Skip to content

[LowerTypeTests] Add debug info to jump table entries #192736

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
vitalybuka merged 7 commits into from
Apr 23, 2026
Merged

[LowerTypeTests] Add debug info to jump table entries #192736

Show file tree
Hide file tree
Changes from 6 commits
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
1d7deb7
[𝘀𝗽𝗿] changes to main this commit is based on
vitalybuka Apr 17, 2026
fc2d08c
[𝘀𝗽𝗿] initial version
vitalybuka Apr 17, 2026
3fb1444
[𝘀𝗽𝗿] changes introduced through rebase
vitalybuka Apr 21, 2026
4976de9
remove opt
vitalybuka Apr 21, 2026
a36c07b
[𝘀𝗽𝗿] changes introduced through rebase
kastiglione Apr 22, 2026
e4e0d6b
better stack trace
vitalybuka Apr 22, 2026
4623238
no llvm::
vitalybuka Apr 23, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
69 changes: 66 additions & 3 deletions llvm/lib/Transforms/IPO/LowerTypeTests.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -35,6 +35,7 @@
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DIBuilder.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/Function.h"
Expand Down Expand Up @@ -1523,25 +1524,87 @@ Triple::ArchType LowerTypeTestsModule::selectJumpTableArmEncoding(
return ArmCount > ThumbCount ? Triple::arm : Triple::thumb;
}

// Create location for each function entry which should look like this:
// frame #0: __ubsan_check_cfi_icall_jt at sanitizer/ubsan_interface.h:0
// frame #1: c::c() (.cfi_jt) at sanitizer/ubsan_interface.h:0:0
// frame #2: .cfi.jumptable.81 at sanitizer/ubsan_interface.h:0:0
static SmallVector<llvm::DILocation *>
createJumpTableDebugInfo(Function *F, ArrayRef<GlobalTypeMember *> Functions) {
Module &M = *F->getParent();
DICompileUnit *CU = nullptr;
auto CUs = M.debug_compile_units();
if (!CUs.empty())
CU = *CUs.begin();

DIBuilder DIB(M, /*AllowUnresolved=*/true, CU);
llvm::DIFile *File = DIB.createFile("ubsan_interface.h", "sanitizer");
if (!CU) {
// Even with debug info enabled it can be missing if not info yet.
CU = DIB.createCompileUnit(
DISourceLanguageName(dwarf::DW_LANG_C), File, "llvm", true, "", 0, "",
DICompileUnit::DebugEmissionKind::LineTablesOnly);
}

DISubroutineType *DIFnTy = DIB.createSubroutineType(nullptr);

llvm::DISubprogram *JTSP = DIB.createFunction(
File, F->getName(), StringRef(), File, 0, DIFnTy, 0,
DINode::FlagArtificial, DISubprogram::SPFlagDefinition);
F->setSubprogram(JTSP);

llvm::DILocation *JTLoc = llvm::DILocation::get(M.getContext(), 0, 0, JTSP);

llvm::DISubprogram *UbsanSP = DIB.createFunction(
File, "__ubsan_check_cfi_icall_jt", StringRef(), File, 0, DIFnTy, 0,
DINode::FlagArtificial, DISubprogram::SPFlagDefinition);

SmallVector<llvm::DILocation *> Locations;
Locations.reserve(Functions.size());

for (auto *Func : Functions) {
StringRef FuncName = Func->getGlobal()->getName();
FuncName.consume_back(".cfi");
llvm::DISubprogram *JumpSP = DIB.createFunction(
File, (FuncName + ".cfi_jt").str(), StringRef(), File, 0, DIFnTy, 0,
DINode::FlagArtificial, DISubprogram::SPFlagDefinition);

llvm::DILocation *EntryLoc = JTLoc;
EntryLoc = llvm::DILocation::get(M.getContext(), 0, 0, JumpSP, EntryLoc);
EntryLoc = llvm::DILocation::get(M.getContext(), 0, 0, UbsanSP, EntryLoc);
Locations.push_back(EntryLoc);
}

DIB.finalize();

return Locations;
}

void LowerTypeTestsModule::createJumpTable(
Function *F, ArrayRef<GlobalTypeMember *> Functions,
Triple::ArchType JumpTableArch) {
BasicBlock *BB = BasicBlock::Create(M.getContext(), "entry", F);
IRBuilder<> IRB(BB);

SmallVector<llvm::DILocation *> Locations;
if (M.getDwarfVersion() != 0)
Locations = createJumpTableDebugInfo(F, Functions);

InlineAsm *JumpTableAsm = createJumpTableEntryAsm(JumpTableArch);

