After issuing a diagnostic for undefining or redefining a builtin macro,
continue parsing the directive rather than silently discarding it.
Allowing undef or redef of __TIME__ and __DATE__ is important to folks
who want stable, reproducible builds.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@176540 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index 07f24c8..8379ca8 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -143,15 +143,14 @@
Diag(MacroNameTok, diag::err_pp_macro_not_identifier);
// Fall through on error.
} else if (isDefineUndef && II->getPPKeywordID() == tok::pp_defined) {
- // Error if defining "defined": C99 6.10.8.4.
+ // Error if defining "defined": C99 6.10.8/4, C++ [cpp.predefined]p4.
Diag(MacroNameTok, diag::err_defined_macro_name);
- } else if (isDefineUndef && II->hasMacroDefinition() &&
+ } else if (isDefineUndef == 2 && II->hasMacroDefinition() &&
getMacroInfo(II)->isBuiltinMacro()) {
- // Error if defining "__LINE__" and other builtins: C99 6.10.8.4.
- if (isDefineUndef == 1)
- Diag(MacroNameTok, diag::pp_redef_builtin_macro);
- else
- Diag(MacroNameTok, diag::pp_undef_builtin_macro);
+ // 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);
+ return;
} else {
// Okay, we got a good identifier node. Return it.
return;
@@ -1925,10 +1924,14 @@
if (!OtherMI->isUsed() && OtherMI->isWarnIfUnused())
Diag(OtherMI->getDefinitionLoc(), diag::pp_macro_not_used);
+ // 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())
+ Diag(MacroNameTok, diag::ext_pp_redef_builtin_macro);
// Macros must be identical. This means all tokens and whitespace
// separation must be the same. C99 6.10.3.2.
- if (!OtherMI->isAllowRedefinitionsWithoutWarning() &&
- !MI->isIdenticalTo(*OtherMI, *this)) {
+ else if (!OtherMI->isAllowRedefinitionsWithoutWarning() &&
+ !MI->isIdenticalTo(*OtherMI, *this)) {
Diag(MI->getDefinitionLoc(), diag::ext_pp_macro_redef)
<< MacroNameTok.getIdentifierInfo();
Diag(OtherMI->getDefinitionLoc(), diag::note_previous_definition);