition with different types ('%0' vs '%1')")
 DIAG(err_conflicting_types, ERROR,
      "conflicting types for '%0'")
 DIAG(err_nested_redefinition, ERROR,

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 4d726cf0a8573f6d9b87a1d2fadeca48aff6ca33..610bf61b60c4aa7c56ead86182534a2a72d5675d 100644 (file)
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -248,6 +248,18 @@ TypedefDecl *Sema::MergeTypeDefDecl(TypedefDecl *New, Decl *OldD) {
     return New;
   }
   
+  // If the typedef types are not identical, reject them in all languages and
+  // with any extensions enabled.
+  if (Old->getUnderlyingType() != New->getUnderlyingType() && 
+      Context.getCanonicalType(Old->getUnderlyingType()) != 
+      Context.getCanonicalType(New->getUnderlyingType())) {
+    Diag(New->getLocation(), diag::err_redefinition_different_typedef,
+         New->getUnderlyingType().getAsString(),
+         Old->getUnderlyingType().getAsString());
+    Diag(Old->getLocation(), diag::err_previous_definition);
+    return Old;
+  }
+  
   // Allow multiple definitions for ObjC built-in typedefs.
   // FIXME: Verify the underlying types are equivalent!
   if (getLangOptions().ObjC1 && isBuiltinObjCType(New))

diff --git a/test/Sema/typedef-redef.c b/test/Sema/typedef-redef.c
index 1b12ae408c021bdf2fa25879c0d37197576a9eb9..d3904dd147d1cbbf17f0875213b7c77e91bae743 100644 (file)
--- a/test/Sema/typedef-redef.c
+++ b/test/Sema/typedef-redef.c
@@ -1,4 +1,13 @@
 // RUN: clang < %s -fsyntax-only -verify
 
+// size_t coming from a system header.
 #include <stddef.h>
-typedef unsigned long size_t;
+typedef __SIZE_TYPE__ size_t;
+
+
+
+typedef const int x; // expected-error {{previous definition is here}}
+extern x a;
+typedef int x;  // expected-error {{typedef redefinition with different types}}
+extern x a;
+