// Check if all entries have the NoUnwind attribute.
// If all entries have it, we can safely mark the
// cfi.jumptable as NoUnwind, otherwise, direct calls
// to the jump table will not handle exceptions properly
bool areAllEntriesNounwind = true;
for (GlobalTypeMember *GTM : Functions) {
if (!llvm::cast<llvm::Function>(GTM->getGlobal())
assert(Locations.empty() || Functions.size() == Locations.size());
for (auto [GTM, Loc] : llvm::zip_longest(Functions, Locations)) {
if (Loc.has_value())
IRB.SetCurrentDebugLocation(*Loc);
if (!llvm::cast<llvm::Function>((*GTM)->getGlobal())
->hasFnAttribute(llvm::Attribute::NoUnwind)) {
areAllEntriesNounwind = false;
}
IRB.CreateCall(JumpTableAsm, GTM->getGlobal());
IRB.CreateCall(JumpTableAsm, (*GTM)->getGlobal());
}
IRB.CreateUnreachable();

Expand Down
20 changes: 16 additions & 4 deletions llvm/test/Transforms/LowerTypeTests/aarch64-jumptable-dbg.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -56,9 +56,9 @@ define i1 @foo(ptr %p) {
; AARCH64: Function Attrs: naked noinline
; AARCH64-LABEL: @.cfi.jumptable(
; AARCH64-NEXT: entry:
; AARCH64-NEXT: call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @f.cfi)
; AARCH64-NEXT: call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @g.cfi)
; AARCH64-NEXT: unreachable
; AARCH64-NEXT: call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @f.cfi), !dbg [[DBG8:![0-9]+]]
; AARCH64-NEXT: call void asm sideeffect "bti c\0Ab $0\0A", "s"(ptr @g.cfi), !dbg [[DBG13:![0-9]+]]
; AARCH64-NEXT: unreachable, !dbg [[DBG13]]
;
;.
; AARCH64: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
Expand All @@ -68,5 +68,17 @@ define i1 @foo(ptr %p) {
; AARCH64: [[META0:![0-9]+]] = !{i32 4, !"branch-target-enforcement", i32 1}
; AARCH64: [[META1:![0-9]+]] = !{i32 7, !"Dwarf Version", i32 5}
; AARCH64: [[META2:![0-9]+]] = !{i32 2, !"Debug Info Version", i32 3}
; AARCH64: [[META3:![0-9]+]] = !{i32 0, !"typeid1"}
; AARCH64: [[META3:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C, file: [[META4:![0-9]+]], producer: "llvm", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly)
; AARCH64: [[META4]] = !DIFile(filename: "{{.*}}ubsan_interface.h", directory: {{.*}})
; AARCH64: [[META5:![0-9]+]] = !{i32 0, !"typeid1"}
; AARCH64: [[META6:![0-9]+]] = distinct !DISubprogram(name: ".cfi.jumptable", scope: [[META4]], file: [[META4]], type: [[META7:![0-9]+]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; AARCH64: [[META7]] = !DISubroutineType(types: null)
; AARCH64: [[DBG8]] = !DILocation(line: 0, scope: [[META9:![0-9]+]], inlinedAt: [[META10:![0-9]+]])
; AARCH64: [[META9]] = distinct !DISubprogram(name: "__ubsan_check_cfi_icall_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; AARCH64: [[META10]] = !DILocation(line: 0, scope: [[META11:![0-9]+]], inlinedAt: [[META12:![0-9]+]])
; AARCH64: [[META11]] = distinct !DISubprogram(name: "f.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; AARCH64: [[META12]] = !DILocation(line: 0, scope: [[META6]])
; AARCH64: [[DBG13]] = !DILocation(line: 0, scope: [[META9]], inlinedAt: [[META14:![0-9]+]])
; AARCH64: [[META14]] = !DILocation(line: 0, scope: [[META15:![0-9]+]], inlinedAt: [[META12]])
; AARCH64: [[META15]] = distinct !DISubprogram(name: "g.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
;.
40 changes: 32 additions & 8 deletions llvm/test/Transforms/LowerTypeTests/x86-jumptable-dbg.ll
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -56,9 +56,9 @@ define i1 @foo(ptr %p) {
;
; X86_32-LABEL: @.cfi.jumptable(
; X86_32-NEXT: entry:
; X86_32-NEXT: call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @f.cfi)
; X86_32-NEXT: call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @g.cfi)
; X86_32-NEXT: unreachable
; X86_32-NEXT: call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @f.cfi), !dbg [[DBG8:![0-9]+]]
; X86_32-NEXT: call void asm sideeffect "endbr32\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @g.cfi), !dbg [[DBG13:![0-9]+]]
; X86_32-NEXT: unreachable, !dbg [[DBG13]]
;
;
; X86_64-LABEL: @f.cfi(
