forked from OSchip/llvm-project
Added Delta IR Reduction Tool
Summary: Tool parses input IR file, and runs the delta debugging algorithm to reduce the functions inside the input file. Reviewers: alexshap, chandlerc Subscribers: mgorny, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D63672 > llvm-svn: 368071 llvm-svn: 368214
This commit is contained in:
Diego Trevino Ferrer
parent
e0eed65e06
commit
b80c4c82d6
|
|
@ -0,0 +1,105 @@
|
|||
# Bugpoint Redesign
|
||||
Author: Diego Treviño (diegotf@google.com)
|
||||
|
||||
Date: 2019-06-05
|
||||
|
||||
Status: Draft
|
||||
|
||||
|
||||
## Introduction
|
||||
As use of bugpoint has grown several areas of improvement have been identified
|
||||
through years of use: confusing to use, slow, it doesn’t always produce high
|
||||
quality test cases, etc. This document proposes a new approach with a narrower
|
||||
focus: minimization of IR test cases.
|
||||
|
||||
|
||||
## Proposed New Design
|
||||
|
||||
|
||||
### Narrow focus: test-case reduction
|
||||
The main focus will be a code reduction strategy to obtain much smaller test
|
||||
cases that still have the same property as the original one. This will be done
|
||||
via classic delta debugging and by adding some IR-specific reductions (e.g.
|
||||
replacing globals, removing unused instructions, etc), similar to what
|
||||
already exists, but with more in-depth minimization.
|
||||
|
||||
|
||||
Granted, if the community differs on this proposal, the legacy code could still
|
||||
be present in the tool, but with the caveat of still being documented and
|
||||
designed towards delta reduction.
|
||||
|
||||
|
||||
### Command-Line Options
|
||||
We are proposing to reduce the plethora of bugpoint’s options to just two: an
|
||||
interesting-ness test and the arguments for said test, similar to other delta
|
||||
reduction tools such as CReduce, Delta, and Lithium; the tool should feel less
|
||||
cluttered, and there should also be no uncertainty about how to operate it.
|
||||
|
||||
|
||||
The interesting-ness test that’s going to be run to reduce the code is given
|
||||
by name:
|
||||
`--test=<test_name>`
|
||||
If a `--test` option is not given, the program exits; this option is similar
|
||||
to bugpoint’s current `-compile-custom` option, which lets the user run a
|
||||
custom script.
|
||||
|
||||
|
||||
The interesting-ness test would be defined as a script that returns 0 when the
|
||||
IR achieves a user-defined behaviour (e.g. failure to compile on clang) and a
|
||||
nonzero value when otherwise. Leaving the user the freedom to determine what is
|
||||
and isn’t interesting to the tool, and thus, streamlining the process of
|
||||
reducing a test-case.
|
||||
|
||||
|
||||
If the test accepts any arguments (excluding the input ll/bc file), they are
|
||||
given via the following flag:
|
||||
`--test_args=<test_arguments>`
|
||||
If unspecified, the test is run as given. It’s worth noting that the input file
|
||||
would be passed as a parameter to the test, similar how `-compile-custom`
|
||||
currently operates.
|
||||
|
||||
|
||||
### Implementation
|
||||
The tool would behave similar to CReduce’s functionality in that it would have a
|
||||
list of passes that try to minimize the given test-case. We should be able to
|
||||
modularize the tool’s behavior, as well as making it easier to maintain and
|
||||
expand.
|
||||
|
||||
|
||||
The first version of this redesign would try to:
|
||||
|
||||
|
||||
* Discard functions, instructions and metadata that don’t influence the
|
||||
interesting-ness test
|
||||
* Remove unused parameters from functions
|
||||
* Eliminate unvisited conditional paths
|
||||
* Rename variables to more regular ones (such as “a”, “b”, “c”, etc.)
|
||||
|
||||
|
||||
Once these passes are implemented, more meaningful reductions (such as type
|
||||
reduction) would be added to the tool, to even further reduce IR.
|
||||
|
||||
|
||||
## Background on historical bugpoint issues
|
||||
|
||||
|
||||
### Root Cause Analysis
|
||||
Presently, bugpoint takes a long time to find the source problem in a given IR
|
||||
file, mainly due to the fact that it tries to debug the input by running
|
||||
various strategies to classify the bug, which in turn run multiple optimizer
|
||||
and compilation passes over the input, taking up a lot of time. Furthermore,
|
||||
when the IR crashes, it tries to reduce it by performing some sub-optimal
|
||||
passes (e.g. a lot of unreachable blocks), and sometimes even fails to minimize
|
||||
at all.
