[clang] [clang] Avoid -Wshadow warning when init-capture named same as class field (PR #74512)

[Mariya Podchishchaeva via cfe-commits]

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@@ -8328,35 +8328,47 @@ void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl,
 
   unsigned WarningDiag = diag::warn_decl_shadow;
   SourceLocation CaptureLoc;
-  if (isa<VarDecl>(D) && isa<VarDecl>(ShadowedDecl) && NewDC &&
-      isa<CXXMethodDecl>(NewDC)) {
+  if (isa<VarDecl>(D) && NewDC && isa<CXXMethodDecl>(NewDC)) {
     if (const auto *RD = dyn_cast<CXXRecordDecl>(NewDC->getParent())) {
       if (RD->isLambda() && OldDC->Encloses(NewDC->getLexicalParent())) {
-        if (RD->getLambdaCaptureDefault() == LCD_None) {
-          // Try to avoid warnings for lambdas with an explicit capture list.
+        if (const auto *VD = dyn_cast<VarDecl>(ShadowedDecl)) {
           const auto *LSI = cast<LambdaScopeInfo>(getCurFunction());
-          // Warn only when the lambda captures the shadowed decl explicitly.
-          CaptureLoc = getCaptureLocation(LSI, cast<VarDecl>(ShadowedDecl));
-          if (CaptureLoc.isInvalid())
-            WarningDiag = diag::warn_decl_shadow_uncaptured_local;
-        } else {
-          // Remember that this was shadowed so we can avoid the warning if the
-          // shadowed decl isn't captured and the warning settings allow it.
+          if (RD->getLambdaCaptureDefault() == LCD_None) {
+            // Try to avoid warnings for lambdas with an explicit capture
+            // list. Warn only when the lambda captures the shadowed decl
+            // explicitly.
+            CaptureLoc = getCaptureLocation(LSI, VD);
+            if (CaptureLoc.isInvalid())
+              WarningDiag = diag::warn_decl_shadow_uncaptured_local;
+          } else {
+            // Remember that this was shadowed so we can avoid the warning if
+            // the shadowed decl isn't captured and the warning settings allow
+            // it.
+            cast<LambdaScopeInfo>(getCurFunction())
+                ->ShadowingDecls.push_back({D, VD});
+            return;
+          }
+        }
+        if (isa<FieldDecl>(ShadowedDecl)) {
+          // If lambda can capture this, then emit default shadowing warning,
+          // Otherwise it is not really a shadowing case since field is not
+          // available in lambda's body.
+          // At this point we don't know that lambda can capture this, so
+          // remember that this was shadowed and delay until we know.
           cast<LambdaScopeInfo>(getCurFunction())
-              ->ShadowingDecls.push_back(
-                  {cast<VarDecl>(D), cast<VarDecl>(ShadowedDecl)});
+              ->ShadowingDecls.push_back({D, ShadowedDecl});
           return;
         }
       }
-
-      if (cast<VarDecl>(ShadowedDecl)->hasLocalStorage()) {
-        // A variable can't shadow a local variable in an enclosing scope, if
-        // they are separated by a non-capturing declaration context.
+      if (const auto *VD = dyn_cast<VarDecl>(ShadowedDecl);
+          VD && VD->hasLocalStorage()) {
+        // A variable can't shadow a local variable in an enclosing scope,
+        // if they are separated by a non-capturing declaration context.
         for (DeclContext *ParentDC = NewDC;
              ParentDC && !ParentDC->Equals(OldDC);
              ParentDC = getLambdaAwareParentOfDeclContext(ParentDC)) {
-          // Only block literals, captured statements, and lambda expressions
-          // can capture; other scopes don't.
+          // Only block literals, captured statements, and lambda
+          // expressions can capture; other scopes don't.
           if (!isa<BlockDecl>(ParentDC) && !isa<CapturedDecl>(ParentDC) &&
               !isLambdaCallOperator(ParentDC)) {
             return;
----------------
Fznamznon wrote:

Reverted. Side effect of messing with the code around and applying clang-format several times.

https://github.com/llvm/llvm-project/pull/74512