Expand All @@ -79,9 +79,9 @@ define i1 @foo(ptr %p) {
;
; X86_64-LABEL: @.cfi.jumptable(
; X86_64-NEXT: entry:
; X86_64-NEXT: call void asm sideeffect "endbr64\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @f.cfi)
; X86_64-NEXT: call void asm sideeffect "endbr64\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @g.cfi)
; X86_64-NEXT: unreachable
; X86_64-NEXT: call void asm sideeffect "endbr64\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @f.cfi), !dbg [[DBG8:![0-9]+]]
; X86_64-NEXT: call void asm sideeffect "endbr64\0Ajmp ${0:c}@plt\0A.balign 16, 0xcc\0A", "s"(ptr @g.cfi), !dbg [[DBG13:![0-9]+]]
; X86_64-NEXT: unreachable, !dbg [[DBG13]]
;
;.
; X86_32: attributes #[[ATTR0:[0-9]+]] = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
Expand All @@ -95,10 +95,34 @@ define i1 @foo(ptr %p) {
; X86_32: [[META0:![0-9]+]] = !{i32 8, !"cf-protection-branch", i32 1}
; X86_32: [[META1:![0-9]+]] = !{i32 7, !"Dwarf Version", i32 5}
; X86_32: [[META2:![0-9]+]] = !{i32 2, !"Debug Info Version", i32 3}
; X86_32: [[META3:![0-9]+]] = !{i32 0, !"typeid1"}
; X86_32: [[META3:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C, file: [[META4:![0-9]+]], producer: "llvm", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly)
; X86_32: [[META4]] = !DIFile(filename: "{{.*}}ubsan_interface.h", directory: {{.*}})
; X86_32: [[META5:![0-9]+]] = !{i32 0, !"typeid1"}
; X86_32: [[META6:![0-9]+]] = distinct !DISubprogram(name: ".cfi.jumptable", scope: [[META4]], file: [[META4]], type: [[META7:![0-9]+]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_32: [[META7]] = !DISubroutineType(types: null)
; X86_32: [[DBG8]] = !DILocation(line: 0, scope: [[META9:![0-9]+]], inlinedAt: [[META10:![0-9]+]])
; X86_32: [[META9]] = distinct !DISubprogram(name: "__ubsan_check_cfi_icall_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_32: [[META10]] = !DILocation(line: 0, scope: [[META11:![0-9]+]], inlinedAt: [[META12:![0-9]+]])
; X86_32: [[META11]] = distinct !DISubprogram(name: "f.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_32: [[META12]] = !DILocation(line: 0, scope: [[META6]])
; X86_32: [[DBG13]] = !DILocation(line: 0, scope: [[META9]], inlinedAt: [[META14:![0-9]+]])
; X86_32: [[META14]] = !DILocation(line: 0, scope: [[META15:![0-9]+]], inlinedAt: [[META12]])
; X86_32: [[META15]] = distinct !DISubprogram(name: "g.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
;.
; X86_64: [[META0:![0-9]+]] = !{i32 8, !"cf-protection-branch", i32 1}
; X86_64: [[META1:![0-9]+]] = !{i32 7, !"Dwarf Version", i32 5}
; X86_64: [[META2:![0-9]+]] = !{i32 2, !"Debug Info Version", i32 3}
; X86_64: [[META3:![0-9]+]] = !{i32 0, !"typeid1"}
; X86_64: [[META3:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C, file: [[META4:![0-9]+]], producer: "llvm", isOptimized: true, runtimeVersion: 0, emissionKind: LineTablesOnly)
; X86_64: [[META4]] = !DIFile(filename: "{{.*}}ubsan_interface.h", directory: {{.*}})
; X86_64: [[META5:![0-9]+]] = !{i32 0, !"typeid1"}
; X86_64: [[META6:![0-9]+]] = distinct !DISubprogram(name: ".cfi.jumptable", scope: [[META4]], file: [[META4]], type: [[META7:![0-9]+]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_64: [[META7]] = !DISubroutineType(types: null)
; X86_64: [[DBG8]] = !DILocation(line: 0, scope: [[META9:![0-9]+]], inlinedAt: [[META10:![0-9]+]])
; X86_64: [[META9]] = distinct !DISubprogram(name: "__ubsan_check_cfi_icall_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_64: [[META10]] = !DILocation(line: 0, scope: [[META11:![0-9]+]], inlinedAt: [[META12:![0-9]+]])
; X86_64: [[META11]] = distinct !DISubprogram(name: "f.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
; X86_64: [[META12]] = !DILocation(line: 0, scope: [[META6]])
; X86_64: [[DBG13]] = !DILocation(line: 0, scope: [[META9]], inlinedAt: [[META14:![0-9]+]])
; X86_64: [[META14]] = !DILocation(line: 0, scope: [[META15:![0-9]+]], inlinedAt: [[META12]])
; X86_64: [[META15]] = distinct !DISubprogram(name: "g.cfi_jt", scope: [[META4]], file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
;.
Loading