[jit] use helper to obtain method signature (#35344)

`mini_method_get ()` doesn't guarantee that `method->signature` is set.

Fixes a problem in https://github.com/mono/mono/pull/19624

/cc @lewing

Co-authored-by: lewurm <lewurm@users.noreply.github.com>

diff --git a/src/mono/mono/mini/method-to-ir.c b/src/mono/mono/mini/method-to-ir.c
index b98b192..6ec2d8b 100644 (file)
--- a/src/mono/mono/mini/method-to-ir.c
+++ b/src/mono/mono/mini/method-to-ir.c
@@ -8924,6 +8924,7 @@ calli_end:
                        MonoInst *val;
                        MonoClass *enum_class;
                        MonoMethod *has_flag;
+                       MonoMethodSignature *has_flag_sig;
 
                        --sp;
                        val = *sp;
@@ -8977,8 +8978,9 @@ calli_end:
                            (has_flag = mini_get_method (cfg, method, callvirt_token, NULL, generic_context)) &&
                            has_flag->klass == mono_defaults.enum_class &&
                            !strcmp (has_flag->name, "HasFlag") &&
-                           has_flag->signature->hasthis &&
-                           has_flag->signature->param_count == 1) {
+                           (has_flag_sig = mono_method_signature_internal (has_flag)) &&
+                           has_flag_sig->hasthis &&
+                           has_flag_sig->param_count == 1) {
                                CHECK_TYPELOAD (enum_class);
 
                                if (enum_class == klass) {