[IROutliner] Adding DebugInfo handling for IR Outlined Functions

This adds support for functions outlined by the IR Outliner to be
recognized by the debugger.  The expected behavior is that it will
skip over the instructions included in that section.  This is due to the
fact that we can not say which of the original locations the
instructions originated from.

These functions will show up in the call stack, but you cannot step
through them.

Reviewers: paquette, vsk, djtodoro

Differential Revision: https://reviews.llvm.org/D87302
This commit is contained in:
Andrew Litteken 2021-06-07 11:05:46 -05:00
parent ff2ef4d684
commit 2c21278e74
3 changed files with 277 additions and 26 deletions

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@ -16,6 +16,9 @@
#include "llvm/Analysis/OptimizationRemarkEmitter.h"
#include "llvm/Analysis/TargetTransformInfo.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/DebugInfoMetadata.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/Mangler.h"
#include "llvm/IR/PassManager.h"
#include "llvm/InitializePasses.h"
#include "llvm/Pass.h"
@ -353,6 +356,19 @@ void OutlinableGroup::collectGVNStoreSets(Module &M) {
ArgumentTypes.push_back(Type::getInt32Ty(M.getContext()));
}
/// Get the subprogram if it exists for one of the outlined regions.
///
/// \param [in] Group - The set of regions to find a subprogram for.
/// \returns the subprogram if it exists, or nullptr.
static DISubprogram *getSubprogramOrNull(OutlinableGroup &Group) {
for (OutlinableRegion *OS : Group.Regions)
if (Function *F = OS->Call->getFunction())
if (DISubprogram *SP = F->getSubprogram())
return SP;
return nullptr;
}
Function *IROutliner::createFunction(Module &M, OutlinableGroup &Group,
unsigned FunctionNameSuffix) {
assert(!Group.OutlinedFunction && "Function is already defined!");
@ -374,12 +390,45 @@ Function *IROutliner::createFunction(Module &M, OutlinableGroup &Group,
Group.OutlinedFunction->addFnAttr(Attribute::OptimizeForSize);
Group.OutlinedFunction->addFnAttr(Attribute::MinSize);
// If there's a DISubprogram associated with this outlined function, then
// emit debug info for the outlined function.
if (DISubprogram *SP = getSubprogramOrNull(Group)) {
Function *F = Group.OutlinedFunction;
// We have a DISubprogram. Get its DICompileUnit.
DICompileUnit *CU = SP->getUnit();
DIBuilder DB(M, true, CU);
DIFile *Unit = SP->getFile();
Mangler Mg;
// Get the mangled name of the function for the linkage name.
std::string Dummy;
llvm::raw_string_ostream MangledNameStream(Dummy);
Mg.getNameWithPrefix(MangledNameStream, F, false);
DISubprogram *OutlinedSP = DB.createFunction(
Unit /* Context */, F->getName(), MangledNameStream.str(),
Unit /* File */,
0 /* Line 0 is reserved for compiler-generated code. */,
DB.createSubroutineType(DB.getOrCreateTypeArray(None)), /* void type */
0, /* Line 0 is reserved for compiler-generated code. */
DINode::DIFlags::FlagArtificial /* Compiler-generated code. */,
/* Outlined code is optimized code by definition. */
DISubprogram::SPFlagDefinition | DISubprogram::SPFlagOptimized);
// Don't add any new variables to the subprogram.
DB.finalizeSubprogram(OutlinedSP);
// Attach subprogram to the function.
F->setSubprogram(OutlinedSP);
// We're done with the DIBuilder.
DB.finalize();
}
return Group.OutlinedFunction;
}
/// Move each BasicBlock in \p Old to \p New.
///
/// \param [in] Old - the function to move the basic blocks from.
/// \param [in] Old - The function to move the basic blocks from.
/// \param [in] New - The function to move the basic blocks to.
/// \returns the first return block for the function in New.
static BasicBlock *moveFunctionData(Function &Old, Function &New) {
@ -394,6 +443,37 @@ static BasicBlock *moveFunctionData(Function &Old, Function &New) {
Instruction *I = CurrBB->getTerminator();
if (isa<ReturnInst>(I))
NewEnd = &(*CurrBB);
for (Instruction &Val : *CurrBB) {
// We must handle the scoping of called functions differently than
// other outlined instructions.
if (!isa<CallInst>(&Val)) {
// Remove the debug information for outlined functions.
