xref: /original-bsd/usr.bin/ranlib/build.c (revision 74d2773b)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * 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	5.2 (Berkeley) 02/26/91";
13 #endif /* not lint */
14 
15 #include <sys/types.h>
16 #include <sys/errno.h>
17 #include <sys/stat.h>
18 #include <fcntl.h>
19 #include <a.out.h>
20 #include <dirent.h>
21 #include <unistd.h>
22 #include <ar.h>
23 #include <ranlib.h>
24 #include <stdio.h>
25 #include <archive.h>
26 
27 extern CHDR chdr;			/* converted header */
28 extern char *archive;			/* archive name */
29 extern char *tname;			/* temporary file "name" */
30 
31 typedef struct _rlib {
32 	struct _rlib *next;		/* next structure */
33 	off_t pos;			/* offset of defining archive file */
34 	char *sym;			/* symbol */
35 	int symlen;			/* strlen(sym) */
36 } RLIB;
37 RLIB *rhead, **pnext;
38 
39 FILE *fp;
40 static void rexec(), symobj();
41 
42 build()
43 {
44 	CF cf;
45 	int afd, tfd;
46 	off_t size;
47 
48 	afd = open_archive(O_RDWR);
49 	fp = fdopen(afd, "r+");
50 	tfd = tmp();
51 
52 	SETCF(afd, archive, tfd, tname, RPAD|WPAD);
53 
54 	/* Read through the archive, creating list of symbols. */
55 	pnext = &rhead;
56 	while(get_header(afd)) {
57 		if (!strcmp(chdr.name, RANLIBMAG)) {
58 			SKIP(afd, chdr.size, archive);
59 			continue;
60 		}
61 		rexec(afd, tfd);
62 		put_header(&cf, (struct stat *)NULL);
63 		copyfile(&cf, chdr.size);
64 	}
65 	*pnext = NULL;
66 
67 	/* Create the symbol table. */
68 	symobj();
69 
70 	/* Copy the saved objects into the archive. */
71 	size = lseek(tfd, (off_t)0, SEEK_CUR);
72 	(void)lseek(tfd, (off_t)0, SEEK_SET);
73 	SETCF(tfd, tname, afd, archive, RPAD|WPAD);
74 	copyfile(&cf, size);
75 	(void)ftruncate(afd, lseek(afd, (off_t)0, SEEK_CUR));
76 	(void)close(tfd);
77 
78 	/* Set the time. */
79 	settime(afd);
80 	close_archive(afd);
81 	return(0);
82 }
83 
84 long symcnt;				/* symbol count */
85 long tsymlen;				/* total string length */
86 
87 /*
88  * rexec
89  *	Read the exec structure; ignore any files that don't look
90  *	exactly right.
91  */
92 static void
93 rexec(rfd, wfd)
94 	register int rfd;
95 	int wfd;
96 {
97 	register RLIB *rp;
98 	register long nsyms;
99 	register int nr, symlen;
100 	register char *strtab, *sym;
101 	struct exec ebuf;
102 	struct nlist nl;
103 	off_t r_off, w_off;
104 	long strsize;
105 	void *emalloc();
106 
107 	/* Get current offsets for original and tmp files. */
108 	r_off = lseek(rfd, (off_t)0, SEEK_CUR);
109 	w_off = lseek(wfd, (off_t)0, SEEK_CUR);
110 
111 	/* Read in exec structure. */
112 	nr = read(rfd, (char *)&ebuf, sizeof(struct exec));
113 	if (nr != sizeof(struct exec))
114 		goto badread;
115 
116 	/* Check magic number and symbol count. */
117 	if (N_BADMAG(ebuf) || ebuf.a_syms == 0)
118 		goto bad1;
119 
120 	/* Seek to string table. */
121 	if (lseek(rfd, N_STROFF(ebuf) + r_off, SEEK_SET) == (off_t)-1)
122 		error(archive);
123 
124 	/* Read in size of the string table. */
125 	nr = read(rfd, (char *)&strsize, sizeof(strsize));
126 	if (nr != sizeof(strsize))
127 		goto badread;
128 
129 	/* Read in the string table. */
130 	strsize -= sizeof(strsize);
131 	strtab = (char *)emalloc(strsize);
132 	nr = read(rfd, strtab, strsize);
133 	if (nr != strsize) {
134 badread:	if (nr < 0)
135 			error(archive);
136 		goto bad2;
137 	}
138 
139 	/* Seek to symbol table. */
140 	if (fseek(fp, N_SYMOFF(ebuf) + r_off, SEEK_SET) == (off_t)-1)
141 		goto bad2;
142 
143 	/* For each symbol read the nlist entry and save it as necessary. */
144 	nsyms = ebuf.a_syms / sizeof(struct nlist);
145 	while (nsyms--) {
146 		if (!fread((char *)&nl, sizeof(struct nlist), 1, fp)) {
147 			if (feof(fp))
148 				badfmt();
149 			error(archive);
150 		}
151 
152 		/* Ignore if no name or local. */
153 		if (!nl.n_un.n_strx || !(nl.n_type & N_EXT))
154 			continue;
155 
156 		/*
157 		 * If the symbol is an undefined external and the n_value
158 		 * field is non-zero, keep it.
