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//===-- SpecialCaseList.cpp - special case list for sanitizers ------------===//
//
// 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 a utility class for instrumentation passes (like AddressSanitizer
// or ThreadSanitizer) to avoid instrumenting some functions or global
// variables, or to instrument some functions or global variables in a specific
// way, based on a user-supplied list.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/SpecialCaseList.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Regex.h"
#include "llvm/Support/VirtualFileSystem.h"
#include <string>
#include <system_error>
#include <utility>
#include <stdio.h>
namespace llvm {
bool SpecialCaseList::Matcher::insert(std::string Regexp,
unsigned LineNumber,
std::string &REError) {
if (Regexp.empty()) {
REError = "Supplied regexp was blank";
return false;
}
if (Regex::isLiteralERE(Regexp)) {
Strings[Regexp] = LineNumber;
return true;
}
Trigrams.insert(Regexp);
// Replace * with .*
for (size_t pos = 0; (pos = Regexp.find('*', pos)) != std::string::npos;
pos += strlen(".*")) {
Regexp.replace(pos, strlen("*"), ".*");
}
Regexp = (Twine("^(") + StringRef(Regexp) + ")$").str();
// Check that the regexp is valid.
Regex CheckRE(Regexp);
if (!CheckRE.isValid(REError))
return false;
RegExes.emplace_back(
std::make_pair(std::make_unique<Regex>(std::move(CheckRE)), LineNumber));
return true;
}
unsigned SpecialCaseList::Matcher::match(StringRef Query) const {
auto It = Strings.find(Query);
if (It != Strings.end())
return It->second;
if (Trigrams.isDefinitelyOut(Query))
return false;
for (const auto &RegExKV : RegExes)
if (RegExKV.first->match(Query))
return RegExKV.second;
return 0;
}
std::unique_ptr<SpecialCaseList>
SpecialCaseList::create(const std::vector<std::string> &Paths,
llvm::vfs::FileSystem &FS, std::string &Error) {
std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList());
if (SCL->createInternal(Paths, FS, Error))
return SCL;
return nullptr;
}
std::unique_ptr<SpecialCaseList> SpecialCaseList::create(const MemoryBuffer *MB,
std::string &Error) {
std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList());
if (SCL->createInternal(MB, Error))
return SCL;
return nullptr;
}
std::unique_ptr<SpecialCaseList>
SpecialCaseList::createOrDie(const std::vector<std::string> &Paths,
llvm::vfs::FileSystem &FS) {
std::string Error;
if (auto SCL = create(Paths, FS, Error))
return SCL;
report_fatal_error(Twine(Error));
}
bool SpecialCaseList::createInternal(const std::vector<std::string> &Paths,
vfs::FileSystem &VFS, std::string &Error) {
StringMap<size_t> Sections;
for (const auto &Path : Paths) {
ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
VFS.getBufferForFile(Path);
if (std::error_code EC = FileOrErr.getError()) {
Error = (Twine("can't open file '") + Path + "': " + EC.message()).str();
return false;
}
std::string ParseError;
if (!parse(FileOrErr.get().get(), Sections, ParseError)) {
Error = (Twine("error parsing file '") + Path + "': " + ParseError).str();
return false;
}
}
return true;
}
bool SpecialCaseList::createInternal(const MemoryBuffer *MB,
std::string &Error) {
StringMap<size_t> Sections;
if (!parse(MB, Sections, Error))
return false;
return true;
}
bool SpecialCaseList::parse(const MemoryBuffer *MB,
StringMap<size_t> &SectionsMap,
std::string &Error) {
// Iterate through each line in the exclusion list file.
SmallVector<StringRef, 16> Lines;
MB->getBuffer().split(Lines, '\n');
unsigned LineNo = 1;
StringRef Section = "*";
for (auto I = Lines.begin(), E = Lines.end(); I != E; ++I, ++LineNo) {
*I = I->trim();
// Ignore empty lines and lines starting with "#"
if (I->empty() || I->startswith("#"))
continue;
// Save section names
if (I->startswith("[")) {
if (!I->endswith("]")) {
Error = (Twine("malformed section header on line ") + Twine(LineNo) +
": " + *I).str();
return false;
}
Section = I->slice(1, I->size() - 1);
std::string REError;
Regex CheckRE(Section);
if (!CheckRE.isValid(REError)) {
Error =
(Twine("malformed regex for section ") + Section + ": '" + REError)
.str();
return false;
}
continue;
}
// Get our prefix and unparsed regexp.
std::pair<StringRef, StringRef> SplitLine = I->split(":");
StringRef Prefix = SplitLine.first;
if (SplitLine.second.empty()) {
// Missing ':' in the line.
Error = (Twine("malformed line ") + Twine(LineNo) + ": '" +
SplitLine.first + "'").str();
return false;
}
std::pair<StringRef, StringRef> SplitRegexp = SplitLine.second.split("=");
std::string Regexp = std::string(SplitRegexp.first);
StringRef Category = SplitRegexp.second;
// Create this section if it has not been seen before.
if (SectionsMap.find(Section) == SectionsMap.end()) {
std::unique_ptr<Matcher> M = std::make_unique<Matcher>();
std::string REError;
if (!M->insert(std::string(Section), LineNo, REError)) {
Error = (Twine("malformed section ") + Section + ": '" + REError).str();
return false;
}
SectionsMap[Section] = Sections.size();
Sections.emplace_back(std::move(M));
}
auto &Entry = Sections[SectionsMap[Section]].Entries[Prefix][Category];
std::string REError;
if (!Entry.insert(std::move(Regexp), LineNo, REError)) {
Error = (Twine("malformed regex in line ") + Twine(LineNo) + ": '" +
SplitLine.second + "': " + REError).str();
return false;
}
}
return true;
}
SpecialCaseList::~SpecialCaseList() {}
bool SpecialCaseList::inSection(StringRef Section, StringRef Prefix,
StringRef Query, StringRef Category) const {
return inSectionBlame(Section, Prefix, Query, Category);
}
unsigned SpecialCaseList::inSectionBlame(StringRef Section, StringRef Prefix,
StringRef Query,
StringRef Category) const {
for (const auto &SectionIter : Sections)
if (SectionIter.SectionMatcher->match(Section)) {
unsigned Blame =
inSectionBlame(SectionIter.Entries, Prefix, Query, Category);
if (Blame)
return Blame;
}
return 0;
}
unsigned SpecialCaseList::inSectionBlame(const SectionEntries &Entries,
StringRef Prefix, StringRef Query,
StringRef Category) const {
SectionEntries::const_iterator I = Entries.find(Prefix);
if (I == Entries.end()) return 0;
StringMap<Matcher>::const_iterator II = I->second.find(Category);
if (II == I->second.end()) return 0;
return II->getValue().match(Query);
}
} // namespace llvm