Val.setDebugLoc(DebugLoc());
continue;
}
// From this point we are only handling call instructions.
CallInst *CI = cast<CallInst>(&Val);
// We add any debug statements here, to be removed after. Since the
// instructions originate from many different locations in the program,
// it will cause incorrect reporting from a debugger if we keep the
// same debug instructions.
if (isa<DbgInfoIntrinsic>(CI)) {
DebugInsts.push_back(&Val);
continue;
}
// Edit the scope of called functions inside of outlined functions.
if (DISubprogram *SP = New.getSubprogram()) {
DILocation *DI = DILocation::get(New.getContext(), 0, 0, SP);
Val.setDebugLoc(DI);
}
}
for (Instruction *I : DebugInsts)
I->eraseFromParent();
}
assert(NewEnd && "No return instruction for new function?");

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@ -0,0 +1,158 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --include-generated-funcs
; RUN: opt -verify -iroutliner -ir-outlining-no-cost < %s | \
; RUN: llc -filetype=obj -mtriple=aarch64-- | llvm-dwarfdump - | FileCheck %s
; RUN: opt -S -verify -iroutliner -ir-outlining-no-cost < %s | FileCheck -check-prefix=IRDEBUG %s
; Ensure that the IR Outliner produces valid DWARF debug information when
; creating outlined functions.
; CHECK: DW_TAG_compile_unit
; CHECK-DAG: DW_AT_name ("outline_debug1")
; Check the high address of bar. This is one past the end of bar. It should be
; the beginning of the outlined function.
; CHECK: DW_AT_high_pc ([[ONE_PAST_BAR:0x[a-f0-9]+]])
; CHECK-NEXT: DW_AT_frame_base (DW_OP_reg31 WSP)
; CHECK-NEXT: DW_AT_linkage_name ("outline_debug2")
; CHECK-NEXT: DW_AT_name ("outline_debug2")
; Check the outlined function's DWARF.
; CHECK-DAG: DW_TAG_subprogram
; CHECK-NEXT: DW_AT_low_pc ([[ONE_PAST_BAR]])
; CHECK-NEXT: DW_AT_high_pc (0x{{[0-9a-f]+}})
; CHECK-NEXT: DW_AT_frame_base (DW_OP_reg31 WSP)
; CHECK-NEXT: DW_AT_linkage_name ("[[NAME:outlined_ir_func_[0-9]+]]")
; CHECK-NEXT: DW_AT_name ("[[NAME]]")
; CHECK-NEXT: DW_AT_artificial (true)
; CHECK-NEXT: DW_AT_external (true)
define void @outline_debug1() !dbg !6 {
entry:
%a = alloca i32, align 4, !dbg !17
call void @llvm.dbg.value(metadata i32* %a, metadata !9, metadata !DIExpression()), !dbg !17
%b = alloca i32, align 4, !dbg !18
call void @llvm.dbg.value(metadata i32* %b, metadata !11, metadata !DIExpression()), !dbg !18
%c = alloca i32, align 4, !dbg !19
call void @llvm.dbg.value(metadata i32* %c, metadata !12, metadata !DIExpression()), !dbg !19
store i32 2, i32* %a, align 4, !dbg !20
store i32 3, i32* %b, align 4, !dbg !21
store i32 4, i32* %c, align 4, !dbg !22
%al = load i32, i32* %a, align 4, !dbg !23
call void @llvm.dbg.value(metadata i32 %al, metadata !13, metadata !DIExpression()), !dbg !23
%bl = load i32, i32* %b, align 4, !dbg !24
call void @llvm.dbg.value(metadata i32 %bl, metadata !15, metadata !DIExpression()), !dbg !24
%cl = load i32, i32* %c, align 4, !dbg !25
call void @llvm.dbg.value(metadata i32 %cl, metadata !16, metadata !DIExpression()), !dbg !25
ret void, !dbg !26
}
define void @outline_debug2() !dbg !27 {
entry:
%a = alloca i32, align 4, !dbg !35
call void @llvm.dbg.value(metadata i32* %a, metadata !29, metadata !DIExpression()), !dbg !35
