Re: [Patch, Fortran] PR 92793 - fix column used for error diagnostic

[Thomas Schwinge <thomas@codesourcery.com>]

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Hi!

On 2020-10-30T11:35:15+0100, I wrote:
> On 2019-12-04T14:37:55+0100, Tobias Burnus <tobias@codesourcery.com> wrote:
>> As reported internally by Frederik, gfortran currently passes
>> LOCATION_COLUMN == 0 to the middle end. The reason for that is how
>> parsing works – gfortran reads the input line by line.
>>
>> For internal error diagnostic (fortran/error.c), the column location was
>> corrected –  but not for locations passed to the middle end. Hence, the
>> diagnostic there wasn't optimal.
>
> Thanks for fixing that aspect.

While working on something completely different -- of course...  ;-) -- I
ran into:

>> Fixed by introducing a new function; now one only needs to make sure
>> that no new code will re-introduce "lb->location" :-)

... another *existing instance* of this problem.


>> -      space = build_decl (sym->declared_at.lb->location,
>> +      space = build_decl (gfc_get_location (&sym->declared_at),

The same change is required in
'gcc/fortran/trans.c:gfc_set_backend_locus'.

That took me a while to figure out...  :-| In OMP offloading compilation
I saw diagnostics *with* column location information for C, C++, but the
very same diagnostics *without* column location information for Fortran.
Once I had some understood the Fortran front end locaiton processing --
uh...  ;-\ -- I came up with the attached patch to "Further improve
Fortran column location information [PR92793]".  OK to push?  (No
testsuite regressions.)


Grüße
 Thomas


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From 3f284dd076b313c2ffbd02a8d7327118ce910c49 Mon Sep 17 00:00:00 2001
From: Thomas Schwinge <thomas@codesourcery.com>
Date: Thu, 29 Oct 2020 14:42:28 +0100
Subject: [PATCH] Further improve Fortran column location information [PR92793]

Building on top of commit 9c81750c5bedd7883182ee2684a012c6210ebe1d "Fortran] PR
92793 - fix column used for error diagnostic", there is another place where we
have to use 'gfc_get_location' returning column-corrected locations.

For example, this improves column location information for OMP constructs.

	gcc/fortran/
	PR fortran/92793
	* trans.c (gfc_set_backend_locus): Use 'gfc_get_location'.
	gcc/testsuite/
	PR fortran/92793
	* gfortran.dg/goacc/pr92793-1.f90: Adjust.
---
 gcc/fortran/trans.c                           |  2 +-
 gcc/testsuite/gfortran.dg/goacc/pr92793-1.f90 | 24 +++++++++----------
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/gcc/fortran/trans.c b/gcc/fortran/trans.c
index 8caa625ab0e8..72ea24125232 100644
--- a/gcc/fortran/trans.c
+++ b/gcc/fortran/trans.c
@@ -1829,7 +1829,7 @@ void
 gfc_set_backend_locus (locus * loc)
 {
   gfc_current_backend_file = loc->lb->file;
-  input_location = loc->lb->location;
+  input_location = gfc_get_location (loc);
 }
 
 
diff --git a/gcc/testsuite/gfortran.dg/goacc/pr92793-1.f90 b/gcc/testsuite/gfortran.dg/goacc/pr92793-1.f90
index a572c6b3437b..72dd6b7b8f81 100644
--- a/gcc/testsuite/gfortran.dg/goacc/pr92793-1.f90
+++ b/gcc/testsuite/gfortran.dg/goacc/pr92793-1.f90
@@ -13,22 +13,22 @@ subroutine check ()
   integer :: i, j, sum, diff
 
  !$acc    parallel &
-     !$acc & & ! Fortran location information points to the last line of the directive, and there is no column location information.
-!$acc  && ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:18:0\\\] #pragma acc parallel" 1 "original" } }
-  !$acc & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:18:0\\\] #pragma omp target oacc_parallel" 1 "gimple" } }
+     !$acc & & ! Fortran location information points to the last line, and last character of the directive.
+!$acc  && ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:18:123\\\] #pragma acc parallel" 1 "original" } }
+  !$acc & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:18:123\\\] #pragma omp target oacc_parallel" 1 "gimple" } }
       !$acc loop &
-    !$acc & & ! Fortran location information points to the last line of the directive, and there is no column location information.
-      !$acc  &   & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:26:0\\\] #pragma acc loop" 1 "original" } }
-     !$acc &     & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:26:0\\\] #pragma acc loop" 1 "gimple" } }
+    !$acc & & ! Fortran location information points to the last line, and last character of the directive.
+      !$acc  &   & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:26:22\\\] #pragma acc loop" 1 "original" } }
+     !$acc &     & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:26:22\\\] #pragma acc loop" 1 "gimple" } }
     !$acc&       reduction  ( +    : sum ) & ! { dg-line sum1 }
  !$acc && ! Fortran location information points to the ':' in 'reduction(+:sum)'.
    !$acc   &    &  ! { dg-message "36: location of the previous reduction for 'sum'" "" { target *-*-* } sum1 }
 !$acc&     independent
   do i = 1, 10
       !$acc loop &
-!$acc & & ! Fortran location information points to the last line of the directive, and there is no column location information.
-   !$acc & & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:36:0\\\] #pragma acc loop" 1 "original" } }
-    !$acc & & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:36:0\\\] #pragma acc loop" 1 "gimple" } }
+!$acc & & ! Fortran location information points to the last line, and last character of the directive.
+   !$acc & & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:36:34\\\] #pragma acc loop" 1 "original" } }
+    !$acc & & ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:36:34\\\] #pragma acc loop" 1 "gimple" } }
   !$acc & reduction(-: diff     ) &
              !$acc&reduction(- :    sum) & ! { dg-line sum2 }
             !$acc & & ! Fortran location information points to the ':' in 'reduction(-:sum)'.
@@ -38,9 +38,9 @@ subroutine check ()
            sum &
    & = &
       & 1
-        ! Fortran location information points to the last line of the statement, and there is no column location information.
-        ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:40:0\\\] sum = 1" 1 "original" } }
-        ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:40:0\\\] sum = 1" 1 "gimple" } }
+        ! Fortran location information points to the last line, and last character of the statement.
+        ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:40:9\\\] sum = 1" 1 "original" } }
+        ! { dg-final { scan-tree-dump-times "pr92793-1\\\.f90:40:9\\\] sum = 1" 1 "gimple" } }
      end do
   end do
 !$acc end  parallel
-- 
2.17.1