6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-23 20:29:30 +00:00
Code Issues Projects Releases Wiki Activity

[WinEH] Fix problem with mapping shared empty handler blocks.

Browse Source 
Differential Revision: http://reviews.llvm.org/D9125



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235354 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Andrew Kaylor 2015-04-20 22:04:09 +00:00
parent 6219380952
commit e0d6a5c90a
2 changed files with 148 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
lib/CodeGen/WinEHPrepare.cpp
View File

@ -770,6 +770,15 @@ static bool isSelectorDispatch(BasicBlock *BB, BasicBlock *&CatchHandler,
return false;
}
static bool isCatchBlock(BasicBlock *BB) {
for (BasicBlock::iterator II = BB->getFirstNonPHIOrDbg(), IE = BB->end();
II != IE; ++II) {
if (match(cast<Value>(II), m_Intrinsic<Intrinsic::eh_begincatch>()))
return true;
}
return false;
}
static BasicBlock *createStubLandingPad(Function *Handler,
Value *PersonalityFn) {
// FIXME: Finish this!
@ -1447,11 +1456,11 @@ void WinEHPrepare::mapLandingPadBlocks(LandingPadInst *LPad,
}
CatchHandler *CatchAction = findCatchHandler(BB, NextBB, VisitedBlocks);
assert(CatchAction);
// See if there is any interesting code executed before the dispatch.
findCleanupHandlers(Actions, BB, CatchAction->getStartBlock());
assert(CatchAction);
// When the source program contains multiple nested try blocks the catch
// handlers can get strung together in such a way that we can encounter
// a dispatch for a selector that we've already had a handler for.
@ -1463,6 +1472,21 @@ void WinEHPrepare::mapLandingPadBlocks(LandingPadInst *LPad,
<< CatchAction->getStartBlock()->getName() << "\n");
Actions.insertCatchHandler(CatchAction);
} else {
// Under some circumstances optimized IR will flow unconditionally into a
// handler block without checking the selector. This can only happen if
// the landing pad has a catch-all handler and the handler for the
// preceeding catch clause is identical to the catch-call handler
// (typically an empty catch). In this case, the handler must be shared
// by all remaining clauses.
if (isa<ConstantPointerNull>(
CatchAction->getSelector()->stripPointerCasts())) {
DEBUG(dbgs() << " Applying early catch-all handler in block "
<< CatchAction->getStartBlock()->getName()
<< " to all remaining clauses.\n");
Actions.insertCatchHandler(CatchAction);
return;
}
DEBUG(dbgs() << " Found extra catch dispatch in block "
<< CatchAction->getStartBlock()->getName() << "\n");
}
@ -1517,6 +1541,18 @@ CatchHandler *WinEHPrepare::findCatchHandler(BasicBlock *BB,
CatchHandlerMap[BB] = Action;
return Action;
}
// If we encounter a block containing an llvm.eh.begincatch before we
// find a selector dispatch block, the handler is assumed to be
// reached unconditionally. This happens for catch-all blocks, but
// it can also happen for other catch handlers that have been combined
// with the catch-all handler during optimization.
if (isCatchBlock(BB)) {
PointerType *Int8PtrTy = Type::getInt8PtrTy(BB->getContext());
Constant *NullSelector = ConstantPointerNull::get(Int8PtrTy);
CatchHandler *Action = new CatchHandler(BB, NullSelector, nullptr);
CatchHandlerMap[BB] = Action;
return Action;
}
}
// Visit each successor, looking for the dispatch.

