john.brawn updated this revision to Diff 503305.
john.brawn added a comment.
Add command line test and release note, and run clang-format.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D144654/new/
https://reviews.llvm.org/D144654
Files:
clang/docs/ReleaseNotes.rst
clang/lib/Lex/PPDirectives.cpp
clang/test/Lexer/builtin_redef.c
clang/test/Preprocessor/macro-reserved.c
clang/test/Preprocessor/macro-reserved.cpp
Index: clang/test/Preprocessor/macro-reserved.cpp
===================================================================
--- clang/test/Preprocessor/macro-reserved.cpp
+++ clang/test/Preprocessor/macro-reserved.cpp
@@ -12,7 +12,7 @@
#undef _HAVE_X
#undef X__Y
-#undef __cplusplus
+#undef __cplusplus // expected-warning {{undefining builtin macro}}
#define __cplusplus
// allowlisted definitions
Index: clang/test/Preprocessor/macro-reserved.c
===================================================================
--- clang/test/Preprocessor/macro-reserved.c
+++ clang/test/Preprocessor/macro-reserved.c
@@ -6,6 +6,7 @@
#define __cplusplus
#define _HAVE_X 0
#define X__Y
+#define __STDC__ 1 // expected-warning {{redefining builtin macro}}
#undef for
#undef final
@@ -13,6 +14,7 @@
#undef __cplusplus
#undef _HAVE_X
#undef X__Y
+#undef __STDC_HOSTED__ // expected-warning {{undefining builtin macro}}
// allowlisted definitions
#define while while
Index: clang/test/Lexer/builtin_redef.c
===================================================================
--- clang/test/Lexer/builtin_redef.c
+++ clang/test/Lexer/builtin_redef.c
@@ -1,12 +1,24 @@
-// RUN: %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -E 2>&1 | FileCheck %s --check-prefix=CHECK-OUT
-// RUN: %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -E 2>&1 | FileCheck %s --check-prefix=CHECK-WARN
-// RUN: not %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -E 2>&1 -pedantic-errors | FileCheck %s --check-prefix=CHECK-ERR
+// RUN: %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -D__STDC__=1 -U__STDC_HOSTED__ -E 2>&1 | FileCheck %s --check-prefix=CHECK-OUT
+// RUN: %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -D__STDC__=1 -U__STDC_HOSTED__ -E 2>&1 | FileCheck %s --check-prefix=CHECK-WARN
+// RUN: not %clang_cc1 %s -D__TIME__=1234 -U__DATE__ -D__STDC__=1 -U__STDC_HOSTED__ -E 2>&1 -pedantic-errors | FileCheck %s --check-prefix=CHECK-ERR
// CHECK-WARN: <command line>:{{.*}} warning: redefining builtin macro
+// CHECK-WARN-NEXT: #define __TIME__ 1234
// CHECK-WARN: <command line>:{{.*}} warning: undefining builtin macro
+// CHECK-WARN-NEXT: #undef __DATE__
+// CHECK-WARN: <command line>:{{.*}} warning: redefining builtin macro
+// CHECK-WARN-NEXT: #define __STDC__ 1
+// CHECK-WARN: <command line>:{{.*}} warning: undefining builtin macro
+// CHECK-WARN-NEXT: #undef __STDC_HOSTED__
// CHECK-ERR: <command line>:{{.*}} error: redefining builtin macro
+// CHECK-ERR-NEXT: #define __TIME__ 1234
+// CHECK-ERR: <command line>:{{.*}} error: undefining builtin macro
+// CHECK-ERR-NEXT: #undef __DATE__
+// CHECK-ERR: <command line>:{{.*}} error: redefining builtin macro
+// CHECK-ERR-NEXT: #define __STDC__ 1
// CHECK-ERR: <command line>:{{.*}} error: undefining builtin macro
+// CHECK-ERR-NEXT: #undef __STDC_HOSTED__
int n = __TIME__;
__DATE__
Index: clang/lib/Lex/PPDirectives.cpp
===================================================================
--- clang/lib/Lex/PPDirectives.cpp
+++ clang/lib/Lex/PPDirectives.cpp
@@ -319,15 +319,6 @@
return Diag(MacroNameTok, diag::err_defined_macro_name);
}
- if (isDefineUndef == MU_Undef) {
- auto *MI = getMacroInfo(II);
- if (MI && MI->isBuiltinMacro()) {
- // Warn if undefining "__LINE__" and other builtins, per C99 6.10.8/4
- // and C++ [cpp.predefined]p4], but allow it as an extension.
- Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro);
- }
- }
-
// If defining/undefining reserved identifier or a keyword, we need to issue
// a warning.
SourceLocation MacroNameLoc = MacroNameTok.getLocation();
@@ -3008,6 +2999,12 @@
MI->setTokens(Tokens, BP);
return MI;
}
+
+static bool isObjCProtectedMacro(const IdentifierInfo *II) {
+ return II->isStr("__strong") || II->isStr("__weak") ||
+ II->isStr("__unsafe_unretained") || II->isStr("__autoreleasing");
+}
+
/// HandleDefineDirective - Implements \#define. This consumes the entire macro
/// line then lets the caller lex the next real token.
void Preprocessor::HandleDefineDirective(
@@ -3079,15 +3076,9 @@
// In Objective-C, ignore attempts to directly redefine the builtin
// definitions of the ownership qualifiers. It's still possible to
// #undef them.
- auto isObjCProtectedMacro = [](const IdentifierInfo *II) -> bool {
- return II->isStr("__strong") ||
- II->isStr("__weak") ||
- II->isStr("__unsafe_unretained") ||
- II->isStr("__autoreleasing");
- };
- if (getLangOpts().ObjC &&
- SourceMgr.getFileID(OtherMI->getDefinitionLoc())
- == getPredefinesFileID() &&
+ if (getLangOpts().ObjC &&
+ SourceMgr.getFileID(OtherMI->getDefinitionLoc()) ==
+ getPredefinesFileID() &&
isObjCProtectedMacro(MacroNameTok.getIdentifierInfo())) {
// Warn if it changes the tokens.
if ((!getDiagnostics().getSuppressSystemWarnings() ||
@@ -3111,7 +3102,8 @@
// Warn if defining "__LINE__" and other builtins, per C99 6.10.8/4 and
// C++ [cpp.predefined]p4, but allow it as an extension.
- if (OtherMI->isBuiltinMacro())
+ if (OtherMI->isBuiltinMacro() ||
+ SourceMgr.isWrittenInBuiltinFile(OtherMI->getDefinitionLoc()))
Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro);
// Macros must be identical. This means all tokens and whitespace
// separation must be the same. C99 6.10.3p2.
@@ -3191,6 +3183,14 @@
if (!MI->isUsed() && MI->isWarnIfUnused())
Diag(MI->getDefinitionLoc(), diag::pp_macro_not_used);
+ // Warn if undefining "__LINE__" and other builtins, per C99 6.10.8/4 and
+ // C++ [cpp.predefined]p4, but allow it as an extension. Don't warn if this
+ // is an Objective-C builtin macro though.
+ if ((MI->isBuiltinMacro() ||
+ SourceMgr.isWrittenInBuiltinFile(MI->getDefinitionLoc())) &&
+ !(getLangOpts().ObjC && isObjCProtectedMacro(II)))
+ Diag(MacroNameTok, diag::ext_pp_undef_builtin_macro);
+
if (MI->isWarnIfUnused())
WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -162,6 +162,8 @@
- Diagnostics relating to macros on the command line of a preprocessed assembly
file are now reported as coming from the file ``<command line>`` instead of
``<built-in>``.
+- Clang now warns when any predefined macro is undefined or redefined, instead
+ of only some of them.
Bug Fixes in This Version
-------------------------
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