%b = alloca i32, align 4, !dbg !36
call void @llvm.dbg.value(metadata i32* %b, metadata !30, metadata !DIExpression()), !dbg !36
%c = alloca i32, align 4, !dbg !37
call void @llvm.dbg.value(metadata i32* %c, metadata !31, metadata !DIExpression()), !dbg !37
store i32 2, i32* %a, align 4, !dbg !38
store i32 3, i32* %b, align 4, !dbg !39
store i32 4, i32* %c, align 4, !dbg !40
%al = load i32, i32* %a, align 4, !dbg !41
call void @llvm.dbg.value(metadata i32 %al, metadata !32, metadata !DIExpression()), !dbg !41
%bl = load i32, i32* %b, align 4, !dbg !42
call void @llvm.dbg.value(metadata i32 %bl, metadata !33, metadata !DIExpression()), !dbg !42
%cl = load i32, i32* %c, align 4, !dbg !43
call void @llvm.dbg.value(metadata i32 %cl, metadata !34, metadata !DIExpression()), !dbg !43
ret void, !dbg !44
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.value(metadata, metadata, metadata) #0
attributes #0 = { nounwind readnone speculatable willreturn }
!llvm.dbg.cu = !{!0}
!llvm.debugify = !{!3, !4}
!llvm.module.flags = !{!5}
!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
!1 = !DIFile(filename: "llvm/test/DebugInfo/ir-outliner.ll", directory: "/")
!2 = !{}
!3 = !{i32 20}
!4 = !{i32 12}
!5 = !{i32 2, !"Debug Info Version", i32 3}
!6 = distinct !DISubprogram(name: "outline_debug1", linkageName: "outline_debug1", scope: null, file: !1, line: 1, type: !7, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8)
!7 = !DISubroutineType(types: !2)
!8 = !{!9, !11, !12, !13, !15, !16}
!9 = !DILocalVariable(name: "1", scope: !6, file: !1, line: 1, type: !10)
!10 = !DIBasicType(name: "ty64", size: 64, encoding: DW_ATE_unsigned)
!11 = !DILocalVariable(name: "2", scope: !6, file: !1, line: 2, type: !10)
!12 = !DILocalVariable(name: "3", scope: !6, file: !1, line: 3, type: !10)
!13 = !DILocalVariable(name: "4", scope: !6, file: !1, line: 7, type: !14)
!14 = !DIBasicType(name: "ty32", size: 32, encoding: DW_ATE_unsigned)
!15 = !DILocalVariable(name: "5", scope: !6, file: !1, line: 8, type: !14)
!16 = !DILocalVariable(name: "6", scope: !6, file: !1, line: 9, type: !14)
!17 = !DILocation(line: 1, column: 1, scope: !6)
!18 = !DILocation(line: 2, column: 1, scope: !6)
!19 = !DILocation(line: 3, column: 1, scope: !6)
!20 = !DILocation(line: 4, column: 1, scope: !6)
!21 = !DILocation(line: 5, column: 1, scope: !6)
!22 = !DILocation(line: 6, column: 1, scope: !6)
!23 = !DILocation(line: 7, column: 1, scope: !6)
!24 = !DILocation(line: 8, column: 1, scope: !6)
!25 = !DILocation(line: 9, column: 1, scope: !6)
!26 = !DILocation(line: 10, column: 1, scope: !6)
!27 = distinct !DISubprogram(name: "outline_debug2", linkageName: "outline_debug2", scope: null, file: !1, line: 11, type: !7, scopeLine: 11, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !28)
!28 = !{!29, !30, !31, !32, !33, !34}
!29 = !DILocalVariable(name: "7", scope: !27, file: !1, line: 11, type: !10)
!30 = !DILocalVariable(name: "8", scope: !27, file: !1, line: 12, type: !10)
!31 = !DILocalVariable(name: "9", scope: !27, file: !1, line: 13, type: !10)
!32 = !DILocalVariable(name: "10", scope: !27, file: !1, line: 17, type: !14)