|
||||
|
||||
|
||||
### "Quirky" Interface
|
||||
Bugpoint’s current interface overwhelms and confuses the user, the help screen
|
||||
alone ends up confusing rather providing guidance, as seen below:
|
||||
|
||||
|
||||
|
||||
And, not only are there numerous features and options, but some of them also
|
||||
work in unexpected ways and most of the time the user ends up using a custom
|
||||
script. Pruning and simplifying the interface will be worth considering in
|
||||
order to make the tool more useful in the general case and easier to maintain.
|
||||
|
|
@ -0,0 +1,10 @@
|
|||
#!/bin/sh
|
||||
set -e
|
||||
|
||||
matches=$(cat $1 | grep "@interesting" | wc -l)
|
||||
|
||||
if [[ $matches > 0 ]]; then
|
||||
exit 0
|
||||
else
|
||||
exit 1
|
||||
fi
|
||||
|
|
@ -0,0 +1,34 @@
|
|||
; Test that llvm-reduce can remove uninteresting functions as well as
|
||||
; their InstCalls.
|
||||
;
|
||||
; RUN: llvm-reduce --test %p/Inputs/remove-funcs.sh %s
|
||||
; RUN: cat reduced.ll | FileCheck %s
|
||||
; REQUIRES: plugins, shell
|
||||
|
||||
; CHECK-NOT: uninteresting1()
|
||||
define i32 @uninteresting1() {
|
||||
entry:
|
||||
ret i32 0
|
||||
}
|
||||
|
||||
; CHECK: interesting()
|
||||
define i32 @interesting() {
|
||||
entry:
|
||||
; CHECK: call i32 @interesting()
|
||||
%call2 = call i32 @interesting()
|
||||
; CHECK-NOT: call i32 @uninteresting1()
|
||||
%call = call i32 @uninteresting1()
|
||||
ret i32 5
|
||||
}
|
||||
|
||||
; CHECK-NOT: uninteresting2()
|
||||
define i32 @uninteresting2() {
|
||||
entry:
|
||||
ret i32 0
|
||||
}
|
||||
|
||||
; CHECK-NOT: uninteresting3()
|
||||
define i32 @uninteresting3() {
|
||||
entry:
|
||||
ret i32 10
|
||||
}
|
||||
|
|
@ -48,6 +48,7 @@ subdirectories =
|
|||
llvm-pdbutil
|
||||
llvm-profdata
|
||||
llvm-rc
|
||||
llvm-reduce
|
||||
llvm-rtdyld
|
||||
llvm-size
|
||||
llvm-split
|
||||
|
|
|
|||
|
|
@ -0,0 +1,24 @@
|
|||
set(LLVM_LINK_COMPONENTS
|
||||
AllTargetsAsmParsers
|
||||
AllTargetsCodeGens
|
||||
AllTargetsDescs
|
||||
AllTargetsInfos
|
||||
IRReader
|
||||
Support
|
||||
Target
|
||||
TransformUtils
|
||||
)
|
||||
|
||||
# Support plugins.
|
||||
set(LLVM_NO_DEAD_STRIP 1)
|
||||
|
||||
add_llvm_tool(llvm-reduce
|
||||
llvm-reduce.cpp
|
||||
TestRunner.cpp
|
||||
deltas/Delta.cpp
|
||||
deltas/ReduceFunctions.cpp
|
||||
|
||||
DEPENDS
|
||||
intrinsics_gen
|
||||
)
|
||||
export_executable_symbols(llvm-reduce)
|
||||
|
|
@ -0,0 +1,25 @@
|
|||
//===- DeltaManager.h - Runs Delta Passes to reduce Input -----------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This file calls each specialized Delta pass in order to reduce the input IR
|
||||
// file.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "TestRunner.h"
|
||||
#include "deltas/Delta.h"
|
||||
#include "deltas/ReduceFunctions.h"
|
||||
|
||||
namespace llvm {
|
||||
|
||||
inline void runDeltaPasses(TestRunner &Tester) {
|
||||
reduceFunctionsDeltaPass(Tester);
|
||||
// TODO: Implement the remaining Delta Passes
|
||||
}
|
||||
|
||||
} // namespace llvm
|
||||
|
|
@ -0,0 +1,24 @@
|
|||
;===- ./tools/llvm-reduce/LLVMBuild.txt ------------------------*- Conf -*--===;
|
||||
;
|
||||
; 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
|
||||
;
|
||||
;===------------------------------------------------------------------------===;
|
||||
;
|
||||
; This is an LLVMBuild description file for the components in this subdirectory.
