llvm/lib/Support/SpecialCaseList.cpp

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//===-- SpecialCaseList.cpp - special case list for sanitizers ------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// 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/ADT/StringSet.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/Regex.h"
#include <string>
#include <system_error>
#include <utility>
namespace llvm {
/// Represents a set of regular expressions. Regular expressions which are
/// "literal" (i.e. no regex metacharacters) are stored in Strings, while all
/// others are represented as a single pipe-separated regex in RegEx. The
/// reason for doing so is efficiency; StringSet is much faster at matching
/// literal strings than Regex.
struct SpecialCaseList::Entry {
Entry() {}
Entry(Entry &&Other)
: Strings(std::move(Other.Strings)), RegEx(std::move(Other.RegEx)) {}
StringSet<> Strings;
std::unique_ptr<Regex> RegEx;
bool match(StringRef Query) const {
return Strings.count(Query) || (RegEx && RegEx->match(Query));
}
};
SpecialCaseList::SpecialCaseList() : Entries(), Regexps(), IsCompiled(false) {}
std::unique_ptr<SpecialCaseList>
SpecialCaseList::create(const std::vector<std::string> &Paths,
std::string &Error) {
std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList());
for (auto Path : Paths) {
ErrorOr<std::unique_ptr<MemoryBuffer>> FileOrErr =
MemoryBuffer::getFile(Path);
if (std::error_code EC = FileOrErr.getError()) {
Error = (Twine("can't open file '") + Path + "': " + EC.message()).str();
return nullptr;
}
std::string ParseError;
if (!SCL->parse(FileOrErr.get().get(), ParseError)) {
Error = (Twine("error parsing file '") + Path + "': " + ParseError).str();
return nullptr;
}
}
SCL->compile();
return SCL;
}
std::unique_ptr<SpecialCaseList> SpecialCaseList::create(const MemoryBuffer *MB,
std::string &Error) {
std::unique_ptr<SpecialCaseList> SCL(new SpecialCaseList());
if (!SCL->parse(MB, Error))
return nullptr;
SCL->compile();
return SCL;
}
std::unique_ptr<SpecialCaseList>
SpecialCaseList::createOrDie(const std::vector<std::string> &Paths) {
std::string Error;
if (auto SCL = create(Paths, Error))
return SCL;
report_fatal_error(Error);
}
bool SpecialCaseList::parse(const MemoryBuffer *MB, std::string &Error) {
// Iterate through each line in the blacklist file.
SmallVector<StringRef, 16> Lines;
SplitString(MB->getBuffer(), Lines, "\n\r");
int LineNo = 1;
for (auto I = Lines.begin(), E = Lines.end(); I != E; ++I, ++LineNo) {
// Ignore empty lines and lines starting with "#"
if (I->empty() || I->startswith("#"))
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 = SplitRegexp.first;
StringRef Category = SplitRegexp.second;
// See if we can store Regexp in Strings.
if (Regex::isLiteralERE(Regexp)) {
Entries[Prefix][Category].Strings.insert(Regexp);
continue;
}
// Replace * with .*
for (size_t pos = 0; (pos = Regexp.find("*", pos)) != std::string::npos;
pos += strlen(".*")) {
Regexp.replace(pos, strlen("*"), ".*");
}
// Check that the regexp is valid.
Regex CheckRE(Regexp);
std::string REError;
if (!CheckRE.isValid(REError)) {
Error = (Twine("malformed regex in line ") + Twine(LineNo) + ": '" +
SplitLine.second + "': " + REError).str();
return false;
}
// Add this regexp into the proper group by its prefix.
if (!Regexps[Prefix][Category].empty())
Regexps[Prefix][Category] += "|";
Regexps[Prefix][Category] += "^" + Regexp + "$";
}
return true;
}
void SpecialCaseList::compile() {
assert(!IsCompiled && "compile() should only be called once");
// Iterate through each of the prefixes, and create Regexs for them.
for (StringMap<StringMap<std::string>>::const_iterator I = Regexps.begin(),
E = Regexps.end();
I != E; ++I) {
for (StringMap<std::string>::const_iterator II = I->second.begin(),
IE = I->second.end();
II != IE; ++II) {
Entries[I->getKey()][II->getKey()].RegEx.reset(new Regex(II->getValue()));
}
}
Regexps.clear();
IsCompiled = true;
}
SpecialCaseList::~SpecialCaseList() {}
bool SpecialCaseList::inSection(StringRef Section, StringRef Query,
StringRef Category) const {
assert(IsCompiled && "SpecialCaseList::compile() was not called!");
StringMap<StringMap<Entry> >::const_iterator I = Entries.find(Section);
if (I == Entries.end()) return false;
StringMap<Entry>::const_iterator II = I->second.find(Category);
if (II == I->second.end()) return false;
return II->getValue().match(Query);
}
} // namespace llvm