root/src/cmd/gc/mkbuiltin1.c

DEFINITIONS

1. main
2. esc
3. fatal

// 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.

// +build ignore

// Compile .go file, import data from .6 file, and generate C string version.

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>

void esc(char*);
void fatal(char*, ...);

int
main(int argc, char **argv)
{
        char *name;
        FILE *fin;
        char buf[1024], initfunc[1024], *p, *q;

        if(argc != 2) {
                fprintf(stderr, "usage: mkbuiltin1 sys\n");
                fatal("in file $1.6 s/PACKAGE/$1/");
        }

        name = argv[1];
        snprintf(initfunc, sizeof(initfunc), "init_%s_function", name);

        snprintf(buf, sizeof(buf), "%s.%s", name, getenv("O"));
        if((fin = fopen(buf, "r")) == NULL) {
                fatal("open %s: %s", buf, strerror(errno));
        }

        // look for $$ that introduces imports
        while(fgets(buf, sizeof buf, fin) != NULL)
                if(strstr(buf, "$$"))
                        goto begin;
        fatal("did not find beginning of imports");

begin:
        printf("char *%simport =\n", name);

        // process imports, stopping at $$ that closes them
        while(fgets(buf, sizeof buf, fin) != NULL) {
                buf[strlen(buf)-1] = 0; // chop \n
                if(strstr(buf, "$$"))
                        goto end;

                // chop leading white space
                for(p=buf; *p==' ' || *p == '\t'; p++)
                        ;

                // cut out decl of init_$1_function - it doesn't exist
                if(strstr(buf, initfunc))
                        continue;

                // sys.go claims to be in package PACKAGE to avoid
                // conflicts during "6g sys.go".  rename PACKAGE to $2.
                printf("\t\"");
                while((q = strstr(p, "PACKAGE")) != NULL) {
                        *q = 0;
                        esc(p); // up to the substitution
                        printf("%s", name);     // the sub name
                        p = q+7;                // continue with rest
                }

                esc(p);
                printf("\\n\"\n");
        }
        fatal("did not find end of imports");

end:
        printf("\t\"$$\\n\";\n");
        return 0;
}

void
esc(char *p)
{
        for(; *p; p++) {
                if(*p == '\\' || *p == '\"')
                        printf("\\");
                putchar(*p);
        }
}

void
fatal(char *msg, ...)
{
        va_list arg;
        
        va_start(arg, msg);
        fprintf(stderr, "fatal: ");
        vfprintf(stderr, msg, arg);
        fprintf(stderr, "\n");
        exit(2);
}