|
||||
;
|
||||
; For more information on the LLVMBuild system, please see:
|
||||
;
|
||||
; http://llvm.org/docs/LLVMBuild.html
|
||||
;
|
||||
;===------------------------------------------------------------------------===;
|
||||
|
||||
[component_0]
|
||||
type = Tool
|
||||
name = llvm-reduce
|
||||
parent = Tools
|
||||
required_libraries =
|
||||
BitReader
|
||||
IRReader
|
||||
all-targets
|
||||
|
|
@ -0,0 +1,60 @@
|
|||
//===-- TestRunner.cpp ----------------------------------------------------===//
|
||||
//
|
||||
// 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 "TestRunner.h"
|
||||
#include <utility>
|
||||
|
||||
using namespace llvm;
|
||||
|
||||
/// Gets Current Working Directory and tries to create a Tmp Directory
|
||||
static SmallString<128> initializeTmpDirectory() {
|
||||
SmallString<128> CWD;
|
||||
if (std::error_code EC = sys::fs::current_path(CWD)) {
|
||||
errs() << "Error getting current directory: " << EC.message() << "!\n";
|
||||
exit(1);
|
||||
}
|
||||
|
||||
SmallString<128> TmpDirectory;
|
||||
sys::path::append(TmpDirectory, CWD, "tmp");
|
||||
if (std::error_code EC = sys::fs::create_directory(TmpDirectory))
|
||||
errs() << "Error creating tmp directory: " << EC.message() << "!\n";
|
||||
|
||||
return TmpDirectory;
|
||||
}
|
||||
|
||||
TestRunner::TestRunner(StringRef TestName, std::vector<std::string> TestArgs,
|
||||
StringRef ReducedFilepath)
|
||||
: TestName(TestName), TestArgs(std::move(TestArgs)),
|
||||
ReducedFilepath(ReducedFilepath) {
|
||||
TmpDirectory = initializeTmpDirectory();
|
||||
}
|
||||
|
||||
/// Runs the interestingness test, passes file to be tested as first argument
|
||||
/// and other specified test arguments after that.
|
||||
int TestRunner::run(StringRef Filename) {
|
||||
std::vector<StringRef> ProgramArgs;
|
||||
ProgramArgs.push_back(TestName);
|
||||
ProgramArgs.push_back(Filename);
|
||||
|
||||
for (auto Arg : TestArgs)
|
||||
ProgramArgs.push_back(Arg.c_str());
|
||||
for (unsigned I = 0, E = ProgramArgs.size(); I != E; ++I)
|
||||
outs() << ProgramArgs[I] << "\n";
|
||||
StringRef SR = "";
|
||||
Optional<StringRef> Redirects[3] = {SR, SR, SR}; // STDIN, STDOUT, STDERR
|
||||
int Result = sys::ExecuteAndWait(TestName, ProgramArgs, None, Redirects);
|
||||
|
||||
if (Result < 0) {
|
||||
Error E = make_error<StringError>("Error running interesting-ness test\n",
|
||||
inconvertibleErrorCode());
|
||||
outs() << toString(std::move(E));
|
||||
exit(1);
|
||||
}
|
||||
|
||||
return !Result;
|
||||
}
|
||||
|
|
@ -0,0 +1,56 @@
|
|||
//===-- tools/llvm-reduce/TestRunner.h ---------------------------*- C++ -*-===/
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#ifndef LLVM_TOOLS_LLVMREDUCE_TESTRUNNER_H
|
||||
#define LLVM_TOOLS_LLVMREDUCE_TESTRUNNER_H
|
||||
|
||||
#include "llvm/ADT/SmallString.h"
|
||||
#include "llvm/IR/Module.h"
|
||||
#include "llvm/Support/Error.h"
|
||||
#include "llvm/Support/FileSystem.h"
|
||||
#include "llvm/Support/Path.h"
|
||||
#include "llvm/Support/Program.h"
|
||||
#include <vector>
|
||||
|
||||
namespace llvm {
|
||||
|
||||
// This class contains all the info necessary for running the provided
|
||||
// interesting-ness test, as well as the most reduced module and its
|
||||
// respective filename.
