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//===- llvm/Support/Program.h ------------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the llvm::sys::Program class.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_PROGRAM_H
#define LLVM_SUPPORT_PROGRAM_H
#include "llvm/ADT/ArrayRef.h"
#include "llvm/Support/ErrorOr.h"
#include <system_error>
namespace llvm {
class StringRef;
namespace sys {
/// This is the OS-specific separator for PATH like environment variables:
// a colon on Unix or a semicolon on Windows.
#if defined(LLVM_ON_UNIX)
const char EnvPathSeparator = ':';
#elif defined (LLVM_ON_WIN32)
const char EnvPathSeparator = ';';
#endif
/// @brief This struct encapsulates information about a process.
struct ProcessInfo {
#if defined(LLVM_ON_UNIX)
typedef pid_t ProcessId;
#elif defined(LLVM_ON_WIN32)
typedef unsigned long ProcessId; // Must match the type of DWORD on Windows.
typedef void * HANDLE; // Must match the type of HANDLE on Windows.
/// The handle to the process (available on Windows only).
HANDLE ProcessHandle;
#else
#error "ProcessInfo is not defined for this platform!"
#endif
enum : ProcessId { InvalidPid = 0 };
/// The process identifier.
ProcessId Pid;
/// The return code, set after execution.
int ReturnCode;
ProcessInfo();
};
/// \brief Find the first executable file \p Name in \p Paths.
///
/// This does not perform hashing as a shell would but instead stats each PATH
/// entry individually so should generally be avoided. Core LLVM library
/// functions and options should instead require fully specified paths.
///
/// \param Name name of the executable to find. If it contains any system
/// slashes, it will be returned as is.
/// \param Paths optional list of paths to search for \p Name. If empty it
/// will use the system PATH environment instead.
///
/// \returns The fully qualified path to the first \p Name in \p Paths if it
/// exists. \p Name if \p Name has slashes in it. Otherwise an error.
ErrorOr<std::string>
findProgramByName(StringRef Name, ArrayRef<StringRef> Paths = None);
// These functions change the specified standard stream (stdin or stdout) to
// binary mode. They return errc::success if the specified stream
// was changed. Otherwise a platform dependent error is returned.
std::error_code ChangeStdinToBinary();
std::error_code ChangeStdoutToBinary();
/// This function executes the program using the arguments provided. The
/// invoked program will inherit the stdin, stdout, and stderr file
/// descriptors, the environment and other configuration settings of the
/// invoking program.
/// This function waits for the program to finish, so should be avoided in
/// library functions that aren't expected to block. Consider using
/// ExecuteNoWait() instead.
/// @returns an integer result code indicating the status of the program.
/// A zero or positive value indicates the result code of the program.
/// -1 indicates failure to execute
/// -2 indicates a crash during execution or timeout
int ExecuteAndWait(
StringRef Program, ///< Path of the program to be executed. It is
///< presumed this is the result of the findProgramByName method.
const char **args, ///< A vector of strings that are passed to the
///< program. The first element should be the name of the program.
///< The list *must* be terminated by a null char* entry.
const char **env = nullptr, ///< An optional vector of strings to use for
///< the program's environment. If not provided, the current program's
///< environment will be used.
const StringRef **redirects = nullptr, ///< An optional array of pointers
///< to paths. If the array is null, no redirection is done. The array
///< should have a size of at least three. The inferior process's
///< stdin(0), stdout(1), and stderr(2) will be redirected to the
///< corresponding paths.
///< When an empty path is passed in, the corresponding file
///< descriptor will be disconnected (ie, /dev/null'd) in a portable
///< way.
unsigned secondsToWait = 0, ///< If non-zero, this specifies the amount
///< of time to wait for the child process to exit. If the time
///< expires, the child is killed and this call returns. If zero,
///< this function will wait until the child finishes or forever if
///< it doesn't.
unsigned memoryLimit = 0, ///< If non-zero, this specifies max. amount
///< of memory can be allocated by process. If memory usage will be
///< higher limit, the child is killed and this call returns. If zero
///< - no memory limit.
std::string *ErrMsg = nullptr, ///< If non-zero, provides a pointer to a
///< string instance in which error messages will be returned. If the
///< string is non-empty upon return an error occurred while invoking the
///< program.
bool *ExecutionFailed = nullptr);
/// Similar to ExecuteAndWait, but returns immediately.
/// @returns The \see ProcessInfo of the newly launced process.
/// \note On Microsoft Windows systems, users will need to either call \see
/// Wait until the process finished execution or win32 CloseHandle() API on
/// ProcessInfo.ProcessHandle to avoid memory leaks.
ProcessInfo
ExecuteNoWait(StringRef Program, const char **args, const char **env = nullptr,
const StringRef **redirects = nullptr, unsigned memoryLimit = 0,
std::string *ErrMsg = nullptr, bool *ExecutionFailed = nullptr);
/// Return true if the given arguments fit within system-specific
/// argument length limits.
bool commandLineFitsWithinSystemLimits(StringRef Program, ArrayRef<const char*> Args);
/// This function waits for the process specified by \p PI to finish.
/// \returns A \see ProcessInfo struct with Pid set to:
/// \li The process id of the child process if the child process has changed
/// state.
/// \li 0 if the child process has not changed state.
/// \note Users of this function should always check the ReturnCode member of
/// the \see ProcessInfo returned from this function.
ProcessInfo Wait(
const ProcessInfo &PI, ///< The child process that should be waited on.
unsigned SecondsToWait, ///< If non-zero, this specifies the amount of
///< time to wait for the child process to exit. If the time expires, the
///< child is killed and this function returns. If zero, this function
///< will perform a non-blocking wait on the child process.
bool WaitUntilTerminates, ///< If true, ignores \p SecondsToWait and waits
///< until child has terminated.
std::string *ErrMsg = nullptr ///< If non-zero, provides a pointer to a
///< string instance in which error messages will be returned. If the
///< string is non-empty upon return an error occurred while invoking the
///< program.
);
}
}
#endif