[clang-tidy] Make misc-static-assert accept assert(!"msg")

Added negated string literals to the set of IsAlwaysFalse expressions to avoid flagging of assert(!"msg").

Differential Revision: http://reviews.llvm.org/D33827

llvm-svn: 304657

clang-tools-extra/clang-tidy/misc/StaticAssertCheck.cpp

@@ -33,9 +33,11 @@ void StaticAssertCheck::registerMatchers(MatchFinder *Finder) {
   if (!(getLangOpts().CPlusPlus11 || getLangOpts().C11))
     return;
 
+  auto NegatedString = unaryOperator(
+      hasOperatorName("!"), hasUnaryOperand(ignoringImpCasts(stringLiteral())));
   auto IsAlwaysFalse =
       expr(anyOf(cxxBoolLiteral(equals(false)), integerLiteral(equals(0)),
-                 cxxNullPtrLiteralExpr(), gnuNullExpr()))
+                 cxxNullPtrLiteralExpr(), gnuNullExpr(), NegatedString))
           .bind("isAlwaysFalse");
   auto IsAlwaysFalseWithCast = ignoringParenImpCasts(anyOf(
       IsAlwaysFalse, cStyleCastExpr(has(ignoringParenImpCasts(IsAlwaysFalse)))

clang-tools-extra/test/clang-tidy/misc-static-assert.cpp

@@ -76,6 +76,9 @@ int main() {
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: found assert() that could be
   // CHECK-FIXES: {{^  }}static_assert(ZERO_MACRO, "");
 
+  assert(!"Don't report me!");
+  // CHECK-FIXES: {{^  }}assert(!"Don't report me!");
+
   assert(0 && "Don't report me!");
   // CHECK-FIXES: {{^  }}assert(0 && "Don't report me!");