|
||||
class TestRunner {
|
||||
public:
|
||||
TestRunner(StringRef TestName, std::vector<std::string> TestArgs,
|
||||
StringRef ReducedFilepath);
|
||||
|
||||
/// Runs the interesting-ness test for the specified file
|
||||
/// @returns 0 if test was successful, 1 if otherwise
|
||||
int run(StringRef Filename);
|
||||
|
||||
/// Filename to the most reduced testcase
|
||||
StringRef getReducedFilepath() const { return ReducedFilepath; }
|
||||
/// Directory where tmp files are created
|
||||
StringRef getTmpDir() const { return TmpDirectory; }
|
||||
/// Returns the most reduced version of the original testcase
|
||||
Module *getProgram() const { return Program.get(); }
|
||||
|
||||
void setReducedFilepath(SmallString<128> F) {
|
||||
ReducedFilepath = std::move(F);
|
||||
}
|
||||
void setProgram(std::unique_ptr<Module> P) { Program = std::move(P); }
|
||||
|
||||
private:
|
||||
SmallString<128> TestName;
|
||||
std::vector<std::string> TestArgs;
|
||||
SmallString<128> ReducedFilepath;
|
||||
SmallString<128> TmpDirectory;
|
||||
std::unique_ptr<Module> Program;
|
||||
};
|
||||
|
||||
} // namespace llvm
|
||||
|
||||
#endif
|
||||
|
|
@ -0,0 +1,203 @@
|
|||
//===- Delta.cpp - Delta Debugging Algorithm Implementation ---------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This file contains the implementation for the Delta Debugging Algorithm:
|
||||
// it splits a given set of Targets (i.e. Functions, Instructions, BBs, etc.)
|
||||
// into chunks and tries to reduce the number chunks that are interesting.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "Delta.h"
|
||||
#include "llvm/Transforms/Utils/Cloning.h"
|
||||
|
||||
/// Writes IR code to the given Filepath
|
||||
static bool writeProgramToFile(StringRef Filepath, int FD, const Module &M) {
|
||||
ToolOutputFile Out(Filepath, FD);
|
||||
M.print(Out.os(), /*AnnotationWriter=*/nullptr);
|
||||
Out.os().close();
|
||||
|
||||
if (!Out.os().has_error()) {
|
||||
Out.keep();
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
/// Creates a temporary (and unique) file inside the tmp folder and writes
|
||||
/// the given module IR.
|
||||
static SmallString<128> createTmpFile(Module *M, StringRef TmpDir) {
|
||||
SmallString<128> UniqueFilepath;
|
||||
int UniqueFD;
|
||||
|
||||
std::error_code EC = sys::fs::createUniqueFile(TmpDir + "/tmp-%%%.ll",
|
||||
UniqueFD, UniqueFilepath);
|
||||
if (EC) {
|
||||
errs() << "Error making unique filename: " << EC.message() << "!\n";
|
||||
exit(1);
|
||||
}
|
||||
|
||||
if (writeProgramToFile(UniqueFilepath, UniqueFD, *M)) {
|
||||
errs() << "Error emitting bitcode to file '" << UniqueFilepath << "'!\n";
|
||||
exit(1);
|
||||
}
|
||||
return UniqueFilepath;
|
||||
}
|
||||
|
||||
/// Prints the Chunk Indexes with the following format: [start, end], if
|
||||
/// chunk is at minimum size (1), then it just displays [start].
|
||||
static void printChunks(std::vector<Chunk> Chunks, bool Oneline = false) {
|
||||
if (Chunks.empty()) {
|
||||
outs() << "No Chunks";
|
||||
return;
|
||||
}
|
||||
|
||||
for (auto C : Chunks) {
|
||||
if (!Oneline)
|
||||
outs() << '\t';
|
||||
C.print();
|
||||
if (!Oneline)
|
||||
outs() << '\n';
|
||||
}
|
||||
}
|
||||
|
||||
/// Counts the amount of lines for a given file
|
||||
static unsigned getLines(StringRef Filepath) {
|
||||
unsigned Lines = 0;
|
||||
std::string CurrLine;
|
||||
std::ifstream FileStream(Filepath);
|
||||
|
||||
while (std::getline(FileStream, CurrLine))
|
||||
++Lines;
|
||||
|
||||
return Lines;
|
||||
}
|
||||
|
||||
/// Splits Chunks in half and prints them.
|
||||
/// If unable to split (when chunk size is 1) returns false.
