Fix #11423 Crash in valueFlowForwardConst() (#4634)

Author: chrchr-github

lib/tokenize.cpp

@@ -3917,7 +3917,15 @@ void Tokenizer::setVarIdPass1()
             if (!scopeStack.top().isExecutable)
                 newFunctionDeclEnd = isFunctionHead(tok, "{:;");
             else {
-                Token const * const tokenLinkNext = tok->link()->next();
+                const Token* tokenLinkNext = tok->link()->next();
+                if (Token::simpleMatch(tokenLinkNext, ".")) { // skip trailing return type
+                    tokenLinkNext = tokenLinkNext->next();
+                    while (Token::Match(tokenLinkNext, "%name%|::")) {
+                        tokenLinkNext = tokenLinkNext->next();
+                        if (Token::simpleMatch(tokenLinkNext, "<") && tokenLinkNext->link())
+                            tokenLinkNext = tokenLinkNext->link()->next();
+                    }
+                }
                 if (tokenLinkNext && tokenLinkNext->str() == "{") // might be for- or while-loop or if-statement
                     newFunctionDeclEnd = tokenLinkNext;
             }

test/testvarid.cpp

@@ -176,6 +176,7 @@ class TestVarID : public TestFixture {
         TEST_CASE(varid_lambda_mutable);
         TEST_CASE(varid_trailing_return1); // #8889
         TEST_CASE(varid_trailing_return2); // #9066
+        TEST_CASE(varid_trailing_return3); // #11423
         TEST_CASE(varid_parameter_pack); // #9383
         TEST_CASE(varid_for_auto_cpp17);
         TEST_CASE(varid_not); // #9689 'not x'
@@ -2822,6 +2823,18 @@ class TestVarID : public TestFixture {
         ASSERT_EQUALS(exp1, tokenize(code1));
     }
 
+    void varid_trailing_return3() { // #11423
+        const char code[] = "void f(int a, int b) {\n"
+                            "    auto g = [](int& a, const int b) -> void {};\n"
+                            "    auto h = [&a, &b]() { std::swap(a, b); };\n"
+                            "}\n";
+        const char exp[] = "1: void f ( int a@1 , int b@2 ) {\n"
+                           "2: auto g@3 ; g@3 = [ ] ( int & a@4 , const int b@5 ) . void { } ;\n"
+                           "3: auto h@6 ; h@6 = [ & a@1 , & b@2 ] ( ) { std :: swap ( a@1 , b@2 ) ; } ;\n"
+                           "4: }\n";
+        ASSERT_EQUALS(exp, tokenize(code));
+    }
+
     void varid_parameter_pack() { // #9383
         const char code1[] = "template <typename... Rest>\n"
                              "void func(Rest... parameters) {\n"