Dear All, debugging this PR sent me deep into the woods. To find where things went wrong, I ran two parallel gdb sessions on a testcase once with character(kind=1) and with character(kind=4), and found that the code diverged in get_array_span, as the TYPE_STRING_FLAG was set for the former but not set for the latter.
I did not find why it was set at all for the former, but decided that it should be set for all character types. That fixed it. (If someone thinks that I am wrong, please speak up!) This allowed to disable the temporary workarounds I put in testcase deferred_character_39.f90, so this should guarantee that the present fix works and does not break something obvious. Regtested on x86_64-pc-linux-gnu. OK for mainline? And for joint backport with the fix for pr108581 to 15-branch? Thanks, Harald
From 9225d903338784b199b6530483c84f4983fd0753 Mon Sep 17 00:00:00 2001 From: Harald Anlauf <[email protected]> Date: Wed, 24 Sep 2025 20:36:32 +0200 Subject: [PATCH] Fortran: ICE in character(kind=4) deferred-length array reference [PR121939] PR fortran/121939 gcc/fortran/ChangeLog: * trans-types.cc (gfc_init_types): Set string flag for all character types. gcc/testsuite/ChangeLog: * gfortran.dg/deferred_character_39.f90: Disable temporary workaround for character(kind=4) deferred-length bug. --- gcc/fortran/trans-types.cc | 1 + gcc/testsuite/gfortran.dg/deferred_character_39.f90 | 12 +++++++----- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/gcc/fortran/trans-types.cc b/gcc/fortran/trans-types.cc index a9e512ed135..26645b0f7f6 100644 --- a/gcc/fortran/trans-types.cc +++ b/gcc/fortran/trans-types.cc @@ -1135,6 +1135,7 @@ gfc_init_types (void) { type = gfc_build_uint_type (gfc_character_kinds[index].bit_size); type = build_qualified_type (type, TYPE_UNQUALIFIED); + TYPE_STRING_FLAG (type) = 1; snprintf (name_buf, sizeof(name_buf), "character(kind=%d)", gfc_character_kinds[index].kind); PUSH_TYPE (name_buf, type); diff --git a/gcc/testsuite/gfortran.dg/deferred_character_39.f90 b/gcc/testsuite/gfortran.dg/deferred_character_39.f90 index 564f94bb9bd..38ec431fc60 100644 --- a/gcc/testsuite/gfortran.dg/deferred_character_39.f90 +++ b/gcc/testsuite/gfortran.dg/deferred_character_39.f90 @@ -1,5 +1,6 @@ ! { dg-do run } ! PR fortran/108581 - issues with rank-2 deferred-length character arrays +! PR fortran/121939 - ICE in gfc_conv_string_parameter program p call pr108581 @@ -79,8 +80,8 @@ subroutine test2 allocate (a, source = reshape (str1,[1,size(str1)])) allocate (b, source = reshape (str1,[1,size(str1)])) allocate (c, source = reshape (str4,[1,size(str4)])) -! allocate (d, source=c) ! ICE, tracked as pr121939 - d => c + allocate (d, source = c) ! fixed with pr121939 +! d => c ! Positive non-unit stride s0 = concat (str1(1::2)) write(s1,'(4A)') a(1,1::2) @@ -124,13 +125,14 @@ subroutine test2 if (s2 /= s0) stop 26 if (s3 /= s0) stop 27 if (s4 /= s0) stop 28 - deallocate (a,b,c) + deallocate (a,b,c,d) ! More complex cases with shape=[2,4] allocate (e, source = reshape (str2,[2,size(str2,2)])) allocate (f, source = reshape (str2,[2,size(str2,2)])) allocate (g, source = reshape (str5,[2,size(str5,2)])) - h => g + allocate (h, source = reshape (str5,[2,size(str5,2)])) ! fixed with pr121939 +! h => g s0 = concat (str2(1,3:1:-2)) write(s1,'(4A)') e(1,3:1:-2) write(s2,'(4A)') f(1,3:1:-2) @@ -220,7 +222,7 @@ subroutine test2 if (s2 /= s0) stop 66 if (s3 /= s0) stop 67 if (s4 /= s0) stop 68 - deallocate (e,f,g) + deallocate (e,f,g,h) contains -- 2.51.0
