+/*
+ * ia32rtools
+ * (C) notaz, 2013,2014
+ *
+ * This work is licensed under the terms of 3-clause BSD license.
+ * See COPYING file in the top-level directory.
+ */
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "protoparse.h"
+static const char *c_save_regs[] = { "ebx", "esi", "edi", "ebp" };
+
static int is_x86_reg_saved(const char *reg)
{
static const char *nosave_regs[] = { "eax", "edx", "ecx" };
}
if (pp->argc_stack == 0 && !must_save && !pp->is_stdcall
- && !pp->is_vararg)
+ && !pp->is_vararg && !pp->has_retreg)
{
// load arg regs
for (i = 0; i < pp->argc; i++) {
return;
}
+ // asm_stack_args | saved_regs | ra | args_from_c
+
// save the regs
- for (i = 0; i < pp->argc; i++) {
- if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg)) {
- fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg);
- sarg_ofs++;
- }
+ // because we don't always know what we are calling,
+ // be safe and save everything that has to be saved in __cdecl
+ for (i = 0; i < ARRAY_SIZE(c_save_regs); i++) {
+ fprintf(f, "\tpushl %%%s\n", c_save_regs[i]);
+ sarg_ofs++;
}
- // reconstruct arg stack
+ // reconstruct arg stack for asm
for (i = argc_repush - 1; i >= 0; i--) {
if (pp->arg[i].reg == NULL) {
fprintf(f, "\tmovl %d(%%esp), %%eax\n",
args_repushed++;
}
}
- // my_assert(args_repushed, pp->argc_stack);
// load arg regs
for (i = 0; i < pp->argc; i++) {
if (pp->arg[i].reg != NULL) {
fprintf(f, "\tmovl %d(%%esp), %%%s\n",
(i + sarg_ofs) * 4, pp->arg[i].reg);
+ if (pp->arg[i].type.is_retreg)
+ fprintf(f, "\tmovl (%%%s), %%%s\n",
+ pp->arg[i].reg, pp->arg[i].reg);
}
}
fprintf(f, "\n\t# %s\n", pp->is_stdcall ? "__stdcall" : "__cdecl");
fprintf(f, "\tcall %s\n\n", sym_out);
- if (args_repushed && !pp->is_stdcall)
+ if (args_repushed && !pp->is_stdcall) {
fprintf(f, "\tadd $%d,%%esp\n", args_repushed * 4);
+ sarg_ofs -= args_repushed;
+ }
- // restore regs
- for (i = pp->argc - 1; i >= 0; i--) {
- if (pp->arg[i].reg != NULL && is_x86_reg_saved(pp->arg[i].reg))
- fprintf(f, "\tpopl %%%s\n", pp->arg[i].reg);
+ // update the retreg regs
+ if (pp->has_retreg) {
+ for (i = 0; i < pp->argc; i++) {
+ if (pp->arg[i].type.is_retreg) {
+ fprintf(f, "\tmovl %d(%%esp), %%ecx\n"
+ "\tmovl %%%s, (%%ecx)\n",
+ (i + sarg_ofs) * 4, pp->arg[i].reg);
+ }
+ }
}
+ // restore regs
+ for (i = ARRAY_SIZE(c_save_regs) - 1; i >= 0; i--)
+ fprintf(f, "\tpopl %%%s\n", c_save_regs[i]);
+
fprintf(f, "\tret\n\n");
}
static void out_fromasm_x86(FILE *f, const char *sym,
const struct parsed_proto *pp)
{
+ int reg_ofs[ARRAY_SIZE(pp->arg)];
int sarg_ofs = 1; // stack offset to args, in DWORDs
int saved_regs = 0;
+ int ecx_ofs = -1;
+ int edx_ofs = -1;
int c_is_stdcall;
int argc_repush;
int stack_args;
fprintf(f, "\tpushl %%ecx\n");
saved_regs++;
sarg_ofs++;
+ ecx_ofs = sarg_ofs;
if (!ret64) {
fprintf(f, "\tpushl %%edx\n");
saved_regs++;
sarg_ofs++;
+ edx_ofs = sarg_ofs;
+ }
+
+ // need space for retreg args
+ if (pp->has_retreg) {
+ for (i = 0; i < pp->argc; i++) {
+ if (!pp->arg[i].type.is_retreg)
+ continue;
+ if (IS(pp->arg[i].reg, "ecx") && ecx_ofs >= 0) {
+ reg_ofs[i] = ecx_ofs;
+ continue;
+ }
+ if (IS(pp->arg[i].reg, "edx") && edx_ofs >= 0) {
+ reg_ofs[i] = edx_ofs;
+ continue;
+ }
+ fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg);
+ saved_regs++;
+ sarg_ofs++;
+ reg_ofs[i] = sarg_ofs;
+ }
}
// construct arg stack
stack_args--;
}
else {
- if (IS(pp->arg[i].reg, "ecx"))
+ const char *reg = pp->arg[i].reg;
+ if (pp->arg[i].type.is_retreg) {
+ reg = "ecx";
+ fprintf(f, "\tlea %d(%%esp), %%ecx\n",
+ (sarg_ofs - reg_ofs[i]) * 4);
+ }
+ else if (IS(reg, "ecx"))
// must reload original ecx
fprintf(f, "\tmovl %d(%%esp), %%ecx\n",
(sarg_ofs - 2) * 4);
- fprintf(f, "\tpushl %%%s\n", pp->arg[i].reg);
+ fprintf(f, "\tpushl %%%s\n", reg);
}
sarg_ofs++;
}
fprintf(f, "\tadd $%d,%%esp\n",
(sarg_ofs - (saved_regs + 1)) * 4);
+ // pop retregs
+ if (pp->has_retreg) {
+ for (i = pp->argc - 1; i >= 0; i--) {
+ if (!pp->arg[i].type.is_retreg)
+ continue;
+ if (IS(pp->arg[i].reg, "ecx") && ecx_ofs >= 0) {
+ continue;
+ }
+ if (IS(pp->arg[i].reg, "edx") && edx_ofs >= 0) {
+ continue;
+ }
+ fprintf(f, "\tpopl %%%s\n", pp->arg[i].reg);
+ }
+ }
+
if (!ret64)
fprintf(f, "\tpopl %%edx\n");
fprintf(f, "\tpopl %%ecx\n");