!33 = !DILocalVariable(name: "11", scope: !27, file: !1, line: 18, type: !14)
!34 = !DILocalVariable(name: "12", scope: !27, file: !1, line: 19, type: !14)
!35 = !DILocation(line: 11, column: 1, scope: !27)
!36 = !DILocation(line: 12, column: 1, scope: !27)
!37 = !DILocation(line: 13, column: 1, scope: !27)
!38 = !DILocation(line: 14, column: 1, scope: !27)
!39 = !DILocation(line: 15, column: 1, scope: !27)
!40 = !DILocation(line: 16, column: 1, scope: !27)
!41 = !DILocation(line: 17, column: 1, scope: !27)
!42 = !DILocation(line: 18, column: 1, scope: !27)
!43 = !DILocation(line: 19, column: 1, scope: !27)
!44 = !DILocation(line: 20, column: 1, scope: !27)
; IRDEBUG-LABEL: @outline_debug1(
; IRDEBUG-NEXT: entry:
; IRDEBUG-NEXT: [[A:%.*]] = alloca i32, align 4, !dbg [[DBG17:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], metadata [[META9:![0-9]+]], metadata !DIExpression()), !dbg [[DBG17]]
; IRDEBUG-NEXT: [[B:%.*]] = alloca i32, align 4, !dbg [[DBG18:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], metadata [[META11:![0-9]+]], metadata !DIExpression()), !dbg [[DBG18]]
; IRDEBUG-NEXT: [[C:%.*]] = alloca i32, align 4, !dbg [[DBG19:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], metadata [[META12:![0-9]+]], metadata !DIExpression()), !dbg [[DBG19]]
; IRDEBUG-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), !dbg [[DBG20:![0-9]+]]
; IRDEBUG-NEXT: ret void, !dbg [[DBG21:![0-9]+]]
;
;
; IRDEBUG-LABEL: @outline_debug2(
; IRDEBUG-NEXT: entry:
; IRDEBUG-NEXT: [[A:%.*]] = alloca i32, align 4, !dbg [[DBG30:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], metadata [[META24:![0-9]+]], metadata !DIExpression()), !dbg [[DBG30]]
; IRDEBUG-NEXT: [[B:%.*]] = alloca i32, align 4, !dbg [[DBG31:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], metadata [[META25:![0-9]+]], metadata !DIExpression()), !dbg [[DBG31]]
; IRDEBUG-NEXT: [[C:%.*]] = alloca i32, align 4, !dbg [[DBG32:![0-9]+]]
; IRDEBUG-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], metadata [[META26:![0-9]+]], metadata !DIExpression()), !dbg [[DBG32]]
; IRDEBUG-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), !dbg [[DBG33:![0-9]+]]
; IRDEBUG-NEXT: ret void, !dbg [[DBG34:![0-9]+]]
;
;
; IRDEBUG: @outlined_ir_func_0(i32* [[TMP0:%.*]], i32* [[TMP1:%.*]], i32* [[TMP2:%.*]])
; IRDEBUG: entry_to_outline:
; IRDEBUG-NEXT: store i32 2, i32* [[TMP0]], align 4
; IRDEBUG-NEXT: store i32 3, i32* [[TMP1]], align 4
; IRDEBUG-NEXT: store i32 4, i32* [[TMP2]], align 4
; IRDEBUG-NEXT: [[AL:%.*]] = load i32, i32* [[TMP0]], align 4
; IRDEBUG-NEXT: [[BL:%.*]] = load i32, i32* [[TMP1]], align 4
; IRDEBUG-NEXT: [[CL:%.*]] = load i32, i32* [[TMP2]], align 4
; IRDEBUG-NEXT: br label [[ENTRY_AFTER_OUTLINE_EXITSTUB:%.*]]
;

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@ -1,21 +1,10 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --include-generated-funcs
; RUN: opt -S -verify -iroutliner -ir-outlining-no-cost < %s | FileCheck %s
; This test looks ahecks that debug info is extracted along with the other
; instructions.
; This test checks that debug info is recognized as able to be extracted along
; with the other instructions, but is not included in the consolidated function.