|
||||
static bool increaseGranularity(std::vector<Chunk> &Chunks) {
|
||||
outs() << "Increasing granularity...";
|
||||
std::vector<Chunk> NewChunks;
|
||||
bool SplitOne = false;
|
||||
|
||||
for (auto &C : Chunks) {
|
||||
if (C.end - C.begin == 0)
|
||||
NewChunks.push_back(C);
|
||||
else {
|
||||
unsigned Half = (C.begin + C.end) / 2;
|
||||
NewChunks.push_back({C.begin, Half});
|
||||
NewChunks.push_back({Half + 1, C.end});
|
||||
SplitOne = true;
|
||||
}
|
||||
}
|
||||
if (SplitOne) {
|
||||
Chunks = NewChunks;
|
||||
outs() << "Success! New Chunks:\n";
|
||||
printChunks(Chunks);
|
||||
}
|
||||
return SplitOne;
|
||||
}
|
||||
|
||||
bool llvm::runTestWithoutChunks(
|
||||
TestRunner &Test, std::function<void(const std::vector<Chunk> &, Module *)>
|
||||
ExtractChunksFromModule) {
|
||||
std::unique_ptr<Module> Clone = CloneModule(*Test.getProgram());
|
||||
|
||||
// Generate Module with only Targets inside Current Chunks
|
||||
ExtractChunksFromModule({}, Clone.get());
|
||||
// Write Module to tmp file
|
||||
SmallString<128> CurrentFilepath =
|
||||
createTmpFile(Clone.get(), Test.getTmpDir());
|
||||
outs() << " | " << sys::path::filename(CurrentFilepath);
|
||||
|
||||
// Completely reduced Program isn't interesting
|
||||
if (!Test.run(CurrentFilepath))
|
||||
return false;
|
||||
|
||||
// Hooray! We reduced the testcase completely
|
||||
Test.setReducedFilepath(CurrentFilepath);
|
||||
Test.setProgram(std::move(Clone));
|
||||
return true;
|
||||
}
|
||||
|
||||
/// Runs the Delta Debugging algorithm, splits the code into chunks and
|
||||
/// reduces the amount of chunks that are considered interesting by the
|
||||
/// given test.
|
||||
void llvm::runDeltaPass(
|
||||
TestRunner &Test, unsigned Targets,
|
||||
std::function<void(const std::vector<Chunk> &, Module *)>
|
||||
ExtractChunksFromModule) {
|
||||
if (!Targets)
|
||||
return;
|
||||
|
||||
std::vector<Chunk> Chunks = {{1, Targets}};
|
||||
std::set<Chunk> UninterestingChunks;
|
||||
std::unique_ptr<Module> ReducedProgram;
|
||||
|
||||
if (!Test.run(Test.getReducedFilepath())) {
|
||||
outs() << "\nInput isn't interesting! Verify interesting-ness test\n";
|
||||
outs() << "----------------------------\n";
|
||||
return;
|
||||
}
|
||||
|
||||
if (!increaseGranularity(Chunks)) {
|
||||
outs() << "\nCan't reduce anymore\n";
|
||||
outs() << "----------------------------\n";
|
||||
return;
|
||||
}
|
||||
|
||||
do {
|
||||
UninterestingChunks = {};
|
||||
for (int I = Chunks.size() - 1; I >= 0; --I) {
|
||||
std::vector<Chunk> CurrentChunks;
|
||||
|
||||
for (auto C : Chunks)
|
||||
if (!UninterestingChunks.count(C) && C != Chunks[I])
|
||||
CurrentChunks.push_back(C);
|
||||
|
||||
if (CurrentChunks.empty())
|
||||
continue;
|
||||
|
||||
// Clone module before hacking it up..
|
||||
std::unique_ptr<Module> CurrentProgram = CloneModule(*Test.getProgram());
|
||||
// Generate Module with only Targets inside Current Chunks
|
||||
ExtractChunksFromModule(CurrentChunks, CurrentProgram.get());
|
||||
// Write Module to tmp file
|
||||
SmallString<128> CurrentFilepath =
|
||||
createTmpFile(CurrentProgram.get(), Test.getTmpDir());
|
||||
|
||||
outs() << "Testing with: ";
|
||||
printChunks(CurrentChunks, /*Oneline=*/true);
|
||||
outs() << " | " << sys::path::filename(CurrentFilepath);
|
||||
|
||||
// Current Chunks aren't interesting
|
||||
if (!Test.run(CurrentFilepath)) {
|
||||
outs() << "\n";
|
||||
continue;
|
||||
}
|
||||
|
||||
UninterestingChunks.insert(Chunks[I]);
|
||||
Test.setReducedFilepath(CurrentFilepath);
|
||||
ReducedProgram = std::move(CurrentProgram);
|
||||
outs() << " **** SUCCESS | lines: " << getLines(CurrentFilepath) << "\n";
|
||||
}
|
||||
// Delete uninteresting chunks
|
||||
auto UnwantedChunks = Chunks.end();
|
||||
UnwantedChunks = std::remove_if(Chunks.begin(), Chunks.end(),
|
||||
[UninterestingChunks](const Chunk &C) {
|
||||
return UninterestingChunks.count(C);
|
||||
});
|
||||
Chunks.erase(UnwantedChunks, Chunks.end());
|
||||
|
||||
} while (!UninterestingChunks.empty() || increaseGranularity(Chunks));
|
||||
|
||||
// If we reduced the testcase replace it
|
||||
if (ReducedProgram)
|
||||
Test.setProgram(std::move(ReducedProgram));
|
||||
outs() << "Couldn't increase anymore.\n";
|
||||
outs() << "----------------------------\n";
|
||||
}
|
||||
|
|
@ -0,0 +1,89 @@
|
|||
//===- Delta.h - Delta Debugging Algorithm Implementation -----------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This file contains the implementation for the Delta Debugging Algorithm:
|
||||
// it splits a given set of Targets (i.e. Functions, Instructions, BBs, etc.)
