connect-3arg-lambda: refactor this check

No longer advises to pass 'this' as 3rd argument, because it might
make sense to pass another object there, should be the user to decide.

1 files changed, 22 insertions, 17 deletions

diff --git a/src/checks/level1/connect-3arg-lambda.cpp b/src/checks/level1/connect-3arg-lambda.cpp
index e036f6f8..12148907 100644
--- a/src/checks/level1/connect-3arg-lambda.cpp
+++ b/src/checks/level1/connect-3arg-lambda.cpp
@@ -52,31 +52,30 @@ void Connect3argLambda::VisitStmt(clang::Stmt *stmt)
     if (!lambda)
         return;
 
-    // The sender can be: this
-    auto senderThis = HierarchyUtils::unpeal<CXXThisExpr>(callExpr->getArg(0), HierarchyUtils::IgnoreImplicitCasts);
+    DeclRefExpr *senderDeclRef = nullptr;
+    MemberExpr *senderMemberExpr = nullptr;
 
-    // Or it can be: a declref (variable)
-    DeclRefExpr *senderDeclRef = senderThis ? nullptr : HierarchyUtils::getFirstChildOfType2<DeclRefExpr>(callExpr->getArg(0));
+    Stmt *s = callExpr->getArg(0);
+    while (s) {
+        if ((senderDeclRef = dyn_cast<DeclRefExpr>(s)))
+            break;
 
+        if ((senderMemberExpr = dyn_cast<MemberExpr>(s)))
+            break;
 
-    // If this is referenced inside the lambda body, for example, by calling a member function
-    auto thisExprs = HierarchyUtils::getStatements<CXXThisExpr>(lambda->getBody());
-    const bool lambdaHasThis = !thisExprs.empty();
+        s = HierarchyUtils::getFirstChild(s);
+    }
 
-    // The variables used inside the lambda
-    auto declrefs = HierarchyUtils::getStatements<DeclRefExpr>(lambda->getBody());
 
-    // If lambda doesn't do anything interesting, don't warn
-    if (declrefs.empty() && !lambdaHasThis)
-        return;
+    // The sender can be: this
+    CXXThisExpr* senderThis = HierarchyUtils::unpeal<CXXThisExpr>(callExpr->getArg(0), HierarchyUtils::IgnoreImplicitCasts);
 
-    if (lambdaHasThis && !senderThis && QtUtils::isQObject(thisExprs[0]->getType())) {
-        emitWarning(stmt->getLocStart(), "Pass 'this' as the 3rd connect parameter");
-        return;
-    }
+    // The variables used inside the lambda
+    auto declrefs = HierarchyUtils::getStatements<DeclRefExpr>(lambda->getBody());
 
     ValueDecl *senderDecl = senderDeclRef ? senderDeclRef->getDecl() : nullptr;
-    // We'll only warn if the lambda is dereferencing another QObject (besides the sender).
+
+    // We'll only warn if the lambda is dereferencing another QObject (besides the sender)
     bool found = false;
     for (auto declref : declrefs) {
         ValueDecl *decl = declref->getDecl();
@@ -89,6 +88,12 @@ void Connect3argLambda::VisitStmt(clang::Stmt *stmt)
         }
     }
 
+    if (!found) {
+        auto thisexprs = HierarchyUtils::getStatements<CXXThisExpr>(lambda->getBody());
+        if (!thisexprs.empty() && !senderThis)
+            found = true;
+    }
+
     if (found)
         emitWarning(stmt->getLocStart(), "Pass a context object as 3rd connect parameter");
 }