[clang-tidy] Fix false positives in the misc-static-assert check http://llvm.org/PR22880

The misc-static-assert check will not warn on assert(false), assert(False),
assert(FALSE); where false / False / FALSE are macros expanding to the false or
0 literals.

Also added corresponding test cases.

http://reviews.llvm.org/D8328

Patch by Szabolcs Sipos!

llvm-svn: 232306

1 files changed, 11 insertions, 3 deletions

diff --git a/clang-tools-extra/clang-tidy/misc/StaticAssertCheck.cpp b/clang-tools-extra/clang-tidy/misc/StaticAssertCheck.cpp
index fd6c4ca..91451e6 100644
--- a/clang-tools-extra/clang-tidy/misc/StaticAssertCheck.cpp
+++ b/clang-tools-extra/clang-tidy/misc/StaticAssertCheck.cpp
@@ -75,9 +75,17 @@ void StaticAssertCheck::check(const MatchFinder::MatchResult &Result) {
     return;
 
   // False literal is not the result of macro expansion.
-  if (IsAlwaysFalse &&
-      !SM.getImmediateSpellingLoc(IsAlwaysFalse->getExprLoc()).isMacroID())
-    return;
+  if (IsAlwaysFalse) {
+    SourceLocation FalseLiteralLoc =
+        SM.getImmediateSpellingLoc(IsAlwaysFalse->getExprLoc());
+    if (!FalseLiteralLoc.isMacroID())
+      return;
+
+    StringRef FalseMacroName =
+        Lexer::getImmediateMacroName(FalseLiteralLoc, SM, Opts);
+    if (FalseMacroName.compare_lower("false") == 0)
+      return;
+  }
 
   SourceLocation AssertLoc = SM.getImmediateMacroCallerLoc(AssertExpansionLoc);