https://gcc.gnu.org/g:90d9cdfa82d9a8d63e35d928e335719a495c79e3
commit r15-7909-g90d9cdfa82d9a8d63e35d928e335719a495c79e3
Author: Thomas Koenig <tkoe...@gcc.gnu.org>
Date: Sat Mar 8 16:13:41 2025 +0100
Fix regression with -Wexternal-argument-mismatch.
The attached patch fixes an ICE regresseion where undo state was not
handled properly when generating formal from actual arguments, which
occurred under certain conditions with the newly introduced
-Wexternal-argument-mismatch option.
The fix is simple: When we are generating these symbols, we no
longer need to undo anything, so we can just remove them.
I had considered adding an extra optional argument, but decided
against it on code clarity grounds.
While looking at the code, I also saw that a member of gfc_symbol
introduced with my patch should be a bitfield of width 1.
gcc/fortran/ChangeLog:
PR fortran/119157
* gfortran.h (gfc_symbol): Make ext_dummy_arglist_mismatch a
one-bit bitfield
(gfc_pop_undo_symbol): Declare prototype.
* symbol.cc (gfc_pop_undo_symbol): New function.
* interface.cc (gfc_get_formal_from_actual_arglist): Call it
for artificially introduced formal variables.
gcc/testsuite/ChangeLog:
PR fortran/119157
* gfortran.dg/interface_57.f90: New test.
Diff:
---
gcc/fortran/gfortran.h | 3 ++-
gcc/fortran/interface.cc | 2 ++
gcc/fortran/symbol.cc | 5 +++++
gcc/testsuite/gfortran.dg/interface_57.f90 | 14 ++++++++++++++
4 files changed, 23 insertions(+), 1 deletion(-)
diff --git a/gcc/fortran/gfortran.h b/gcc/fortran/gfortran.h
index 927f22cffd17..f81be1d984c5 100644
--- a/gcc/fortran/gfortran.h
+++ b/gcc/fortran/gfortran.h
@@ -2026,7 +2026,7 @@ typedef struct gfc_symbol
/* Set if an external dummy argument is called with different argument lists.
This is legal in Fortran, but can cause problems with autogenerated
C prototypes for C23. */
- unsigned ext_dummy_arglist_mismatch;
+ unsigned ext_dummy_arglist_mismatch:1;
/* Reference counter, used for memory management.
@@ -3736,6 +3736,7 @@ void gfc_traverse_user_op (gfc_namespace *, void
(*)(gfc_user_op *));
void gfc_save_all (gfc_namespace *);
void gfc_enforce_clean_symbol_state (void);
+void gfc_pop_undo_symbol (void);
gfc_gsymbol *gfc_get_gsymbol (const char *, bool bind_c);
gfc_gsymbol *gfc_find_gsymbol (gfc_gsymbol *, const char *);
diff --git a/gcc/fortran/interface.cc b/gcc/fortran/interface.cc
index edec907d33a3..e3bc22f25e58 100644
--- a/gcc/fortran/interface.cc
+++ b/gcc/fortran/interface.cc
@@ -5836,6 +5836,8 @@ gfc_get_formal_from_actual_arglist (gfc_symbol *sym,
{
snprintf (name, GFC_MAX_SYMBOL_LEN, "_formal_%d", var_num ++);
gfc_get_symbol (name, gfc_current_ns, &s);
+ /* We do not need this in an undo table. */
+ gfc_pop_undo_symbol();
if (a->expr->ts.type == BT_PROCEDURE)
{
gfc_symbol *asym = a->expr->symtree->n.sym;
diff --git a/gcc/fortran/symbol.cc b/gcc/fortran/symbol.cc
index 81aa81df2eec..92cba4187842 100644
--- a/gcc/fortran/symbol.cc
+++ b/gcc/fortran/symbol.cc
@@ -3898,6 +3898,11 @@ enforce_single_undo_checkpoint (void)
gcc_checking_assert (single_undo_checkpoint_p ());
}
+void
+gfc_pop_undo_symbol ()
+{
+ latest_undo_chgset->syms.pop();
+}
/* Undoes all the changes made to symbols in the current statement. */
diff --git a/gcc/testsuite/gfortran.dg/interface_57.f90
b/gcc/testsuite/gfortran.dg/interface_57.f90
new file mode 100644
index 000000000000..8c99864c0fbd
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/interface_57.f90
@@ -0,0 +1,14 @@
+! { dg-do compile }
+! { dg-options "-Wexternal-argument-mismatch" }
+! PR 119157 - this used to ICE because undo state was not
+! correctly handled.
+
+MODULE lmdif_module
+ implicit none
+ CONTAINS
+ SUBROUTINE lmdif (fcn, m)
+ EXTERNAL fcn
+ integer m
+ call fcn (m)
+ END SUBROUTINE lmdif
+END MODULE
