mpi/fortran: fix parsing arrays of Fortran strings

jsquyres · jsquyres · commit 0ab6b201fed0 · 2018-04-04T18:56:44.000-07:00
MPI defines the "argv" param to Fortran MPI_COMM_SPAWN as being
terminated by a blank string.  While not precisely defined (except
through a non-binding example, Example 10.2, MPI-3.1 p382:6-29), one
can infer that the "array_of_argv" param to Fortran
MPI_COMM_SPAWN_MULTIPLE is also a set of argv, each of which are
terminated by a blank line.

The "array_of_commands" argument to Fortran MPI_COMM_SPAWN_MULTIPLE is
a little less well-defined.  It is *assumed* to be of length "count"
(another parameter to MPI_COMM_SPAWN_MULTIPLE) -- and *not* be
terminated by a blank string.  This is also given credence by the same
example 10.2 in MPI-3.1.

The previous code assumed that "array_of_commands" should also be
terminated by a blank line -- but per the above, this is incorrect.
Instead, we should just parse our "count" number of strings from
"array_of_commands" and *not* look for a blank line termination.

This commit separates these two cases:

* ompi_fortran_argv_blank_f2c(): parse a Fortran array of strings out
  and stop when reaching a blank string.
* ompi_fortran_argv_count_f2c(): parse a Fortran array of strings out
  and stop when "count" number of strings have been parsed.

Signed-off-by: Jeff Squyres &lt;jsquyres@cisco.com&gt;
diff --git a/ompi/mpi/fortran/base/fortran_base_strings.h b/ompi/mpi/fortran/base/fortran_base_strings.h
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2010-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2010-2018 Cisco Systems, Inc.  All rights reserved
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -58,8 +58,8 @@ BEGIN_C_DECLS
     OMPI_DECLSPEC int ompi_fortran_string_c2f(char *cstr, char *fstr, int len);
 
     /**
-     * Convert an array of Fortran strings to an argv-style array of C
-     * strings.
+     * Convert an array of Fortran strings that are terminated with a
+     * blank line to an argv-style array of C strings.
      *
      * @param farray Array of fortran strings
      * @param string_len Length of each fortran string in the array
@@ -86,8 +86,29 @@ BEGIN_C_DECLS
      * number_of_argv_arrays).  Hence, the advance parameter is used
      * to specify this displacement.
      */
-    OMPI_DECLSPEC int ompi_fortran_argv_f2c(char *farray, int string_len,
-                                            int advancex, char ***cargv);
+    OMPI_DECLSPEC int ompi_fortran_argv_blank_f2c(char *farray, int string_len,
+                                                  int advancex, char ***cargv);
+
+    /**
+     * Convert an array of a specific number of Fortran strings to an
+     * argv-style array of C strings.
+     *
+     * @param farray Array of fortran strings
+     * @param farray_length Number of entries in the farray array
+     * @param string_len Length of each fortran string in the array
+     * @param advance Number of bytes to advance to get to the next string
+     * @param cargv Returned argv-style array of C strings
+     *
+     * @retval OMPI_SUCCESS upon success
+     * @retval OMPI_ERROR upon error
+     *
+     * This function is just like ompi_fortran_argv_blank_f2c(),
+     * except that it uses farray_length to determine the length of
+     * farray (vs. looking for a blank string to look for the end of
+     * the array).
+     */
+    OMPI_DECLSPEC int ompi_fortran_argv_count_f2c(char *farray, int farray_length, int string_len,
+                                                  int advancex, char ***cargv);
 
     /**
      * Convert an array of argvs to a C style array of argvs
diff --git a/ompi/mpi/fortran/base/strings.c b/ompi/mpi/fortran/base/strings.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2010-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2010-2018 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2017      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
@@ -101,11 +101,19 @@ int ompi_fortran_string_c2f(char *cstr, char *fstr, int len)
 
 
 /*
- * creates a C argument vector from an F77 array of strings
- * (terminated by a blank string)
+ * Creates a C argument vector from an F77 array of strings.  The
+ * array is terminated by a blank string.
+ *
+ * This function is quite similar to ompi_fortran_argv_count_f2c(),
+ * that it looks for a blank string to know when it has finished
+ * traversing the entire array (vs. having the length of the array
+ * passed in as a parameter).
+ *
+ * This function is used to convert "argv" in MPI_COMM_SPAWN (which is
+ * defined to be terminated by a blank string).
  */
-int ompi_fortran_argv_f2c(char *array, int string_len, int advance,
-                          char ***argv)
+int ompi_fortran_argv_blank_f2c(char *array, int string_len, int advance,
+                                char ***argv)
 {
     int err, argc = 0;
     char *cstr;
@@ -141,8 +149,52 @@ int ompi_fortran_argv_f2c(char *array, int string_len, int advance,
 
