gcc/libgo/runtime/goc2c.c

760 lines
14 KiB
C

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
/*
* Translate a .goc file into a .c file. A .goc file is a combination
* of a limited form of Go with C.
*/
/*
package PACKAGENAME
{# line}
func NAME([NAME TYPE { , NAME TYPE }]) [(NAME TYPE { , NAME TYPE })] \{
C code with proper brace nesting
\}
*/
/*
* We generate C code which implements the function such that it can
* be called from Go and executes the C code.
*/
#include <assert.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
/* Whether we're emitting for gcc */
static int gcc;
/* Package prefix to use; only meaningful for gcc */
static const char *prefix;
/* File and line number */
static const char *file;
static unsigned int lineno = 1;
/* List of names and types. */
struct params {
struct params *next;
char *name;
char *type;
};
/* index into type_table */
enum {
Bool,
Float,
Int,
Uint,
Uintptr,
String,
Slice,
Eface,
};
static struct {
char *name;
int size;
} type_table[] = {
/* variable sized first, for easy replacement */
/* order matches enum above */
/* default is 32-bit architecture sizes */
"bool", 1,
"float", 4,
"int", 4,
"uint", 4,
"uintptr", 4,
"String", 8,
"Slice", 12,
"Eface", 8,
/* fixed size */
"float32", 4,
"float64", 8,
"byte", 1,
"int8", 1,
"uint8", 1,
"int16", 2,
"uint16", 2,
"int32", 4,
"uint32", 4,
"int64", 8,
"uint64", 8,
NULL,
};
/* Fixed structure alignment (non-gcc only) */
int structround = 4;
char *argv0;
static void
sysfatal(char *fmt, ...)
{
char buf[256];
va_list arg;
va_start(arg, fmt);
vsnprintf(buf, sizeof buf, fmt, arg);
va_end(arg);
fprintf(stderr, "%s: %s\n", argv0 ? argv0 : "<prog>", buf);
exit(1);
}
/* Unexpected EOF. */
static void
bad_eof(void)
{
sysfatal("%s:%ud: unexpected EOF\n", file, lineno);
}
/* Out of memory. */
static void
bad_mem(void)
{
sysfatal("%s:%ud: out of memory\n", file, lineno);
}
/* Allocate memory without fail. */
static void *
xmalloc(unsigned int size)
{
void *ret = malloc(size);
if (ret == NULL)
bad_mem();
return ret;
}
/* Reallocate memory without fail. */
static void*
xrealloc(void *buf, unsigned int size)
{
void *ret = realloc(buf, size);
if (ret == NULL)
bad_mem();
return ret;
}
/* Free a list of parameters. */
static void
free_params(struct params *p)
{
while (p != NULL) {
struct params *next;
next = p->next;
free(p->name);
free(p->type);
free(p);
p = next;
}
}
/* Read a character, tracking lineno. */
static int
getchar_update_lineno(void)
{
int c;
c = getchar();
if (c == '\n')
++lineno;
return c;
}
/* Read a character, giving an error on EOF, tracking lineno. */
static int
getchar_no_eof(void)
{
int c;
c = getchar_update_lineno();
if (c == EOF)
bad_eof();
return c;
}
/* Read a character, skipping comments. */
static int
getchar_skipping_comments(void)
{
int c;
while (1) {
c = getchar_update_lineno();
if (c != '/')
return c;
c = getchar();
if (c == '/') {
do {
c = getchar_update_lineno();
} while (c != EOF && c != '\n');
return c;
} else if (c == '*') {
while (1) {
c = getchar_update_lineno();
if (c == EOF)
return EOF;
if (c == '*') {
do {
c = getchar_update_lineno();
} while (c == '*');
if (c == '/')
break;
}
}
} else {
ungetc(c, stdin);
return '/';
}
}
}
/*
* Read and return a token. Tokens are delimited by whitespace or by
* [(),{}]. The latter are all returned as single characters.
*/
static char *
read_token(void)
{
int c;
char *buf;
unsigned int alc, off;
const char* delims = "(),{}";
while (1) {
c = getchar_skipping_comments();
if (c == EOF)
return NULL;
if (!isspace(c))
break;
}
alc = 16;
buf = xmalloc(alc + 1);
off = 0;
if (strchr(delims, c) != NULL) {
buf[off] = c;
++off;
} else {
while (1) {
if (off >= alc) {
alc *= 2;
buf = xrealloc(buf, alc + 1);
}
buf[off] = c;
++off;
c = getchar_skipping_comments();
if (c == EOF)
break;
if (isspace(c) || strchr(delims, c) != NULL) {
if (c == '\n')
lineno--;
ungetc(c, stdin);
break;
}
}
}
buf[off] = '\0';
return buf;
}
/* Read a token, giving an error on EOF. */
static char *
read_token_no_eof(void)
{
char *token = read_token();
if (token == NULL)
bad_eof();
return token;
}
/* Read the package clause, and return the package name. */
static char *
read_package(void)
{
char *token;
token = read_token_no_eof();
if (token == NULL)
sysfatal("%s:%ud: no token\n", file, lineno);
if (strcmp(token, "package") != 0) {
sysfatal("%s:%ud: expected \"package\", got \"%s\"\n",
file, lineno, token);
}
return read_token_no_eof();
}
/* Read and copy preprocessor lines. */
static void
read_preprocessor_lines(void)
{
while (1) {
int c;
do {
c = getchar_skipping_comments();
} while (isspace(c));
if (c != '#') {
ungetc(c, stdin);
break;
}
putchar(c);
do {
c = getchar_update_lineno();
putchar(c);
} while (c != '\n');
}
}
/*
* Read a type in Go syntax and return a type in C syntax. We only
* permit basic types and pointers.