159 		 */
160 		if ((nl.n_type & N_TYPE) == N_UNDF && !nl.n_value)
161 			continue;
162 
163 		/* First four bytes are the table size. */
164 		sym = strtab + nl.n_un.n_strx - sizeof(long);
165 		symlen = strlen(sym) + 1;
166 
167 		rp = (RLIB *)emalloc(sizeof(RLIB));
168 		rp->sym = (char *)emalloc(symlen);
169 		bcopy(sym, rp->sym, symlen);
170 		rp->symlen = symlen;
171 		rp->pos = w_off;
172 
173 		/* Build in forward order for "ar -m" command. */
174 		*pnext = rp;
175 		pnext = &rp->next;
176 
177 		++symcnt;
178 		tsymlen += symlen;
179 	}
180 
181 bad2:	free(strtab);
182 bad1:	(void)lseek(rfd, (off_t)r_off, SEEK_SET);
183 }
184 
185 /*
186  * symobj --
187  *	Write the symbol table into the archive, computing offsets as
188  *	writing.
189  */
190 static void
191 symobj()
192 {
193 	register RLIB *rp;
194 	struct ranlib rn;
195 	char hb[sizeof(struct ar_hdr) + 1], pad;
196 	long ransize, size, stroff;
197 	gid_t getgid();
198 	uid_t getuid();
199 
200 	/* Rewind the archive, leaving the magic number. */
201 	if (fseek(fp, (off_t)SARMAG, SEEK_SET) == (off_t)-1)
202 		error(archive);
203 
204 	/* Size of the ranlib archive file, pad if necessary. */
205 	ransize = sizeof(long) +
206 	    symcnt * sizeof(struct ranlib) + sizeof(long) + tsymlen;
207 	if (ransize & 01) {
208 		++ransize;
209 		pad = '\n';
210 	} else
211 		pad = '\0';
212 
213 	/* Put out the ranlib archive file header. */
214 #define	DEFMODE	(S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
215 	(void)sprintf(hb, HDR2, RANLIBMAG, 0L, getuid(), getgid(),
216 	    DEFMODE & ~umask(0), ransize, ARFMAG);
217 	if (!fwrite(hb, sizeof(struct ar_hdr), 1, fp))
218 		error(tname);
219 
220 	/* First long is the size of the ranlib structure section. */
221 	size = symcnt * sizeof(struct ranlib);
222 	if (!fwrite((char *)&size, sizeof(size), 1, fp))
223 		error(tname);
224 
225 	/* Offset of the first archive file. */
226 	size = SARMAG + sizeof(struct ar_hdr) + ransize;
227 
228 	/*
229 	 * Write out the ranlib structures.  The offset into the string
230 	 * table is cumulative, the offset into the archive is the value
231 	 * set in rexec() plus the offset to the first archive file.
232 	 */
233 	for (rp = rhead, stroff = 0; rp; rp = rp->next) {
234 		rn.ran_un.ran_strx = stroff;
235 		stroff += rp->symlen;
236 		rn.ran_off = size + rp->pos;
237 		if (!fwrite((char *)&rn, sizeof(struct ranlib), 1, fp))
238 			error(archive);
239 	}
240 
241 	/* Second long is the size of the string table. */
242 	if (!fwrite((char *)&tsymlen, sizeof(tsymlen), 1, fp))
243 		error(tname);
244 
245 	/* Write out the string table. */
246 	for (rp = rhead; rp; rp = rp->next)
247 		if (!fwrite(rp->sym, rp->symlen, 1, fp))
248 			error(tname);
249 
250 	if (pad && !fwrite(&pad, sizeof(pad), 1, fp))
251 		error(tname);
252 
253 	(void)fflush(fp);
254 }
255