[patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[Jerry DeLisle]

[-- Attachment #1: Type: text/plain, Size: 611 bytes --]

The attached patch fixes this by adding code to match a default character
expression if the left paren is first matched on a READ statement.  If the
expression is matched the dt-format is set and processing continues.  Otherwise
execution drops through to match a control list as usual.

Regression tested on x86-64-linux. Test case attached.

OK for trunk?

Regards,

Jerry

2016-05-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/52393
	* io.c (match_io): For READ, try to match a default character
	expression. If found, set the dt format expression to this,
	otherwise go back and try control list.

[-- Attachment #2: pr52393.diff --]
[-- Type: text/x-patch, Size: 2185 bytes --]

diff --git a/gcc/fortran/io.c b/gcc/fortran/io.c
index da0e1c5..204cce2 100644
--- a/gcc/fortran/io.c
+++ b/gcc/fortran/io.c
@@ -3689,7 +3689,7 @@ match_io (io_kind k)
   gfc_symbol *sym;
   int comma_flag;
   locus where;
-  locus spec_end;
+  locus spec_end, control;
   gfc_dt *dt;
   match m;
 
@@ -3751,21 +3751,56 @@ match_io (io_kind k)
     {
       /* Before issuing an error for a malformed 'print (1,*)' type of
 	 error, check for a default-char-expr of the form ('(I0)').  */
-      if (k == M_PRINT && m == MATCH_YES)
-	{
-	  /* Reset current locus to get the initial '(' in an expression.  */
-	  gfc_current_locus = where;
-	  dt->format_expr = NULL;
-	  m = match_dt_format (dt);
+      if (m == MATCH_YES)
+        {
+	  control = gfc_current_locus;
+	  if (k == M_PRINT)
+	    {
+	      /* Reset current locus to get the initial '(' in an expression.  */
+	      gfc_current_locus = where;
+	      dt->format_expr = NULL;
+	      m = match_dt_format (dt);
 
-	  if (m == MATCH_ERROR)
-	    goto cleanup;
-	  if (m == MATCH_NO || dt->format_expr == NULL)
-	    goto syntax;
+	      if (m == MATCH_ERROR)
+		goto cleanup;
+	      if (m == MATCH_NO || dt->format_expr == NULL)
+		goto syntax;
 
-	  comma_flag = 1;
-	  dt->io_unit = default_unit (k);
-	  goto get_io_list;
+	      comma_flag = 1;
+	      dt->io_unit = default_unit (k);
+	      goto get_io_list;
+	    }
+	  if (k == M_READ)
+	    {
+	      /* Reset current locus to get the initial '(' in an expression.  */
+	      gfc_current_locus = where;
+	      dt->format_expr = NULL;
+	      m = gfc_match_expr (&dt->format_expr);
+	      if (m == MATCH_YES)
+	        {
+		  if (dt->format_expr
+		      && dt->format_expr->ts.type == BT_CHARACTER)
+		    {
+		      comma_flag = 1;
+		      dt->io_unit = default_unit (k);
+		      goto get_io_list;
+		    }
+		  else
+		    {
+		      gfc_free_expr (dt->format_expr);
+		      dt->format_expr = NULL;
+		      gfc_current_locus = control;
+		    }
+		}
+	      else
+	        {
+		  gfc_clear_error ();
+		  gfc_undo_symbols ();
+		  gfc_free_expr (dt->format_expr);
+		  dt->format_expr = NULL;
+		  gfc_current_locus = control;
+		}
+	    }
 	}
     }
 

[-- Attachment #3: fmt_read_3.f90 --]
[-- Type: text/x-fortran, Size: 300 bytes --]

! { dg-do compile }
! PR52392 "READ format" statement with parenthesed default-char-expr
PROGRAM ReadMeTwo
  IMPLICIT NONE
  CHARACTER(10) :: var
  var = "TestStr"
  PRINT ('(') // 'A)', var 
  PRINT ('(') // 'A)', var 
  READ ('(') // 'A)', var  
  PRINT *, var
  READ *, var
END PROGRAM ReadMeTwo

Re: [patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[FX]

> 2016-05-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
> 
> 	PR fortran/52393
> 	* io.c (match_io): For READ, try to match a default character
> 	expression. If found, set the dt format expression to this,
> 	otherwise go back and try control list.

OK. Maybe you could add some “negative” tests too? To be sure we still catch malformed parenthesized formats?

FX

Re: [patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[Jerry DeLisle]

On 06/01/2016 12:25 AM, FX wrote:
>> 2016-05-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
>>
>> 	PR fortran/52393
>> 	* io.c (match_io): For READ, try to match a default character
>> 	expression. If found, set the dt format expression to this,
>> 	otherwise go back and try control list.
> 
> OK. Maybe you could add some “negative” tests too? To be sure we still catch malformed parenthesized formats?
> 
> FX
> 

Thanks for review!  yes I will add some tests.

Jerry

Re: [patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[H.J. Lu]

On Wed, Jun 1, 2016 at 9:28 AM, Jerry DeLisle <jvdelisle@charter.net> wrote:
> On 06/01/2016 12:25 AM, FX wrote:
>>> 2016-05-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
>>>
>>>      PR fortran/52393
>>>      * io.c (match_io): For READ, try to match a default character
>>>      expression. If found, set the dt format expression to this,
>>>      otherwise go back and try control list.
>>
>> OK. Maybe you could add some “negative” tests too? To be sure we still catch malformed parenthesized formats?
>>
>> FX
>>
>
> Thanks for review!  yes I will add some tests.
>

It caused:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71404


-- 
H.J.

Re: [patch, fortran] PR52393 I/O: "READ format" statement with parenthesized default-char-expr

[Jerry DeLisle]

On 06/03/2016 12:40 PM, H.J. Lu wrote:
> On Wed, Jun 1, 2016 at 9:28 AM, Jerry DeLisle <jvdelisle@charter.net> wrote:
>> On 06/01/2016 12:25 AM, FX wrote:
>>>> 2016-05-30  Jerry DeLisle  <jvdelisle@gcc.gnu.org>
>>>>
>>>>      PR fortran/52393
>>>>      * io.c (match_io): For READ, try to match a default character
>>>>      expression. If found, set the dt format expression to this,
>>>>      otherwise go back and try control list.
>>>
>>> OK. Maybe you could add some “negative” tests too? To be sure we still catch malformed parenthesized formats?
>>>
>>> FX
>>>
>>
>> Thanks for review!  yes I will add some tests.
>>
> 
> It caused:
> 
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71404
> 
> 

Patch committed.

Author: jvdelisle
Date: Sun Jun  5 19:49:59 2016
New Revision: 237108

URL: https://gcc.gnu.org/viewcvs?rev=237108&root=gcc&view=rev
Log:
2016-06-05  Jerry DeLisle  <jvdelisle@gcc.gnu.org>

	PR fortran/71404
	* io.c (match_io): For READ, commit in pending symbols in the
	current statement before trying to match an expression so that
	if the match fails and we undo symbols we dont toss good symbols.

Modified:
    trunk/gcc/fortran/ChangeLog
    trunk/gcc/fortran/io.c