X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Futil%2Fos_file.c;h=c5970ddb2431b058334dd6b97b0b142e2bb724ff;hb=9760a7ed9138b84d83a712afeb0e673399d9e200;hp=b502ff4b0ef8f9bda5e7b62022e64daf84cc92ea;hpb=f76cbc7901f7d500f5a4f74aedfd29970d1efd00;p=mesa.git

diff --git a/src/util/os_file.c b/src/util/os_file.c
index b502ff4b0ef..c5970ddb243 100644
--- a/src/util/os_file.c
+++ b/src/util/os_file.c
@@ -4,20 +4,25 @@
  */
 
 #include "os_file.h"
+#include "detect_os.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <sys/stat.h>
 
-
-#if defined(WIN32)
+#if DETECT_OS_WINDOWS
 #include <io.h>
 #define open _open
 #define fdopen _fdopen
 #define O_CREAT _O_CREAT
 #define O_EXCL _O_EXCL
 #define O_WRONLY _O_WRONLY
+#else
+#include <unistd.h>
+#ifndef F_DUPFD_CLOEXEC
+#define F_DUPFD_CLOEXEC 1030
+#endif
 #endif
 
 
@@ -31,14 +36,59 @@ os_file_create_unique(const char *filename, int filemode)
 }
 
 
-#if defined(__linux__)
+#if DETECT_OS_WINDOWS
+int
+os_dupfd_cloexec(int fd)
+{
+   /*
+    * On Windows child processes don't inherit handles by default:
+    * https://devblogs.microsoft.com/oldnewthing/20111216-00/?p=8873
+    */
+   return dup(fd);
+}
+#else
+int
+os_dupfd_cloexec(int fd)
+{
+   int minfd = 3;
+   int newfd = fcntl(fd, F_DUPFD_CLOEXEC, minfd);
+
+   if (newfd >= 0)
+      return newfd;
+
+   if (errno != EINVAL)
+      return -1;
+
+   newfd = fcntl(fd, F_DUPFD, minfd);
+
+   if (newfd < 0)
+      return -1;
+
+   long flags = fcntl(newfd, F_GETFD);
+   if (flags == -1) {
+      close(newfd);
+      return -1;
+   }
+
+   if (fcntl(newfd, F_SETFD, flags | FD_CLOEXEC) == -1) {
+      close(newfd);
+      return -1;
+   }
+
+   return newfd;
+}
+#endif
+
+
+#if DETECT_OS_LINUX
 
 #include <fcntl.h>
-#include <linux/kcmp.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <unistd.h>
 
+/* copied from <linux/kcmp.h> */
+#define KCMP_FILE 0
 
 static ssize_t
 readN(int fd, char *buf, size_t len)
@@ -66,7 +116,7 @@ readN(int fd, char *buf, size_t len)
 }
 
 char *
-os_read_file(const char *filename)
+os_read_file(const char *filename, size_t *size)
 {
    /* Note that this also serves as a slight margin to avoid a 2x grow when
     * the file is just a few bytes larger when we read it than when we
@@ -129,15 +179,22 @@ os_read_file(const char *filename)
 
    buf[offset] = '\0';
 
+   if (size)
+      *size = offset;
+
    return buf;
 }
 
-bool
+int
 os_same_file_description(int fd1, int fd2)
 {
    pid_t pid = getpid();
 
-   return syscall(SYS_kcmp, pid, pid, KCMP_FILE, fd1, fd2) == 0;
+   /* Same file descriptor trivially implies same file description */
+   if (fd1 == fd2)
+      return 0;
+
+   return syscall(SYS_kcmp, pid, pid, KCMP_FILE, fd1, fd2);
 }
 
 #else
@@ -145,21 +202,21 @@ os_same_file_description(int fd1, int fd2)
 #include "u_debug.h"
 
 char *
-os_read_file(const char *filename)
+os_read_file(const char *filename, size_t *size)
 {
    errno = -ENOSYS;
    return NULL;
 }
 
-bool
+int
 os_same_file_description(int fd1, int fd2)
 {
+   /* Same file descriptor trivially implies same file description */
    if (fd1 == fd2)
-      return true;
+      return 0;
 
-   debug_warn_once("Can't tell if different file descriptors reference the same"
-                   " file description, false negatives might cause trouble!\n");
-   return false;
+   /* Otherwise we can't tell */
+   return -1;
 }
 
 #endif