fix #12605: internalAstError with C11 _Atomic() (#7311)

Author: ludviggunne

lib/tokenize.cpp

@@ -9585,6 +9585,10 @@ void Tokenizer::simplifyKeyword()
 
             if (mSettings.standards.c >= Standards::C11) {
                 while (tok->str() == "_Atomic") {
+                    if (Token::simpleMatch(tok->next(), "(")) {
+                        tok->linkAt(1)->deleteThis();
+                        tok->next()->deleteThis();
+                    }
                     for (Token* temp: getTypeTokens())
                         temp->isAtomic(true);
                     tok->deleteThis();

test/testtokenize.cpp

@@ -471,6 +471,8 @@ class TestTokenizer : public TestFixture {
         TEST_CASE(genericInIf); // #13561
 
         TEST_CASE(preincrementInLambda); // #13312
+
+        TEST_CASE(atomicCast); // #12605
     }
 
 #define tokenizeAndStringify(...) tokenizeAndStringify_(__FILE__, __LINE__, __VA_ARGS__)
@@ -8431,6 +8433,14 @@ class TestTokenizer : public TestFixture {
             "}\n";
         ASSERT_NO_THROW(tokenizeAndStringify(code));
     }
+
+    void atomicCast() { // #12605
+        const char code[] = "int atomic_add_int(int *ptr, int v)\n"
+                            "{\n"
+                            "    return atomic_fetch_add((_Atomic(unsigned int) *)ptr, v) + v;\n"
+                            "}\n";
+        ASSERT_NO_THROW(tokenizeAndStringify(code, settingsDefault, false));
+    }
 };
 
 REGISTER_TEST(TestTokenizer)