[clang-tidy] Fix for llvm.org/PR23355

[eszasip]

Summary

misc-static-assert now recognizes __builtin_expect based assert macros.

I also added __builtin_expect to the white list of misc-assert-side-effect.

[alexfh]

Thanks!

Looks good with one nit.

clang-tidy/misc/AssertSideEffectCheck.cpp

59

There's no need to use getAsString(), as you're only checking whether it's a specific unqualified name. I'd try to use the more effective version: getName(). Something along the lines of:

if (FuncDecl->getDeclName().isIdentifier() && FuncDecl->getName() == "...") 
  ...

[eszasip]

Committed in r238548.

clang-tidy/misc/AssertSideEffectCheck.cpp

59

Thanks. Changed it as you suggested.

clang-tidy/misc/AssertSideEffectCheck.cpp

 
   if (const auto *CExpr = dyn_cast<CallExpr>(E)) {
     bool Result = CheckFunctionCalls;
-    if (const auto *FuncDecl = CExpr->getDirectCallee())
-      if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
+    if (const auto *FuncDecl = CExpr->getDirectCallee()) {
+      const std::string FunctionName = FuncDecl->getNameInfo().getAsString();
+      if (FunctionName == "__builtin_expect") // exceptions come here
+        Result = false;
+      else if (const auto *MethodDecl = dyn_cast<CXXMethodDecl>(FuncDecl))
         Result &= !MethodDecl->isConst();
+    }
     return Result;
   }
 

clang-tidy/misc/StaticAssertCheck.cpp

       IsAlwaysFalse);
   auto NonConstexprFunctionCall =
       callExpr(hasDeclaration(functionDecl(unless(isConstexpr()))));
-  auto Condition = expr(anyOf(
+  auto AssertCondition = expr(anyOf(
       expr(ignoringParenCasts(anyOf(
           AssertExprRoot,
           unaryOperator(hasUnaryOperand(ignoringParenCasts(AssertExprRoot)))))),
-      anything()), unless(findAll(NonConstexprFunctionCall)));
+      anything()), unless(findAll(NonConstexprFunctionCall))).bind("condition");
+  auto Condition = anyOf(ignoringParenImpCasts(callExpr(
+      hasDeclaration(functionDecl(hasName("__builtin_expect"))),
+      hasArgument(0, AssertCondition))), AssertCondition);
 
   Finder->addMatcher(
-      stmt(anyOf(conditionalOperator(hasCondition(Condition.bind("condition"))),
-                 ifStmt(hasCondition(Condition.bind("condition")))),
+      stmt(anyOf(conditionalOperator(hasCondition(Condition)),
+                 ifStmt(hasCondition(Condition))),
            unless(isInTemplateInstantiation())).bind("condStmt"),
       this);
 }

test/clang-tidy/misc-assert-side-effect.cpp

-// RUN: $(dirname %s)/check_clang_tidy.sh %s misc-assert-side-effect %t -config="{CheckOptions: [{key: misc-assert-side-effect.CheckFunctionCalls, value: 1}, {key: misc-assert-side-effect.AssertMacros, value: 'assert,my_assert'}]}" -- -fexceptions
+// RUN: $(dirname %s)/check_clang_tidy.sh %s misc-assert-side-effect %t -config="{CheckOptions: [{key: misc-assert-side-effect.CheckFunctionCalls, value: 1}, {key: misc-assert-side-effect.AssertMacros, value: 'assert,assert2,my_assert'}]}" -- -fexceptions
 // REQUIRES: shell
 
 //===--- assert definition block ------------------------------------------===//

   (void)abort()
 #endif
 
+void print(...);
+#define assert2(e) (__builtin_expect(!(e), 0) ?                                \
+                       print (#e, __FILE__, __LINE__) : (void)0)
+
 #ifdef NDEBUG
 #define my_assert(x) 1
 #else

   assert((throw 1, false));
   // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: found assert() with side effect
 
+  assert2(1 == 2 - 1);
+
   return 0;
 }

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

   abort()
 #endif
 
+void print(...);
+
 #define ZERO_MACRO 0
 
 #define False false

   assert(strlen("12345") == 5);
   // CHECK-FIXES: {{^  }}assert(strlen("12345") == 5);
 
+#define assert(e) (__builtin_expect(!(e), 0) ? print (#e, __FILE__, __LINE__) : (void)0)
+  assert(false);
+  // CHECK-FIXES: {{^  }}assert(false);
+
+  assert(10 == 5 + 5);
+  // CHECK-MESSAGES: :[[@LINE-1]]:3: warning: found assert() that could be
+  // CHECK-FIXES: {{^  }}static_assert(10 == 5 + 5, "");
+#undef assert
+
   return 0;
 }