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[BOLT] Gadget scanner: make use of C++17 features and LLVM helpers
Perform trivial syntactical cleanups: * make use of structured binding declarations * use LLVM utility functions when appropriate * omit braces around single expression inside single-line LLVM_DEBUG() This patch is NFC aside from minor debug output changes.
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+38
-43
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2 files changed

+38
-43
lines changed

‎bolt/lib/Passes/PAuthGadgetScanner.cpp

Lines changed: 31 additions & 36 deletions
Original file line numberDiff line numberDiff line change
@@ -88,8 +88,8 @@ class TrackedRegisters {
8888
TrackedRegisters(ArrayRef<MCPhysReg> RegsToTrack)
8989
: Registers(RegsToTrack),
9090
RegToIndexMapping(getMappingSize(RegsToTrack), NoIndex) {
91-
for (unsigned I = 0; I < RegsToTrack.size(); ++I)
92-
RegToIndexMapping[RegsToTrack[I]] = I;
91+
for (auto [MappedIndex, Reg] : llvm::enumerate(RegsToTrack))
92+
RegToIndexMapping[Reg] = MappedIndex;
9393
}
9494

9595
ArrayRef<MCPhysReg> getRegisters() const { return Registers; }
@@ -203,9 +203,9 @@ struct SrcState {
203203

204204
SafeToDerefRegs &= StateIn.SafeToDerefRegs;
205205
TrustedRegs &= StateIn.TrustedRegs;
206-
for (unsigned I = 0; I < LastInstWritingReg.size(); ++I)
207-
for (const MCInst *J : StateIn.LastInstWritingReg[I])
208-
LastInstWritingReg[I].insert(J);
206+
for (auto [ThisSet, OtherSet] :
207+
llvm::zip_equal(LastInstWritingReg, StateIn.LastInstWritingReg))
208+
ThisSet.insert_range(OtherSet);
209209
return *this;
210210
}
211211

@@ -224,11 +224,9 @@ struct SrcState {
224224
static void printInstsShort(raw_ostream &OS,
225225
ArrayRef<SetOfRelatedInsts> Insts) {
226226
OS << "Insts: ";
227-
for (unsigned I = 0; I < Insts.size(); ++I) {
228-
auto &Set = Insts[I];
227+
for (auto [I, PtrSet] : llvm::enumerate(Insts)) {
229228
OS << "[" << I << "](";
230-
for (const MCInst *MCInstP : Set)
231-
OS << MCInstP << " ";
229+
interleave(PtrSet, OS, " ");
232230
OS << ")";
233231
}
234232
}
@@ -416,8 +414,9 @@ class SrcSafetyAnalysis {
416414
// ... an address can be updated in a safe manner, producing the result
417415
// which is as trusted as the input address.
418416
if (auto DstAndSrc = BC.MIB->analyzeAddressArithmeticsForPtrAuth(Point)) {
419-
if (Cur.SafeToDerefRegs[DstAndSrc->second])
420-
Regs.push_back(DstAndSrc->first);
417+
auto [DstReg, SrcReg] = *DstAndSrc;
418+
if (Cur.SafeToDerefRegs[SrcReg])
419+
Regs.push_back(DstReg);
421420
}
422421

423422
// Make sure explicit checker sequence keeps register safe-to-dereference
@@ -469,8 +468,9 @@ class SrcSafetyAnalysis {
469468
// ... an address can be updated in a safe manner, producing the result
470469
// which is as trusted as the input address.
471470
if (auto DstAndSrc = BC.MIB->analyzeAddressArithmeticsForPtrAuth(Point)) {
472-
if (Cur.TrustedRegs[DstAndSrc->second])
473-
Regs.push_back(DstAndSrc->first);
471+
auto [DstReg, SrcReg] = *DstAndSrc;
472+
if (Cur.TrustedRegs[SrcReg])
473+
Regs.push_back(DstReg);
474474
}
475475

476476
return Regs;
@@ -868,9 +868,9 @@ struct DstState {
868868
return (*this = StateIn);
869869

870870
CannotEscapeUnchecked &= StateIn.CannotEscapeUnchecked;
871-
for (unsigned I = 0; I < FirstInstLeakingReg.size(); ++I)
872-
for (const MCInst *J : StateIn.FirstInstLeakingReg[I])
873-
FirstInstLeakingReg[I].insert(J);
871+
for (auto [ThisSet, OtherSet] :
872+
llvm::zip_equal(FirstInstLeakingReg, StateIn.FirstInstLeakingReg))
873+
ThisSet.insert_range(OtherSet);
874874
return *this;
875875
}
876876

