Merge pull request #3142 from henricm/fix-for-win-mono_string_to_utf8

[mono.git] / mono / mini / mini-amd64.c

diff --git a/mono/mini/mini-amd64.c b/mono/mini/mini-amd64.c
index 9cdeae95394f60bf55d471ec28e3ab2cd9e5ca69..4771ab861844e3f850c96be5d0d2470403076d39 100644 (file)
--- a/mono/mini/mini-amd64.c
+++ b/mono/mini/mini-amd64.c
@@ -392,6 +392,17 @@ add_valuetype_win64 (MonoMethodSignature *sig, ArgInfo *ainfo, MonoType *type,
 
        klass = mono_class_from_mono_type (type);
        size = mini_type_stack_size_full (&klass->byval_arg, NULL, sig->pinvoke);
+
+       /*
+       * Standard C and C++ doesn't allow empty structs, empty structs will always have a size of 1 byte.
+       * GCC have an extension to allow empty structs, https://gcc.gnu.org/onlinedocs/gcc/Empty-Structures.html.
+       * This cause a little dilemma since runtime build using none GCC compiler will not be compatible with
+       * GCC build C libraries and the other way around. On platforms where empty structs has size of 1 byte
+       * it must be represented in call and cannot be dropped.
+       */
+       if (0 == size && MONO_TYPE_ISSTRUCT (type) && sig->pinvoke)
+               ainfo->pass_empty_struct = TRUE;
+       
        if (!sig->pinvoke)
                pass_on_stack = TRUE;
 
@@ -448,13 +459,17 @@ add_valuetype_win64 (MonoMethodSignature *sig, ArgInfo *ainfo, MonoType *type,
        } else {
                g_assert (info);
 
-               if (!fields) {
+               /*Only drop value type if its not an empty struct as input that must be represented in call*/
+               if ((!fields && !ainfo->pass_empty_struct) || (!fields && ainfo->pass_empty_struct && is_return)) {
                        ainfo->storage = ArgValuetypeInReg;
                        ainfo->pair_storage [0] = ainfo->pair_storage [1] = ArgNone;
                        return;
                }
 
                switch (info->native_size) {
+               case 0:
+                       g_assert (!fields && MONO_TYPE_ISSTRUCT (type) && !is_return);
+                       break;
                case 1: case 2: case 4: case 8:
                        break;
                default:
@@ -487,7 +502,11 @@ add_valuetype_win64 (MonoMethodSignature *sig, ArgInfo *ainfo, MonoType *type,
                guint32 align;
                ArgumentClass class1;
 
-               if (nfields == 0)
+               if (nfields == 0 && ainfo->pass_empty_struct) {
+                       g_assert (!fields && !is_return);
+                       class1 = ARG_CLASS_INTEGER;
+               }
+               else if (nfields == 0)
                        class1 = ARG_CLASS_MEMORY;
                else
                        class1 = ARG_CLASS_NO_CLASS;
@@ -586,6 +605,7 @@ add_valuetype (MonoMethodSignature *sig, ArgInfo *ainfo, MonoType *type,
 
        klass = mono_class_from_mono_type (type);
        size = mini_type_stack_size_full (&klass->byval_arg, NULL, sig->pinvoke);
+
        if (!sig->pinvoke && ((is_return && (size == 8)) || (!is_return && (size <= 16)))) {
                /* We pass and return vtypes of size 8 in a register */
        } else if (!sig->pinvoke || (size == 0) || (size > 16)) {
@@ -2112,7 +2132,7 @@ mono_arch_emit_call (MonoCompile *cfg, MonoCallInst *call)
                                /* Continue normally */
                        }
 
-                       if (size > 0) {
+                       if (size > 0 || ainfo->pass_empty_struct) {
                                MONO_INST_NEW (cfg, arg, OP_OUTARG_VT);
                                arg->sreg1 = in->dreg;
                                arg->klass = mono_class_from_mono_type (t);
@@ -2210,21 +2230,28 @@ mono_arch_emit_outarg_vt (MonoCompile *cfg, MonoInst *ins, MonoInst *src)
                        if (ainfo->pair_storage [part] == ArgNone)
                                continue;
 
-                       MONO_INST_NEW (cfg, load, arg_storage_to_load_membase (ainfo->pair_storage [part]));
-                       load->inst_basereg = src->dreg;
-                       load->inst_offset = part * sizeof(mgreg_t);
+                       if (ainfo->pass_empty_struct) {
+                               //Pass empty struct value as 0 on platforms representing empty structs as 1 byte.
+                               NEW_ICONST (cfg, load, 0);
+                       }
+                       else {
+                               MONO_INST_NEW (cfg, load, arg_storage_to_load_membase (ainfo->pair_storage [part]));
+                               load->inst_basereg = src->dreg;
+                               load->inst_offset = part * sizeof(mgreg_t);
 
-                       switch (ainfo->pair_storage [part]) {
-                       case ArgInIReg:
-                               load->dreg = mono_alloc_ireg (cfg);
-                               break;
-                       case ArgInDoubleSSEReg:
-                       case ArgInFloatSSEReg:
-                               load->dreg = mono_alloc_freg (cfg);
-                               break;
-                       default:
-                               g_assert_not_reached ();
+                               switch (ainfo->pair_storage [part]) {
+                               case ArgInIReg:
+                                       load->dreg = mono_alloc_ireg (cfg);
+                                       break;
+                               case ArgInDoubleSSEReg:
+                               case ArgInFloatSSEReg:
+                                       load->dreg = mono_alloc_freg (cfg);
+                                       break;
+                               default:
+                                       g_assert_not_reached ();
+                               }
                        }
+
                        MONO_ADD_INS (cfg->cbb, load);
 
                        add_outarg_reg (cfg, call, ainfo->pair_storage [part], ainfo->pair_regs [part], load);
@@ -2469,14 +2496,14 @@ mono_arch_start_dyn_call (MonoDynCallInfo *info, gpointer **args, guint8 *ret, g
        if (dinfo->cinfo->ret.storage == ArgValuetypeAddrInIReg || dinfo->cinfo->ret.storage == ArgGsharedvtVariableInReg)
                p->regs [greg ++] = PTR_TO_GREG(ret);
 
-       for (i = pindex; i < sig->param_count; i++) {
-               MonoType *t = mini_get_underlying_type (sig->params [i]);
+       for (; pindex < sig->param_count; pindex++) {
+               MonoType *t = mini_get_underlying_type (sig->params [pindex]);
                gpointer *arg = args [arg_index ++];
-               ArgInfo *ainfo = &dinfo->cinfo->args [i + sig->hasthis];
+               ArgInfo *ainfo = &dinfo->cinfo->args [pindex + sig->hasthis];
                int slot;
 
                if (ainfo->storage == ArgOnStack) {
-                       slot = PARAM_REGS + 1 + (ainfo->offset / sizeof (mgreg_t));
+                       slot = PARAM_REGS + (ainfo->offset / sizeof (mgreg_t));
                } else {
                        slot = param_reg_to_index [ainfo->reg];
                }