https://github.com/AhmedKamel10 updated https://github.com/llvm/llvm-project/pull/221249
>From bc4566e50feea6d63445521d0e2fbc9326867d69 Mon Sep 17 00:00:00 2001 From: ahmedkamel10 <[email protected]> Date: Fri, 11 Sep 2026 17:07:07 +0300 Subject: [PATCH 1/2] [clang][Sema] Fix false-positive -Wshadow for friend functions Distinguish friend functions from NSDMI-lambda context in -Wshadow when checking for shadowed fields. --- clang/docs/ReleaseNotes.md | 2 ++ clang/lib/Sema/SemaDecl.cpp | 8 ++++---- clang/test/SemaCXX/warn-shadow.cpp | 16 ++++++++++++++++ 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index 6a2201012693e..f03819ad9e97a 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -492,6 +492,8 @@ features cannot lower the translation-unit ABI level; `operator delete`, since such a delete expression never invokes the destructor. (#GH65524) +- Fixed a false-positive `-Wshadow` warning when a function parameter in an inline-defined friend function shares the name of a non-static class member variable. (#GH221190) + ### Improvements to Clang's time-trace ### Improvements to Coverage Mapping diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index a9047f61a8bf5..3dc6f9a9770ce 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -8627,12 +8627,12 @@ void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl, DeclContext *NewDC = D->getDeclContext(); if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) { - if (const auto *MD = - dyn_cast<CXXMethodDecl>(getFunctionLevelDeclContext())) { - // Fields aren't shadowed in C++ static members or in member functions - // with an explicit object parameter. + DeclContext *FnDC = getFunctionLevelDeclContext(); + if (const auto *MD = dyn_cast<CXXMethodDecl>(FnDC)) { if (MD->isStatic() || MD->isExplicitObjectMemberFunction()) return; + } else if (isa<FunctionDecl>(FnDC)) { + return; } // Fields shadowed by constructor parameters are a special case. Usually // the constructor initializes the field with the parameter. diff --git a/clang/test/SemaCXX/warn-shadow.cpp b/clang/test/SemaCXX/warn-shadow.cpp index 98a235a73c7e5..fc184e5a1eb90 100644 --- a/clang/test/SemaCXX/warn-shadow.cpp +++ b/clang/test/SemaCXX/warn-shadow.cpp @@ -90,6 +90,22 @@ class A { } }; +class FriendFunction { + int x; // expected-note {{previous declaration is here}} + friend bool operator==(const FriendFunction &f, int x) { + return f.x == x; + } + void test(int x) { // expected-warning {{declaration shadows a field of 'FriendFunction'}} + } +}; + +struct NSDMILambda { + int a; // expected-note {{previous declaration is here}} + int x = [this] { + int a = 0; // expected-warning {{declaration shadows a field of 'NSDMILambda'}} + return a; + }(); +}; struct path { using value_type = char; typedef char value_type2; >From 89a4bbd80271d5b526968e4342fd92fef178648f Mon Sep 17 00:00:00 2001 From: ahmedkamel10 <[email protected]> Date: Tue, 15 Sep 2026 14:51:04 +0300 Subject: [PATCH 2/2] Address review: reword release note, restore comments, add plain friend test --- clang/docs/ReleaseNotes.md | 4 +++- clang/lib/Sema/SemaDecl.cpp | 6 ++++++ clang/test/SemaCXX/warn-shadow.cpp | 7 +++++++ 3 files changed, 16 insertions(+), 1 deletion(-) diff --git a/clang/docs/ReleaseNotes.md b/clang/docs/ReleaseNotes.md index f03819ad9e97a..8d34dd1822989 100644 --- a/clang/docs/ReleaseNotes.md +++ b/clang/docs/ReleaseNotes.md @@ -492,7 +492,9 @@ features cannot lower the translation-unit ABI level; `operator delete`, since such a delete expression never invokes the destructor. (#GH65524) -- Fixed a false-positive `-Wshadow` warning when a function parameter in an inline-defined friend function shares the name of a non-static class member variable. (#GH221190) +- Fixed a false-positive `-Wshadow` warning when a variable in an + inline-defined friend function shares the name of a non-static class + member variable. (#GH221190) ### Improvements to Clang's time-trace diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 3dc6f9a9770ce..3f52732ea1c40 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -8629,9 +8629,15 @@ void Sema::CheckShadow(NamedDecl *D, NamedDecl *ShadowedDecl, if (FieldDecl *FD = dyn_cast<FieldDecl>(ShadowedDecl)) { DeclContext *FnDC = getFunctionLevelDeclContext(); if (const auto *MD = dyn_cast<CXXMethodDecl>(FnDC)) { + // Fields aren't shadowed in C++ static members or in member functions + // with an explicit object parameter. if (MD->isStatic() || MD->isExplicitObjectMemberFunction()) return; } else if (isa<FunctionDecl>(FnDC)) { + // A FunctionDecl here (not a CXXMethodDecl) can only be an + // inline-defined friend function, since that's the only way to + // introduce a non-member function inside a class body. Friends have + // no implicit `this`, so nothing here can shadow a field. return; } // Fields shadowed by constructor parameters are a special case. Usually diff --git a/clang/test/SemaCXX/warn-shadow.cpp b/clang/test/SemaCXX/warn-shadow.cpp index fc184e5a1eb90..81ca79c410e3e 100644 --- a/clang/test/SemaCXX/warn-shadow.cpp +++ b/clang/test/SemaCXX/warn-shadow.cpp @@ -106,6 +106,13 @@ struct NSDMILambda { return a; }(); }; + +class PlainFriendFunction { + int x; + friend void plainFriend(int x) { + } +}; + struct path { using value_type = char; typedef char value_type2; _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
