[gcc r11-11287] Fortran: error recovery in frontend optimization [PR103715]

[Harald Anlauf via Gcc-cvs]

https://gcc.gnu.org/g:7294f1a7aa457fe24d11270f06fd15c2b3ffd4ab

commit r11-11287-g7294f1a7aa457fe24d11270f06fd15c2b3ffd4ab
Author: Harald Anlauf <anl...@gmx.de>
Date:   Mon Mar 18 19:36:59 2024 +0100

    Fortran: error recovery in frontend optimization [PR103715]
    
    gcc/fortran/ChangeLog:
    
            PR fortran/103715
            * frontend-passes.c (check_externals_expr): Prevent invalid read
            in case of mismatch of external subroutine with function.
    
    gcc/testsuite/ChangeLog:
    
            PR fortran/103715
            * gfortran.dg/pr103715.f90: New test.
    
    (cherry picked from commit 3be2b8f475f22c531d6cef1b041c0573b3ea5133)

Diff:
---
 gcc/fortran/frontend-passes.c          |  3 +++
 gcc/testsuite/gfortran.dg/pr103715.f90 | 12 ++++++++++++
 2 files changed, 15 insertions(+)

diff --git a/gcc/fortran/frontend-passes.c b/gcc/fortran/frontend-passes.c
index ebc5a7f3699..439a311e4a5 100644
--- a/gcc/fortran/frontend-passes.c
+++ b/gcc/fortran/frontend-passes.c
@@ -5782,6 +5782,9 @@ check_externals_expr (gfc_expr **ep, int *walk_subtrees 
ATTRIBUTE_UNUSED,
   if (e->expr_type != EXPR_FUNCTION)
     return 0;
 
+  if (e->symtree && e->symtree->n.sym->attr.subroutine)
+    return 0;
+
   sym = e->value.function.esym;
   if (sym == NULL)
     return 0;
diff --git a/gcc/testsuite/gfortran.dg/pr103715.f90 
b/gcc/testsuite/gfortran.dg/pr103715.f90
new file mode 100644
index 00000000000..72c5a31fb21
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr103715.f90
@@ -0,0 +1,12 @@
+! { dg-do compile }
+! PR fortran/103715 - ICE in gfc_find_gsymbol
+!
+! valgrind did report an invalid read in check_externals_procedure
+
+program p
+  select type (y => g()) ! { dg-error "Selector shall be polymorphic" }
+  end select
+  call g()
+end
+
+! { dg-prune-output "already being used as a FUNCTION" }