Fortran: Fix issue with using snprintf function.

The previous patch used snprintf to set the message
string. The message string is not a formatted string
and the snprintf will interpret '%' related characters
as format specifiers when there are no associated
output variables. A segfault ensues.

This change replaces snprintf with a fortran string copy
function and null terminates the message string.

	PR libfortran/105456

libgfortran/ChangeLog:

	* io/list_read.c (list_formatted_read_scalar): Use fstrcpy
	from libgfortran/runtime/string.c to replace snprintf.
	(nml_read_obj): Likewise.
	* io/transfer.c (unformatted_read): Likewise.
	(unformatted_write): Likewise.
	(formatted_transfer_scalar_read): Likewise.
	(formatted_transfer_scalar_write): Likewise.
	* io/write.c (list_formatted_write_scalar): Likewise.
	(nml_write_obj): Likewise.

gcc/testsuite/ChangeLog:

	* gfortran.dg/pr105456.f90: Revise using '%' characters
	in users error message.

diff --git a/gcc/testsuite/gfortran.dg/pr105456.f90 b/gcc/testsuite/gfortran.dg/pr105456.f90
index 188323847a7aeb71c66b5a99387d234d3e7f50b0..60cd3b6f3e86bd022e2cc3829f1fd9a6fa0e53f2 100644 (file)
--- a/gcc/testsuite/gfortran.dg/pr105456.f90
+++ b/gcc/testsuite/gfortran.dg/pr105456.f90
@@ -19,7 +19,7 @@ contains
     character :: ch
     read (unit,fmt='(A1)', advance="no", iostat=piostat, iomsg=piomsg) ch
     piostat = 42
-    piomsg="The users message"
+    piomsg="The users message containing % and %% and %s and other stuff"
     dtv%ch = ch
   end subroutine read_formatted
 end module sk1
@@ -35,4 +35,4 @@ program skip1
   write (*,'(10(A))') "Read: '",x%ch,"'"
 end program skip1
 ! { dg-output ".*(unit = 10, file = .*)" }
-! { dg-output "Fortran runtime error: The users message" }
+! { dg-output "Fortran runtime error: The users message containing % and %% and %s and other stuff" }

diff --git a/libgfortran/io/list_read.c b/libgfortran/io/list_read.c
index 707afaeb8dcb994b997165f1363ce98b339f5aa9..e38e9a84976545e799bc677ef3fc49ef6f6d6832 100644 (file)
--- a/libgfortran/io/list_read.c
+++ b/libgfortran/io/list_read.c
@@ -2268,9 +2268,10 @@ list_formatted_read_scalar (st_parameter_dt *dtp, bt type, void *p,
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
              free_line (dtp);
-             snprintf (message, child_iomsg_len, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }
@@ -3082,8 +3083,9 @@ nml_read_obj (st_parameter_dt *dtp, namelist_info *nl, index_type offset,
                    !(dtp->common.flags & IOPARM_HAS_IOSTAT))
                  {
                    char message[IOMSG_LEN + 1];
-                   child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-                   snprintf (message, child_iomsg_len, child_iomsg);
+                   child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+                   fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+                   message[child_iomsg_len] = '\0';
                    generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                                    message);
                    goto nml_err_ret;

diff --git a/libgfortran/io/transfer.c b/libgfortran/io/transfer.c
index 9523a14c4bf0122fb4b90d60a10b1114d0f43ae0..a86099d46f5645dd2f4068412536ef22156d5b5d 100644 (file)
--- a/libgfortran/io/transfer.c
+++ b/libgfortran/io/transfer.c
@@ -1128,8 +1128,9 @@ unformatted_read (st_parameter_dt *dtp, bt type,
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-             snprintf (message, child_iomsg_len, child_iomsg);
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }
@@ -1271,8 +1272,9 @@ unformatted_write (st_parameter_dt *dtp, bt type,
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-             snprintf (message, child_iomsg_len, child_iomsg);
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }
@@ -1763,8 +1765,9 @@ formatted_transfer_scalar_read (st_parameter_dt *dtp, bt type, void *p, int kind
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-             snprintf (message, child_iomsg_len, child_iomsg);
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }
@@ -2259,8 +2262,9 @@ formatted_transfer_scalar_write (st_parameter_dt *dtp, bt type, void *p, int kin
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-             snprintf (message, child_iomsg_len, child_iomsg);
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }

diff --git a/libgfortran/io/write.c b/libgfortran/io/write.c
index cdcaf8decb66e171298d9e85a3f6e6e82c9535e1..91d1da2007ae57991b161c42dbee6f16f959f5bf 100644 (file)
--- a/libgfortran/io/write.c
+++ b/libgfortran/io/write.c
@@ -1999,8 +1999,9 @@ list_formatted_write_scalar (st_parameter_dt *dtp, bt type, void *p, int kind,
              !(dtp->common.flags & IOPARM_HAS_IOSTAT))
            {
              char message[IOMSG_LEN + 1];
-             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-             snprintf (message, child_iomsg_len, child_iomsg);
+             child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+             fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+             message[child_iomsg_len] = '\0';
              generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                              message);
            }
@@ -2352,8 +2353,9 @@ nml_write_obj (st_parameter_dt *dtp, namelist_info *obj, index_type offset,
                      char message[IOMSG_LEN + 1];
 
                      /* Trim trailing spaces from the message.  */
-                     child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg) + 1;
-                     snprintf (message, child_iomsg_len, child_iomsg);
+                     child_iomsg_len = string_len_trim (IOMSG_LEN, child_iomsg);
+                     fstrcpy (message, child_iomsg_len, child_iomsg, child_iomsg_len);
+                     message[child_iomsg_len] = '\0';
                      generate_error (&dtp->common, dtp->u.p.child_saved_iostat,
                                      message);
                    }