[PATCH] Fix ICE in tree_inlinable_function_p.

[Martin Liška]

After g:1a2a7096e5e20d736c6138179470b21aa5a74864 we forbid inlining
for a VLA types. What we miss is setting inline_forbidden_reason
variable.
Fixes:

./xgcc -B. -O3 -c /home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr99122-2.c 
-Winline

during GIMPLE pass: local-fnsummary
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr99122-2.c: In function 
‘foo’:
/home/marxin/Programming/gcc/gcc/testsuite/gcc.dg/pr99122-2.c:21:1: internal 
compiler error: Segmentation fault
   21 | }
      | ^
0xe8b2ca crash_signal
        /home/marxin/Programming/gcc/gcc/toplev.c:327
0x1a92733 pp_format(pretty_printer*, text_info*)
        /home/marxin/Programming/gcc/gcc/pretty-print.c:1096
0x1a76b90 diagnostic_report_diagnostic(diagnostic_context*, diagnostic_info*)
        /home/marxin/Programming/gcc/gcc/diagnostic.c:1244
0x1a79994 diagnostic_impl
        /home/marxin/Programming/gcc/gcc/diagnostic.c:1406
0x1a79994 warning(int, char const*, ...)
        /home/marxin/Programming/gcc/gcc/diagnostic.c:1527
0xf1bb16 tree_inlinable_function_p(tree_node*)
        /home/marxin/Programming/gcc/gcc/tree-inline.c:4123
0xc3f1c5 compute_fn_summary(cgraph_node*, bool)
        /home/marxin/Programming/gcc/gcc/ipa-fnsummary.c:3110
0xc3f937 compute_fn_summary_for_current
        /home/marxin/Programming/gcc/gcc/ipa-fnsummary.c:3160
0xc3f937 execute
        /home/marxin/Programming/gcc/gcc/ipa-fnsummary.c:4768

Ready to be installed?
Thanks,
Martin

gcc/ChangeLog:

        * tree-inline.c (inline_forbidden_p): Set
        inline_forbidden_reason.
---
 gcc/tree-inline.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c
index c993b1fee8a..1dcb31c0267 100644
--- a/gcc/tree-inline.c
+++ b/gcc/tree-inline.c
@@ -4027,10 +4027,20 @@ inline_forbidden_p (tree fndecl)
      the caller.  */
   if (COMPLETE_TYPE_P (TREE_TYPE (TREE_TYPE (fndecl)))
       && !poly_int_tree_p (TYPE_SIZE (TREE_TYPE (TREE_TYPE (fndecl)))))
-    return true;
+    {
+      inline_forbidden_reason
+       = G_("function %q+F can never be inlined because "
+            "it has a VLA return argument");
+      return true;
+    }
   for (tree parm = DECL_ARGUMENTS (fndecl); parm; parm = DECL_CHAIN (parm))
     if (!poly_int_tree_p (DECL_SIZE (parm)))
-      return true;
+      {
+       inline_forbidden_reason
+         = G_("function %q+F can never be inlined because "
+              "it has a VLA argument");
+       return true;
+      }
 
   FOR_EACH_BB_FN (bb, fun)
     {
--
2.30.1