[mono][aot] Generate 'native-indirect' wrappers in full-aot mode. (#85923)

Fixes #80853.

Author: vargaz

src/libraries/System.Runtime.InteropServices/tests/LibraryImportGenerator.Tests/FunctionPointerTests.cs

@@ -115,5 +115,17 @@ static int CallbackUnmanagedStdcall(int a, int b)
                 return Callback(a, b);
             }
         }
+
+        [UnmanagedCallersOnly]
+        public static int Increment (int i) {
+            return i + 1;
+        }
+
+        [Fact]
+        public unsafe void CalliUnmanaged()
+        {
+            delegate* unmanaged<int, int> callbackProc = (delegate* unmanaged<int, int>)&Increment;
+            Assert.Equal(6, callbackProc(5));
+        }
     }
 }

src/mono/mono/metadata/marshal.c

@@ -3867,17 +3867,11 @@ mono_marshal_get_native_func_wrapper_indirect (MonoClass *caller_class, MonoMeth
 	if ((res = mono_marshal_find_in_cache (cache, sig)))
 	    return res;
 
-#if 0
-	fprintf (stderr, "generating wrapper for signature %s\n", mono_signature_full_name (sig));
-#endif
-
-	/* FIXME: better wrapper name */
-	char * name = g_strdup_printf ("wrapper_native_indirect_%p", sig);
+	char *name = mono_signature_to_name (sig, "wrapper_native_indirect");
 	MonoMethodBuilder *mb = mono_mb_new (caller_class, name, MONO_WRAPPER_MANAGED_TO_NATIVE);
 	mb->method->save_lmf = 1;
 
 	WrapperInfo *info = mono_wrapper_info_create (mb, WRAPPER_SUBTYPE_NATIVE_FUNC_INDIRECT);
-	//info->d.managed_to_native.method = NULL;
 	info->d.native_func.klass = caller_class;
 	info->d.native_func.sig = sig;
 
@@ -3889,6 +3883,7 @@ mono_marshal_get_native_func_wrapper_indirect (MonoClass *caller_class, MonoMeth
 	mono_marshal_emit_native_wrapper (image, mb, sig, piinfo, mspecs, /*func*/NULL, flags);
 	g_free (mspecs);
 
+	/* Add an extra argument which the caller will use to pass in the ftnptr to call */
 	MonoMethodSignature *csig = mono_metadata_signature_dup_add_this (image, sig, mono_defaults.int_class);
 	csig->pinvoke = 0;
 

src/mono/mono/mini/aot-compiler.c

@@ -9659,6 +9659,13 @@ compile_method (MonoAotCompile *acfg, MonoMethod *method)
 			add_gsharedvt_wrappers (acfg, mono_method_signature_internal (cfg->method), FALSE, TRUE, TRUE);
 	}
 
+	for (GSList *l = cfg->pinvoke_calli_signatures; l; l = l->next) {
+		MonoMethodSignature *sig = mono_metadata_signature_dup ((MonoMethodSignature*)l->data);
+
+		MonoMethod *wrapper = mono_marshal_get_native_func_wrapper_indirect (cfg->method->klass, sig, TRUE);
+		add_extra_method (acfg, wrapper);
+	}
+
 	if (cfg->llvm_only)
 		acfg->stats.llvm_count ++;
 

src/mono/mono/mini/method-to-ir.c

@@ -7471,6 +7471,10 @@ mono_method_to_ir (MonoCompile *cfg, MonoMethod *method, MonoBasicBlock *start_b
 #if 0
 					fprintf (stderr, "generating wrapper for calli in method %s with wrapper type %s\n", method->name, mono_wrapper_type_to_str (method->wrapper_type));
 #endif
+
+					if (cfg->compile_aot)
+						cfg->pinvoke_calli_signatures = g_slist_prepend_mempool (cfg->mempool, cfg->pinvoke_calli_signatures, fsig);
+
 					/* Call the wrapper that will do the GC transition instead */
 					MonoMethod *wrapper = mono_marshal_get_native_func_wrapper_indirect (method->klass, fsig, cfg->compile_aot);
 

src/mono/mono/mini/mini.h

@@ -1629,6 +1629,7 @@ typedef struct {
 
 	GSList *signatures;
 	GSList *interp_in_signatures;
+	GSList *pinvoke_calli_signatures;
 
 	/* GC Maps */