@@ -1036,8 +1036,7 @@ class DstSafetyAnalysis {
10361036

10371037
// ... an address can be updated in a safe manner, or
10381038
if (auto DstAndSrc = BC.MIB->analyzeAddressArithmeticsForPtrAuth(Inst)) {
1039-
MCPhysReg DstReg, SrcReg;
1040-
std::tie(DstReg, SrcReg) = *DstAndSrc;
1039+
auto [DstReg, SrcReg] = *DstAndSrc;
10411040
// Note that *all* registers containing the derived values must be safe,
10421041
// both source and destination ones. No temporaries are supported at now.
10431042
if (Cur.CannotEscapeUnchecked[SrcReg] &&
@@ -1077,7 +1076,7 @@ class DstSafetyAnalysis {
10771076
// If this instruction terminates the program immediately, no
10781077
// authentication oracles are possible past this point.
10791078
if (BC.MIB->isTrap(Point)) {
1080-
LLVM_DEBUG({ traceInst(BC, "Trap instruction found", Point); });
1079+
LLVM_DEBUG(traceInst(BC, "Trap instruction found", Point));
10811080
DstState Next(NumRegs, RegsToTrackInstsFor.getNumTrackedRegisters());
10821081
Next.CannotEscapeUnchecked.set();
10831082
return Next;
@@ -1255,7 +1254,7 @@ class CFGUnawareDstSafetyAnalysis : public DstSafetyAnalysis,
12551254
// starting to analyze Inst.
12561255
if (BC.MIB->isCall(Inst) || BC.MIB->isBranch(Inst) ||
12571256
BC.MIB->isReturn(Inst)) {
1258-
LLVM_DEBUG({ traceInst(BC, "Control flow instruction", Inst); });
1257+
LLVM_DEBUG(traceInst(BC, "Control flow instruction", Inst));
12591258
S = createUnsafeState();
12601259
}
12611260

@@ -1393,12 +1392,12 @@ shouldReportUnsafeTailCall(const BinaryContext &BC, const BinaryFunction &BF,
13931392
// such libc, ignore tail calls performed by ELF entry function.
13941393
if (BC.StartFunctionAddress &&
13951394
*BC.StartFunctionAddress == Inst.getFunction()->getAddress()) {
1396-
LLVM_DEBUG({ dbgs() << " Skipping tail call in ELF entry function.\n"; });
1395+
LLVM_DEBUG(dbgs() << " Skipping tail call in ELF entry function.\n");
13971396
return std::nullopt;
13981397
}
13991398

14001399
if (BC.MIB->isSafeJumpTableBranchForPtrAuth(Inst)) {
1401-
LLVM_DEBUG({ dbgs() << " Safe jump table detected, skipping.\n"; });
1400+
LLVM_DEBUG(dbgs() << " Safe jump table detected, skipping.\n");
14021401
return std::nullopt;
14031402
}
14041403

@@ -1433,7 +1432,7 @@ shouldReportCallGadget(const BinaryContext &BC, const MCInstReference &Inst,
14331432
return std::nullopt;
14341433

14351434
if (BC.MIB->isSafeJumpTableBranchForPtrAuth(Inst)) {
1436-
LLVM_DEBUG({ dbgs() << " Safe jump table detected, skipping.\n"; });
1435+
LLVM_DEBUG(dbgs() << " Safe jump table detected, skipping.\n");
14371436
return std::nullopt;
14381437
}
14391438

@@ -1477,7 +1476,7 @@ shouldReportAuthOracle(const BinaryContext &BC, const MCInstReference &Inst,
14771476
});
14781477

14791478
if (S.empty()) {
1480-
LLVM_DEBUG({ dbgs() << " DstState is empty!\n"; });
1479+
LLVM_DEBUG(dbgs() << " DstState is empty!\n");
14811480
return make_generic_report(
14821481
Inst, "Warning: no state computed for an authentication instruction "
14831482
"(possibly unreachable)");
@@ -1504,7 +1503,7 @@ collectRegsToTrack(ArrayRef<PartialReport<MCPhysReg>> Reports) {
15041503
void FunctionAnalysisContext::findUnsafeUses(
15051504
SmallVector<PartialReport<MCPhysReg>> &Reports) {
15061505
auto Analysis = SrcSafetyAnalysis::create(BF, AllocatorId, {});
1507-
LLVM_DEBUG({ dbgs() << "Running src register safety analysis...\n"; });
1506+
LLVM_DEBUG(dbgs() << "Running src register safety analysis...\n");
15081507
Analysis->run();
15091508
LLVM_DEBUG({
15101509
dbgs() << "After src register safety analysis:\n";
@@ -1561,8 +1560,7 @@ void FunctionAnalysisContext::findUnsafeUses(
15611560

