Commit 93992ee3 authored by Kevin Locke's avatar Kevin Locke Committed by David Gibson

configurator: Reimplement run using popen

Rather than using fork+pipe+system+waitpid, most of which are only
available on POSIX-like systems, use popen which is also available on
Windows (under the name _popen).

Changes since v1:
- Create fread_noeintr to avoid EINTR in fread without reading any data.
- Handle short reads from fread.  This can happen with non-conformant
  libc or if EINTR occurs after reading some data.
- Define _POSIX_C_SOURCE for popen/pclose with strict implementations
  which require it (e.g. gcc with -std=c11).

Changes since v2:
- Revert fread_noeintr and short read changes in v1 as unnecessary.
Signed-off-by: default avatarKevin Locke <kevin@kevinlocke.name>
Signed-off-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
parent 5dbd87b8
......@@ -21,17 +21,19 @@
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#define _POSIX_C_SOURCE 200809L /* For pclose, popen, strdup */
#include <stdio.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>
#include <err.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#ifdef _MSC_VER
#define popen _popen
#define pclose _pclose
#endif
#define DEFAULT_COMPILER "cc"
#define DEFAULT_FLAGS "-g3 -ggdb -Wall -Wundef -Wmissing-prototypes -Wmissing-declarations -Wstrict-prototypes -Wold-style-definition"
......@@ -375,20 +377,19 @@ static struct test tests[] = {
},
};
static char *grab_fd(int fd)
static char *grab_stream(FILE *file)
{
int ret;
size_t max, size = 0;
size_t max, ret, size = 0;
char *buffer;
max = 16384;
buffer = malloc(max+1);
while ((ret = read(fd, buffer + size, max - size)) > 0) {
max = BUFSIZ;
buffer = malloc(max);
while ((ret = fread(buffer+size, 1, max - size, file)) == max - size) {
size += ret;
if (size == max)
buffer = realloc(buffer, max *= 2);
buffer = realloc(buffer, max *= 2);
}
if (ret < 0)
size += ret;
if (ferror(file))
err(1, "reading from command");
buffer[size] = '\0';
return buffer;
......@@ -396,43 +397,25 @@ static char *grab_fd(int fd)
static char *run(const char *cmd, int *exitstatus)
{
pid_t pid;
int p[2];
static const char redir[] = " 2>&1";
size_t cmdlen;
char *cmdredir;
FILE *cmdout;
char *ret;
int status;
if (pipe(p) != 0)
err(1, "creating pipe");
pid = fork();
if (pid == -1)
err(1, "forking");
if (pid == 0) {
if (dup2(p[1], STDOUT_FILENO) != STDOUT_FILENO
|| dup2(p[1], STDERR_FILENO) != STDERR_FILENO
|| close(p[0]) != 0
|| close(STDIN_FILENO) != 0
|| open("/dev/null", O_RDONLY) != STDIN_FILENO)
exit(128);
status = system(cmd);
if (WIFEXITED(status))
exit(WEXITSTATUS(status));
/* Here's a hint... */
exit(128 + WTERMSIG(status));
}
cmdlen = strlen(cmd);
cmdredir = malloc(cmdlen + sizeof(redir));
memcpy(cmdredir, cmd, cmdlen);
memcpy(cmdredir + cmdlen, redir, sizeof(redir));
cmdout = popen(cmdredir, "r");
if (!cmdout)
err(1, "popen \"%s\"", cmdredir);
free(cmdredir);
close(p[1]);
ret = grab_fd(p[0]);
/* This shouldn't fail... */
if (waitpid(pid, &status, 0) != pid)
err(1, "Failed to wait for child");
close(p[0]);
if (WIFEXITED(status))
*exitstatus = WEXITSTATUS(status);
else
*exitstatus = -WTERMSIG(status);
ret = grab_stream(cmdout);
*exitstatus = pclose(cmdout);
return ret;
}
......
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