|
||||
// into chunks and tries to reduce the number chunks that are interesting.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#ifndef LLVM_TOOLS_LLVMREDUCE_LLVMREDUCE_DELTA_H
|
||||
#define LLVM_TOOLS_LLVMREDUCE_LLVMREDUCE_DELTA_H
|
||||
|
||||
#include "../TestRunner.h"
|
||||
#include "llvm/IR/Verifier.h"
|
||||
#include "llvm/Support/FileSystem.h"
|
||||
#include "llvm/Support/Path.h"
|
||||
#include "llvm/Support/ScopedPrinter.h"
|
||||
#include "llvm/Support/ToolOutputFile.h"
|
||||
#include "llvm/Transforms/Utils/Cloning.h"
|
||||
#include <fstream>
|
||||
#include <set>
|
||||
#include <vector>
|
||||
|
||||
using namespace llvm;
|
||||
|
||||
struct Chunk {
|
||||
unsigned begin;
|
||||
unsigned end;
|
||||
|
||||
/// Helper function to verify if a given Target-index is inside the Chunk
|
||||
bool contains(unsigned Index) const { return Index >= begin && Index <= end; }
|
||||
|
||||
void print() const {
|
||||
outs() << "[" << begin;
|
||||
if (end - begin != 0)
|
||||
outs() << "," << end;
|
||||
outs() << "]";
|
||||
}
|
||||
|
||||
/// Operator when populating CurrentChunks in Generic Delta Pass
|
||||
friend bool operator!=(const Chunk &C1, const Chunk &C2) {
|
||||
return C1.begin != C2.begin || C1.end != C2.end;
|
||||
}
|
||||
|
||||
/// Operator used for sets
|
||||
friend bool operator<(const Chunk &C1, const Chunk &C2) {
|
||||
return std::tie(C1.begin, C1.end) < std::tie(C2.begin, C2.end);
|
||||
}
|
||||
};
|
||||
|
||||
namespace llvm {
|
||||
|
||||
/// This function implements the Delta Debugging algorithm, it receives a
|
||||
/// number of Targets (e.g. Functions, Instructions, Basic Blocks, etc.) and
|
||||
/// splits them in half; these chunks of targets are then tested while ignoring
|
||||
/// one chunk, if a chunk is proven to be uninteresting (i.e. fails the test)
|
||||
/// it is removed from consideration. The algorithm will attempt to split the
|
||||
/// Chunks in half and start the process again until it can't split chunks
|
||||
/// anymore.
|
||||
///
|
||||
/// This function is intended to be called by each specialized delta pass (e.g.
|
||||
/// RemoveFunctions) and receives three key parameters:
|
||||
/// * Test: The main TestRunner instance which is used to run the provided
|
||||
/// interesting-ness test, as well as to store and access the reduced Program.
|
||||
/// * Targets: The amount of Targets that are going to be reduced by the
|
||||
/// algorithm, for example, the RemoveGlobalVars pass would send the amount of
|
||||
/// initialized GVs.
|
||||
/// * ExtractChunksFromModule: A function used to tailor the main program so it
|
||||
/// only contains Targets that are inside Chunks of the given iteration.
|
||||
/// Note: This function is implemented by each specialized Delta pass
|
||||
///
|
||||
/// Other implementations of the Delta Debugging algorithm can also be found in
|
||||
/// the CReduce, Delta, and Lithium projects.
