[Coroutines] Avoid assert splitting hidden coros

Summary:
When attempting to split a coroutine with 'hidden' visibility (for
example, a C++ coroutine that is inlined when compiled with the option
'-fvisibility-inlines-hidden'), LLVM would hit an assertion in
include/llvm/IR/GlobalValue.h:240: "local linkage requires default
visibility". The issue is that the visibility is copied from the source
of the function split in the `CloneFunctionInto` function, but the linkage
is not. To fix, create the new function first with external linkage,
then copy the linkage from the original function *after* `CloneFunctionInto`
is called.

Since `GlobalValue::setLinkage` in turn calls `maybeSetDsoLocal`, the
explicit call to `setDSOLocal` can be removed in CoroSplit.cpp.

Test Plan: check-llvm

Reviewers: GorNishanov, lewissbaker, EricWF, majnemer, rnk

Reviewed By: rnk

Subscribers: llvm-commits, eric_niebler

Differential Revision: https://reviews.llvm.org/D44185

llvm-svn: 329033
This commit is contained in:
Brian Gesiak 2018-04-02 23:39:40 +00:00
parent bae4856d31
commit 64521bed0d
2 changed files with 83 additions and 2 deletions

View File

@ -250,7 +250,7 @@ static Function *createClone(Function &F, Twine Suffix, coro::Shape &Shape,
auto *FnTy = cast<FunctionType>(FnPtrTy->getElementType());
Function *NewF =
Function::Create(FnTy, GlobalValue::LinkageTypes::InternalLinkage,
Function::Create(FnTy, GlobalValue::LinkageTypes::ExternalLinkage,
F.getName() + Suffix, M);
NewF->addParamAttr(0, Attribute::NonNull);
NewF->addParamAttr(0, Attribute::NoAlias);
@ -265,7 +265,7 @@ static Function *createClone(Function &F, Twine Suffix, coro::Shape &Shape,
SmallVector<ReturnInst *, 4> Returns;
CloneFunctionInto(NewF, &F, VMap, /*ModuleLevelChanges=*/true, Returns);
NewF->setDSOLocal(true);
NewF->setLinkage(GlobalValue::LinkageTypes::InternalLinkage);
// Remove old returns.
for (ReturnInst *Return : Returns)

View File

@ -0,0 +1,81 @@
; Tests that coro-split can convert functions with hidden visibility.
; These may be generated by a frontend such as Clang, when inlining with
; '-fvisibility-inlines-hidden'.
; RUN: opt < %s -coro-split -S | FileCheck %s
define hidden i8* @f() "coroutine.presplit"="1" {
entry:
%id = call token @llvm.coro.id(i32 0, i8* null, i8* null, i8* null)
%need.alloc = call i1 @llvm.coro.alloc(token %id)
br i1 %need.alloc, label %dyn.alloc, label %begin
dyn.alloc:
%size = call i32 @llvm.coro.size.i32()
%alloc = call i8* @malloc(i32 %size)
br label %begin
begin:
%phi = phi i8* [ null, %entry ], [ %alloc, %dyn.alloc ]
%hdl = call i8* @llvm.coro.begin(token %id, i8* %phi)
call void @print(i32 0)
%0 = call i8 @llvm.coro.suspend(token none, i1 false)
switch i8 %0, label %suspend [i8 0, label %resume
i8 1, label %cleanup]
resume:
call void @print(i32 1)
br label %cleanup
cleanup:
%mem = call i8* @llvm.coro.free(token %id, i8* %hdl)
call void @free(i8* %mem)
br label %suspend
suspend:
call i1 @llvm.coro.end(i8* %hdl, i1 0)
ret i8* %hdl
}
; CHECK-LABEL: hidden{{.*}}@f(
; CHECK: call i8* @malloc
; CHECK: @llvm.coro.begin(token %id, i8* %phi)
; CHECK: store void (%f.Frame*)* @f.resume, void (%f.Frame*)** %resume.addr
; CHECK: %[[SEL:.+]] = select i1 %need.alloc, void (%f.Frame*)* @f.destroy, void (%f.Frame*)* @f.cleanup
; CHECK: store void (%f.Frame*)* %[[SEL]], void (%f.Frame*)** %destroy.addr
; CHECK: call void @print(i32 0)
; CHECK-NOT: call void @print(i32 1)
; CHECK-NOT: call void @free(
; CHECK: ret i8* %hdl
; CHECK-LABEL: internal{{.*}}@f.resume(
; CHECK-NOT: call i8* @malloc
; CHECK-NOT: call void @print(i32 0)
; CHECK: call void @print(i32 1)
; CHECK-NOT: call void @print(i32 0)
; CHECK: call void @free(
; CHECK: ret void
; CHECK-LABEL: internal{{.*}}@f.destroy(
; CHECK-NOT: call i8* @malloc
; CHECK-NOT: call void @print(
; CHECK: call void @free(
; CHECK: ret void
; CHECK-LABEL: internal{{.*}}@f.cleanup(
; CHECK-NOT: call i8* @malloc
; CHECK-NOT: call void @print(
; CHECK-NOT: call void @free(
; CHECK: ret void
declare i8* @llvm.coro.free(token, i8*)
declare i32 @llvm.coro.size.i32()
declare i8 @llvm.coro.suspend(token, i1)
declare void @llvm.coro.resume(i8*)
declare void @llvm.coro.destroy(i8*)
declare token @llvm.coro.id(i32, i8*, i8*, i8*)
declare i1 @llvm.coro.alloc(token)
declare i8* @llvm.coro.begin(token, i8*)
declare i1 @llvm.coro.end(i8*, i1)
declare noalias i8* @malloc(i32)
declare void @print(i32)
declare void @free(i8*)