Files
RedBear-OS/local/recipes/dev/libclc/source/llvm/lib/Analysis/StackLifetime.cpp
T
vasilito cb424d7448 build: static patch-sanity linter (shift-left the malformed-patch class)
verify-patch-sanity.py validates every active recipe .patch has internally-
consistent hunk line counts — catching the 'malformed patch at line N' failure
at commit/CI/preflight time instead of hours into a cook. This cycle hit that
class three times (qtwaylandscanner, sddm, xwayland), each only discovered when
cookbook tried to apply the patch.

Running it across the repo found 29 latent malformed patches (validated against
GNU patch: e.g. relibc/P3-sysv-ipc reproduces 'malformed patch at line 22').
They were harmless only because they sit in vendored recipes (baked, not re-
applied) — but would fail on any version-bump re-derivation. --fix recounts the
hunk headers (body untouched) and repaired all 29.

Wired into build-preflight.sh (Phase 1.0D) and redbear-ci.yml, with a unit test
(test-patch-sanity.sh). Skips archived/legacy trees and unvalidatable formats
(empty placeholders, bare-@@ git hunks).
2026-08-01 05:13:02 +03:00

428 lines
14 KiB
C++

//===- StackLifetime.cpp - Alloca Lifetime Analysis -----------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/Analysis/StackLifetime.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/Config/llvm-config.h"
#include "llvm/IR/AssemblyAnnotationWriter.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/CFG.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Value.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/FormattedStream.h"
#include <algorithm>
#include <tuple>
using namespace llvm;
#define DEBUG_TYPE "stack-lifetime"
const StackLifetime::LiveRange &
StackLifetime::getLiveRange(const AllocaInst *AI) const {
const auto IT = AllocaNumbering.find(AI);
assert(IT != AllocaNumbering.end());
return LiveRanges[IT->second];
}
bool StackLifetime::isReachable(const Instruction *I) const {
return BlockInstRange.contains(I->getParent());
}
bool StackLifetime::isAliveAfter(const AllocaInst *AI,
const Instruction *I) const {
const BasicBlock *BB = I->getParent();
auto ItBB = BlockInstRange.find(BB);
assert(ItBB != BlockInstRange.end() && "Unreachable is not expected");
// Search the block for the first instruction following 'I'.
auto It = std::upper_bound(Instructions.begin() + ItBB->getSecond().first + 1,
Instructions.begin() + ItBB->getSecond().second, I,
[](const Instruction *L, const Instruction *R) {
return L->comesBefore(R);
});
--It;
unsigned InstNum = It - Instructions.begin();
return getLiveRange(AI).test(InstNum);
}
// Returns unique alloca annotated by lifetime marker only if
// markers has the same size and points to the alloca start.
static const AllocaInst *findMatchingAlloca(const IntrinsicInst &II,
const DataLayout &DL) {
const AllocaInst *AI = findAllocaForValue(II.getArgOperand(1), true);
if (!AI)
return nullptr;
auto AllocaSize = AI->getAllocationSize(DL);
if (!AllocaSize)
return nullptr;
auto *Size = dyn_cast<ConstantInt>(II.getArgOperand(0));
if (!Size)
return nullptr;
int64_t LifetimeSize = Size->getSExtValue();
if (LifetimeSize != -1 && uint64_t(LifetimeSize) != *AllocaSize)
return nullptr;
return AI;
}
void StackLifetime::collectMarkers() {
InterestingAllocas.resize(NumAllocas);
DenseMap<const BasicBlock *, SmallDenseMap<const IntrinsicInst *, Marker>>
BBMarkerSet;
const DataLayout &DL = F.getDataLayout();
// Compute the set of start/end markers per basic block.