*/
static char *
read_type(void)
{
char *p, *op, *q;
int pointer_count;
unsigned int len;
p = read_token_no_eof();
if (*p != '*')
return p;
op = p;
pointer_count = 0;
while (*p == '*') {
++pointer_count;
++p;
}
len = strlen(p);
q = xmalloc(len + pointer_count + 1);
memcpy(q, p, len);
while (pointer_count > 0) {
q[len] = '*';
++len;
--pointer_count;
}
q[len] = '\0';
free(op);
return q;
}
/* Return the size of the given type. */
static int
type_size(char *p)
{
int i;
if(p[strlen(p)-1] == '*')
return type_table[Uintptr].size;
for(i=0; type_table[i].name; i++)
if(strcmp(type_table[i].name, p) == 0)
return type_table[i].size;
if(!gcc) {
sysfatal("%s:%ud: unknown type %s\n", file, lineno, p);
}
return 1;
}
/*
* Read a list of parameters. Each parameter is a name and a type.
* The list ends with a ')'. We have already read the '('.
*/
static struct params *
read_params(int *poffset)
{
char *token;
struct params *ret, **pp, *p;
int offset, size, rnd;
ret = NULL;
pp = &ret;
token = read_token_no_eof();
offset = 0;
if (strcmp(token, ")") != 0) {
while (1) {
p = xmalloc(sizeof(struct params));
p->name = token;
p->type = read_type();
p->next = NULL;
*pp = p;
pp = &p->next;
size = type_size(p->type);
rnd = size;
if(rnd > structround)
rnd = structround;
if(offset%rnd)
offset += rnd - offset%rnd;
offset += size;
token = read_token_no_eof();
if (strcmp(token, ",") != 0)
break;
token = read_token_no_eof();
}
}
if (strcmp(token, ")") != 0) {
sysfatal("%s:%ud: expected '('\n",
file, lineno);
}
if (poffset != NULL)
*poffset = offset;
return ret;
}
/*
* Read a function header. This reads up to and including the initial
* '{' character. Returns 1 if it read a header, 0 at EOF.
*/
static int
read_func_header(char **name, struct params **params, int *paramwid, struct params **rets)
{
int lastline;
char *token;
lastline = -1;
while (1) {
token = read_token();
if (token == NULL)
return 0;
if (strcmp(token, "func") == 0) {
if(lastline != -1)
printf("\n");
break;
}
if (lastline != lineno) {
if (lastline == lineno-1)
printf("\n");
else
printf("\n#line %d \"%s\"\n", lineno, file);
lastline = lineno;
}
printf("%s ", token);
}
*name = read_token_no_eof();
token = read_token();
if (token == NULL || strcmp(token, "(") != 0) {
sysfatal("%s:%ud: expected \"(\"\n",
file, lineno);
}
*params = read_params(paramwid);
token = read_token();
if (token == NULL || strcmp(token, "(") != 0)
*rets = NULL;
else {
*rets = read_params(NULL);
token = read_token();
}
if (token == NULL || strcmp(token, "{") != 0) {
sysfatal("%s:%ud: expected \"{\"\n",
file, lineno);
}
return 1;
}
/* Write out parameters. */
static void
write_params(struct params *params, int *first)
{
struct params *p;
for (p = params; p != NULL; p = p->next) {
if (*first)
*first = 0;
else
printf(", ");
printf("%s %s", p->type, p->name);
}
}
/* Write a 6g function header. */
static void
write_6g_func_header(char *package, char *name, struct params *params,
int paramwid, struct params *rets)
{
int first, n;
printf("void\n%s·%s(", package, name);
first = 1;
write_params(params, &first);
/* insert padding to align output struct */
if(rets != NULL && paramwid%structround != 0) {
n = structround - paramwid%structround;
if(n & 1)
printf(", uint8");
if(n & 2)
printf(", uint16");
if(n & 4)
printf(", uint32");
}
write_params(rets, &first);
printf(")\n{\n");
}
/* Write a 6g function trailer. */
static void
write_6g_func_trailer(struct params *rets)
{
struct params *p;
for (p = rets; p != NULL; p = p->next)
printf("\tFLUSH(&%s);\n", p->name);
printf("}\n");
}
/* Define the gcc function return type if necessary. */
static void
define_gcc_return_type(char *package, char *name, struct params *rets)
{
struct params *p;
if (rets == NULL || rets->next == NULL)
return;
printf("struct %s_%s_ret {\n", package, name);
for (p = rets; p != NULL; p = p->next)
printf(" %s %s;\n", p->type, p->name);
printf("};\n");
}
/* Write out the gcc function return type. */
static void
write_gcc_return_type(char *package, char *name, struct params *rets)
