Author: Reid Kleckner Date: 2020-03-20T09:02:21-07:00 New Revision: ce5173c0e174870934d1b3a026f631d996136191
URL: https://github.com/llvm/llvm-project/commit/ce5173c0e174870934d1b3a026f631d996136191 DIFF: https://github.com/llvm/llvm-project/commit/ce5173c0e174870934d1b3a026f631d996136191.diff LOG: Use FinishThunk to finish musttail thunks FinishThunk, and the invariant of setting and then unsetting CurCodeDecl, was added in 7f416cc42638 (2015). The invariant didn't exist when I added this musttail codepath in ab2090d10765 (2014). Recently in 28328c3771, I started using this codepath on non-Windows platforms, and users reported problems during release testing (PR44987). The issue was already present for users of EH on i686-windows-msvc, so I added a test for that case as well. Reviewed By: hans Differential Revision: https://reviews.llvm.org/D76444 Added: clang/test/CodeGenCXX/ms-thunks-ehspec.cpp clang/test/CodeGenCXX/thunks-ehspec.cpp Modified: clang/lib/CodeGen/CGVTables.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp index 403b9e25f7a3..412fc693c5b2 100644 --- a/clang/lib/CodeGen/CGVTables.cpp +++ b/clang/lib/CodeGen/CGVTables.cpp @@ -437,7 +437,8 @@ void CodeGenFunction::EmitMustTailThunk(GlobalDecl GD, // Finish the function to maintain CodeGenFunction invariants. // FIXME: Don't emit unreachable code. EmitBlock(createBasicBlock()); - FinishFunction(); + + FinishThunk(); } void CodeGenFunction::generateThunk(llvm::Function *Fn, @@ -564,7 +565,7 @@ llvm::Constant *CodeGenVTables::maybeEmitThunk(GlobalDecl GD, CGM.SetLLVMFunctionAttributesForDefinition(GD.getDecl(), ThunkFn); // Thunks for variadic methods are special because in general variadic - // arguments cannot be perferctly forwarded. In the general case, clang + // arguments cannot be perfectly forwarded. In the general case, clang // implements such thunks by cloning the original function body. However, for // thunks with no return adjustment on targets that support musttail, we can // use musttail to perfectly forward the variadic arguments. diff --git a/clang/test/CodeGenCXX/ms-thunks-ehspec.cpp b/clang/test/CodeGenCXX/ms-thunks-ehspec.cpp new file mode 100644 index 000000000000..f72100d5078b --- /dev/null +++ b/clang/test/CodeGenCXX/ms-thunks-ehspec.cpp @@ -0,0 +1,27 @@ +// RUN: %clang_cc1 -fexceptions -fcxx-exceptions %s -triple=i686-windows-msvc -emit-llvm -o - | FileCheck %s + +// When generating thunks using musttail due to inalloca parameters, don't push +// and pop terminate scopes. PR44987 + +struct NonTrivial { + NonTrivial(); + NonTrivial(const NonTrivial &o); + ~NonTrivial(); + int x; +}; +struct A { + virtual void f(NonTrivial o) noexcept; +}; +struct B { + virtual void f(NonTrivial o) noexcept; +}; +class C : A, B { + virtual void f(NonTrivial o) noexcept; +}; +C c; + +// CHECK-LABEL: define linkonce_odr dso_local x86_thiscallcc void @"?f@C@@G3AEXUNonTrivial@@@Z"(%class.C* %this, <{ %struct.NonTrivial }>* inalloca %0) +// CHECK-NOT: invoke +// CHECK: musttail call x86_thiscallcc void @"?f@C@@EAEXUNonTrivial@@@Z"(%class.C* %{{.*}}, <{ %struct.NonTrivial }>* inalloca %0) +// CHECK-NEXT ret void + diff --git a/clang/test/CodeGenCXX/thunks-ehspec.cpp b/clang/test/CodeGenCXX/thunks-ehspec.cpp new file mode 100644 index 000000000000..30276948d3fc --- /dev/null +++ b/clang/test/CodeGenCXX/thunks-ehspec.cpp @@ -0,0 +1,29 @@ +// RUN: %clang_cc1 -fexceptions -fcxx-exceptions %s -triple=x86_64-pc-linux-gnu -munwind-tables -emit-llvm -o - -O1 -disable-llvm-passes | FileCheck %s + +// When generating the thunk for secondary, do not push terminate scopes for +// either the varargs or non-varargs case. Related to PR44987. + +struct A { + virtual void primary_key(); +}; +struct B { + virtual void secondary(); + virtual void secondary_vararg(int, ...); +}; +class C : A, B { + virtual void primary_key(); + void secondary() noexcept; + void secondary_vararg(int, ...) noexcept; +}; +void C::primary_key() {} + +// CHECK-LABEL: define available_externally void @_ZThn8_N1C9secondaryEv(%class.C* %this) +// CHECK-NOT: invoke +// CHECK: tail call void @_ZN1C9secondaryEv(%class.C* %{{.*}}) +// CHECK-NOT: invoke +// CHECK: ret void + +// CHECK-LABEL: define available_externally void @_ZThn8_N1C16secondary_varargEiz(%class.C* %this, i32 %0, ...) +// CHECK-NOT: invoke +// CHECK: musttail call void (%class.C*, i32, ...) @_ZN1C16secondary_varargEiz(%class.C* %{{.*}}, i32 %{{.*}}, ...) #2 +// CHECK-NEXT: ret void _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
