From 63e30d1b8cc598571b1b81e8343de3f63224d493 Mon Sep 17 00:00:00 2001
From: gerboengels <github@gerbo.org>
Date: Sun, 18 Dec 2022 16:46:04 +0100
Subject: [PATCH] Fix syntaxError on lambda inside decltype (#4650)

Use case where it gave an issue:

using customComparator = decltype([] (const X& lhs, const X& rhs) { return lhs.CompareTo(rhs); });
std::map<X, int, costomComparator> m;

Co-authored-by: Gerbo Engels <gerbo.engels@ortec-finance.com>
---
 lib/symboldatabase.cpp      |  8 ++++++--
 lib/symboldatabase.h        |  8 ++++++--
 test/testsymboldatabase.cpp | 10 ++++++++++
 3 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/lib/symboldatabase.cpp b/lib/symboldatabase.cpp
index bd18cf24e..ef3811dbb 100644
--- a/lib/symboldatabase.cpp
+++ b/lib/symboldatabase.cpp
@@ -387,8 +387,12 @@ void SymbolDatabase::createSymbolDatabaseFindAllScopes()
 
             tok = tok->tokAt(3);
 
-            while (tok && tok->str() != ";")
-                tok = tok->next();
+            while (tok && tok->str() != ";") {
+                if (Token::simpleMatch(tok, "decltype ("))
+                    tok = tok->linkAt(1);
+                else
+                    tok = tok->next();
+            }
         }
 
         // unnamed struct and union
diff --git a/lib/symboldatabase.h b/lib/symboldatabase.h
index 6d0a0fa3d..5626c362e 100644
--- a/lib/symboldatabase.h
+++ b/lib/symboldatabase.h
@@ -122,8 +122,12 @@ public:
         else if (classDef_ && classDef_->str() == "using") {
             typeStart = classDef->tokAt(3);
             typeEnd = typeStart;
-            while (typeEnd->next() && typeEnd->next()->str() != ";")
-                typeEnd = typeEnd->next();
+            while (typeEnd->next() && typeEnd->next()->str() != ";") {
+                if (Token::simpleMatch(typeEnd, "decltype ("))
+                    typeEnd = typeEnd->linkAt(1);
+                else
+                    typeEnd = typeEnd->next();
+            }
         }
     }
 
diff --git a/test/testsymboldatabase.cpp b/test/testsymboldatabase.cpp
index 003a9dcca..49abc9317 100644
--- a/test/testsymboldatabase.cpp
+++ b/test/testsymboldatabase.cpp
@@ -366,6 +366,7 @@ private:
         TEST_CASE(symboldatabase100); // #10174
         TEST_CASE(symboldatabase101);
         TEST_CASE(symboldatabase102);
+        TEST_CASE(symboldatabase103);
 
         TEST_CASE(createSymbolDatabaseFindAllScopes1);
         TEST_CASE(createSymbolDatabaseFindAllScopes2);
@@ -5060,6 +5061,15 @@ private:
         ASSERT(db->scopeList.back().className == "g");
     }
 
+    void symboldatabase103() {
+        GET_SYMBOL_DB("void f() {\n"
+                      "using lambda = decltype([]() { return true; });\n"
+                      "lambda{}();\n"
+                      "}\n");
+        ASSERT(db != nullptr);
+        ASSERT_EQUALS("", errout.str());
+    }
+
     void createSymbolDatabaseFindAllScopes1() {
         GET_SYMBOL_DB("void f() { union {int x; char *p;} a={0}; }");
         ASSERT(db->scopeList.size() == 3);