view contrib/chg/util.c @ 43617:697c2e32c490

packaging: ship all help .txt files on WiX

These are technically not needed. But it is easier to ship
all files than to cherry-pick. A `make install` will copy
these files, so the new behavior is consistent with that.
This also makes WiX consistent with Inno, which is my main
reason for doing this.

If we don't want to ship the files (which is a valid argument),
I think we can do that in a follow up.

Differential Revision: https://phab.mercurial-scm.org/D7166

/*
 * Utility functions
 *
 * Copyright (c) 2011 Yuya Nishihara <[e-mail]>
 *
 * This software may be used and distributed according to the terms of the
 * GNU General Public License version 2 or any later version.
 */

#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>

#include "util.h"

static int colorenabled = 0;

static inline void fsetcolor(FILE *fp, const char *code)
{
	if (!colorenabled) {
		return;
	}
	fprintf(fp, "\033[%sm", code);
}

static void vabortmsgerrno(int no, const char *fmt, va_list args)
{
	fsetcolor(stderr, "1;31");
	fputs("chg: abort: ", stderr);
	vfprintf(stderr, fmt, args);
	if (no != 0) {
		fprintf(stderr, " (errno = %d, %s)", no, strerror(no));
	}
	fsetcolor(stderr, "");
	fputc('\n', stderr);
	exit(255);
}

void abortmsg(const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	vabortmsgerrno(0, fmt, args);
	va_end(args);
}

void abortmsgerrno(const char *fmt, ...)
{
	int no = errno;
	va_list args;
	va_start(args, fmt);
	vabortmsgerrno(no, fmt, args);
	va_end(args);
}

static int debugmsgenabled = 0;
static double debugstart = 0;

static double now()
{
	struct timeval t;
	gettimeofday(&t, NULL);
	return t.tv_usec / 1e6 + t.tv_sec;
}

void enablecolor(void)
{
	colorenabled = 1;
}

void enabledebugmsg(void)
{
	debugmsgenabled = 1;
	debugstart = now();
}

void debugmsg(const char *fmt, ...)
{
	if (!debugmsgenabled) {
		return;
	}

	va_list args;
	va_start(args, fmt);
	fsetcolor(stderr, "1;30");
	fprintf(stderr, "chg: debug: %4.6f ", now() - debugstart);
	vfprintf(stderr, fmt, args);
	fsetcolor(stderr, "");
	fputc('\n', stderr);
	va_end(args);
}

void fchdirx(int dirfd)
{
	int r = fchdir(dirfd);
	if (r == -1) {
		abortmsgerrno("failed to fchdir");
	}
}

void fsetcloexec(int fd)
{
	int flags = fcntl(fd, F_GETFD);
	if (flags < 0) {
		abortmsgerrno("cannot get flags of fd %d", fd);
	}
	if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) {
		abortmsgerrno("cannot set flags of fd %d", fd);
	}
}

void *mallocx(size_t size)
{
	void *result = malloc(size);
	if (!result) {
		abortmsg("failed to malloc");
	}
	return result;
}

void *reallocx(void *ptr, size_t size)
{
	void *result = realloc(ptr, size);
	if (!result) {
		abortmsg("failed to realloc");
	}
	return result;
}

/*
 * Execute a shell command in mostly the same manner as system(), with the
 * give environment variables, after chdir to the given cwd. Returns a status
 * code compatible with the Python subprocess module.
 */
int runshellcmd(const char *cmd, const char *envp[], const char *cwd)
{
	enum { F_SIGINT = 1, F_SIGQUIT = 2, F_SIGMASK = 4, F_WAITPID = 8 };
	unsigned int doneflags = 0;
	int status = 0;
	struct sigaction newsa, oldsaint, oldsaquit;
	sigset_t oldmask;

	/* block or mask signals just as system() does */
	memset(&newsa, 0, sizeof(newsa));
	newsa.sa_handler = SIG_IGN;
	newsa.sa_flags = 0;
	if (sigemptyset(&newsa.sa_mask) < 0) {
		goto done;
	}
	if (sigaction(SIGINT, &newsa, &oldsaint) < 0) {
		goto done;
	}
	doneflags |= F_SIGINT;
	if (sigaction(SIGQUIT, &newsa, &oldsaquit) < 0) {
		goto done;
	}
	doneflags |= F_SIGQUIT;

	if (sigaddset(&newsa.sa_mask, SIGCHLD) < 0) {
		goto done;
	}
	if (sigprocmask(SIG_BLOCK, &newsa.sa_mask, &oldmask) < 0) {
		goto done;
	}
	doneflags |= F_SIGMASK;

	pid_t pid = fork();
	if (pid < 0) {
		goto done;
	}
	if (pid == 0) {
		sigaction(SIGINT, &oldsaint, NULL);
		sigaction(SIGQUIT, &oldsaquit, NULL);
		sigprocmask(SIG_SETMASK, &oldmask, NULL);
		if (cwd && chdir(cwd) < 0) {
			_exit(127);
		}
		const char *argv[] = {"sh", "-c", cmd, NULL};
		if (envp) {
			execve("/bin/sh", (char **)argv, (char **)envp);
		} else {
			execv("/bin/sh", (char **)argv);
		}
		_exit(127);
	} else {
		if (waitpid(pid, &status, 0) < 0) {
			goto done;
		}
		doneflags |= F_WAITPID;
	}

done:
	if (doneflags & F_SIGINT) {
		sigaction(SIGINT, &oldsaint, NULL);
	}
	if (doneflags & F_SIGQUIT) {
		sigaction(SIGQUIT, &oldsaquit, NULL);
	}
	if (doneflags & F_SIGMASK) {
		sigprocmask(SIG_SETMASK, &oldmask, NULL);
	}

	/* no way to report other errors, use 127 (= shell termination) */
	if (!(doneflags & F_WAITPID)) {
		return 127;
	}
	if (WIFEXITED(status)) {
		return WEXITSTATUS(status);
	}
	if (WIFSIGNALED(status)) {
		return -WTERMSIG(status);
	}
	return 127;
}