aaboud created this revision.
aaboud added reviewers: rnk, hans.
aaboud added a subscriber: cfe-commits.
aaboud set the repository for this revision to rL LLVM.
This patch fix PR24235.
When thunk function is being generated with a call to the original adjusted
function, the thunk function will appear in the call stack of the debugger.
To solve this issue, the thunk function should try replace the call instruction
with a jump instruction.
This patch mark the call function with musttail attribute, when it is
applicable, to force the backend to replace the call with a jump.
Notice that marking the call with a tail might be safer, however, it is not
good enough to remove the call in the 32-bit mode.
Repository:
rL LLVM
http://reviews.llvm.org/D11476
Files:
lib/CodeGen/CGVTables.cpp
test/CodeGenCXX/microsoft-abi-structors.cpp
Index: lib/CodeGen/CGVTables.cpp
===================================================================
--- lib/CodeGen/CGVTables.cpp
+++ lib/CodeGen/CGVTables.cpp
@@ -312,6 +312,8 @@
// Consider return adjustment if we have ThunkInfo.
if (Thunk && !Thunk->Return.isEmpty())
RV = PerformReturnAdjustment(*this, ResultType, RV, *Thunk);
+ else if (llvm::CallInst* Call = dyn_cast<llvm::CallInst>(CallOrInvoke))
+ Call->setTailCallKind(llvm::CallInst::TCK_MustTail);
// Emit return.
if (!ResultType->isVoidType() && Slot.isNull())
Index: test/CodeGenCXX/microsoft-abi-structors.cpp
===================================================================
--- test/CodeGenCXX/microsoft-abi-structors.cpp
+++ test/CodeGenCXX/microsoft-abi-structors.cpp
@@ -176,7 +176,7 @@
// Do an adjustment from B* to C*.
// DTORS2: getelementptr i8, i8* %{{.*}}, i32 -4
// DTORS2: bitcast i8* %{{.*}} to %"struct.dtor_in_second_nvbase::C"*
-// DTORS2: %[[CALL:.*]] = call x86_thiscallcc i8*
@"\01??_GC@dtor_in_second_nvbase@@UAEPAXI@Z"
+// DTORS2: %[[CALL:.*]] = musttail call x86_thiscallcc i8*
@"\01??_GC@dtor_in_second_nvbase@@UAEPAXI@Z"
// DTORS2: ret i8* %[[CALL]]
}
Index: lib/CodeGen/CGVTables.cpp
===================================================================
--- lib/CodeGen/CGVTables.cpp
+++ lib/CodeGen/CGVTables.cpp
@@ -312,6 +312,8 @@
// Consider return adjustment if we have ThunkInfo.
if (Thunk && !Thunk->Return.isEmpty())
RV = PerformReturnAdjustment(*this, ResultType, RV, *Thunk);
+ else if (llvm::CallInst* Call = dyn_cast<llvm::CallInst>(CallOrInvoke))
+ Call->setTailCallKind(llvm::CallInst::TCK_MustTail);
// Emit return.
if (!ResultType->isVoidType() && Slot.isNull())
Index: test/CodeGenCXX/microsoft-abi-structors.cpp
===================================================================
--- test/CodeGenCXX/microsoft-abi-structors.cpp
+++ test/CodeGenCXX/microsoft-abi-structors.cpp
@@ -176,7 +176,7 @@
// Do an adjustment from B* to C*.
// DTORS2: getelementptr i8, i8* %{{.*}}, i32 -4
// DTORS2: bitcast i8* %{{.*}} to %"struct.dtor_in_second_nvbase::C"*
-// DTORS2: %[[CALL:.*]] = call x86_thiscallcc i8* @"\01??_GC@dtor_in_second_nvbase@@UAEPAXI@Z"
+// DTORS2: %[[CALL:.*]] = musttail call x86_thiscallcc i8* @"\01??_GC@dtor_in_second_nvbase@@UAEPAXI@Z"
// DTORS2: ret i8* %[[CALL]]
}
_______________________________________________
cfe-commits mailing list
[email protected]
http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