|
||||
void runDeltaPass(TestRunner &Test, unsigned Targets,
|
||||
std::function<void(const std::vector<Chunk> &, Module *)>
|
||||
ExtractChunksFromModule);
|
||||
|
||||
bool runTestWithoutChunks(
|
||||
TestRunner &Test, std::function<void(const std::vector<Chunk> &, Module *)>
|
||||
ExtractChunksFromModule);
|
||||
|
||||
} // namespace llvm
|
||||
|
||||
#endif
|
||||
|
|
@ -0,0 +1,80 @@
|
|||
//===- ReduceFunctions.cpp - Specialized Delta Pass -----------------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This file implements a function which calls the Generic Delta pass in order
|
||||
// to reduce functions (and any instruction that calls it) in the provided
|
||||
// Module.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "ReduceFunctions.h"
|
||||
|
||||
/// Removes all the Defined Functions (as well as their calls)
|
||||
/// that aren't inside any of the desired Chunks.
|
||||
/// @returns the Module stripped of out-of-chunk functions
|
||||
static void extractFunctionsFromModule(const std::vector<Chunk> &ChunksToKeep,
|
||||
Module *Program) {
|
||||
// Get functions inside desired chunks
|
||||
std::set<Function *> FuncsToKeep;
|
||||
unsigned I = 0, FunctionCount = 0;
|
||||
for (auto &F : *Program) {
|
||||
if (!F.isDeclaration() && I < ChunksToKeep.size()) {
|
||||
if (ChunksToKeep[I].contains(++FunctionCount))
|
||||
FuncsToKeep.insert(&F);
|
||||
if (FunctionCount == ChunksToKeep[I].end)
|
||||
++I;
|
||||
}
|
||||
}
|
||||
|
||||
// Delete out-of-chunk functions, and replace their calls with undef
|
||||
std::vector<Function *> FuncsToRemove;
|
||||
for (auto &F : *Program) {
|
||||
if (!F.isDeclaration() && !FuncsToKeep.count(&F)) {
|
||||
F.replaceAllUsesWith(UndefValue::get(F.getType()));
|
||||
FuncsToRemove.push_back(&F);
|
||||
}
|
||||
}
|
||||
for (auto *F : FuncsToRemove)
|
||||
F->eraseFromParent();
|
||||
|
||||
// Delete instructions with undef calls
|
||||
std::vector<Instruction *> InstToRemove;
|
||||
for (auto &F : *Program)
|
||||
for (auto &BB : F)
|
||||
for (auto &I : BB)
|
||||
if (auto *Call = dyn_cast<CallInst>(&I))
|
||||
if (!Call->getCalledFunction()) {
|
||||
// Instruction might be stored / used somewhere else
|
||||
I.replaceAllUsesWith(UndefValue::get(I.getType()));
|
||||
InstToRemove.push_back(&I);
|
||||
}
|
||||
|
||||
for (auto *I : InstToRemove)
|
||||
I->eraseFromParent();
|
||||
}
|
||||
|
||||
/// Counts the amount of non-declaration functions and prints their
|
||||
/// respective name & index
|
||||
static unsigned countDefinedFunctions(Module *Program) {
|
||||
// TODO: Silence index with --quiet flag
|
||||
outs() << "----------------------------\n";
|
||||
outs() << "Function Index Reference:\n";
|
||||
unsigned FunctionCount = 0;
|
||||
for (auto &F : *Program)
|
||||
if (!F.isDeclaration())
|
||||
outs() << "\t" << ++FunctionCount << ": " << F.getName() << "\n";
|
||||
|
||||
outs() << "----------------------------\n";
|
||||
return FunctionCount;
|
||||
}
|
||||
|
||||
void llvm::reduceFunctionsDeltaPass(TestRunner &Test) {
|
||||
outs() << "*** Reducing Functions...\n";
|
||||
unsigned Functions = countDefinedFunctions(Test.getProgram());
|
||||
runDeltaPass(Test, Functions, extractFunctionsFromModule);
|
||||
}
|
||||
|
|
@ -0,0 +1,20 @@
|
|||
//===- ReduceFunctions.h - Specialized Delta Pass -------------------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This file implements a function which calls the Generic Delta pass in order
|
||||
// to reduce functions (and any instruction that calls it) in the provided
|
||||
// Module.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "Delta.h"
|
||||
#include "llvm/Transforms/Utils/Cloning.h"
|
||||
|
||||
namespace llvm {
|
||||
void reduceFunctionsDeltaPass(TestRunner &Test);
|
||||
} // namespace llvm
|
||||
|
|
@ -0,0 +1,105 @@
|
|||
//===- llvm-reduce.cpp - The LLVM Delta Reduction utility -----------------===//
|
||||
//
|
||||
// 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
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
//
|
||||
// This program tries to reduce an IR test case for a given interesting-ness
|
||||
// test. It runs multiple delta debugging passes in order to minimize the input
|
||||
// file. It's worth noting that this is a *temporary* tool that will eventually
|
||||
// be integrated into the bugpoint tool itself.
