[llvm] 5af06ba - [Coro][Debuginfo] Add debug info to `__NoopCoro_ResumeDestroy` function
Adrian Vogelsgesang via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 26 05:50:23 PDT 2022
Author: Adrian Vogelsgesang
Date: 2022-08-26T05:49:52-07:00
New Revision: 5af06ba7dc26f614989a9a9e16e69f6ecc811519
URL: https://github.com/llvm/llvm-project/commit/5af06ba7dc26f614989a9a9e16e69f6ecc811519
DIFF: https://github.com/llvm/llvm-project/commit/5af06ba7dc26f614989a9a9e16e69f6ecc811519.diff
LOG: [Coro][Debuginfo] Add debug info to `__NoopCoro_ResumeDestroy` function
With this commit, we now attach an `DISubprogram` to the LLVM-generated
`_NoopCoro_ResumeDestroy` function. Thereby, lldb can show a
`std::coroutine_handle` to a `std::noop_coroutine` as
```
continuation = coro frame = 0x555555560d98 {
resume = 0x0000555555555c50 (a.out`__NoopCoro_ResumeDestroy)
destroy = 0x0000555555555c50 (a.out`__NoopCoro_ResumeDestroy)
}
```
instead of
```
continuation = coro frame = 0x555555560d98 {
resume = 0x0000555555555c50 (a.out`___lldb_unnamed_symbol211)
destroy = 0x0000555555555c50 (a.out`___lldb_unnamed_symbol211)
}
```
I renamed the function from `NoopCoro.ResumeDestroy` to
`_NoopCoro_ResumeDestroy` because:
* the leading `_` makes sure this is a reserved name and should not
clash with any user-provided names
* the `.` was replaced by a `_`, so the name is now a valid identifier
in C, making it allows me to type its name in the debugger
Differential Revision: https://reviews.llvm.org/D132580
Added:
llvm/test/Transforms/Coroutines/coro-noop.ll
llvm/test/Transforms/Coroutines/coro-resume-destroy.ll
Modified:
llvm/lib/Transforms/Coroutines/CoroEarly.cpp
Removed:
llvm/test/Transforms/Coroutines/coro-early.ll
################################################################################
diff --git a/llvm/lib/Transforms/Coroutines/CoroEarly.cpp b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
index dd7cb23f3f3d..d510b90d9dec 100644
--- a/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
+++ b/llvm/lib/Transforms/Coroutines/CoroEarly.cpp
@@ -8,6 +8,7 @@
#include "llvm/Transforms/Coroutines/CoroEarly.h"
#include "CoroInternal.h"
+#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstIterator.h"
@@ -100,6 +101,25 @@ void Lowerer::lowerCoroDone(IntrinsicInst *II) {
II->eraseFromParent();
}
+static void buildDebugInfoForNoopResumeDestroyFunc(Function *NoopFn) {
+ Module &M = *NoopFn->getParent();
+ if (M.debug_compile_units().empty())
+ return;
+
+ DICompileUnit *CU = *M.debug_compile_units_begin();
+ DIBuilder DB(M, /*AllowUnresolved*/ false, CU);
+ std::array<Metadata *, 2> Params{nullptr, nullptr};
+ auto *SubroutineType =
+ DB.createSubroutineType(DB.getOrCreateTypeArray(Params));
+ StringRef Name = NoopFn->getName();
+ auto *SP = DB.createFunction(
+ CU, /*Name=*/Name, /*LinkageName=*/Name, /*File=*/ CU->getFile(),
+ /*LineNo=*/0, SubroutineType, /*ScopeLine=*/0, DINode::FlagArtificial,
+ DISubprogram::SPFlagDefinition);
+ NoopFn->setSubprogram(SP);
+ DB.finalize();
+}
+
void Lowerer::lowerCoroNoop(IntrinsicInst *II) {
if (!NoopCoro) {
LLVMContext &C = Builder.getContext();
@@ -116,8 +136,9 @@ void Lowerer::lowerCoroNoop(IntrinsicInst *II) {
// Create a Noop function that does nothing.
