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//=======- CaptureTrackingTest.cpp - Unit test for the Capture Tracking ---===//
//
// 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/CaptureTracking.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
using namespace llvm;
TEST(CaptureTracking, MaxUsesToExplore) {
StringRef Assembly = R"(
; Function Attrs: nounwind ssp uwtable
declare void @doesnt_capture(i8* nocapture, i8* nocapture, i8* nocapture,
i8* nocapture, i8* nocapture)
; %arg has 5 uses
define void @test_few_uses(i8* %arg) {
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
ret void
}
; %arg has 50 uses
define void @test_many_uses(i8* %arg) {
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
call void @doesnt_capture(i8* %arg, i8* %arg, i8* %arg, i8* %arg, i8* %arg)
ret void
}
)";
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(Assembly, Error, Context);
ASSERT_TRUE(M) << "Bad assembly?";
auto Test = [&M](const char *FName, unsigned FalseMaxUsesLimit,
unsigned TrueMaxUsesLimit) {
Function *F = M->getFunction(FName);
ASSERT_NE(F, nullptr);
Value *Arg = &*F->arg_begin();
ASSERT_NE(Arg, nullptr);
ASSERT_FALSE(PointerMayBeCaptured(Arg, true, FalseMaxUsesLimit));
ASSERT_TRUE(PointerMayBeCaptured(Arg, true, TrueMaxUsesLimit));
BasicBlock *EntryBB = &F->getEntryBlock();
DominatorTree DT(*F);
Instruction *Ret = EntryBB->getTerminator();
ASSERT_TRUE(isa<ReturnInst>(Ret));
ASSERT_FALSE(PointerMayBeCapturedBefore(Arg, true, Ret, &DT, false,
FalseMaxUsesLimit));
ASSERT_TRUE(PointerMayBeCapturedBefore(Arg, true, Ret, &DT, false,
TrueMaxUsesLimit));
};
Test("test_few_uses", 6, 4);
Test("test_many_uses", 50, 30);
}
struct CollectingCaptureTracker : public CaptureTracker {
SmallVector<const Use *, 4> Captures;
void tooManyUses() override { }
Action captured(const Use *U, UseCaptureInfo CI) override {
Captures.push_back(U);
return Continue;
}
};
TEST(CaptureTracking, MultipleUsesInSameInstruction) {
StringRef Assembly = R"(
declare void @call(i8*, i8*, i8*)
define void @test(i8* %arg, i8** %ptr) {
call void @call(i8* %arg, i8* nocapture %arg, i8* %arg) [ "bundle"(i8* %arg) ]
cmpxchg i8** %ptr, i8* %arg, i8* %arg acq_rel monotonic
icmp eq i8* %arg, %arg
ret void
}
)";
LLVMContext Context;
SMDiagnostic Error;
auto M = parseAssemblyString(Assembly, Error, Context);
ASSERT_TRUE(M) << "Bad assembly?";
Function *F = M->getFunction("test");
Value *Arg = &*F->arg_begin();
BasicBlock *BB = &F->getEntryBlock();
Instruction *Call = &*BB->begin();
Instruction *CmpXChg = Call->getNextNode();
Instruction *ICmp = CmpXChg->getNextNode();
CollectingCaptureTracker CT;
PointerMayBeCaptured(Arg, &CT);
EXPECT_EQ(7u, CT.Captures.size());
// Call arg 1
EXPECT_EQ(Call, CT.Captures[0]->getUser());
EXPECT_EQ(0u, CT.Captures[0]->getOperandNo());
// Call arg 3
EXPECT_EQ(Call, CT.Captures[1]->getUser());
EXPECT_EQ(2u, CT.Captures[1]->getOperandNo());
// Operand bundle arg
EXPECT_EQ(Call, CT.Captures[2]->getUser());
EXPECT_EQ(3u, CT.Captures[2]->getOperandNo());
// Cmpxchg compare operand
EXPECT_EQ(CmpXChg, CT.Captures[3]->getUser());
EXPECT_EQ(1u, CT.Captures[3]->getOperandNo());
// Cmpxchg new value operand
EXPECT_EQ(CmpXChg, CT.Captures[4]->getUser());
EXPECT_EQ(2u, CT.Captures[4]->getOperandNo());
// ICmp first operand
EXPECT_EQ(ICmp, CT.Captures[5]->getUser());
EXPECT_EQ(0u, CT.Captures[5]->getOperandNo());
// ICmp second operand
EXPECT_EQ(ICmp, CT.Captures[6]->getUser());
EXPECT_EQ(1u, CT.Captures[6]->getOperandNo());
}
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