[gcc r12-11223] lto/113207 - fix free_lang_data_in_type

[Richard Biener]

https://gcc.gnu.org/g:07490d983161912fa314607c5a5beb9c49cc4a3f

commit r12-11223-g07490d983161912fa314607c5a5beb9c49cc4a3f
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Feb 3 14:27:01 2025 +0100

    lto/113207 - fix free_lang_data_in_type
    
    When we process function types we strip volatile and const qualifiers
    after building a simplified type variant (which preserves those).
    The qualified type handling of both isn't really compatible, so avoid
    bad interaction by swapping this, first dropping const/volatile
    qualifiers and then building the simplified type thereof.
    
            PR lto/113207
            * ipa-free-lang-data.cc (free_lang_data_in_type): First drop
            const/volatile qualifiers from function argument types,
            then build a simplified type.
    
            * gcc.dg/pr113207.c: New testcase.
    
    (cherry picked from commit a55e14b239181381204c615335929b3316d75370)

Diff:
---
 gcc/ipa-free-lang-data.cc       |  3 +--
 gcc/testsuite/gcc.dg/pr113207.c | 10 ++++++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/gcc/ipa-free-lang-data.cc b/gcc/ipa-free-lang-data.cc
index a742156858cd..6fef047e3beb 100644
--- a/gcc/ipa-free-lang-data.cc
+++ b/gcc/ipa-free-lang-data.cc
@@ -436,9 +436,7 @@ free_lang_data_in_type (tree type, class free_lang_data_d *fld)
 	 different front ends.  */
       for (tree p = TYPE_ARG_TYPES (type); p; p = TREE_CHAIN (p))
 	{
-	  TREE_VALUE (p) = fld_simplified_type (TREE_VALUE (p), fld);
 	  tree arg_type = TREE_VALUE (p);
-
 	  if (TYPE_READONLY (arg_type) || TYPE_VOLATILE (arg_type))
 	    {
 	      int quals = TYPE_QUALS (arg_type)
@@ -448,6 +446,7 @@ free_lang_data_in_type (tree type, class free_lang_data_d *fld)
 	      if (!fld->pset.add (TREE_VALUE (p)))
 		free_lang_data_in_type (TREE_VALUE (p), fld);
 	    }
+	  TREE_VALUE (p) = fld_simplified_type (TREE_VALUE (p), fld);
 	  /* C++ FE uses TREE_PURPOSE to store initial values.  */
 	  TREE_PURPOSE (p) = NULL;
 	}
diff --git a/gcc/testsuite/gcc.dg/pr113207.c b/gcc/testsuite/gcc.dg/pr113207.c
new file mode 100644
index 000000000000..81f53d8fcc2f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr113207.c
@@ -0,0 +1,10 @@
+/* { dg-compile } */
+/* { dg-require-effective-target lto } */
+/* { dg-options "-flto -fchecking" }  */
+
+typedef struct cl_lispunion *cl_object;
+struct cl_lispunion {};
+cl_object cl_error() __attribute__((noreturn));
+volatile cl_object cl_coerce_value0;
+void cl_coerce() { cl_error(); }
+void L66safe_canonical_type(cl_object volatile);