[libFuzzer] Encapsulate commands in a class.
Summary:
To be more portable (especially w.r.t. platforms without system()),
commands should be managed programmatically rather than via string
manipulation on the command line. This change introduces
Fuzzer::Command, with methods to manage arguments and flags, set output
options, and execute the command.
Patch By: aarongreen
Reviewers: kcc, morehouse
Reviewed By: kcc, morehouse
Subscribers: llvm-commits, mgorny
Differential Revision: https://reviews.llvm.org/D40103
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk/lib/fuzzer@319680 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/FuzzerCommand.h b/FuzzerCommand.h
new file mode 100644
index 0000000..2e674ee
--- /dev/null
+++ b/FuzzerCommand.h
@@ -0,0 +1,180 @@
+//===- FuzzerCommand.h - Interface representing a process -------*- C++ -* ===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+// FuzzerCommand represents a command to run in a subprocess. It allows callers
+// to manage command line arguments and output and error streams.
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_FUZZER_COMMAND_H
+#define LLVM_FUZZER_COMMAND_H
+
+#include "FuzzerDefs.h"
+#include "FuzzerIO.h"
+
+#include <algorithm>
+#include <sstream>
+#include <string>
+#include <vector>
+
+namespace fuzzer {
+
+class Command final {
+public:
+ // This command line flag is used to indicate that the remaining command line
+ // is immutable, meaning this flag effectively marks the end of the mutable
+ // argument list.
+ static inline const char *const ignoreRemainingArgs() {
+ static const char *const kIgnoreRemaining = "-ignore_remaining_args=1";
+ return kIgnoreRemaining;
+ }
+
+ Command() : CombinedOutAndErr(false) {}
+
+ explicit Command(const Vector<std::string> &ArgsToAdd)
+ : Args(ArgsToAdd), CombinedOutAndErr(false) {}
+
+ explicit Command(const Command &Other)
+ : Args(Other.Args), CombinedOutAndErr(Other.CombinedOutAndErr),
+ OutputFile(Other.OutputFile) {}
+
+ Command &operator=(const Command &Other) {
+ Args = Other.Args;
+ CombinedOutAndErr = Other.CombinedOutAndErr;
+ OutputFile = Other.OutputFile;
+ return *this;
+ }
+
+ ~Command() {}
+
+ // Returns true if the given Arg is present in Args. Only checks up to
+ // "-ignore_remaining_args=1".
+ bool hasArgument(const std::string &Arg) const {
+ auto i = endMutableArgs();
+ return std::find(Args.begin(), i, Arg) != i;
+ }
+
+ // Gets all of the current command line arguments, **including** those after
+ // "-ignore-remaining-args=1".
+ const Vector<std::string> &getArguments() const { return Args; }
+
+ // Adds the given argument before "-ignore_remaining_args=1", or at the end
+ // if that flag isn't present.
+ void addArgument(const std::string &Arg) {
+ Args.insert(endMutableArgs(), Arg);
+ }
+
+ // Adds all given arguments before "-ignore_remaining_args=1", or at the end
+ // if that flag isn't present.
+ void addArguments(const Vector<std::string> &ArgsToAdd) {
+ Args.insert(endMutableArgs(), ArgsToAdd.begin(), ArgsToAdd.end());
+ }
+
+ // Removes the given argument from the command argument list. Ignores any
+ // occurrences after "-ignore_remaining_args=1", if present.
+ void removeArgument(const std::string &Arg) {
+ auto i = endMutableArgs();
+ Args.erase(std::remove(Args.begin(), i, Arg), i);
+ }
+
+ // Like hasArgument, but checks for "-[Flag]=...".
+ bool hasFlag(const std::string &Flag) {
+ std::string Arg("-" + Flag + "=");
+ auto IsMatch = [&](const std::string &Other) {
+ return Arg.compare(0, std::string::npos, Other, 0, Arg.length()) == 0;
+ };
+ return std::any_of(Args.begin(), endMutableArgs(), IsMatch);
+ }
+
+ // Returns the value of the first instance of a given flag, or an empty string
+ // if the flag isn't present. Ignores any occurrences after
+ // "-ignore_remaining_args=1", if present.
+ std::string getFlagValue(const std::string &Flag) {
+ std::string Arg("-" + Flag + "=");
+ auto IsMatch = [&](const std::string &Other) {
+ return Arg.compare(0, std::string::npos, Other, 0, Arg.length()) == 0;
+ };
+ auto i = endMutableArgs();
+ auto j = std::find_if(Args.begin(), i, IsMatch);
+ std::string result;
+ if (j != i) {
+ result = j->substr(Arg.length());
+ }
+ return result;
+ }
+
+ // Like AddArgument, but adds "-[Flag]=[Value]".
+ void addFlag(const std::string &Flag, const std::string &Value) {
+ addArgument("-" + Flag + "=" + Value);
+ }
+
+ // Like RemoveArgument, but removes "-[Flag]=...".
+ void removeFlag(const std::string &Flag) {
+ std::string Arg("-" + Flag + "=");
+ auto IsMatch = [&](const std::string &Other) {
+ return Arg.compare(0, std::string::npos, Other, 0, Arg.length()) == 0;
+ };
+ auto i = endMutableArgs();
+ Args.erase(std::remove_if(Args.begin(), i, IsMatch), i);
+ }
+
+ // Returns whether the command's stdout is being written to an output file.
+ bool hasOutputFile() const { return !OutputFile.empty(); }
+
+ // Returns the currently set output file.
+ const std::string &getOutputFile() const { return OutputFile; }
+
+ // Configures the command to redirect its output to the name file.
+ void setOutputFile(const std::string &FileName) { OutputFile = FileName; }
+
+ // Returns whether the command's stderr is redirected to stdout.
+ bool isOutAndErrCombined() const { return CombinedOutAndErr; }
+
+ // Sets whether to redirect the command's stderr to its stdout.
+ void combineOutAndErr(bool combine = true) { CombinedOutAndErr = combine; }
+
+ // Returns a string representation of the command. On many systems this will
+ // be the equivalent command line.
+ std::string toString() const {
+ std::stringstream SS;
+ for (auto arg : getArguments())
+ SS << arg << " ";
+ if (isOutAndErrCombined())
+ SS << "2>&1 ";
+ if (hasOutputFile())
+ SS << ">" << getOutputFile() << " ";
+ std::string result = SS.str();
+ if (!result.empty())
+ result = result.substr(0, result.length() - 1);
+ return result;
+ }
+
+private:
+ Command(Command &&Other) = delete;
+ Command &operator=(Command &&Other) = delete;
+
+ Vector<std::string>::iterator endMutableArgs() {
+ return std::find(Args.begin(), Args.end(), ignoreRemainingArgs());
+ }
+
+ Vector<std::string>::const_iterator endMutableArgs() const {
+ return std::find(Args.begin(), Args.end(), ignoreRemainingArgs());
+ }
+
+ // The command arguments. Args[0] is the command name.
+ Vector<std::string> Args;
+
+ // True indicates stderr is redirected to stdout.
+ bool CombinedOutAndErr;
+
+ // If not empty, stdout is redirected to the named file.
+ std::string OutputFile;
+};
+
+} // namespace fuzzer
+
+#endif // LLVM_FUZZER_COMMAND_H