define void @function1() !dbg !6 {
; CHECK-LABEL: @function1(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4, [[DBG17:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], [[META9:metadata !.*]], metadata !DIExpression()), [[DBG17]]
; CHECK-NEXT: [[B:%.*]] = alloca i32, align 4, [[DBG18:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], [[META11:metadata !.*]], metadata !DIExpression()), [[DBG18]]
; CHECK-NEXT: [[C:%.*]] = alloca i32, align 4, [[DBG19:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], [[META12:metadata !.*]], metadata !DIExpression()), [[DBG19]]
; CHECK-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), [[DBG20:!dbg !.*]]
; CHECK-NEXT: ret void, [[DBG21:!dbg !.*]]
;
entry:
%a = alloca i32, align 4, !dbg !17
call void @llvm.dbg.value(metadata i32* %a, metadata !9, metadata !DIExpression()), !dbg !17
@ -36,17 +25,6 @@ entry:
}
define void @function2() !dbg !27 {
; CHECK-LABEL: @function2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4, [[DBG30:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], [[META24:metadata !.*]], metadata !DIExpression()), [[DBG30]]
; CHECK-NEXT: [[B:%.*]] = alloca i32, align 4, [[DBG31:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], [[META25:metadata !.*]], metadata !DIExpression()), [[DBG31]]
; CHECK-NEXT: [[C:%.*]] = alloca i32, align 4, [[DBG32:!dbg !.*]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], [[META26:metadata !.*]], metadata !DIExpression()), [[DBG32]]
; CHECK-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), [[DBG33:!dbg !.*]]
; CHECK-NEXT: ret void, [[DBG34:!dbg !.*]]
;
entry:
%a = alloca i32, align 4, !dbg !35
call void @llvm.dbg.value(metadata i32* %a, metadata !29, metadata !DIExpression()), !dbg !35
@ -66,6 +44,7 @@ entry:
ret void, !dbg !44
}
; Function Attrs: nounwind readnone speculatable willreturn
declare void @llvm.dbg.value(metadata, metadata, metadata) #0
@ -120,3 +99,37 @@ attributes #0 = { nounwind readnone speculatable willreturn }
!42 = !DILocation(line: 18, column: 1, scope: !27)
!43 = !DILocation(line: 19, column: 1, scope: !27)
!44 = !DILocation(line: 20, column: 1, scope: !27)
; CHECK-LABEL: @function1(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4, !dbg [[DBG17:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], metadata [[META9:![0-9]+]], metadata !DIExpression()), !dbg [[DBG17]]
; CHECK-NEXT: [[B:%.*]] = alloca i32, align 4, !dbg [[DBG18:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], metadata [[META11:![0-9]+]], metadata !DIExpression()), !dbg [[DBG18]]
; CHECK-NEXT: [[C:%.*]] = alloca i32, align 4, !dbg [[DBG19:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], metadata [[META12:![0-9]+]], metadata !DIExpression()), !dbg [[DBG19]]
; CHECK-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), !dbg [[DBG20:![0-9]+]]
; CHECK-NEXT: ret void, !dbg [[DBG21:![0-9]+]]
;
;
; CHECK-LABEL: @function2(
; CHECK-NEXT: entry:
; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4, !dbg [[DBG30:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[A]], metadata [[META24:![0-9]+]], metadata !DIExpression()), !dbg [[DBG30]]
; CHECK-NEXT: [[B:%.*]] = alloca i32, align 4, !dbg [[DBG31:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[B]], metadata [[META25:![0-9]+]], metadata !DIExpression()), !dbg [[DBG31]]
; CHECK-NEXT: [[C:%.*]] = alloca i32, align 4, !dbg [[DBG32:![0-9]+]]
; CHECK-NEXT: call void @llvm.dbg.value(metadata i32* [[C]], metadata [[META26:![0-9]+]], metadata !DIExpression()), !dbg [[DBG32]]
; CHECK-NEXT: call void @outlined_ir_func_0(i32* [[A]], i32* [[B]], i32* [[C]]), !dbg [[DBG33:![0-9]+]]
; CHECK-NEXT: ret void, !dbg [[DBG34:![0-9]+]]
;
;
; CHECK: @outlined_ir_func_0(i32* [[TMP0:%.*]], i32* [[TMP1:%.*]], i32* [[TMP2:%.*]])
; CHECK: entry_to_outline:
; CHECK-NEXT: store i32 2, i32* [[TMP0]], align 4
; CHECK-NEXT: store i32 3, i32* [[TMP1]], align 4
; CHECK-NEXT: store i32 4, i32* [[TMP2]], align 4
; CHECK-NEXT: [[AL:%.*]] = load i32, i32* [[TMP0]], align 4
; CHECK-NEXT: [[BL:%.*]] = load i32, i32* [[TMP1]], align 4
; CHECK-NEXT: [[CL:%.*]] = load i32, i32* [[TMP2]], align 4
; CHECK-NEXT: br label [[ENTRY_AFTER_OUTLINE_EXITSTUB:%.*]]
;