Author: arphaman
Date: Wed Apr 5 09:07:21 2017
New Revision: 299541
URL: http://llvm.org/viewvc/llvm-project?rev=299541&view=rev
Log:
-Wunreachable-code: 'true' and 'false' should not be treated as configuration
macros
Clang should emit -Wunreachable-code warnings in C mode for code that's
unreachable because of a 'false' or '!true' condition.
Modified:
cfe/trunk/lib/Analysis/ReachableCode.cpp
cfe/trunk/test/Sema/warn-unreachable.c
Modified: cfe/trunk/lib/Analysis/ReachableCode.cpp
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Analysis/ReachableCode.cpp?rev=299541&r1=299540&r2=299541&view=diff
==============================================================================
--- cfe/trunk/lib/Analysis/ReachableCode.cpp (original)
+++ cfe/trunk/lib/Analysis/ReachableCode.cpp Wed Apr 5 09:07:21 2017
@@ -132,15 +132,21 @@ static bool isExpandedFromConfigurationM
// so that we can refine it later.
SourceLocation L = S->getLocStart();
if (L.isMacroID()) {
+ SourceManager &SM = PP.getSourceManager();
if (IgnoreYES_NO) {
// The Objective-C constant 'YES' and 'NO'
// are defined as macros. Do not treat them
// as configuration values.
- SourceManager &SM = PP.getSourceManager();
SourceLocation TopL = getTopMostMacro(L, SM);
StringRef MacroName = PP.getImmediateMacroName(TopL);
if (MacroName == "YES" || MacroName == "NO")
return false;
+ } else if (!PP.getLangOpts().CPlusPlus) {
+ // Do not treat C 'false' and 'true' macros as configuration values.
+ SourceLocation TopL = getTopMostMacro(L, SM);
+ StringRef MacroName = PP.getImmediateMacroName(TopL);
+ if (MacroName == "false" || MacroName == "true")
+ return false;
}
return true;
}
Modified: cfe/trunk/test/Sema/warn-unreachable.c
URL:
http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/warn-unreachable.c?rev=299541&r1=299540&r2=299541&view=diff
==============================================================================
--- cfe/trunk/test/Sema/warn-unreachable.c (original)
+++ cfe/trunk/test/Sema/warn-unreachable.c Wed Apr 5 09:07:21 2017
@@ -451,3 +451,13 @@ void unaryOpFixitCastSubExpr(int x) {
// CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:15-[[@LINE-2]]:15}:")"
unaryOpFixitCastSubExpr(x); // expected-warning {{code will never be
executed}}
}
+
+#define false 0
+#define true 1
+
+void testTrueFalseMacros() {
+ if (false) // expected-note {{silence by adding parentheses to mark code as
explicitly dead}}
+ testTrueFalseMacros(); // expected-warning {{code will never be executed}}
+ if (!true) // expected-note {{silence by adding parentheses to mark code as
explicitly dead}}
+ testTrueFalseMacros(); // expected-warning {{code will never be executed}}
+}
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