Re: [patch, libgfortran] PR114304 - [13/14 Regression] libgfortran I/O – bogus "Semicolon not allowed as separator with DECIMAL='point'"

[Jerry D <jvdelisle2@gmail.com>]

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On 4/4/24 2:31 AM, Tobias Burnus wrote:
> Hi Jerry,
> 
--- snip ---
> The patch looks mostly like I would expect, except for decimal='point' 
> and a ';' which is *not* preceded by a space.
> 
> Thanks for working on it.
> 
> Regarding the 'except' case:
> 
--- snip ---
> i.e. for the following string, I had *expected an error*:
> 
>   point, isreal =  F , testinput = ";"n=          42  ios=           0
>   point, isreal =  F , testinput = "5;"n=           5  ios=           0
>   point, isreal =  T , testinput = "8;"r=   8.00000000      ios= 0
>   point, isreal =  T , testinput = "3.3;"r=   3.29999995      ios= 0
>   point, isreal =  T , testinput = "3,3;"r=   3.00000000      ios= 0
> 
--- snip ---
> I have attached the modified testcase linked above; consider adding it 
> as well. - Changes to the one of the attachment:
> - I added a few additional (albeit boring) tests
> - I added an expected output + error diagnostic.
> 
> The testcase assumes an error for ';' as separator (with 'point'), 
> unless there is a space before it.
> 
--- snip ---

Here attached is the revised patch.  I replaced the new test case I had 
with the one you provided modified and it now passes.

I modified the test case pr105473.f90 to expect the error on semicolon.

Regression tested on X86_64.  OK for trunk and a bit later back port to 13?

Cheers,

Jerry

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commit 9c8318cd8703d49ad7563e89765f8849ebc14385
Author: Jerry DeLisle <jvdelisle@gcc.gnu.org>
Date:   Thu Apr 4 13:48:20 2024 -0700

    libfortran: Fix handling of formatted separators.
    
            PR libfortran/114304
            PR libfortran/105473
    
    libgfortran/ChangeLog:
    
            * io/list_read.c (eat_separator): Add logic to handle spaces
            preceding a comma or semicolon such that that a 'null' read
            occurs without error at the end of comma or semicolon
            terminated input lines. Add check and error message for ';'.
    
    gcc/testsuite/ChangeLog:
    
            * gfortran.dg/pr105473.f90: Modify to verify new error message.
            * gfortran.dg/pr114304.f90: New test.

diff --git a/gcc/testsuite/gfortran.dg/pr105473.f90 b/gcc/testsuite/gfortran.dg/pr105473.f90
index 2679f6bb447..863a312c794 100644
--- a/gcc/testsuite/gfortran.dg/pr105473.f90
+++ b/gcc/testsuite/gfortran.dg/pr105473.f90
@@ -9,11 +9,11 @@
   n = 999; m = 777; r=1.2345
   z = cmplx(0.0,0.0)
 
-! Check that semi-colon is allowed as separator with decimal=point.
+! Check that semi-colon is not allowed as separator with decimal=point.
   ios=0
   testinput = '1;17;3.14159'
   read(testinput,*,decimal='point',iostat=ios) n, m, r
-  if (ios /= 0) stop 1
+  if (ios /= 5010) stop 1
 
