llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Younan Zhang (zyn0217) <details> <summary>Changes</summary> We ensure immediate access control checking when evaluating the enable_if attribute to rule out inaccessible constructors during potential overload resolution, treating them as SFINAE errors rather than hard errors, making the behavior more preferable with the nature of the enable_if attribute. Compared to the last patch, we now avoid switching the DC directly because there are cases where we're checking enable_if attribute within a lambda and getCurLambda() requires a lambda context to distinguish from template instantiation. This reapplies #<!-- -->175899 --- Full diff: https://github.com/llvm/llvm-project/pull/176080.diff 3 Files Affected: - (modified) clang/docs/ReleaseNotes.rst (+1) - (modified) clang/lib/Sema/SemaOverload.cpp (+5) - (modified) clang/test/SemaCXX/enable_if.cpp (+48) ``````````diff diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index b91d99647855c..cd2f4dd581bad 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -120,6 +120,7 @@ Bug Fixes to Compiler Builtins Bug Fixes to Attribute Support ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +- Fixed a behavioral discrepancy between deleted functions and private members when checking the ``enable_if`` attribute. (#GH175895) Bug Fixes to C++ Support ^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index 7115b8b7d446a..bc3a5c8e567f0 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -7551,6 +7551,11 @@ EnableIfAttr *Sema::CheckEnableIf(FunctionDecl *Function, return nullptr; SFINAETrap Trap(*this); + // Perform the access checking immediately so any access diagnostics are + // caught by the SFINAE trap. + llvm::scope_exit _([&, CurrentState(DelayedDiagnostics.pushUndelayed())] { + DelayedDiagnostics.popUndelayed(CurrentState); + }); SmallVector<Expr *, 16> ConvertedArgs; // FIXME: We should look into making enable_if late-parsed. Expr *DiscardedThis; diff --git a/clang/test/SemaCXX/enable_if.cpp b/clang/test/SemaCXX/enable_if.cpp index 1c307881e5d4a..4b0a253d89fed 100644 --- a/clang/test/SemaCXX/enable_if.cpp +++ b/clang/test/SemaCXX/enable_if.cpp @@ -562,6 +562,54 @@ namespace IgnoreUnusedArgSideEffects { #endif } +namespace GH175895 { + +using int32_t = int; + +struct wxuin_t { + wxuin_t() {} + wxuin_t(int32_t v) __attribute__((enable_if(v == 0, "Expect only constant expressions"))) {} +}; + +struct wxuin64_t { + wxuin64_t() {} + + explicit operator wxuin_t() const { return {}; } + +private: + operator int() const { return 0; } +}; + +struct wxuin64_t_deleted { + wxuin64_t_deleted() {} + + explicit operator wxuin_t() const { return {}; } + + operator int() = delete; +}; + +void main() { + wxuin64_t uin64{}; + wxuin64_t_deleted deleted{}; + auto b = static_cast<wxuin_t>(uin64); + auto c = static_cast<wxuin_t>(deleted); +} + +namespace Regression { + +const int kMaxNumber = 1; +struct Arg { + Arg(int); +}; +void PlaceholderBitmask(); +void Substitute(Arg) __attribute__((enable_if(PlaceholderBitmask, ""))) { + (void)[] { Substitute(kMaxNumber); }; +} + +} + +} + namespace DefaultArgs { void f(int n = __builtin_LINE()) __attribute__((enable_if(n == 12345, "only callable on line 12345"))); // expected-note {{only callable on line 12345}} void g() { f(); } // expected-error {{no matching function}} `````````` </details> https://github.com/llvm/llvm-project/pull/176080 _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