for (const BasicBlock *BB : depth_first(&F)) {
for (const Instruction &I : *BB) {
const IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
if (!II || !II->isLifetimeStartOrEnd())
continue;
const AllocaInst *AI = findMatchingAlloca(*II, DL);
if (!AI) {
HasUnknownLifetimeStartOrEnd = true;
continue;
}
auto It = AllocaNumbering.find(AI);
if (It == AllocaNumbering.end())
continue;
auto AllocaNo = It->second;
bool IsStart = II->getIntrinsicID() == Intrinsic::lifetime_start;
if (IsStart)
InterestingAllocas.set(AllocaNo);
BBMarkerSet[BB][II] = {AllocaNo, IsStart};
}
}
// Compute instruction numbering. Only the following instructions are
// considered:
// * Basic block entries
// * Lifetime markers
// For each basic block, compute
// * the list of markers in the instruction order
// * the sets of allocas whose lifetime starts or ends in this BB
LLVM_DEBUG(dbgs() << "Instructions:\n");
for (const BasicBlock *BB : depth_first(&F)) {
LLVM_DEBUG(dbgs() << " " << Instructions.size() << ": BB " << BB->getName()
<< "\n");
auto BBStart = Instructions.size();
Instructions.push_back(nullptr);
BlockLifetimeInfo &BlockInfo =
BlockLiveness.try_emplace(BB, NumAllocas).first->getSecond();
auto &BlockMarkerSet = BBMarkerSet[BB];
if (BlockMarkerSet.empty()) {
BlockInstRange[BB] = std::make_pair(BBStart, Instructions.size());
continue;
}
auto ProcessMarker = [&](const IntrinsicInst *I, const Marker &M) {
LLVM_DEBUG(dbgs() << " " << Instructions.size() << ": "
<< (M.IsStart ? "start " : "end ") << M.AllocaNo
<< ", " << *I << "\n");
BBMarkers[BB].push_back({Instructions.size(), M});
Instructions.push_back(I);
if (M.IsStart) {
BlockInfo.End.reset(M.AllocaNo);
BlockInfo.Begin.set(M.AllocaNo);
} else {
BlockInfo.Begin.reset(M.AllocaNo);
BlockInfo.End.set(M.AllocaNo);
}
};
if (BlockMarkerSet.size() == 1) {
ProcessMarker(BlockMarkerSet.begin()->getFirst(),
BlockMarkerSet.begin()->getSecond());
} else {
// Scan the BB to determine the marker order.
for (const Instruction &I : *BB) {
const IntrinsicInst *II = dyn_cast<IntrinsicInst>(&I);
if (!II)
continue;
auto It = BlockMarkerSet.find(II);
if (It == BlockMarkerSet.end())
continue;
ProcessMarker(II, It->getSecond());
}
}
BlockInstRange[BB] = std::make_pair(BBStart, Instructions.size());
}
}
void StackLifetime::calculateLocalLiveness() {
bool Changed = true;
// LiveIn, LiveOut and BitsIn have a different meaning deppends on type.
// ::Maybe true bits represent "may be alive" allocas, ::Must true bits
// represent "may be dead". After the loop we will convert ::Must bits from
// "may be dead" to "must be alive".
while (Changed) {
// TODO: Consider switching to worklist instead of traversing entire graph.
Changed = false;
for (const BasicBlock *BB : depth_first(&F)) {
BlockLifetimeInfo &BlockInfo = BlockLiveness.find(BB)->getSecond();
// Compute BitsIn by unioning together the LiveOut sets of all preds.
BitVector BitsIn;
for (const auto *PredBB : predecessors(BB)) {
LivenessMap::const_iterator I = BlockLiveness.find(PredBB);
// If a predecessor is unreachable, ignore it.
if (I == BlockLiveness.end())
continue;
BitsIn |= I->second.LiveOut;
}
// Everything is "may be dead" for entry without predecessors.
if (Type == LivenessType::Must && BitsIn.empty())
BitsIn.resize(NumAllocas, true);
// Update block LiveIn set, noting whether it has changed.
if (BitsIn.test(BlockInfo.LiveIn)) {
BlockInfo.LiveIn |= BitsIn;
}
// Compute LiveOut by subtracting out lifetimes that end in this
// block, then adding in lifetimes that begin in this block. If
// we have both BEGIN and END markers in the same basic block
// then we know that the BEGIN marker comes after the END,
// because we already handle the case where the BEGIN comes
// before the END when collecting the markers (and building the
// BEGIN/END vectors).
switch (Type) {
case LivenessType::May:
BitsIn.reset(BlockInfo.End);
// "may be alive" is set by lifetime start.
