[PATCH][RFC] Extend locations where to seach for Fortran pre-include.

[Martin Liška]

Hi.

Following patch is a follow up of the discussion we had on IRC about
locations where a Fortran pre-include should be searched.

With the patch applied I see now:
$ strace -f -s512 ./xgcc -B. ~/Programming/testcases/usage.F90  -c 2>&1 | grep 
math-vector
access("./x86_64-pc-linux-gnu/9.0.0/math-vector-fortran.h", R_OK) = -1 ENOENT 
(No such file or directory)
access("./math-vector-fortran.h", R_OK) = -1 ENOENT (No such file or directory)
access("/home/marxin/bin/gcc2/bin/../include/finclude/x86_64-pc-linux-gnu/9.0.0/math-vector-fortran.h",
 R_OK) = -1 ENOENT (No such file or directory)
access("/home/marxin/bin/gcc2/bin/../include/finclude/math-vector-fortran.h", 
R_OK) = -1 ENOENT (No such file or directory)
access("/usr/include/finclude/x86_64-pc-linux-gnu/9.0.0/math-vector-fortran.h", 
R_OK) = -1 ENOENT (No such file or directory)
access("/usr/include/finclude/math-vector-fortran.h", R_OK) = -1 ENOENT (No 
such file or directory)

Martin

>From c89d25005ae649d652d316cefe2aab8c676cd6ca Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Tue, 20 Nov 2018 15:09:16 +0100
Subject: [PATCH] Extend locations where to seach for Fortran pre-include.

---
 gcc/gcc.c | 49 +++++++++++++++++++++++++++++++------------------
 1 file changed, 31 insertions(+), 18 deletions(-)

diff --git a/gcc/gcc.c b/gcc/gcc.c
index 4d01e1e2f3b..bd6b83a3e6d 100644
--- a/gcc/gcc.c
+++ b/gcc/gcc.c
@@ -9891,20 +9891,49 @@ debug_level_greater_than_spec_func (int argc, const char **argv)
   return NULL;
 }
 
+static void
+path_prefix_reset (path_prefix *prefix)
+{
+  struct prefix_list *iter, *next;
+  iter = prefix->plist;
+  while (iter)
+    {
+      next = iter->next;
+      free (const_cast <char *> (iter->prefix));
+      XDELETE (iter);
+      iter = next;
+    }
+  prefix->plist = 0;
+  prefix->max_len = 0;
+}
+
 /* The function takes 2 arguments: OPTION name and file name.
    When the FILE is found by find_file, return OPTION=path_to_file.  */
 
 static const char *
 find_fortran_preinclude_file (int argc, const char **argv)
 {
+  char *result = NULL;
   if (argc != 2)
     return NULL;
 
+  struct path_prefix prefixes = { 0, 0, "preinclude" };
+  add_prefix (&prefixes, STANDARD_BINDIR_PREFIX "../include/finclude/", NULL,
+	      0, 0, 0);
+  add_prefix (&prefixes, "/usr/include/finclude/", NULL, 0, 0, 0);
+
   const char *path = find_a_file (&include_prefixes, argv[1], R_OK, true);
   if (path != NULL)
-    return concat (argv[0], path, NULL);
+    result = concat (argv[0], path, NULL);
+  else
+    {
+      path = find_a_file (&prefixes, argv[1], R_OK, true);
+      if (path != NULL)
+	result = concat (argv[0], path, NULL);
+    }
 
-  return NULL;
+  path_prefix_reset (&prefixes);
+  return result;
 }
 
 
@@ -9956,22 +9985,6 @@ convert_white_space (char *orig)
     return orig;
 }
 
-static void
-path_prefix_reset (path_prefix *prefix)
-{
-  struct prefix_list *iter, *next;
-  iter = prefix->plist;
-  while (iter)
-    {
-      next = iter->next;
-      free (const_cast <char *> (iter->prefix));
-      XDELETE (iter);
-      iter = next;
-    }
-  prefix->plist = 0;
-  prefix->max_len = 0;
-}
-
 /* Restore all state within gcc.c to the initial state, so that the driver
    code can be safely re-run in-process.
 
-- 
2.19.1