 
 /*
- * Creates a set of C argv arrays from an F77 array of argv's.  The
- * returned arrays need to be freed by the caller.
+ * Creates a C argument vector from an F77 array of array_len strings.
+ *
+ * This function is quite similar to ompi_fortran_argv_blank_f2c(),
+ * except that the length of the array is a parameter (vs. looking for
+ * a blank line to end the array).
+ *
+ * This function is used to convert "array_of_commands" in
+ * MPI_COMM_SPAWN_MULTIPLE (which is not precisely defined, but is
+ * assumed to be of length "count", and *not* terminated by a blank
+ * line).
+ */
+int ompi_fortran_argv_count_f2c(char *array, int array_len, int string_len, int advance,
+                                char ***argv)
+{
+    int err, argc = 0;
+    char *cstr;
+
+    /* Fortran lines up strings in memory, each delimited by \0.  So
+       just convert them until we hit an extra \0. */
+
+    *argv = NULL;
+    for (int i = 0; i < array_len; ++i) {
+	if (OMPI_SUCCESS != (err = ompi_fortran_string_f2c(array, string_len,
+                                                           &cstr))) {
+	    opal_argv_free(*argv);
+	    return err;
+	}
+
+	if (OMPI_SUCCESS != (err = opal_argv_append(&argc, argv, cstr))) {
+	    opal_argv_free(*argv);
+            free(cstr);
+	    return err;
+	}
+
+	free(cstr);
+	array += advance;
+    }
+
+    return OMPI_SUCCESS;
+}
+
+
+/*
+ * Creates a set of C argv arrays from an F77 array of argv's (where
+ * each argv array is terminated by a blank string).  The returned
+ * arrays need to be freed by the caller.
  */
 int ompi_fortran_multiple_argvs_f2c(int num_argv_arrays, char *array,
                                     int string_len, char ****argv)
@@ -155,9 +207,9 @@ int ompi_fortran_multiple_argvs_f2c(int num_argv_arrays, char *array,
     argv_array = (char ***) malloc (num_argv_arrays * sizeof(char **));
 
     for (i = 0; i < num_argv_arrays; ++i) {
-        ret = ompi_fortran_argv_f2c(current_array, string_len,
-                                    string_len * num_argv_arrays,
-                                    &argv_array[i]);
+        ret = ompi_fortran_argv_blank_f2c(current_array, string_len,
+                                          string_len * num_argv_arrays,
+                                          &argv_array[i]);
         if (OMPI_SUCCESS != ret) {
             free(argv_array);
             return ret;
diff --git a/ompi/mpi/fortran/mpif-h/comm_spawn_f.c b/ompi/mpi/fortran/mpif-h/comm_spawn_f.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2010-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2010-2018 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2015-2017 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * $COPYRIGHT$
@@ -101,7 +101,7 @@ void ompi_comm_spawn_f(char *command, char *argv, MPI_Fint *maxprocs,
     if (OMPI_IS_FORTRAN_ARGV_NULL(argv)) {
         c_argv = MPI_ARGV_NULL;
     } else {
-        ompi_fortran_argv_f2c(argv, string_len, string_len, &c_argv);
+        ompi_fortran_argv_blank_f2c(argv, string_len, string_len, &c_argv);
     }
 
     c_ierr = PMPI_Comm_spawn(c_command, c_argv,
diff --git a/ompi/mpi/fortran/mpif-h/comm_spawn_multiple_f.c b/ompi/mpi/fortran/mpif-h/comm_spawn_multiple_f.c
@@ -9,7 +9,7 @@
  *                         University of Stuttgart.  All rights reserved.
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
- * Copyright (c) 2010-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2010-2018 Cisco Systems, Inc.  All rights reserved
  * Copyright (c) 2015-2017 Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2016      Los Alamos National Security, LLC. All rights
@@ -115,8 +115,8 @@ void ompi_comm_spawn_multiple_f(MPI_Fint *count, char *array_commands,
 
     OMPI_ARRAY_FINT_2_INT(array_maxprocs, array_size);
 
-    ompi_fortran_argv_f2c(array_commands, cmd_string_len,
-                          cmd_string_len, &c_array_commands);
+    ompi_fortran_argv_count_f2c(array_commands, array_size, cmd_string_len,
+                                cmd_string_len, &c_array_commands);
 
     c_info = (MPI_Info *) malloc (array_size * sizeof(MPI_Info));
     for (i = 0; i < array_size; ++i) {
