Support portable boot files on more platforms

cisco · Oct 19, 2023 · ea56574 · ea56574
1 parent a55ce4f
commit ea56574
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Showing 2 changed files with 58 additions and 6 deletions.
diff --git a/c/scheme.c b/c/scheme.c
@@ -26,6 +26,10 @@
 #include <fcntl.h>
 #include <stddef.h>
 
+#if defined(__APPLE__) && defined(__MACH__)
+#include <mach-o/dyld.h>
+#endif
+
 #ifndef O_BINARY
 #define O_BINARY 0
 #endif /* O_BINARY */
@@ -542,10 +546,10 @@ static IBOOL next_path(char *path, const char *name, const char *ext,
         case '%':
           s += 1;
           switch (*s) {
-#ifdef WIN32
             case 'x': {
-              wchar_t exepath[BOOT_PATH_MAX]; DWORD n;
               s += 1;
+#ifdef WIN32
+              wchar_t exepath[BOOT_PATH_MAX]; DWORD n;
               n = GetModuleFileNameW(NULL, exepath, BOOT_PATH_MAX);
               if (n == 0 || (n == BOOT_PATH_MAX && GetLastError() == ERROR_INSUFFICIENT_BUFFER)) {
                 fprintf(stderr, "warning: executable path is too long; ignoring %%x\n");
@@ -559,9 +563,57 @@ static IBOOL next_path(char *path, const char *name, const char *ext,
                 while (t != tend) setp(*t++);
                 free(tstart);
               }
+#else
+#if defined(__APPLE__) && defined(__MACH__)
+              char exepath[BOOT_PATH_MAX]; uint32_t n;
+              if (_NSGetExecutablePath(exepath, &n) != 0) {
+                fprintf(stderr, "warning: executable path is too long; ignoring %%x\n");
+                break;
+              }
+#elif defined(__sun__) && defined(__svr4__)
+              char exepath[BOOT_PATH_MAX]; ssize_t n;
+              int fd = OPEN("/proc/self/execname", O_RDONLY);
+              if (fd == -1) {
+                fprintf(stderr, "warning: failed to open execname (%s); ignoring %%x\n", strerror(errno));
+                break;
+              }
+              n = READ(fd, exepath, BOOT_PATH_MAX);
+              CLOSE(fd);
+              if (n < 0) {
+                fprintf(stderr, "warning: failed to read execname (%s); ignoring %%x\n", strerror(errno));
+                break;
+              }
+              if (n == BOOT_PATH_MAX) {
+                fprintf(stderr, "warning: executable path is too long; ignoring %%x\n");
+                break;
+              }
+              exepath[n] = '\0';
+#elif defined(__linux__) || defined(__gnu_hurd__)
+              char *exepath = "/proc/self/exe";
+#elif defined(__FreeBSD_kernel__) || defined(__NetBSD__)
+              char *exepath = "/proc/curproc/file";
+#else
+              char *exepath;
+              fprintf(stderr, "warning: %%x is not supported; ignoring %%x\n");
               break;
-            }
 #endif
+              char tstart[BOOT_PATH_MAX];
+              if (realpath(exepath, tstart) == NULL) {
+                if (errno == ENAMETOOLONG) {
+                  fprintf(stderr, "warning: executable path is too long; ignoring %%x\n");
+                } else {
+                  fprintf(stderr, "warning: failed to get executable path (%s); ignoring %%x\n", strerror(errno));
+                }
+              } else {
+                const char *tend;
+                t = tstart;
+                tend = path_last(t);
+                if (tend != t) tend -= 1; /* back up to directory separator */
+                while (t != tend) setp(*t++);
+              }
+#endif
+              break;
+            }
             case 'm':
               s += 1;
               t = MACHINE_TYPE;

diff --git a/csug/use.stex b/csug/use.stex
@@ -1844,16 +1844,16 @@ the order in which they should be searched.
 Within each directory, the two-character escape sequence ``\scheme{%v}''
 is replaced by the current version, and the two-character escape sequence
 ``\scheme{%m}'' is replaced by the machine type.
+On supported platforms, the two-character escape sequence ``\scheme{%x}''
+is replaced by the directory in which the executable file resides.
 A percent followed by any other character is replaced by the second
 character; in particular, ``\scheme{%%}'' is replaced by ``\scheme{%}'', and
 ``\scheme{%:}'' is replaced by ``\scheme{:}''.
 If \scheme{SCHEMEHEAPDIRS} ends in a non-escaped colon, the default directories are
 searched after those in \scheme{SCHEMEHEAPDIRS}; otherwise, only those listed in
 \scheme{SCHEMEHEAPDIRS} are searched.
 
-Under Windows, semi-colons are used in place of colons, and one additional
-escape is recognized: ``\scheme{%x},'' which is replaced by the directory in
-which the executable file resides.
+Under Windows, semi-colons are used in place of colons.
 The default search path under Windows consists of ``\scheme{%x}''
 and ``\scheme{%x\..\..\boot\%m}.''
 The registry key \scheme{HeapSearchPath} in