110
test/CodeGen/WinEH/cppeh-shared-empty-catch.ll Normal file
View File

@ -0,0 +1,110 @@
; RUN: opt -mtriple=x86_64-pc-windows-msvc -winehprepare -S -o - < %s | FileCheck %s
; This test is based on the following source, built with -O2
;
; void f() {
; try {
; g();
; try {
; throw;
; } catch (int) {
; }
; } catch (...) {
; }
; }
;
; ModuleID = '<stdin>'
target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-windows-msvc"
%rtti.TypeDescriptor2 = type { i8**, i8*, [3 x i8] }
%eh.CatchHandlerType = type { i32, i8* }
%eh.ThrowInfo = type { i32, i32, i32, i32 }
$"\01??_R0H@8" = comdat any
@"\01??_7type_info@@6B@" = external constant i8*
@"\01??_R0H@8" = linkonce_odr global %rtti.TypeDescriptor2 { i8** @"\01??_7type_info@@6B@", i8* null, [3 x i8] c".H\00" }, comdat
@llvm.eh.handlertype.H.0 = private unnamed_addr constant %eh.CatchHandlerType { i32 0, i8* bitcast (%rtti.TypeDescriptor2* @"\01??_R0H@8" to i8*) }, section "llvm.metadata"
; CHECK-LABEL: define void @"\01?f@@YAXXZ"()
; CHECK: entry:
; CHECK: call void (...) @llvm.frameescape()
; CHECK: invoke void @"\01?g@@YAXXZ"()
; Function Attrs: nounwind
define void @"\01?f@@YAXXZ"() #0 {
entry:
invoke void @"\01?g@@YAXXZ"()
to label %invoke.cont unwind label %lpad
; CHECK-LABEL: invoke.cont:
; CHECK: invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null)
; CHECK: to label %unreachable unwind label %[[LPAD1_LABEL:lpad[0-9]+]]
invoke.cont: ; preds = %entry
invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #4
to label %unreachable unwind label %lpad1
lpad: ; preds = %entry
%0 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)
catch i8* null
%1 = extractvalue { i8*, i32 } %0, 0
br label %catch2
; Note: Even though this landing pad has two catch clauses, it only has one action because both
; handlers do the same thing.
; CHECK: [[LPAD1_LABEL]]:
; CHECK: landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)
; CHECK-NEXT: catch %eh.CatchHandlerType* @llvm.eh.handlertype.H.0
; CHECK-NEXT: catch i8* null
; CHECK-NEXT: [[RECOVER:\%.+]] = call i8* (...) @llvm.eh.actions(i32 1, i8* null, i32 -1, i8* (i8*, i8*)* @"\01?f@@YAXXZ.catch1")
; CHECK-NEXT: indirectbr i8* [[RECOVER]], [label %try.cont4]
lpad1: ; preds = %invoke.cont
%2 = landingpad { i8*, i32 } personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*)
catch %eh.CatchHandlerType* @llvm.eh.handlertype.H.0
catch i8* null
%3 = extractvalue { i8*, i32 } %2, 0
br label %catch2
catch2: ; preds = %lpad1, %lpad
%exn.slot.0 = phi i8* [ %3, %lpad1 ], [ %1, %lpad ]
tail call void @llvm.eh.begincatch(i8* %exn.slot.0, i8* null) #3
tail call void @llvm.eh.endcatch() #3
br label %try.cont4
try.cont4: ; preds = %catch, %catch2
ret void
unreachable: ; preds = %invoke.cont
unreachable
; CHECK: }
}
declare void @"\01?g@@YAXXZ"() #1
declare i32 @__CxxFrameHandler3(...)
declare void @_CxxThrowException(i8*, %eh.ThrowInfo*)
; Function Attrs: nounwind readnone
declare i32 @llvm.eh.typeid.for(i8*) #2
; Function Attrs: nounwind
declare void @llvm.eh.begincatch(i8* nocapture, i8* nocapture) #3
; Function Attrs: nounwind
declare void @llvm.eh.endcatch() #3
attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #1 = { "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "no-realign-stack" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
attributes #2 = { nounwind readnone }
attributes #3 = { nounwind }
attributes #4 = { noreturn }
!llvm.ident = !{!0}
!0 = !{!"clang version 3.7.0 (trunk 235112) (llvm/trunk 235121)"}