xref: /original-bsd/usr.bin/ranlib/build.c (revision ec35a16d)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Hugh Smith at The University of Guelph.
7  *
8  * %sccs.include.redist.c%
9  */
10 
11 #ifndef lint
12 static char sccsid[] = "@(#)build.c	8.1 (Berkeley) 06/06/93";
13 #endif /* not lint */
14 
15 #include <sys/types.h>
16 #include <sys/errno.h>
17 #include <sys/stat.h>
18 
19 #include <a.out.h>
20 #include <ar.h>
21 #include <dirent.h>
22 #include <fcntl.h>
23 #include <ranlib.h>
24 #include <stdio.h>
25 #include <unistd.h>
26 
27 #include "archive.h"
28 
29 extern CHDR chdr;			/* converted header */
30 extern char *archive;			/* archive name */
31 extern char *tname;			/* temporary file "name" */
32 
33 typedef struct _rlib {
34 	struct _rlib *next;		/* next structure */
35 	off_t pos;			/* offset of defining archive file */
36 	char *sym;			/* symbol */
37 	int symlen;			/* strlen(sym) */
38 } RLIB;
39 RLIB *rhead, **pnext;
40 
41 FILE *fp;
42 
43 long symcnt;				/* symbol count */
44 long tsymlen;				/* total string length */
45 
46 static void rexec __P((int, int));
47 static void symobj __P((void));
48 
49 build()
50 {
51 	CF cf;
52 	int afd, tfd;
53 	off_t size;
54 
55 	afd = open_archive(O_RDWR);
56 	fp = fdopen(afd, "r+");
57 	tfd = tmp();
58 
59 	SETCF(afd, archive, tfd, tname, RPAD|WPAD);
60 
61 	/* Read through the archive, creating list of symbols. */
62 	pnext = &rhead;
63 	symcnt = tsymlen = 0;
64 	while(get_arobj(afd)) {
65 		if (!strcmp(chdr.name, RANLIBMAG)) {
66 			skip_arobj(afd);
67 			continue;
68 		}
69 		rexec(afd, tfd);
70 		put_arobj(&cf, (struct stat *)NULL);
71 	}
72 	*pnext = NULL;
73 
74 	/* Create the symbol table. */
75 	symobj();
76 
77 	/* Copy the saved objects into the archive. */
78 	size = lseek(tfd, (off_t)0, SEEK_CUR);
79 	(void)lseek(tfd, (off_t)0, SEEK_SET);
80 	SETCF(tfd, tname, afd, archive, RPAD|WPAD);
81 	copy_ar(&cf, size);
82 	(void)ftruncate(afd, lseek(afd, (off_t)0, SEEK_CUR));
83 	(void)close(tfd);
84 
85 	/* Set the time. */
86 	settime(afd);
87 	close_archive(afd);
88 	return(0);
89 }
90 
91 /*
92  * rexec
93  *	Read the exec structure; ignore any files that don't look
94  *	exactly right.
95  */
96 static void
97 rexec(rfd, wfd)
98 	register int rfd;
99 	int wfd;
100 {
101 	register RLIB *rp;
102 	register long nsyms;
103 	register int nr, symlen;
104 	register char *strtab, *sym;
105 	struct exec ebuf;
106 	struct nlist nl;
107 	off_t r_off, w_off;
108 	long strsize;
109 	void *emalloc();
110 
111 	/* Get current offsets for original and tmp files. */
112 	r_off = lseek(rfd, (off_t)0, SEEK_CUR);
113 	w_off = lseek(wfd, (off_t)0, SEEK_CUR);
114 
115 	/* Read in exec structure. */
116 	nr = read(rfd, &ebuf, sizeof(struct exec));
117 	if (nr != sizeof(struct exec))
118 		goto badread;
119 
120 	/* Check magic number and symbol count. */
121 	if (N_BADMAG(ebuf) || ebuf.a_syms == 0)
122 		goto bad1;
123 
124 	/* Seek to string table. */
125 	if (lseek(rfd, r_off + N_STROFF(ebuf), SEEK_SET) == (off_t)-1)
126 		error(archive);
127 
128 	/* Read in size of the string table. */
129 	nr = read(rfd, &strsize, sizeof(strsize));
130 	if (nr != sizeof(strsize))
131 		goto badread;
132 
133 	/* Read in the string table. */
134 	strsize -= sizeof(strsize);
135 	strtab = emalloc(strsize);
136 	nr = read(rfd, strtab, strsize);
137 	if (nr != strsize) {
138 badread:	if (nr < 0)
139 			error(archive);
140 		goto bad2;
141 	}
142 
143 	/* Seek to symbol table. */
144 	if (fseek(fp, (long)r_off + N_SYMOFF(ebuf), SEEK_SET))
145 		goto bad2;
146 
147 	/* For each symbol read the nlist entry and save it as necessary. */
148 	nsyms = ebuf.a_syms / sizeof(struct nlist);
149 	while (nsyms--) {
150 		if (!fread(&nl, sizeof(struct nlist), 1, fp)) {
151 			if (feof(fp))
152 				badfmt();
153 			error(archive);
154 		}
155 
156 		/* Ignore if no name or local. */
157 		if (!nl.n_un.n_strx || !(nl.n_type & N_EXT))
158 			continue;
159 
160 		/*
161 		 * If the symbol is an undefined external and the n_value
162 		 * field is non-zero, keep it.
