[Patch, RFC] PR81651/Fortran - Enhancement request: have f951 print out fully qualified module file name

[Harald Anlauf]

Dear all,

the attached patch prints the fully qualified path if an error occurs
during module read.  E.g., instead of a less helpful error message,

pr81651.f90:2:6:

    2 |   use netcdf
      |      1
Fatal Error: File 'netcdf.mod' opened at (1) is not a GNU Fortran module
file

gfortran will print

pr81651.f90:2:7:

    2 |   use netcdf
      |       1
Fatal Error: File '/opt/pgi/pkg/netcdf/include/netcdf.mod' opened at (1)
is not a GNU Fortran module file

Regtested on x86_64-pc-linux-gnu.

I couldn't think of a sensible test for the testsuite, thus no testcase
provided.

OK for trunk?

Thanks,
Harald

2019-11-11  Harald Anlauf  <anl...@gmx.de>

        PR fortran/81651
        * module.c (gzopen_included_file, gzopen_included_file_1)
        (gzopen_intrinsic_module, bad_module, gfc_use_module): Use fully
        qualified module path for error reporting.

Index: gcc/fortran/module.c
===================================================================
--- gcc/fortran/module.c        (revision 278064)
+++ gcc/fortran/module.c        (working copy)
@@ -187,6 +187,8 @@
 /* The gzFile for the module we're reading or writing.  */
 static gzFile module_fp;

+/* Fully qualified module path */
+static char *module_fullpath = NULL;

 /* The name of the module we're reading (USE'ing) or writing.  */
 static const char *module_name;
@@ -1101,6 +1103,8 @@
          if (gfc_cpp_makedep ())
            gfc_cpp_add_dep (fullname, system);

+        free (module_fullpath);
+        module_fullpath = xstrdup (fullname);
          return f;
        }
     }
@@ -1116,8 +1120,14 @@
   if (IS_ABSOLUTE_PATH (name) || include_cwd)
     {
       f = gzopen (name, "r");
-      if (f && gfc_cpp_makedep ())
-       gfc_cpp_add_dep (name, false);
+      if (f)
+       {
+         if (gfc_cpp_makedep ())
+           gfc_cpp_add_dep (name, false);
+
+         free (module_fullpath);
+         module_fullpath = xstrdup (name);
+       }
     }

   if (!f)
@@ -1134,8 +1144,14 @@
   if (IS_ABSOLUTE_PATH (name))
     {
       f = gzopen (name, "r");
-      if (f && gfc_cpp_makedep ())
-        gfc_cpp_add_dep (name, true);
+      if (f)
+       {
+         if (gfc_cpp_makedep ())
+           gfc_cpp_add_dep (name, true);
+
+         free (module_fullpath);
+         module_fullpath = xstrdup (name);
+       }
     }

   if (!f)
@@ -1181,7 +1197,7 @@
     {
     case IO_INPUT:
       gfc_fatal_error ("Reading module %qs at line %d column %d: %s",
-                      module_name, module_line, module_column, msgid);
+                      module_fullpath, module_line, module_column, msgid);
       break;
     case IO_OUTPUT:
       gfc_fatal_error ("Writing module %qs at line %d column %d: %s",
@@ -7141,7 +7157,7 @@
       if ((start == 1 && strcmp (atom_name, "GFORTRAN") != 0)
          || (start == 2 && strcmp (atom_name, " module") != 0))
        gfc_fatal_error ("File %qs opened at %C is not a GNU Fortran"
-                        " module file", filename);
+                        " module file", module_fullpath);
       if (start == 3)
        {
          if (strcmp (atom_name, " version") != 0
@@ -7150,7 +7166,7 @@
              || strcmp (atom_string, MOD_VERSION))
            gfc_fatal_error ("Cannot read module file %qs opened at %C,"
                             " because it was created by a different"
-                            " version of GNU Fortran", filename);
+                            " version of GNU Fortran", module_fullpath);

          free (atom_string);
        }