Author: Nick Desaulniers Date: 2023-08-31T11:58:41-07:00 New Revision: f0f395e00e2ec3f1f20ca9021d1554fde73d56c9
URL: https://github.com/llvm/llvm-project/commit/f0f395e00e2ec3f1f20ca9021d1554fde73d56c9 DIFF: https://github.com/llvm/llvm-project/commit/f0f395e00e2ec3f1f20ca9021d1554fde73d56c9.diff LOG: Revert "Reland "[Clang][SemaCXX] Add unused warning for variables declared in condition expressions"" This reverts commit 92023b15099012a657da07ebf49dd7d94a260f84. Further issues were uncovered: - False positive -Wunused-variable on function-static variables with the used attribute. https://github.com/ClangBuiltLinux/linux/issues/1926 A test case needs to be added for this. - Request for a new flag for these. https://reviews.llvm.org/D152495#4628877 https://reviews.llvm.org/D152495#4628887 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaDecl.cpp clang/lib/Sema/SemaExprCXX.cpp clang/lib/Sema/SemaTemplateInstantiateDecl.cpp clang/test/SemaCXX/warn-unused-variables.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index 138730336f7426..15d318ef75f05a 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -162,9 +162,6 @@ Improvements to Clang's diagnostics (`#64871: <https://github.com/llvm/llvm-project/issues/64871>`_). Also clang no longer emits false positive warnings about the output length of ``%g`` format specifier. -- Clang now warns on unused variables declared and initialized in condition - expressions. - (`#61681: <https://github.com/llvm/llvm-project/issues/61681>`_) Bug Fixes in This Version ------------------------- diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp index 9facf2187f76a5..2ee216fffaa275 100644 --- a/clang/lib/Sema/SemaDecl.cpp +++ b/clang/lib/Sema/SemaDecl.cpp @@ -1995,7 +1995,7 @@ static bool ShouldDiagnoseUnusedDecl(const LangOptions &LangOpts, return false; } else if (!D->getDeclName()) { return false; - } else if (D->isReferenced() || (!isa<VarDecl>(D) && D->isUsed())) { + } else if (D->isReferenced() || D->isUsed()) { return false; } diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp index e3b3b7bdad4a89..472fbdbdb5d0e6 100644 --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -4021,10 +4021,6 @@ ExprResult Sema::CheckConditionVariable(VarDecl *ConditionVar, ConditionVar, ConditionVar->getType().getNonReferenceType(), VK_LValue, ConditionVar->getLocation()); - // Ensure that `-Wunused-variable` will be emitted for condition variables - // that are not referenced later. e.g.: if (int var = init()); - ConditionVar->setReferenced(/*R=*/false); - switch (CK) { case ConditionKind::Boolean: return CheckBooleanCondition(StmtLoc, Condition.get()); diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp index bb8ea187ecf91c..63f022d5c2ff09 100644 --- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp +++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp @@ -5353,7 +5353,7 @@ void Sema::BuildVariableInstantiation( // will have been deferred. if (!NewVar->isInvalidDecl() && NewVar->getDeclContext()->isFunctionOrMethod() && - OldVar->getType()->isDependentType() && !OldVar->isImplicit()) + OldVar->getType()->isDependentType()) DiagnoseUnusedDecl(NewVar); } diff --git a/clang/test/SemaCXX/warn-unused-variables.cpp b/clang/test/SemaCXX/warn-unused-variables.cpp index db33086436d3af..4db8bdf12e5de0 100644 --- a/clang/test/SemaCXX/warn-unused-variables.cpp +++ b/clang/test/SemaCXX/warn-unused-variables.cpp @@ -1,5 +1,5 @@ // RUN: %clang_cc1 -fsyntax-only -Wunused-variable -Wunused-label -Wno-c++1y-extensions -verify %s -// RUN: %clang_cc1 -fsyntax-only -Wunused-variable -Wunused-label -Wno-c++14-extensions -Wno-c++17-extensions -verify -std=c++11 %s +// RUN: %clang_cc1 -fsyntax-only -Wunused-variable -Wunused-label -Wno-c++1y-extensions -verify -std=c++11 %s template<typename T> void f() { T t; t = 17; @@ -294,115 +294,3 @@ void RAIIWrapperTest() { } } // namespace gh54489 - -namespace inside_condition { - void ifs() { - if (int hoge = 0) // expected-warning {{unused variable 'hoge'}} - return; - if (const int const_hoge = 0) // expected-warning {{unused variable 'const_hoge'}} - return; - else if (int fuga = 0) - (void)fuga; - else if (int used = 1; int catched = used) // expected-warning {{unused variable 'catched'}} - return; - else if (int refed = 1; int used = refed) - (void)used; - else if (int unused1 = 2; int unused2 = 3) // expected-warning {{unused variable 'unused1'}} \ - // expected-warning {{unused variable 'unused2'}} - return; - else if (int unused = 4; int used = 5) // expected-warning {{unused variable 'unused'}} - (void)used; - else if (int used = 6; int unused = 7) // expected-warning {{unused variable 'unused'}} - (void)used; - else if (int used1 = 8; int used2 = 9) - (void)(used1 + used2); - else if (auto [a, b] = (int[2]){ 1, 2 }; 1) // expected-warning {{unused variable '[a, b]'}} - return; - else if (auto [a, b] = (int[2]){ 1, 2 }; a) - return; - } - - void fors() { - for (int i = 0;int unused = 0;); // expected-warning {{unused variable 'i'}} \ - // expected-warning {{unused variable 'unused'}} - for (int i = 0;int used = 0;) // expected-warning {{unused variable 'i'}} - (void)used; - while(int var = 1) // expected-warning {{unused variable 'var'}} - return; - } - - void whiles() { - while(int unused = 1) // expected-warning {{unused variable 'unused'}} - return; - while(int used = 1) - (void)used; - } - - - void switches() { - switch(int unused = 1) { // expected-warning {{unused variable 'unused'}} - case 1: return; - } - switch(constexpr int used = 3; int unused = 4) { // expected-warning {{unused variable 'unused'}} - case used: return; - } - switch(int used = 3; int unused = 4) { // expected-warning {{unused variable 'unused'}} - case 3: (void)used; - } - switch(constexpr int used1 = 0; constexpr int used2 = 6) { - case (used1+used2): return; - } - switch(auto [a, b] = (int[2]){ 1, 2 }; 1) { // expected-warning {{unused variable '[a, b]'}} - case 1: return; - } - switch(auto [a, b] = (int[2]){ 1, 2 }; b) { - case 1: return; - } - switch(auto [a, b] = (int[2]){ 1, 2 }; 1) { - case 1: (void)a; - } - } - template <typename T> - struct Vector { - void doIt() { - for (auto& e : elements){} // expected-warning {{unused variable 'e'}} - } - T elements[10]; - }; - void ranged_for() { - Vector<int> vector; - vector.doIt(); // expected-note {{here}} - } - - - struct RAII { - int &x; - RAII(int &ref) : x(ref) {} - ~RAII() { x = 0;} - operator int() const { return 1; } - }; - void aggregate() { - int x = 10; - int y = 10; - if (RAII var = x) {} - for(RAII var = x; RAII var2 = y;) {} - while (RAII var = x) {} - switch (RAII var = x) {} - } - - struct TrivialDtor{ - int &x; - TrivialDtor(int &ref) : x(ref) { ref = 32; } - operator int() const { return 1; } - }; - void trivial_dtor() { - int x = 10; - int y = 10; - if (TrivialDtor var = x) {} // expected-warning {{unused variable 'var'}} - for(TrivialDtor var = x; TrivialDtor var2 = y;) {} // expected-warning {{unused variable 'var'}} \ - // expected-warning {{unused variable 'var2'}} - while (TrivialDtor var = x) {} // expected-warning {{unused variable 'var'}} - switch (TrivialDtor var = x) {} // expected-warning {{unused variable 'var'}} - } - -} // namespace inside_condition _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
