[clang] [Clang][diagnostics] Fix structured binding shadows template param loc (PR #129116)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: Amr Hesham (AmrDeveloper)

<details>
<summary>Changes</summary>

Fix structured binding shadows template parameter location

Fixes: #<!-- -->129060

---
Full diff: https://github.com/llvm/llvm-project/pull/129116.diff


2 Files Affected:

- (modified) clang/lib/Sema/SemaDeclCXX.cpp (+1-2) 
- (modified) clang/test/CXX/temp/temp.res/temp.local/p6.cpp (+5) 


``````````diff
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 664d48ccbc382..a3a028b9485d6 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -883,8 +883,7 @@ Sema::ActOnDecompositionDeclarator(Scope *S, Declarator &D,
     // It's not permitted to shadow a template parameter name.
     if (Previous.isSingleResult() &&
         Previous.getFoundDecl()->isTemplateParameter()) {
-      DiagnoseTemplateParameterShadow(D.getIdentifierLoc(),
-                                      Previous.getFoundDecl());
+      DiagnoseTemplateParameterShadow(B.NameLoc, Previous.getFoundDecl());
       Previous.clear();
     }
 
diff --git a/clang/test/CXX/temp/temp.res/temp.local/p6.cpp b/clang/test/CXX/temp/temp.res/temp.local/p6.cpp
index 00bb35813c39a..e464bb5e7eaef 100644
--- a/clang/test/CXX/temp/temp.res/temp.local/p6.cpp
+++ b/clang/test/CXX/temp/temp.res/temp.local/p6.cpp
@@ -162,3 +162,8 @@ struct A {
 };
 A<0>::B a;
 }
+
+template <typename T> void shadow9() {  // expected-note{{template parameter is declared here}}
+  using arr = int[1]; // expected-warning at +1 {{decomposition declarations are a C++17 extension}}
+  auto [T] = arr{}; // expected-error {{declaration of 'T' shadows template parameter}}
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/129116