15621561
const SrcState &S = Analysis->getStateBefore(Inst);
15631562
if (S.empty()) {
1564-
LLVM_DEBUG(
1565-
{ traceInst(BC, "Instruction has no state, skipping", Inst); });
1563+
LLVM_DEBUG(traceInst(BC, "Instruction has no state, skipping", Inst));
15661564
assert(UnreachableBBReported && "Should be reported at least once");
15671565
(void)UnreachableBBReported;
15681566
return;
@@ -1589,8 +1587,7 @@ void FunctionAnalysisContext::augmentUnsafeUseReports(
15891587
SmallVector<MCPhysReg> RegsToTrack = collectRegsToTrack(Reports);
15901588
// Re-compute the analysis with register tracking.
15911589
auto Analysis = SrcSafetyAnalysis::create(BF, AllocatorId, RegsToTrack);
1592-
LLVM_DEBUG(
1593-
{ dbgs() << "\nRunning detailed src register safety analysis...\n"; });
1590+
LLVM_DEBUG(dbgs() << "\nRunning detailed src register safety analysis...\n");
15941591
Analysis->run();
15951592
LLVM_DEBUG({
15961593
dbgs() << "After detailed src register safety analysis:\n";
@@ -1600,7 +1597,7 @@ void FunctionAnalysisContext::augmentUnsafeUseReports(
16001597
// Augment gadget reports.
16011598
for (auto &Report : Reports) {
16021599
MCInstReference Location = Report.Issue->Location;
1603-
LLVM_DEBUG({ traceInst(BC, "Attaching clobbering info to", Location); });
1600+
LLVM_DEBUG(traceInst(BC, "Attaching clobbering info to", Location));
16041601
assert(Report.RequestedDetails &&
16051602
"Should be removed by handleSimpleReports");
16061603
auto DetailedInfo =
@@ -1618,7 +1615,7 @@ void FunctionAnalysisContext::findUnsafeDefs(
16181615
return;
16191616

16201617
auto Analysis = DstSafetyAnalysis::create(BF, AllocatorId, {});
1621-
LLVM_DEBUG({ dbgs() << "Running dst register safety analysis...\n"; });
1618+
LLVM_DEBUG(dbgs() << "Running dst register safety analysis...\n");
16221619
Analysis->run();
16231620
LLVM_DEBUG({
16241621
dbgs() << "After dst register safety analysis:\n";
@@ -1641,8 +1638,7 @@ void FunctionAnalysisContext::augmentUnsafeDefReports(
16411638
SmallVector<MCPhysReg> RegsToTrack = collectRegsToTrack(Reports);
16421639
// Re-compute the analysis with register tracking.
16431640
auto Analysis = DstSafetyAnalysis::create(BF, AllocatorId, RegsToTrack);
1644-
LLVM_DEBUG(
1645-
{ dbgs() << "\nRunning detailed dst register safety analysis...\n"; });
1641+
LLVM_DEBUG(dbgs() << "\nRunning detailed dst register safety analysis...\n");
16461642
Analysis->run();
16471643
LLVM_DEBUG({
16481644
dbgs() << "After detailed dst register safety analysis:\n";
@@ -1652,7 +1648,7 @@ void FunctionAnalysisContext::augmentUnsafeDefReports(
16521648
// Augment gadget reports.
16531649
for (auto &Report : Reports) {
16541650
MCInstReference Location = Report.Issue->Location;
1655-
LLVM_DEBUG({ traceInst(BC, "Attaching leakage info to", Location); });
1651+
LLVM_DEBUG(traceInst(BC, "Attaching leakage info to", Location));
16561652
assert(Report.RequestedDetails &&
16571653
"Should be removed by handleSimpleReports");
16581654
auto DetailedInfo = std::make_shared<LeakageInfo>(
@@ -1785,8 +1781,7 @@ static void printRelatedInstrs(raw_ostream &OS, const MCInstReference Location,
17851781
// Sort the references to make output deterministic.
17861782
SmallVector<MCInstReference> RI(RelatedInstrs);
17871783
llvm::sort(RI);
1788-
for (unsigned I = 0; I < RI.size(); ++I) {
1789-
MCInstReference InstRef = RI[I];
1784+
for (auto [I, InstRef] : llvm::enumerate(RI)) {
17901785
OS << " " << (I + 1) << ". ";
17911786
BC.printInstruction(OS, InstRef, getAddress(InstRef), &BF);
17921787
};

