[LowerTypeTests] Add debug info to jump table entries

compiler-rt/lib/ubsan/ubsan_handlers.cpp

@@ -855,6 +855,32 @@ void __ubsan::__ubsan_handle_pointer_overflow_abort(PointerOverflowData *Data,
   Die();
 }
 
+// Returns true if this is an artificial debug location created by the
+// LowerTypeTests pass (see createJumpTableDebugInfo in LLVM).
+static bool isArtificialStack(const SymbolizedStack *S) {
+  static constexpr char kSuffix[] = "ubsan_interface.h";
+  if (!S || !S->info.function || !S->info.file)
+    return false;
+  const char *File = S->info.file;
+  uptr FileLen = internal_strlen(File);
+  uptr SuffixLen = internal_strlen(kSuffix);
+  if (FileLen < SuffixLen)
+    return false;
+  return internal_strcmp(File + FileLen - SuffixLen, kSuffix) == 0;
+}
+
+// Stripping the file name from artificial frames forces the UBSan Diag
+// to fall back to module names. This preserves the original behavior
+// of showing the module, while still allowing the symbolizer
+// to include the helpful (.cfi_jt) function suffix.
+static SymbolizedStack *removeArtificialFiles(SymbolizedStack *FS) {
+  for (SymbolizedStack *S = FS; S; S = S->next) {
+    if (isArtificialStack(S))
+      S->info.file = nullptr;
+  }
+  return FS;
+}
+
 static void handleCFIBadIcall(CFICheckFailData *Data, ValueHandle Function,
                               ReportOptions Opts) {
   if (Data->CheckKind != CFITCK_ICall && Data->CheckKind != CFITCK_NVMFCall)
@@ -875,7 +901,9 @@ static void handleCFIBadIcall(CFICheckFailData *Data, ValueHandle Function,
        "control flow integrity check for type %0 failed during %1")
       << Data->Type << CheckKindStr;
 
-  SymbolizedStackHolder FLoc(getSymbolizedLocation(Function));
+  SymbolizedStackHolder FLoc(
+      removeArtificialFiles(getSymbolizedLocation(Function)));
+
   const char *FName = FLoc.get()->info.function;
   if (!FName)
     FName = "(unknown)";

compiler-rt/test/cfi/cross-dso/icall/diag.cpp

@@ -113,7 +113,7 @@ int main(int argc, char *argv[]) {
   void *p;
   if (argv[1][0] == 'i') {
     // ICALL-DIAG: runtime error: control flow integrity check for type 'void *(int)' failed during indirect function call
-    // ICALL-DIAG-NEXT: dynamic.so+0x{{[[:xdigit:]]+}}): note: create_B() defined here
+    // ICALL-DIAG-NEXT: dynamic.so+0x{{[[:xdigit:]]+}}): note: create_B() {{(\(.cfi_jt\) )?}}defined here
     // ICALL-NODIAG-NOT: runtime error: control flow integrity check {{.*}} during indirect function call
     p = ((void *(*)(int))create_B)(42);
   } else {

compiler-rt/test/cfi/cross-dso/icall/icall-from-dso.cpp

@@ -18,7 +18,7 @@ void f() {
   // CHECK: =2=
   fprintf(stderr, "=2=\n");
   // CFI-DIAG: runtime error: control flow integrity check for type 'void (int)' failed during indirect function call
-  // CFI-DIAG-NEXT: ({{.*}}exe+0x{{[[:xdigit:]]+}}): note: g() defined here
+  // CFI-DIAG-NEXT: ({{.*}}exe+0x{{[[:xdigit:]]+}}): note: g() {{(\(.cfi_jt\) )?}}defined here
   ((void (*)(int))g)(42); // UB here
   // CHECK-DIAG: =3=
   // CHECK-NOT: =3=

compiler-rt/test/cfi/cross-dso/icall/icall.cpp

@@ -21,7 +21,7 @@ int main() {
   // CHECK: =2=
   fprintf(stderr, "=2=\n");
   // CFI-DIAG: runtime error: control flow integrity check for type 'void (int)' failed during indirect function call
-  // CFI-DIAG-NEXT: ({{.*}}dynamic.so+0x{{[[:xdigit:]]+}}): note: f() defined here
+  // CFI-DIAG-NEXT: ({{.*}}dynamic.so+0x{{[[:xdigit:]]+}}): note: f() {{(\(.cfi_jt\) )?}}defined here
   ((void (*)(int))f)(42); // UB here
   // CHECK-DIAG: =3=
   // CHECK-NOT: =3=