Function *NoopFn =
Function::Create(FnTy, GlobalValue::LinkageTypes::PrivateLinkage,
- "NoopCoro.ResumeDestroy", &M);
+ "__NoopCoro_ResumeDestroy", &M);
NoopFn->setCallingConv(CallingConv::Fast);
+ buildDebugInfoForNoopResumeDestroyFunc(NoopFn);
auto *Entry = BasicBlock::Create(C, "entry", NoopFn);
ReturnInst::Create(C, Entry);
diff --git a/llvm/test/Transforms/Coroutines/coro-noop.ll b/llvm/test/Transforms/Coroutines/coro-noop.ll
new file mode 100644
index 000000000000..23533c87a18f
--- /dev/null
+++ b/llvm/test/Transforms/Coroutines/coro-noop.ll
@@ -0,0 +1,33 @@
+; Tests that CoroEarly pass correctly lowers coro.noop
+; RUN: opt < %s -S -passes=coro-early | FileCheck %s
+
+; CHECK: %NoopCoro.Frame = type { void (%NoopCoro.Frame*)*, void (%NoopCoro.Frame*)* }
+; CHECK: @NoopCoro.Frame.Const = private constant %NoopCoro.Frame { void (%NoopCoro.Frame*)* @__NoopCoro_ResumeDestroy, void (%NoopCoro.Frame*)* @__NoopCoro_ResumeDestroy }
+
+
+; CHECK-LABEL: @noop(
+define i8* @noop() {
+; CHECK-NEXT: entry
+entry:
+; CHECK-NEXT: ret i8* bitcast (%NoopCoro.Frame* @NoopCoro.Frame.Const to i8*)
+ %n = call i8* @llvm.coro.noop()
+ ret i8* %n
+}
+
+declare i8* @llvm.coro.noop()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "hand-written", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "<stdin>", directory: "")
+!2 = !{}
+!3 = !{i32 2, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+
+
+; CHECK: define private fastcc void @__NoopCoro_ResumeDestroy(%NoopCoro.Frame* %0) !dbg ![[RESUME:[0-9]+]] {
+; CHECK-NEXT: entry
+; CHECK-NEXT: ret void
+
+; CHECK: ![[RESUME]] = distinct !DISubprogram(name: "__NoopCoro_ResumeDestroy", linkageName: "__NoopCoro_ResumeDestroy", {{.*}} flags: DIFlagArtificial,
diff --git a/llvm/test/Transforms/Coroutines/coro-early.ll b/llvm/test/Transforms/Coroutines/coro-resume-destroy.ll
similarity index 63%
rename from llvm/test/Transforms/Coroutines/coro-early.ll
rename to llvm/test/Transforms/Coroutines/coro-resume-destroy.ll
index 048937223279..86e4a814f58c 100644
--- a/llvm/test/Transforms/Coroutines/coro-early.ll
+++ b/llvm/test/Transforms/Coroutines/coro-resume-destroy.ll
@@ -1,10 +1,6 @@
; Tests that CoroEarly pass correctly lowers coro.resume, coro.destroy
-; and other intrinsics managed by this pass.
; RUN: opt < %s -S -passes=coro-early | FileCheck %s
-; CHECK: %NoopCoro.Frame = type { void (%NoopCoro.Frame*)*, void (%NoopCoro.Frame*)* }
-; CHECK: @NoopCoro.Frame.Const = private constant %NoopCoro.Frame { void (%NoopCoro.Frame*)* @NoopCoro.ResumeDestroy, void (%NoopCoro.Frame*)* @NoopCoro.ResumeDestroy }
-
; CHECK-LABEL: @callResume(
define void @callResume(i8* %hdl) {
; CHECK-NEXT: entry
@@ -41,20 +37,5 @@ ehcleanup:
}
-; CHECK-LABEL: @noop(
-define i8* @noop() {
-; CHECK-NEXT: entry
-entry:
-; CHECK-NEXT: ret i8* bitcast (%NoopCoro.Frame* @NoopCoro.Frame.Const to i8*)
- %n = call i8* @llvm.coro.noop()
- ret i8* %n
-}
-
-; CHECK-LABEL: define private fastcc void @NoopCoro.ResumeDestroy(%NoopCoro.Frame* %0) {
-; CHECK-NEXT: entry
-; CHECK-NEXT: ret void
-
-
declare void @llvm.coro.resume(i8*)
declare void @llvm.coro.destroy(i8*)
-declare i8* @llvm.coro.noop()
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