{
if (rets == NULL)
printf("void");
else if (rets->next == NULL)
printf("%s", rets->type);
else
printf("struct %s_%s_ret", package, name);
}
/* Write out a gcc function header. */
static void
write_gcc_func_header(char *package, char *name, struct params *params,
struct params *rets)
{
int first;
struct params *p;
define_gcc_return_type(package, name, rets);
write_gcc_return_type(package, name, rets);
printf(" %s_%s(", package, name);
first = 1;
write_params(params, &first);
printf(") asm (\"");
if (prefix != NULL)
printf("%s.", prefix);
printf("%s.%s\");\n", package, name);
write_gcc_return_type(package, name, rets);
printf(" %s_%s(", package, name);
first = 1;
write_params(params, &first);
printf(")\n{\n");
for (p = rets; p != NULL; p = p->next)
printf(" %s %s;\n", p->type, p->name);
}
/* Write out a gcc function trailer. */
static void
write_gcc_func_trailer(char *package, char *name, struct params *rets)
{
if (rets == NULL)
;
else if (rets->next == NULL)
printf("return %s;\n", rets->name);
else {
struct params *p;
printf(" {\n struct %s_%s_ret __ret;\n", package, name);
for (p = rets; p != NULL; p = p->next)
printf(" __ret.%s = %s;\n", p->name, p->name);
printf(" return __ret;\n }\n");
}
printf("}\n");
}
/* Write out a function header. */
static void
write_func_header(char *package, char *name,
struct params *params, int paramwid,
struct params *rets)
{
if (gcc)
write_gcc_func_header(package, name, params, rets);
else
write_6g_func_header(package, name, params, paramwid, rets);
printf("#line %d \"%s\"\n", lineno, file);
}
/* Write out a function trailer. */
static void
write_func_trailer(char *package, char *name,
struct params *rets)
{
if (gcc)
write_gcc_func_trailer(package, name, rets);
else
write_6g_func_trailer(rets);
}
/*
* Read and write the body of the function, ending in an unnested }
* (which is read but not written).
*/
static void
copy_body(void)
{
int nesting = 0;
while (1) {
int c;
c = getchar_no_eof();
if (c == '}' && nesting == 0)
return;
putchar(c);
switch (c) {
default:
break;
case '{':
++nesting;
break;
case '}':
--nesting;
break;
case '/':
c = getchar_update_lineno();
putchar(c);
if (c == '/') {
do {
c = getchar_no_eof();
putchar(c);
} while (c != '\n');
} else if (c == '*') {
while (1) {
c = getchar_no_eof();
putchar(c);
if (c == '*') {
do {
c = getchar_no_eof();
putchar(c);
} while (c == '*');
if (c == '/')
break;
}
}
}
break;
case '"':
case '\'':
{
int delim = c;
do {
c = getchar_no_eof();
putchar(c);
if (c == '\\') {
c = getchar_no_eof();
putchar(c);
c = '\0';
}
} while (c != delim);
}
break;
}
}
}
/* Process the entire file. */
static void
process_file(void)
{
char *package, *name;
struct params *params, *rets;
int paramwid;
package = read_package();
read_preprocessor_lines();
while (read_func_header(&name, &params, &paramwid, &rets)) {
write_func_header(package, name, params, paramwid, rets);
copy_body();
write_func_trailer(package, name, rets);
free(name);
free_params(params);
free_params(rets);
}
free(package);
}
static void
usage(void)
{
sysfatal("Usage: goc2c [--6g | --gc] [--go-prefix PREFIX] [file]\n");
}
void
main(int argc, char **argv)
{
char *goarch;
argv0 = argv[0];
while(argc > 1 && argv[1][0] == '-') {
if(strcmp(argv[1], "-") == 0)
break;
if(strcmp(argv[1], "--6g") == 0)
gcc = 0;
else if(strcmp(argv[1], "--gcc") == 0)
gcc = 1;
else if (strcmp(argv[1], "--go-prefix") == 0 && argc > 2) {
prefix = argv[2];
argc--;
argv++;
} else
usage();
argc--;
argv++;
}
if(argc <= 1 || strcmp(argv[1], "-") == 0) {
file = "<stdin>";
process_file();
exit(0);
}
if(argc > 2)
usage();
file = argv[1];
if(freopen(file, "r", stdin) == 0) {
sysfatal("open %s: %r\n", file);
}
if(!gcc) {
// 6g etc; update size table
goarch = getenv("GOARCH");
if(goarch != NULL && strcmp(goarch, "amd64") == 0) {
type_table[Uintptr].size = 8;
type_table[String].size = 16;
type_table[Slice].size = 8+4+4;
type_table[Eface].size = 8+8;
structround = 8;
}
}
process_file();
exit(0);
}