BitsIn |= BlockInfo.Begin;
break;
case LivenessType::Must:
BitsIn.reset(BlockInfo.Begin);
// "may be dead" is set by lifetime end.
BitsIn |= BlockInfo.End;
break;
}
// Update block LiveOut set, noting whether it has changed.
if (BitsIn.test(BlockInfo.LiveOut)) {
Changed = true;
BlockInfo.LiveOut |= BitsIn;
}
}
} // while changed.
if (Type == LivenessType::Must) {
// Convert from "may be dead" to "must be alive".
for (auto &[BB, BlockInfo] : BlockLiveness) {
BlockInfo.LiveIn.flip();
BlockInfo.LiveOut.flip();
}
}
}
void StackLifetime::calculateLiveIntervals() {
for (auto IT : BlockLiveness) {
const BasicBlock *BB = IT.getFirst();
BlockLifetimeInfo &BlockInfo = IT.getSecond();
unsigned BBStart, BBEnd;
std::tie(BBStart, BBEnd) = BlockInstRange[BB];
BitVector Started, Ended;
Started.resize(NumAllocas);
Ended.resize(NumAllocas);
SmallVector<unsigned, 8> Start;
Start.resize(NumAllocas);
// LiveIn ranges start at the first instruction.
for (unsigned AllocaNo = 0; AllocaNo < NumAllocas; ++AllocaNo) {
if (BlockInfo.LiveIn.test(AllocaNo)) {
Started.set(AllocaNo);
Start[AllocaNo] = BBStart;
}
}
for (auto &It : BBMarkers[BB]) {
unsigned InstNo = It.first;
bool IsStart = It.second.IsStart;
unsigned AllocaNo = It.second.AllocaNo;
if (IsStart) {
if (!Started.test(AllocaNo)) {
Started.set(AllocaNo);
Ended.reset(AllocaNo);
Start[AllocaNo] = InstNo;
}
} else {
if (Started.test(AllocaNo)) {
LiveRanges[AllocaNo].addRange(Start[AllocaNo], InstNo);
Started.reset(AllocaNo);
}
Ended.set(AllocaNo);
}
}
for (unsigned AllocaNo = 0; AllocaNo < NumAllocas; ++AllocaNo)
if (Started.test(AllocaNo))
LiveRanges[AllocaNo].addRange(Start[AllocaNo], BBEnd);
}
}
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
LLVM_DUMP_METHOD void StackLifetime::dumpAllocas() const {
dbgs() << "Allocas:\n";
for (unsigned AllocaNo = 0; AllocaNo < NumAllocas; ++AllocaNo)
dbgs() << " " << AllocaNo << ": " << *Allocas[AllocaNo] << "\n";
}
LLVM_DUMP_METHOD void StackLifetime::dumpBlockLiveness() const {
dbgs() << "Block liveness:\n";
for (auto IT : BlockLiveness) {
const BasicBlock *BB = IT.getFirst();
const BlockLifetimeInfo &BlockInfo = BlockLiveness.find(BB)->getSecond();
auto BlockRange = BlockInstRange.find(BB)->getSecond();
dbgs() << " BB (" << BB->getName() << ") [" << BlockRange.first << ", " << BlockRange.second
<< "): begin " << BlockInfo.Begin << ", end " << BlockInfo.End
<< ", livein " << BlockInfo.LiveIn << ", liveout "
<< BlockInfo.LiveOut << "\n";
}
}
LLVM_DUMP_METHOD void StackLifetime::dumpLiveRanges() const {
dbgs() << "Alloca liveness:\n";
for (unsigned AllocaNo = 0; AllocaNo < NumAllocas; ++AllocaNo)
dbgs() << " " << AllocaNo << ": " << LiveRanges[AllocaNo] << "\n";
}
#endif
StackLifetime::StackLifetime(const Function &F,
ArrayRef<const AllocaInst *> Allocas,
LivenessType Type)
: F(F), Type(Type), Allocas(Allocas), NumAllocas(Allocas.size()) {
LLVM_DEBUG(dumpAllocas());
for (unsigned I = 0; I < NumAllocas; ++I)
AllocaNumbering[Allocas[I]] = I;
collectMarkers();
}
void StackLifetime::run() {
if (HasUnknownLifetimeStartOrEnd) {
// There is marker which we can't assign to a specific alloca, so we
// fallback to the most conservative results for the type.