compiler-rt/test/cfi/mfcall.cpp

@@ -63,12 +63,12 @@ int main(int argc, char **argv) {
   switch (argv[1][0]) {
     case 'a':
       // A: runtime error: control flow integrity check for type 'int (S::*)()' failed during non-virtual pointer to member function call
-      // A: note: S::f1() defined here
+      // A: note: S::f1() {{(\(.cfi_jt\) )?}}defined here
       (s.*bitcast<S_int>(&S::f1))();
       break;
     case 'b':
       // B: runtime error: control flow integrity check for type 'int (T::*)()' failed during non-virtual pointer to member function call
-      // B: note: S::f2() defined here
+      // B: note: S::f2() {{(\(.cfi_jt\) )?}}defined here
       (t.*bitcast<T_int>(&S::f2))();
       break;
     case 'c':

llvm/lib/Transforms/IPO/LowerTypeTests.cpp

@@ -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"
@@ -123,6 +124,11 @@ static cl::opt<std::string> ClWriteSummary(
     cl::desc("Write summary to given YAML file after running pass"),
     cl::Hidden);
 
+// FIXME: Remove in clang 24.
+static cl::opt<bool> EnableJumpTableDebugInfo(
+    "lowertypetests-jump-table-debug-info", cl::init(true), cl::Hidden,
+    cl::desc("Enable debug info generation for jump tables"));
+
 bool BitSetInfo::containsGlobalOffset(uint64_t Offset) const {
   if (Offset < ByteOffset)
     return false;
@@ -1523,25 +1529,84 @@ Triple::ArchType LowerTypeTestsModule::selectJumpTableArmEncoding(
   return ArmCount > ThumbCount ? Triple::arm : Triple::thumb;
 }
 
+// Create location for each function entry which should look like this:
+// frame #0: c::c() (.cfi_jt) at sanitizer/ubsan_interface.h:0:0
+// frame #1: __ubsan_check_cfi_icall_jt at sanitizer/ubsan_interface.h:0
+static SmallVector<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);
+  DIFile *File = DIB.createFile("ubsan_interface.h", "sanitizer");
+  if (!CU) {
+    // Synthetic module (like ld-temp.o), it frequently lacks a DICompileUnit
+    // even if the rest of the program has debug info.
+    CU = DIB.createCompileUnit(
+        DISourceLanguageName(dwarf::DW_LANG_C), File, "llvm", true, "", 0, "",
+        DICompileUnit::DebugEmissionKind::LineTablesOnly);
+  }
+
+  DISubroutineType *DIFnTy = DIB.createSubroutineType(nullptr);
+
+  DISubprogram *UbsanSP = DIB.createFunction(
+      CU, "__ubsan_check_cfi_icall_jt", {}, File, 0, DIFnTy, 0,
+      DINode::FlagArtificial, DISubprogram::SPFlagDefinition);
+
+  F->setSubprogram(UbsanSP);
+
+  DILocation *UbsanLoc = DILocation::get(M.getContext(), 0, 0, UbsanSP);
+
+  SmallVector<DILocation *> Locations;
+  Locations.reserve(Functions.size());
+
+  for (auto *Func : Functions) {
+    StringRef FuncName = Func->getGlobal()->getName();
+    FuncName.consume_back(".cfi");
+    DISubprogram *JumpSP = DIB.createFunction(
+        CU, (FuncName + ".cfi_jt").str(), {}, File, 0, DIFnTy, 0,
+        DINode::FlagArtificial, DISubprogram::SPFlagDefinition);
+
+    DILocation *EntryLoc =
+        DILocation::get(M.getContext(), 0, 0, JumpSP, UbsanLoc);
+
+    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<DILocation *> Locations;
+  if (M.getDwarfVersion() != 0 && EnableJumpTableDebugInfo)
+    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())
-             ->hasFnAttribute(llvm::Attribute::NoUnwind)) {
+  assert(Locations.empty() || Functions.size() == Locations.size());
+  for (auto [GTM, Loc] : zip_longest(Functions, Locations)) {
+    if (Loc.has_value())
+      IRB.SetCurrentDebugLocation(*Loc);
+    if (!cast<Function>((*GTM)->getGlobal())
+             ->hasFnAttribute(Attribute::NoUnwind)) {
       areAllEntriesNounwind = false;
     }
-    IRB.CreateCall(JumpTableAsm, GTM->getGlobal());
+    IRB.CreateCall(JumpTableAsm, (*GTM)->getGlobal());
   }
   IRB.CreateUnreachable();
 

llvm/test/Transforms/LowerTypeTests/aarch64-jumptable-dbg.ll

@@ -1,6 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-attributes --check-globals --include-generated-funcs
 ; RUN: opt -S -passes=lowertypetests -mtriple=aarch64-unknown-linux-gnu %s | FileCheck --check-prefixes=AARCH64 %s
-; RUN: opt -S -passes=lowertypetests -mtriple=aarch64-unknown-linux-gnu %s | FileCheck --check-prefixes=AARCH64-OFF %s
+; RUN: opt -S -passes=lowertypetests -lowertypetests-jump-table-debug-info=0 -mtriple=aarch64-unknown-linux-gnu %s | FileCheck --check-prefixes=AARCH64-OFF %s
 
