Remove the error about redefining library functions. It's causing too

much pain when compiling the Linux kernel (PR3592).

llvm-svn: 64767

3 files changed, 4 insertions, 12 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.def b/clang/include/clang/Basic/DiagnosticSemaKinds.def
index 3f7ad9a5caa..11db059c269 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.def
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.def
@@ -97,10 +97,6 @@ DIAG(warn_redecl_library_builtin, WARNING,
      "incompatible redeclaration of library function %0 will be ignored")
 DIAG(err_builtin_definition, ERROR,
      "definition of builtin function %0")
-DIAG(err_builtin_lib_definition, ERROR,
-     "definition of library function %0 in a hosted implementation")
-DIAG(note_builtin_lib_def_freestanding, NOTE,
-     "use -ffreestanding to compile as a freestanding implementation")
 
 /// parser diagnostics
 DIAG(ext_typedef_without_a_name, EXTWARN,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index bf6a637ac26..b5e6bd69739 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -2802,12 +2802,10 @@ Sema::DeclTy *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, DeclTy *D) {
 
   // Builtin functions cannot be defined.
   if (unsigned BuiltinID = FD->getBuiltinID(Context)) {
-    if (Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
-      Diag(FD->getLocation(), diag::err_builtin_lib_definition) << FD;
-      Diag(FD->getLocation(), diag::note_builtin_lib_def_freestanding);
-    } else 
+    if (!Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID)) {
       Diag(FD->getLocation(), diag::err_builtin_definition) << FD;
-    FD->setInvalidDecl();
+      FD->setInvalidDecl();
+    }
   }
 
   PushDeclContext(FnBodyScope, FD);
diff --git a/clang/test/Sema/implicit-builtin-decl.c b/clang/test/Sema/implicit-builtin-decl.c
index efaf3ed4553..4c28d8cf3eb 100644
--- a/clang/test/Sema/implicit-builtin-decl.c
+++ b/clang/test/Sema/implicit-builtin-decl.c
@@ -36,8 +36,6 @@ int f0() {
 }
 
 void * realloc(void *p, int size) { // expected-warning{{incompatible redeclaration of library function 'realloc' will be ignored}} \
-// expected-note{{'realloc' is a builtin with type 'void *(void *, unsigned long)'}} \
-// expected-error{{definition of library function 'realloc' in a hosted implementation}} \
-  // expected-note{{use -ffreestanding to compile as a freestanding implementation}}
+// expected-note{{'realloc' is a builtin with type 'void *(void *, unsigned long)'}}
   return p;
 }