[preprocessor] Don't warn about "disabled expansion of recursive macro"
for "#define X X".
This is a pattern that, for example, stdbool.h uses.
rdar://12435773
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173952 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 6379144..939c4fa 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -459,7 +459,10 @@
if (MacroInfo *NewMI = getMacroInfo(NewII))
if (!NewMI->isEnabled() || NewMI == MI) {
Identifier.setFlag(Token::DisableExpand);
- Diag(Identifier, diag::pp_disabled_macro_expansion);
+ // Don't warn for "#define X X" like "#define bool bool" from
+ // stdbool.h.
+ if (NewMI != MI)
+ Diag(Identifier, diag::pp_disabled_macro_expansion);
}
}
diff --git a/test/Headers/stdbool.cpp b/test/Headers/stdbool.cpp
index a252cca..7c927db 100644
--- a/test/Headers/stdbool.cpp
+++ b/test/Headers/stdbool.cpp
@@ -1,5 +1,6 @@
// RUN: %clang_cc1 -E -dM %s | FileCheck --check-prefix=CHECK-GNU-COMPAT %s
// RUN: %clang_cc1 -std=c++98 -E -dM %s | FileCheck --check-prefix=CHECK-CONFORMING %s
+// RUN: %clang_cc1 -fsyntax-only -std=gnu++98 -verify -Weverything %s
#include <stdbool.h>
#define zzz
@@ -12,3 +13,7 @@
// CHECK-CONFORMING: #define __CHAR_BIT__
// CHECK-CONFORMING-NOT: #define false false
// CHECK-CONFORMING: #define zzz
+
+zzz
+// expected-no-diagnostics
+extern bool x;
diff --git a/test/Preprocessor/warn-disabled-macro-expansion.c b/test/Preprocessor/warn-disabled-macro-expansion.c
index b01b63f..c97a4ee 100644
--- a/test/Preprocessor/warn-disabled-macro-expansion.c
+++ b/test/Preprocessor/warn-disabled-macro-expansion.c
@@ -16,7 +16,7 @@
#define z(x) (z)(x)
-p // expected-warning {{recursive macro}}
+p // no warning
a // expected-warning {{recursive macro}}