 ; Test for the jump table generation with branch protection on AArch64
 
@@ -62,9 +62,9 @@ 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 [[DBG11:![0-9]+]]
+; AARCH64-NEXT:    unreachable, !dbg [[DBG11]]
 ;
 ;
 ; AARCH64-OFF-LABEL: @f.cfi(
@@ -102,7 +102,16 @@ 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: "__ubsan_check_cfi_icall_jt", scope: null, 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: "f.cfi_jt", scope: null, file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
+; AARCH64: [[META10]] = !DILocation(line: 0, scope: [[META6]])
+; AARCH64: [[DBG11]] = !DILocation(line: 0, scope: [[META12:![0-9]+]], inlinedAt: [[META10]])
+; AARCH64: [[META12]] = distinct !DISubprogram(name: "g.cfi_jt", scope: null, file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
 ;.
 ; AARCH64-OFF: [[META0:![0-9]+]] = !{i32 4, !"branch-target-enforcement", i32 1}
 ; AARCH64-OFF: [[META1:![0-9]+]] = !{i32 7, !"Dwarf Version", i32 5}

llvm/test/Transforms/LowerTypeTests/x86-jumptable-dbg.ll

@@ -2,7 +2,7 @@
 ;; Test jump table generation with Indirect Branch Tracking on x86.
 ; RUN: opt -S -passes=lowertypetests -mtriple=i686 %s | FileCheck --check-prefixes=X86_32 %s
 ; RUN: opt -S -passes=lowertypetests -mtriple=x86_64 %s | FileCheck --check-prefixes=X86_64 %s
-; RUN: opt -S -passes=lowertypetests -mtriple=x86_64 %s | FileCheck --check-prefixes=X86_64-OFF %s
+; RUN: opt -S -passes=lowertypetests -lowertypetests-jump-table-debug-info=0 -mtriple=x86_64 %s | FileCheck --check-prefixes=X86_64-OFF %s
 
 @0 = private unnamed_addr constant [2 x ptr] [ptr @f, ptr @g], align 16
 
@@ -62,9 +62,9 @@ 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 [[DBG11:![0-9]+]]
+; X86_32-NEXT:    unreachable, !dbg [[DBG11]]
 ;
 ;
 ; X86_64-LABEL: @f.cfi(
@@ -85,9 +85,9 @@ 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 [[DBG11:![0-9]+]]
+; X86_64-NEXT:    unreachable, !dbg [[DBG11]]
 ;
 ;
 ; X86_64-OFF-LABEL: @f.cfi(
@@ -128,12 +128,30 @@ 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: "__ubsan_check_cfi_icall_jt", scope: null, 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: "f.cfi_jt", scope: null, file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
+; X86_32: [[META10]] = !DILocation(line: 0, scope: [[META6]])
+; X86_32: [[DBG11]] = !DILocation(line: 0, scope: [[META12:![0-9]+]], inlinedAt: [[META10]])
+; X86_32: [[META12]] = distinct !DISubprogram(name: "g.cfi_jt", scope: null, 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: "__ubsan_check_cfi_icall_jt", scope: null, 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: "f.cfi_jt", scope: null, file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
+; X86_64: [[META10]] = !DILocation(line: 0, scope: [[META6]])
+; X86_64: [[DBG11]] = !DILocation(line: 0, scope: [[META12:![0-9]+]], inlinedAt: [[META10]])
+; X86_64: [[META12]] = distinct !DISubprogram(name: "g.cfi_jt", scope: null, file: [[META4]], type: [[META7]], flags: DIFlagArtificial, spFlags: DISPFlagDefinition, unit: [[META3]])
 ;.
 ; X86_64-OFF: [[META0:![0-9]+]] = !{i32 8, !"cf-protection-branch", i32 1}
 ; X86_64-OFF: [[META1:![0-9]+]] = !{i32 7, !"Dwarf Version", i32 5}