163 		 */
164 		if ((nl.n_type & N_TYPE) == N_UNDF && !nl.n_value)
165 			continue;
166 
167 		/* First four bytes are the table size. */
168 		sym = strtab + nl.n_un.n_strx - sizeof(long);
169 		symlen = strlen(sym) + 1;
170 
171 		rp = (RLIB *)emalloc(sizeof(RLIB));
172 		rp->sym = (char *)emalloc(symlen);
173 		bcopy(sym, rp->sym, symlen);
174 		rp->symlen = symlen;
175 		rp->pos = w_off;
176 
177 		/* Build in forward order for "ar -m" command. */
178 		*pnext = rp;
179 		pnext = &rp->next;
180 
181 		++symcnt;
182 		tsymlen += symlen;
183 	}
184 
185 bad2:	free(strtab);
186 bad1:	(void)lseek(rfd, r_off, SEEK_SET);
187 }
188 
189 /*
190  * symobj --
191  *	Write the symbol table into the archive, computing offsets as
192  *	writing.
193  */
194 static void
195 symobj()
196 {
197 	register RLIB *rp;
198 	struct ranlib rn;
199 	off_t ransize;
200 	long size, stroff;
201 	char hb[sizeof(struct ar_hdr) + 1], pad;
202 
203 	/* Rewind the archive, leaving the magic number. */
204 	if (fseek(fp, (long)SARMAG, SEEK_SET))
205 		error(archive);
206 
207 	/* Size of the ranlib archive file, pad if necessary. */
208 	ransize = sizeof(long) +
209 	    symcnt * sizeof(struct ranlib) + sizeof(long) + tsymlen;
210 	if (ransize & 01) {
211 		++ransize;
212 		pad = '\n';
213 	} else
214 		pad = '\0';
215 
216 	/* Put out the ranlib archive file header. */
217 #define	DEFMODE	(S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
218 	(void)sprintf(hb, HDR2, RANLIBMAG, 0L, getuid(), getgid(),
219 	    DEFMODE & ~umask(0), ransize, ARFMAG);
220 	if (!fwrite(hb, sizeof(struct ar_hdr), 1, fp))
221 		error(tname);
222 
223 	/* First long is the size of the ranlib structure section. */
224 	size = symcnt * sizeof(struct ranlib);
225 	if (!fwrite(&size, sizeof(size), 1, fp))
226 		error(tname);
227 
228 	/* Offset of the first archive file. */
229 	size = SARMAG + sizeof(struct ar_hdr) + ransize;
230 
231 	/*
232 	 * Write out the ranlib structures.  The offset into the string
233 	 * table is cumulative, the offset into the archive is the value
234 	 * set in rexec() plus the offset to the first archive file.
235 	 */
236 	for (rp = rhead, stroff = 0; rp; rp = rp->next) {
237 		rn.ran_un.ran_strx = stroff;
238 		stroff += rp->symlen;
239 		rn.ran_off = size + rp->pos;
240 		if (!fwrite(&rn, sizeof(struct ranlib), 1, fp))
241 			error(archive);
242 	}
243 
244 	/* Second long is the size of the string table. */
245 	if (!fwrite(&tsymlen, sizeof(tsymlen), 1, fp))
246 		error(tname);
247 
248 	/* Write out the string table. */
249 	for (rp = rhead; rp; rp = rp->next)
250 		if (!fwrite(rp->sym, rp->symlen, 1, fp))
251 			error(tname);
252 
253 	if (pad && !fwrite(&pad, sizeof(pad), 1, fp))
254 		error(tname);
255 
256 	(void)fflush(fp);
257 }
258