X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=tools%2Fmkbridge.c;h=29bdd9a55a708547c58d269fb284e68ac8fef7d8;hb=HEAD;hp=8b4650420326d20fadd6380640dedea09f9b6628;hpb=f2de0a9771982cf393302e8b91adee715701af61;p=ia32rtools.git

diff --git a/tools/mkbridge.c b/tools/mkbridge.c
index 8b46504..29bdd9a 100644
--- a/tools/mkbridge.c
+++ b/tools/mkbridge.c
@@ -1,15 +1,23 @@
+/*
+ * 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 "my_assert.h"
 #include "my_str.h"
-
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
-#define IS(w, y) !strcmp(w, y)
+#include "common.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" };
@@ -23,13 +31,38 @@ static int is_x86_reg_saved(const char *reg)
 	return !nosave;
 }
 
-static void out_toasm_x86(FILE *f, const char *sym_in,
-	const char *sym_out, const struct parsed_proto *pp)
+// output decorated name
+static const char *pp_to_name(const struct parsed_proto *pp)
+{
+	static char buf[256];
+	char atval[16];
+
+	if (!pp->is_fastcall && pp->argc_reg != 0) {
+		// can only be handled by __cdecl C func
+		snprintf(buf, sizeof(buf), "_%s", pp->name);
+		return buf;
+	}
+
+	atval[0] = 0;
+	if (pp->is_stdcall) {
+		snprintf(atval, sizeof(atval), "@%d",
+			pp->argc * 4);
+	}
+	snprintf(buf, sizeof(buf), "%s%s%s",
+		pp->is_fastcall ? "@" : "_",
+		pp->name, atval);
+
+	return buf;
+}
+
+static void out_toasm_x86(FILE *f, const char *sym_out,
+	const struct parsed_proto *pp)
 {
 	int must_save = 0;
 	int sarg_ofs = 1; // stack offset to args, in DWORDs
 	int args_repushed = 0;
 	int argc_repush;
+	const char *name;
 	int i;
 
 	argc_repush = pp->argc;
@@ -41,8 +74,9 @@ static void out_toasm_x86(FILE *f, const char *sym_in,
 			must_save |= is_x86_reg_saved(pp->arg[i].reg);
 	}
 
-	fprintf(f, ".global %s%s\n", pp->is_fastcall ? "@" : "_", sym_in);
-	fprintf(f, "%s%s:\n", pp->is_fastcall ? "@" : "_", sym_in);
+	name = pp_to_name(pp);
+	fprintf(f, ".global %s\n", name);
+	fprintf(f, "%s:\n", name);
 
 	if (pp->argc_reg == 0 || pp->is_fastcall) {
 		fprintf(f, "\t# %s\n",
@@ -53,7 +87,7 @@ static void out_toasm_x86(FILE *f, const char *sym_in,
 	}
 
 	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++) {
@@ -64,15 +98,17 @@ static void out_toasm_x86(FILE *f, const char *sym_in,
 		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",
@@ -82,36 +118,52 @@ static void out_toasm_x86(FILE *f, const char *sym_in,
 			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;
@@ -131,18 +183,28 @@ static void out_fromasm_x86(FILE *f, const char *sym,
 	  pp->is_fastcall ? "__fastcall" :
 	  (pp->is_stdcall ? "__stdcall" : "__cdecl"));
 	if (ret64)
-		 fprintf(f, " ret64");
+		fprintf(f, " ret64");
+	if (!pp->is_fastcall && pp->argc_reg != 0)
+		fprintf(f, " +reg");
+
+	if (pp->is_stdcall && !pp->is_fastcall && pp->argc_reg != 0
+	    && !IS_START(sym, "sub_") && !IS_START(sym, "f_"))
+	{
+		// alias for possible .def export
+		char sym2[256];
+
+		snprintf(sym2, sizeof(sym2), "_%s@%d",
+			 sym, pp->argc * 4);
+		fprintf(f, "\n.global %s # for .def\n", sym2);
+		fprintf(f, "%s:", sym2);
+	}
 	fprintf(f, "\n.global %s\n", sym);
 	fprintf(f, "%s:\n", sym);
 
 	if ((pp->argc_reg == 0 || pp->is_fastcall)
 	    && !IS(pp->name, "storm_491")) // wants edx save :(
 	{
-		fprintf(f, "\tjmp %s%s",
-			pp->is_fastcall ? "@" : "_", sym);
-		if (pp->is_stdcall)
-			fprintf(f, "@%d", pp->argc * 4);
-		fprintf(f, "\n\n");
+		fprintf(f, "\tjmp %s\n\n", pp_to_name(pp));
 		return;
 	}
 
@@ -154,10 +216,32 @@ static void out_fromasm_x86(FILE *f, const char *sym,
 	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
@@ -169,25 +253,43 @@ static void out_fromasm_x86(FILE *f, const char *sym,
 			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, "\n\tcall _%s", sym);
-	if (c_is_stdcall)
-		fprintf(f, "@%d", pp->argc_stack * 4);
-	fprintf(f, "\n\n");
+	fprintf(f, "\n\tcall %s\n\n", pp_to_name(pp));
 
 	if (!c_is_stdcall && sarg_ofs > saved_regs + 1)
 		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");
@@ -228,7 +330,7 @@ int main(int argc, char *argv[])
 	my_assert_not(fout, NULL);
 
 	fprintf(fout, ".text\n\n");
-	fprintf(fout, "# to asm\n\n");
+	fprintf(fout, "# C -> asm\n\n");
 
 	while (fgets(line, sizeof(line), fsyms_to))
 	{
@@ -246,10 +348,10 @@ int main(int argc, char *argv[])
 		if (pp == NULL)
 			goto out;
 
-		out_toasm_x86(fout, sym, sym_noat, pp);
+		out_toasm_x86(fout, sym_noat, pp);
 	}
 
-	fprintf(fout, "# from asm\n\n");
+	fprintf(fout, "# asm -> C\n\n");
 
 	while (fgets(line, sizeof(line), fsyms_from))
 	{