C11 allows typedefs to be redefined. Implement this in C11 mode, and
downgrade the default-error warning to an ExtWarn in
C90/99. <rdar://problem/10668057>
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@147925 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index d4a07ee..74189ca 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -2751,9 +2751,9 @@
DiagGroup<"undefined-internal">;
def note_used_here : Note<"used here">;
-def warn_redefinition_of_typedef : Warning<
- "redefinition of typedef %0 is invalid in C">,
- InGroup<DiagGroup<"typedef-redefinition"> >, DefaultError;
+def warn_redefinition_of_typedef : ExtWarn<
+ "redefinition of typedef %0 is a C11 feature">,
+ InGroup<DiagGroup<"typedef-redefinition"> >;
def err_inline_declaration_block_scope : Error<
"inline declaration of %0 not allowed in block scope">;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index a2bf48e..588fc14 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -1463,8 +1463,6 @@
// The types match. Link up the redeclaration chain if the old
// declaration was a typedef.
- // FIXME: this is a potential source of weirdness if the type
- // spellings don't match exactly.
if (TypedefNameDecl *Typedef = dyn_cast<TypedefNameDecl>(Old))
New->setPreviousDeclaration(Typedef);
@@ -1509,8 +1507,8 @@
return New->setInvalidDecl();
}
- // Modules always permit redefinition of typedefs.
- if (getLangOptions().Modules)
+ // Modules always permit redefinition of typedefs, as does C11.
+ if (getLangOptions().Modules || getLangOptions().C11)
return;
// If we have a redefinition of a typedef in C, emit a warning. This warning
diff --git a/test/Preprocessor/line-directive.c b/test/Preprocessor/line-directive.c
index 878d067..1024694 100644
--- a/test/Preprocessor/line-directive.c
+++ b/test/Preprocessor/line-directive.c
@@ -41,7 +41,7 @@
# 192 "glomp.h" // not a system header.
typedef int x; // expected-note {{previous definition is here}}
-typedef int x; // expected-error {{redefinition of typedef 'x' is invalid in C}}
+typedef int x; // expected-warning {{redefinition of typedef 'x' is a C11 feature}}
# 192 "glomp.h" 3 // System header.
typedef int y; // ok
@@ -62,7 +62,7 @@
# 42 "blonk.h" // DOES change system headerness.
typedef int w; // expected-note {{previous definition is here}}
-typedef int w; // expected-error {{redefinition of typedef 'w' is invalid in C}}
+typedef int w; // expected-warning {{redefinition of typedef 'w' is a C11 feature}}
typedef int q; // original definition in system header, should not diagnose.
diff --git a/test/Sema/c11-typedef-redef.c b/test/Sema/c11-typedef-redef.c
new file mode 100644
index 0000000..7e213f4
--- /dev/null
+++ b/test/Sema/c11-typedef-redef.c
@@ -0,0 +1,14 @@
+// RUN: %clang_cc1 -std=c11 %s -verify
+
+typedef int type;
+typedef type type;
+typedef int type;
+
+void f(int N) {
+ typedef int type2;
+ typedef type type2;
+ typedef int type2;
+
+ typedef int vla[N]; // expected-note{{previous definition is here}}
+ typedef int vla[N]; // expected-error{{typedef redefinition with different types ('int [N]' vs 'int [N]')}}
+}