switch (Type) {
case LivenessType::May:
LiveRanges.resize(NumAllocas, getFullLiveRange());
break;
case LivenessType::Must:
LiveRanges.resize(NumAllocas, LiveRange(Instructions.size()));
break;
}
return;
}
LiveRanges.resize(NumAllocas, LiveRange(Instructions.size()));
for (unsigned I = 0; I < NumAllocas; ++I)
if (!InterestingAllocas.test(I))
LiveRanges[I] = getFullLiveRange();
calculateLocalLiveness();
LLVM_DEBUG(dumpBlockLiveness());
calculateLiveIntervals();
LLVM_DEBUG(dumpLiveRanges());
}
class StackLifetime::LifetimeAnnotationWriter
: public AssemblyAnnotationWriter {
const StackLifetime &SL;
void printInstrAlive(unsigned InstrNo, formatted_raw_ostream &OS) {
SmallVector<StringRef, 16> Names;
for (const auto &KV : SL.AllocaNumbering) {
if (SL.LiveRanges[KV.getSecond()].test(InstrNo))
Names.push_back(KV.getFirst()->getName());
}
llvm::sort(Names);
OS << " ; Alive: <" << llvm::join(Names, " ") << ">\n";
}
void emitBasicBlockStartAnnot(const BasicBlock *BB,
formatted_raw_ostream &OS) override {
auto ItBB = SL.BlockInstRange.find(BB);
if (ItBB == SL.BlockInstRange.end())
return; // Unreachable.
printInstrAlive(ItBB->getSecond().first, OS);
}
void printInfoComment(const Value &V, formatted_raw_ostream &OS) override {
const Instruction *Instr = dyn_cast<Instruction>(&V);
if (!Instr || !SL.isReachable(Instr))
return;
SmallVector<StringRef, 16> Names;
for (const auto &KV : SL.AllocaNumbering) {
if (SL.isAliveAfter(KV.getFirst(), Instr))
Names.push_back(KV.getFirst()->getName());
}
llvm::sort(Names);
OS << "\n ; Alive: <" << llvm::join(Names, " ") << ">\n";
}
public:
LifetimeAnnotationWriter(const StackLifetime &SL) : SL(SL) {}
};
void StackLifetime::print(raw_ostream &OS) {
LifetimeAnnotationWriter AAW(*this);
F.print(OS, &AAW);
}
PreservedAnalyses StackLifetimePrinterPass::run(Function &F,
FunctionAnalysisManager &AM) {
SmallVector<const AllocaInst *, 8> Allocas;
for (auto &I : instructions(F))
if (const AllocaInst *AI = dyn_cast<AllocaInst>(&I))
Allocas.push_back(AI);
StackLifetime SL(F, Allocas, Type);
SL.run();
SL.print(OS);
return PreservedAnalyses::all();
}
void StackLifetimePrinterPass::printPipeline(
raw_ostream &OS, function_ref<StringRef(StringRef)> MapClassName2PassName) {
static_cast<PassInfoMixin<StackLifetimePrinterPass> *>(this)->printPipeline(
OS, MapClassName2PassName);
OS << '<';
switch (Type) {
case StackLifetime::LivenessType::May:
OS << "may";
break;
case StackLifetime::LivenessType::Must:
OS << "must";
break;
}
OS << '>';
}