‎bolt/test/binary-analysis/AArch64/gs-pauth-debug-output.s

Lines changed: 7 additions & 7 deletions
Original file line numberDiff line numberDiff line change
@@ -177,9 +177,9 @@ clobber:
177177
// CHECK-EMPTY:
178178
// CHECK-NEXT: Running detailed src register safety analysis...
179179
// CHECK-NEXT: SrcSafetyAnalysis::ComputeNext( mov w30, #0x0, src-state<SafeToDerefRegs: LR W30 W30_HI , TrustedRegs: LR W30 W30_HI , Insts: [0]()>)
180-
// CHECK-NEXT: .. result: (src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}} )>)
181-
// CHECK-NEXT: SrcSafetyAnalysis::ComputeNext( ret x30, src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}} )>)
182-
// CHECK-NEXT: .. result: (src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}} )>)
180+
// CHECK-NEXT: .. result: (src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}})>)
181+
// CHECK-NEXT: SrcSafetyAnalysis::ComputeNext( ret x30, src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}})>)
182+
// CHECK-NEXT: .. result: (src-state<SafeToDerefRegs: W30_HI , TrustedRegs: W30_HI , Insts: [0](0x{{[0-9a-f]+}})>)
183183
// CHECK-NEXT: After detailed src register safety analysis:
184184
// CHECK-NEXT: Binary Function "clobber" {
185185
// ...
@@ -189,7 +189,7 @@ clobber:
189189
// Iterating over the reports and attaching clobbering info:
190190

191191
// CHECK-EMPTY:
192-
// CHECK-NEXT: Attaching clobbering info to: 00000000: ret # DataflowSrcSafetyAnalysis: src-state<SafeToDerefRegs: BitVector, TrustedRegs: BitVector, Insts: [0](0x{{[0-9a-f]+}} )>
192+
// CHECK-NEXT: Attaching clobbering info to: 00000000: ret # DataflowSrcSafetyAnalysis: src-state<SafeToDerefRegs: BitVector, TrustedRegs: BitVector, Insts: [0](0x{{[0-9a-f]+}})>
193193

194194
.globl nocfg
195195
.type nocfg,@function
@@ -315,7 +315,7 @@ auth_oracle:
315315
// AUTH-ORACLES-NEXT: DstSafetyAnalysis::ComputeNext( ret x30, dst-state<CannotEscapeUnchecked: , Insts: [0]()>)
316316
// AUTH-ORACLES-NEXT: .. result: (dst-state<CannotEscapeUnchecked: LR W30 W30_HI , Insts: [0]()>)
317317
// AUTH-ORACLES-NEXT: DstSafetyAnalysis::ComputeNext( autia x0, x1, dst-state<CannotEscapeUnchecked: LR W30 W30_HI , Insts: [0]()>)
318-
// AUTH-ORACLES-NEXT: .. result: (dst-state<CannotEscapeUnchecked: LR W30 W30_HI , Insts: [0](0x{{[0-9a-f]+}} )>)
318+
// AUTH-ORACLES-NEXT: .. result: (dst-state<CannotEscapeUnchecked: LR W30 W30_HI , Insts: [0](0x{{[0-9a-f]+}})>)
319319
// AUTH-ORACLES-NEXT: After detailed dst register safety analysis:
320320
// AUTH-ORACLES-NEXT: Binary Function "auth_oracle" {
321321
// AUTH-ORACLES-NEXT: Number : 4
@@ -325,14 +325,14 @@ auth_oracle:
325325
// AUTH-ORACLES-NEXT: }
326326
// AUTH-ORACLES-NEXT: [[BB0]] (2 instructions, align : 1)
327327
// AUTH-ORACLES-NEXT: Entry Point
328-
// AUTH-ORACLES-NEXT: 00000000: autia x0, x1 # DataflowDstSafetyAnalysis: dst-state<CannotEscapeUnchecked: BitVector, Insts: [0](0x{{[0-9a-f]+}} )>
328+
// AUTH-ORACLES-NEXT: 00000000: autia x0, x1 # DataflowDstSafetyAnalysis: dst-state<CannotEscapeUnchecked: BitVector, Insts: [0](0x{{[0-9a-f]+}})>
329329
// AUTH-ORACLES-NEXT: 00000004: ret # DataflowDstSafetyAnalysis: dst-state<CannotEscapeUnchecked: BitVector, Insts: [0]()>
330330
// AUTH-ORACLES-EMPTY:
331331
// AUTH-ORACLES-NEXT: DWARF CFI Instructions:
332332
// AUTH-ORACLES-NEXT: <empty>
333333
// AUTH-ORACLES-NEXT: End of Function "auth_oracle"
334334
// AUTH-ORACLES-EMPTY:
335-
// AUTH-ORACLES-NEXT: Attaching leakage info to: 00000000: autia x0, x1 # DataflowDstSafetyAnalysis: dst-state<CannotEscapeUnchecked: BitVector, Insts: [0](0x{{[0-9a-f]+}} )>
335+
// AUTH-ORACLES-NEXT: Attaching leakage info to: 00000000: autia x0, x1 # DataflowDstSafetyAnalysis: dst-state<CannotEscapeUnchecked: BitVector, Insts: [0](0x{{[0-9a-f]+}})>
336336

337337
// Gadget scanner should not crash on CFI instructions, including when debug-printing them.
338338
// Note that the particular debug output is not checked, but BOLT should be

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