Fix #12962 FP returnByReference with noexcept (#6637)

Author: chrchr-github

lib/symboldatabase.cpp

@@ -2497,6 +2497,13 @@ static bool isOperator(const Token *tokenDef)
     return name.size() > 8 && startsWith(name,"operator") && std::strchr("+-*/%&|~^<>!=[(", name[8]);
 }
 
+static bool isTrailingReturnType(const Token* tok)
+{
+    while (tok && tok->isKeyword())
+        tok = tok->next();
+    return Token::Match(tok, "&|&&| .");
+}
+
 Function::Function(const Token *tok,
                    const Scope *scope,
                    const Token *tokDef,
@@ -2540,7 +2547,7 @@ Function::Function(const Token *tok,
     if (!isConstructor() && !isDestructor()) {
         // @todo auto type deduction should be checked
         // @todo attributes and exception specification can also precede trailing return type
-        if (Token::Match(argDef->link()->next(), "const|volatile| &|&&| .")) { // Trailing return type
+        if (isTrailingReturnType(argDef->link()->next())) { // Trailing return type
             hasTrailingReturnType(true);
             if (argDef->link()->strAt(1) == ".")
                 retDef = argDef->link()->tokAt(2);

test/testsymboldatabase.cpp

@@ -4980,40 +4980,58 @@ class TestSymbolDatabase : public TestFixture {
     }
 
     void symboldatabase75() {
-        GET_SYMBOL_DB("template <typename T>\n"
-                      "class optional {\n"
-                      "  auto     value() & -> T &;\n"
-                      "  auto     value() && -> T &&;\n"
-                      "  auto     value() const& -> T const &;\n"
-                      "};\n"
-                      "template <typename T>\n"
-                      "auto optional<T>::value() & -> T & {}\n"
-                      "template <typename T>\n"
-                      "auto optional<T>::value() && -> T && {}\n"
-                      "template <typename T>\n"
-                      "auto optional<T>::value() const & -> T const & {}\n"
-                      "optional<int> i;");
+        {
+            GET_SYMBOL_DB("template <typename T>\n"
+                          "class optional {\n"
+                          "  auto     value() & -> T &;\n"
+                          "  auto     value() && -> T &&;\n"
+                          "  auto     value() const& -> T const &;\n"
+                          "};\n"
+                          "template <typename T>\n"
+                          "auto optional<T>::value() & -> T & {}\n"
+                          "template <typename T>\n"
+                          "auto optional<T>::value() && -> T && {}\n"
+                          "template <typename T>\n"
+                          "auto optional<T>::value() const & -> T const & {}\n"
+                          "optional<int> i;");
 
-        ASSERT_EQUALS(5, db->scopeList.size());
-        ASSERT_EQUALS(3, db->functionScopes.size());
-
-        const Scope *f = db->functionScopes[0];
-        ASSERT(f->function->hasBody());
-        ASSERT(!f->function->isConst());
-        ASSERT(f->function->hasTrailingReturnType());
-        ASSERT(f->function->hasLvalRefQualifier());
-
-        f = db->functionScopes[1];
-        ASSERT(f->function->hasBody());
-        ASSERT(!f->function->isConst());
-        ASSERT(f->function->hasTrailingReturnType());
-        ASSERT(f->function->hasRvalRefQualifier());
-
-        f = db->functionScopes[2];
-        ASSERT(f->function->hasBody());
-        ASSERT(f->function->isConst());
-        ASSERT(f->function->hasTrailingReturnType());
-        ASSERT(f->function->hasLvalRefQualifier());
+            ASSERT_EQUALS(5, db->scopeList.size());
+            ASSERT_EQUALS(3, db->functionScopes.size());
+
+            const Scope *f = db->functionScopes[0];
+            ASSERT(f->function->hasBody());
+            ASSERT(!f->function->isConst());
+            ASSERT(f->function->hasTrailingReturnType());
+            ASSERT(f->function->hasLvalRefQualifier());
+
+            f = db->functionScopes[1];
+            ASSERT(f->function->hasBody());
+            ASSERT(!f->function->isConst());
+            ASSERT(f->function->hasTrailingReturnType());
+            ASSERT(f->function->hasRvalRefQualifier());
+
+            f = db->functionScopes[2];
+            ASSERT(f->function->hasBody());
+            ASSERT(f->function->isConst());
+            ASSERT(f->function->hasTrailingReturnType());
+            ASSERT(f->function->hasLvalRefQualifier());
+        }
+        {
+            GET_SYMBOL_DB("struct S {\n" // #12962
+                          "    auto bar() const noexcept -> std::string const& { return m; }\n"
+                          "    std::string m;\n"
+                          "};\n");
+
+            ASSERT_EQUALS(3, db->scopeList.size());
+            ASSERT_EQUALS(1, db->functionScopes.size());
+
+            const Scope* f = db->functionScopes[0];
+            ASSERT(f->function->hasBody());
+            ASSERT(f->function->isConst());
+            ASSERT(f->function->hasTrailingReturnType());
+            ASSERT(f->function->isNoExcept());
+            ASSERT(Function::returnsReference(f->function));
+        }
     }
 
     void symboldatabase76() { // #9056