Fix #12338 "Analysis failed (lambda not recognized)" with trailing type in lambda parameter (danmar#5869)

Author: chrchr-github

lib/tokenlist.cpp

@@ -1373,6 +1373,15 @@ const Token* findLambdaEndTokenWithoutAST(const Token* tok) {
     tok = tok->link()->next();
     if (Token::simpleMatch(tok, "(") && tok->link())
         tok = tok->link()->next();
+    if (Token::simpleMatch(tok, ".")) { // trailing return type
+        tok = tok->next();
+        while (Token::Match(tok, "%type%|%name%|::|&|&&|*|<|(")) {
+            if (tok->link())
+                tok = tok->link()->next();
+            else
+                tok = tok->next();
+        }
+    }
     if (!(Token::simpleMatch(tok, "{") && tok->link()))
         return nullptr;
     return tok->link()->next();

test/testsymboldatabase.cpp

@@ -2814,15 +2814,42 @@ class TestSymbolDatabase : public TestFixture {
         ASSERT_EQUALS(3, func->argCount());
     }
 
-    void functionArgs20() { // #11769
-        const char code[] = "void f(void *(*g)(void *) = [](void *p) { return p; }) {}";
-        GET_SYMBOL_DB(code);
-        ASSERT(db != nullptr);
-        const Scope *scope = db->functionScopes.front();
-        const Function *func = scope->function;
-        ASSERT_EQUALS(1, func->argCount());
-        const Variable* arg = func->getArgumentVar(0);
-        TODO_ASSERT(arg->hasDefault());
+    void functionArgs20() {
+        {
+            const char code[] = "void f(void *(*g)(void *) = [](void *p) { return p; }) {}"; // #11769
+            GET_SYMBOL_DB(code);
+            ASSERT(db != nullptr);
+            const Scope *scope = db->functionScopes.front();
+            const Function *func = scope->function;
+            ASSERT_EQUALS(1, func->argCount());
+            const Variable* arg = func->getArgumentVar(0);
+            TODO_ASSERT(arg->hasDefault());
+        }
+        {
+            const char code[] = "void f() { auto g = [&](const std::function<int(int)>& h = [](int i) -> int { return i; }) {}; }"; // #12338
+            GET_SYMBOL_DB(code);
+            ASSERT(db != nullptr);
+            ASSERT_EQUALS(3, db->scopeList.size());
+            ASSERT_EQUALS(Scope::ScopeType::eLambda, db->scopeList.back().type);
+        }
+        {
+            const char code[] = "void f() {\n"
+                                "    auto g = [&](const std::function<const std::vector<int>&(const std::vector<int>&)>& h = [](const std::vector<int>& v) -> const std::vector<int>& { return v; }) {};\n"
+                                "}\n";
+            GET_SYMBOL_DB(code);
+            ASSERT(db != nullptr);
+            ASSERT_EQUALS(3, db->scopeList.size());
+            ASSERT_EQUALS(Scope::ScopeType::eLambda, db->scopeList.back().type);
+        }
+        {
+            const char code[] = "void f() {\n"
+                                "    auto g = [&](const std::function<int(int)>& h = [](int i) -> decltype(0) { return i; }) {};\n"
+                                "}\n";
+            GET_SYMBOL_DB(code);
+            ASSERT(db != nullptr);
+            ASSERT_EQUALS(3, db->scopeList.size());
+            ASSERT_EQUALS(Scope::ScopeType::eLambda, db->scopeList.back().type);
+        }
     }
 
     void functionArgs21() {