github.com/yanyiwu/go@v0.0.0-20150106053140-03d6637dbb7f/src/cmd/gc/mkbuiltin1.c (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build ignore
     6  
     7  // Compile .go file, import data from .6 file, and generate C string version.
     8  
     9  #include <stdio.h>
    10  #include <stdlib.h>
    11  #include <unistd.h>
    12  #include <string.h>
    13  #include <errno.h>
    14  #include <stdarg.h>
    15  
    16  void esc(char*);
    17  void fatal(char*, ...);
    18  
    19  int
    20  main(int argc, char **argv)
    21  {
    22  	char *name;
    23  	FILE *fin;
    24  	char buf[1024], initfunc[1024], *p, *q;
    25  
    26  	if(argc != 2) {
    27  		fprintf(stderr, "usage: mkbuiltin1 sys\n");
    28  		fatal("in file $1.6 s/PACKAGE/$1/");
    29  	}
    30  
    31  	name = argv[1];
    32  	snprintf(initfunc, sizeof(initfunc), "init_%s_function", name);
    33  
    34  	snprintf(buf, sizeof(buf), "%s.%s", name, getenv("O"));
    35  	if((fin = fopen(buf, "r")) == NULL) {
    36  		fatal("open %s: %s", buf, strerror(errno));
    37  	}
    38  
    39  	// look for $$ that introduces imports
    40  	while(fgets(buf, sizeof buf, fin) != NULL)
    41  		if(strstr(buf, "$$"))
    42  			goto begin;
    43  	fatal("did not find beginning of imports");
    44  
    45  begin:
    46  	printf("char *%simport =\n", name);
    47  
    48  	// process imports, stopping at $$ that closes them
    49  	while(fgets(buf, sizeof buf, fin) != NULL) {
    50  		buf[strlen(buf)-1] = 0;	// chop \n
    51  		if(strstr(buf, "$$"))
    52  			goto end;
    53  
    54  		// chop leading white space
    55  		for(p=buf; *p==' ' || *p == '\t'; p++)
    56  			;
    57  
    58  		// cut out decl of init_$1_function - it doesn't exist
    59  		if(strstr(buf, initfunc))
    60  			continue;
    61  
    62  		// sys.go claims to be in package PACKAGE to avoid
    63  		// conflicts during "6g sys.go".  rename PACKAGE to $2.
    64  		printf("\t\"");
    65  		while((q = strstr(p, "PACKAGE")) != NULL) {
    66  			*q = 0;
    67  			esc(p);	// up to the substitution
    68  			printf("%s", name);	// the sub name
    69  			p = q+7;		// continue with rest
    70  		}
    71  
    72  		esc(p);
    73  		printf("\\n\"\n");
    74  	}
    75  	fatal("did not find end of imports");
    76  
    77  end:
    78  	printf("\t\"$$\\n\";\n");
    79  	return 0;
    80  }
    81  
    82  void
    83  esc(char *p)
    84  {
    85  	for(; *p; p++) {
    86  		if(*p == '\\' || *p == '\"')
    87  			printf("\\");
    88  		putchar(*p);
    89  	}
    90  }
    91  
    92  void
    93  fatal(char *msg, ...)
    94  {
    95  	va_list arg;
    96  	
    97  	va_start(arg, msg);
    98  	fprintf(stderr, "fatal: ");
    99  	vfprintf(stderr, msg, arg);
   100  	fprintf(stderr, "\n");
   101  	exit(2);
   102  }