 ! Check that semi-colon allowed as a separator with decimal=point.
   ios=0
diff --git a/gcc/testsuite/gfortran.dg/pr114304.f90 b/gcc/testsuite/gfortran.dg/pr114304.f90
new file mode 100644
index 00000000000..8344a9ea857
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr114304.f90
@@ -0,0 +1,101 @@
+! { dg-do run }
+!
+! PR fortran/114304
+!
+! See also PR fortran/105473
+!
+! Testing: Does list-directed reading an integer/real allow some non-integer input?
+!
+! Note: GCC result comments before fix of this PR.
+
+  implicit none
+  call t(.true.,  'comma', ';') ! No error shown
+  call t(.false., 'point', ';') ! /!\ gfortran: no error, others: error
+  call t(.false., 'comma', ',') ! Error shown
+  call t(.true.,  'point', ',') ! No error shown
+  call t(.false., 'comma', '.') ! Error shown
+  call t(.false., 'point', '.') ! Error shown
+  call t(.false., 'comma', '5.') ! Error shown
+  call t(.false., 'point', '5.') ! gfortran/flang: Error shown, ifort: no error
+  call t(.false., 'comma', '5,') ! gfortran: error; others: no error
+  call t(.true.,  'point', '5,') ! No error shown
+  call t(.true.,  'comma', '5;') ! No error shown
+  call t(.false., 'point', '5;') ! /!\ gfortran: no error shown, others: error
+  call t(.true.,  'comma', '7 .') ! No error shown
+  call t(.true.,  'point', '7 .') ! No error shown
+  call t(.true.,  'comma', '7 ,') ! /!\ gfortran: error; others: no error
+  call t(.true.,  'point', '7 ,') ! No error shown
+  call t(.true.,  'comma', '7 ;') ! No error shown
+  call t(.true.,  'point', '7 ;') ! No error shown
+
+!  print *, '---------------'
+
+  call t(.false., 'comma', '8.', .true.) ! Error shown
+  call t(.true.,  'point', '8.', .true.) ! gfortran/flang: Error shown, ifort: no error
+  call t(.true.,  'comma', '8,', .true.) ! gfortran: error; others: no error
+  call t(.true.,  'point', '8,', .true.) ! No error shown
+  call t(.true.,  'comma', '8;', .true.) ! No error shown
+  call t(.false., 'point', '8;', .true.) ! /!\ gfortran: no error shown, others: error
+  call t(.true.,  'comma', '9 .', .true.) ! No error shown
+  call t(.true.,  'point', '9 .', .true.) ! No error shown
+  call t(.true.,  'comma', '9 ,', .true.) ! /!\ gfortran: error; others: no error
+  call t(.true.,  'point', '9 ,', .true.) ! No error shown
+  call t(.true.,  'comma', '9 ;', .true.) ! No error shown
+  call t(.true.,  'point', '9 ;', .true.) ! No error shown
+  call t(.false., 'comma', '3,3.', .true.) ! Error shown
+  call t(.false., 'point', '3.3.', .true.) ! Error shown
+  call t(.false., 'comma', '3,3,', .true.) ! gfortran/flang: no error; ifort: error
+  call t(.true.,  'comma', '3,3;', .true.) ! No error shown
+  call t(.false., 'point', '3.3;', .true.) ! gfortran/flang: no error; ifort: error
+  call t(.true.,  'comma', '4,4 .', .true.) ! N error shown
+  call t(.true.,  'point', '4.4 .', .true.) ! No error shown
+  call t(.true.,  'comma', '4,4 ,', .true.) ! /!\ gfortran: error; others: no error
+  call t(.true.,  'point', '4.4 ,', .true.) ! No error shown
+  call t(.true.,  'comma', '4,4 ;', .true.) ! No error shown
+  call t(.true.,  'point', '4.4 ;', .true.) ! No error shown
+
+!  print *, '---------------'
+
+  call t(.true.,  'comma', '8', .true.)
+  call t(.true.,  'point', '8', .true.)
+  call t(.true.,  'point', '9 ;', .true.)
+  call t(.true.,  'comma', '3;3.', .true.)
+  call t(.true.,  'point', '3,3.', .true.)
+  call t(.true.,  'comma', '3;3,', .true.)
+  call t(.true.,  'comma', '3;3;', .true.)
+  call t(.true.,  'point', '3,3;', .true.)
+  call t(.true.,  'comma', '4;4 .', .true.)
+  call t(.true.,  'point', '4,4 .', .true.)
+  call t(.true.,  'comma', '4;4 ,', .true.)
+  call t(.true.,  'point', '4,4 ,', .true.)
+  call t(.true.,  'comma', '4;4 ;', .true.)
+  call t(.true.,  'point', '4,4 ;', .true.)
+contains
+subroutine t(valid, dec, testinput, isreal)
+  logical, value :: valid
+  character(len=*) :: dec, testinput
+  logical, optional :: isreal
+  logical :: isreal2
+  integer n,ios
+  real :: r
+  r = 42; n = 42
+  isreal2 = .false.
+  if (present(isreal)) isreal2 = isreal
+
+  if (isreal2) then
+    read(testinput,*,decimal=dec,iostat=ios) r
+    if ((valid .and. ios /= 0) .or. (.not.valid .and. ios == 0)) then
+      print '(*(g0))', valid, ', ', dec,', isreal = ',isreal2,', testinput = "',testinput,'"',', r=',r,' ios=',ios
+      print *, 'ERROR'
+      stop 1
+    end if
+  else
+    read(testinput,*,decimal=dec,iostat=ios) n
+    if ((valid .and. ios /= 0) .or. (.not.valid .and. ios == 0)) then
+      print '(*(g0))', valid, ', ', dec,', isreal = ',isreal2,', testinput = "',testinput,'"',', n=',n,' ios=',ios
+      print *, 'ERROR'
+      stop 1
+    end if
+  end if
+end
+end program
diff --git a/libgfortran/io/list_read.c b/libgfortran/io/list_read.c
index fb3f7dbc34d..6bf59329add 100644
--- a/libgfortran/io/list_read.c
+++ b/libgfortran/io/list_read.c
@@ -461,11 +461,30 @@ eat_separator (st_parameter_dt *dtp)
   int c, n;
   int err = 0;
 
-  eat_spaces (dtp);
   dtp->u.p.comma_flag = 0;
+  c = next_char (dtp);
+  if (c == ' ')
+    {
+      eat_spaces (dtp);
+      c = next_char (dtp);
+      if (c == ',')
+	{
+	  if (dtp->u.p.current_unit->decimal_status == DECIMAL_COMMA)
+	    unget_char (dtp, ';');
+	  dtp->u.p.comma_flag = 1;
+	  eat_spaces (dtp);
+	  return err;
+	}
+      if (c == ';')
+	{
+	  if (dtp->u.p.current_unit->decimal_status == DECIMAL_POINT)
+	    unget_char (dtp, ',');
+	  dtp->u.p.comma_flag = 1;
+	  eat_spaces (dtp);
+	  return err;
+	}
+    }
 
-  if ((c = next_char (dtp)) == EOF)
-    return LIBERROR_END;
   switch (c)
     {
     case ',':
@@ -476,8 +495,18 @@ eat_separator (st_parameter_dt *dtp)
 	  unget_char (dtp, c);
 	  break;
 	}
-    /* Fall through. */
+      dtp->u.p.comma_flag = 1;
+      eat_spaces (dtp);
+      break;
+
     case ';':
+      if (dtp->u.p.current_unit->decimal_status == DECIMAL_POINT)
+	{
+	  generate_error (&dtp->common, LIBERROR_READ_VALUE,
+	   "Semicolon not allowed as separator with DECIMAL='point'");
+	  unget_char (dtp, c);
+	  break;
+	}
       dtp->u.p.comma_flag = 1;
       eat_spaces (dtp);
       break;