[PATCH 5/5] a68: add import from .m68 file

[Mohammad-Reza Nabipoor]

Signed-off-by: Mohammad-Reza Nabipoor <mnabip...@gnu.org>

gcc/ChangeLog

        * algol68/a68-imports.cc (a68_find_export_data): Implement
        reading from module's .m68 file if available.
---
 gcc/algol68/a68-imports.cc | 50 ++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 5 deletions(-)

diff --git a/gcc/algol68/a68-imports.cc b/gcc/algol68/a68-imports.cc
index 9cd6615b7a4..4a92c197610 100644
--- a/gcc/algol68/a68-imports.cc
+++ b/gcc/algol68/a68-imports.cc
@@ -169,15 +169,56 @@ a68_find_export_data (const std::string &filename, int 
fd, size_t *psize)
     }
 
   char buf[A68_EXPORT_MAGIC_LEN];
-  ssize_t c = ::read(fd, buf, A68_EXPORT_MAGIC_LEN);
+  ssize_t c = read (fd, buf, A68_EXPORT_MAGIC_LEN);
   if (c < A68_EXPORT_MAGIC_LEN)
     return NULL;
 
   /* Check for a file containing nothing but Algol 68 export data.  */
-  if (buf[0] == '\x0a' && buf[1] == '\xad')
+  if (buf[0] == '\x0a' && buf[1] == '\x68')
     {
-      /* XXX read whole file.  */
-      return exports;
+      /* read whole file.  */
+
+      char *buf;
+      off_t len;
+      ssize_t nread;
+
+      len = lseek (fd, 0, SEEK_END);
+      if (len < 0)
+        {
+          a68_error (NO_NODE, "lseek Z failed", filename.c_str ());
+          return NULL;
+        }
+      if (lseek (fd, 0, SEEK_SET) < 0)
+        {
+          a68_error (NO_NODE, "lseek Z failed", filename.c_str ());
+          return NULL;
+        }
+
+      buf = XNEWVEC (char, len);
+      if (buf == NULL)
+        {
+          a68_error (NO_NODE,
+                     "memory allocation failed while reading export data");
+          return NULL;
+        }
+
+      nread = read (fd, buf, len);
+      if (nread < 0)
+        {
+          free (buf);
+          a68_error (NO_NODE, "read failed while reading export data");
+          return NULL;
+        }
+
+      if (nread < len)
+        {
+          free (buf);
+          a68_error (NO_NODE, "short read while reading export data");
+          return NULL;
+        }
+
+      *psize = len;
+      return buf;
     }
 
 #if 0
@@ -187,7 +228,6 @@ a68_find_export_data (const std::string &filename, int fd, 
size_t *psize)
 #endif
 
   return NULL;
-
 }
 
 /* Given *PFILENAME, where *PFILENAME does not exist, try various suffixes.  If
-- 
2.52.0