|
||||
//
|
||||
//===----------------------------------------------------------------------===//
|
||||
|
||||
#include "DeltaManager.h"
|
||||
#include "llvm/ADT/SmallString.h"
|
||||
#include "llvm/IR/LLVMContext.h"
|
||||
#include "llvm/IR/Verifier.h"
|
||||
#include "llvm/IRReader/IRReader.h"
|
||||
#include "llvm/Support/CommandLine.h"
|
||||
#include "llvm/Support/InitLLVM.h"
|
||||
#include "llvm/Support/SourceMgr.h"
|
||||
#include "llvm/Support/raw_ostream.h"
|
||||
#include <system_error>
|
||||
#include <vector>
|
||||
|
||||
using namespace llvm;
|
||||
|
||||
static cl::opt<bool> Help("h", cl::desc("Alias for -help"), cl::Hidden);
|
||||
static cl::opt<bool> Version("v", cl::desc("Alias for -version"), cl::Hidden);
|
||||
|
||||
static cl::opt<std::string> InputFilename(cl::Positional, cl::Required,
|
||||
cl::desc("<input llvm ll/bc file>"));
|
||||
|
||||
static cl::opt<std::string>
|
||||
TestFilename("test", cl::Required,
|
||||
cl::desc("Name of the interesting-ness test to be run"));
|
||||
|
||||
static cl::list<std::string>
|
||||
TestArguments("test-arg", cl::ZeroOrMore,
|
||||
cl::desc("Arguments passed onto the interesting-ness test"));
|
||||
|
||||
static cl::opt<std::string>
|
||||
OutputFilename("output",
|
||||
cl::desc("Specify the output file. default: reduced.ll"));
|
||||
static cl::alias OutputFileAlias("o", cl::desc("Alias for -output"),
|
||||
cl::aliasopt(OutputFilename));
|
||||
|
||||
static cl::opt<bool>
|
||||
ReplaceInput("in-place",
|
||||
cl::desc("WARNING: This option will replace your input file"
|
||||
"with the reduced version!"));
|
||||
|
||||
// Parses IR into a Module and verifies it
|
||||
static std::unique_ptr<Module> parseInputFile(StringRef Filename,
|
||||
LLVMContext &Ctxt) {
|
||||
SMDiagnostic Err;
|
||||
std::unique_ptr<Module> Result = parseIRFile(Filename, Err, Ctxt);
|
||||
if (!Result) {
|
||||
Err.print("llvm-reduce", errs());
|
||||
return Result;
|
||||
}
|
||||
|
||||
if (verifyModule(*Result, &errs())) {
|
||||
errs() << "Error: " << Filename << " - input module is broken!\n";
|
||||
return std::unique_ptr<Module>();
|
||||
}
|
||||
|
||||
return Result;
|
||||
}
|
||||
|
||||
int main(int argc, char **argv) {
|
||||
InitLLVM X(argc, argv);
|
||||
|
||||
cl::ParseCommandLineOptions(argc, argv, "LLVM automatic testcase reducer.\n");
|
||||
|
||||
LLVMContext Context;
|
||||
std::unique_ptr<Module> OriginalProgram =
|
||||
parseInputFile(InputFilename, Context);
|
||||
|
||||
// Initialize test environment
|
||||
TestRunner Tester(TestFilename, TestArguments, InputFilename);
|
||||
Tester.setProgram(std::move(OriginalProgram));
|
||||
|
||||
// Try to reduce code
|
||||
runDeltaPasses(Tester);
|
||||
StringRef ReducedFilename = sys::path::filename(Tester.getReducedFilepath());
|
||||
|
||||
if (ReducedFilename == InputFilename) {
|
||||
outs() << "\nCouldnt reduce input :/\n";
|
||||
} else {
|
||||
if (ReplaceInput) // In-place
|
||||
OutputFilename = InputFilename.c_str();
|
||||
else if (OutputFilename.empty())
|
||||
OutputFilename = "reduced.ll";
|
||||
else
|
||||
OutputFilename += ".ll";
|
||||
|
||||
sys::fs::copy_file(Tester.getReducedFilepath(), OutputFilename);
|
||||
outs() << "\nDone reducing! Reduced IR to file: " << OutputFilename << "\n";
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
Loading…
Reference in New Issue