shithub: scc

Download patch

ref: fcc4d827f855bae3c6e3f1fb7eaaec326bc4765c
parent: 8370fd16f8e62614b67941b32e2cd0e00fcc6e02
author: Roberto E. Vargas Caballero <k0ga@shike2.com>
date: Tue Mar 13 15:46:42 EDT 2018 

[ld] Add basic support for objects and libraries

This code is still a skeleton, but this skeleton is taken from
nm because they have to run over the same kind of archives.


--- a/ld/Makefile
+++ b/ld/Makefile
@@ -5,7 +5,7 @@
 include $(PROJECTDIR)/rules.mk
 include $(LIBDIR)/libdep.mk
 
-OBJ = main.o
+OBJ = main.o formats.o coff32.o
 
 all: ld
 	mkdir -p $(PROJECTDIR)
@@ -26,3 +26,9 @@
 distclean: clean
 
 #deps
+coff32.c: ld.h
+formats.c: ld.h
+main.c: ../inc/arg.h
+main.c: ../inc/ar.h
+main.c: ../inc/scc.h
+main.c: ld.h
--- /dev/null
+++ b/ld/coff32.c
@@ -1,0 +1,26 @@
+static char sccsid[] = "@(#) ./ld/coff32.c";
+
+#include <stdio.h>
+
+#include "ld.h"
+
+static int
+probe(char *fname, char *member, FILE *fp)
+{
+}
+
+static int
+pass1(char *fname, char *member, FILE *fp)
+{
+}
+
+static int
+pass2(char *fname, char *member, FILE *fp)
+{
+}
+
+struct objfile coff32 = {
+	.probe = probe,
+	.pass1 = pass1,
+	.pass2 = pass2,
+};
--- /dev/null
+++ b/ld/formats.c
@@ -1,0 +1,13 @@
+static char sccsid[] = "@(#) ./ld/probe.c";
+
+#include <stdio.h>
+
+#include "ld.h"
+
+/* TODO: Autogenerate this file */
+struct objfile coff32;
+
+struct objfile *formats[] = {
+	&coff32,
+	NULL,
+};
--- /dev/null
+++ b/ld/ld.h
@@ -1,0 +1,6 @@
+
+struct objfile {
+	int (*probe)(char *fname, char *member, FILE *fp);
+	int (*pass1)(char *fname, char *member, FILE *fp);
+	int (*pass2)(char *fname, char *member, FILE *fp);
+};
--- a/ld/main.c
+++ b/ld/main.c
@@ -1,12 +1,230 @@
 static char sccsid[] = "@(#) ./ld/main.c";
 
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include "../inc/arg.h"
 #include "../inc/scc.h"
+#include "../inc/ar.h"
+#include "ld.h"
 
+char *argv0;
+int pass;
+
+static int
+object(char *fname, char *member, FILE *fp)
+{
+	extern struct objfile *formats[];
+	struct objfile **p, *obj;
+	void *data;
+	int (*fun)(char *, char *, FILE *);
+
+	for (p = formats; *p; ++p) {
+		obj = *p;
+		if ((*obj->probe)(fname, member, fp))
+			break;
+	}
+	if (*p == NULL)
+		return 0;
+
+	fun = (pass == 1) ? obj->pass1 : obj->pass2;
+	return (*fun)(fname, member, fp);
+}
+
+static char *
+getfname(struct ar_hdr *hdr, char *dst)
+{
+	char *p;
+	int i;
+
+	memcpy(dst, hdr->ar_name, SARNAM);
+	dst[SARNAM] = '\0';
+
+	for (i = SARNAM-1; i >= 0; i--) {
+		if (dst[i] != ' ' && dst[i] != '/')
+			break;
+		dst[i] = '\0';
+	}
+	return dst;
+}
+
+static void
+ar(char *fname, FILE *fp)
+{
+	struct ar_hdr hdr;
+	long pos, siz;
+	char member[SARNAM+1];
+
+	if (fseek(fp, SARMAG, SEEK_SET) == EOF)
+		goto file_error;
+
+	while (fread(&hdr, sizeof(hdr), 1, fp) == 1) {
+		pos = ftell(fp);
+		if (strncmp(hdr.ar_fmag, ARFMAG, sizeof(hdr.ar_fmag)))
+			goto corrupted;
+
+		siz = 0;
+		sscanf(hdr.ar_size, "%10ld", &siz);
+		if (siz == 0)
+			goto corrupted;
+
+		if (siz & 1)
+			siz++;
+		if (pos == -1 || pos > LONG_MAX - siz)
+			die("ld: %s: overflow in size of archive", fname);
+		pos += siz;
+
+		getfname(&hdr, member);
+		object(fname, member, fp);
+		if (fseek(fp, pos, SEEK_SET) == EOF)
+			goto file_error;
+	}
+
+	if (ferror(fp))
+		goto file_error;
+	return;
+
+corrupted:
+	die("ld: %s: corrupted archive", fname);
+file_error:
+	die("ld: %s: %s", fname, strerror(errno));
+}
+
+static int
+archive(char *fname, FILE *fp)
+{
+	char magic[SARMAG];
+	fpos_t pos;
+
+	fgetpos(fp, &pos);
+	fread(magic, SARMAG, 1, fp);
+	fsetpos(fp, &pos);
+
+	if (ferror(fp))
+		die("ld: %s: %s", fname, strerror(errno));
+	if (strncmp(magic, ARMAG, SARMAG) != 0)
+		return 0;
+
+	ar(fname, fp);
+	return 1;
+}
+
+static void
+process(char *fname)
+{
+	FILE *fp;
+
+	if ((fp = fopen(fname, "rb")) == NULL)
+		die("ld: %s: %s", fname, strerror(errno));
+
+	if (!object(fname, fname, fp) && !archive(fname, fp))
+		die("ld: %s: File format not recognized", fname);
+
+	if (ferror(fp))
+		die("ld: %s: %s", fname, strerror(errno));
+
+	fclose(fp);
+}
+
+static void
+pass1(struct items *list)
+{
+	unsigned i;
+
+	pass = 1;
+	for (i = 0; i < list->n; ++i)
+		process(list->s[i]);
+}
+
+static void
+pass2(struct items *list)
+{
+	unsigned i;
+
+	pass = 2;
+	for (i = 0; i < list->n; ++i)
+		process(list->s[i]);
+}
+
+static void
+readflist(struct items *list, char *fname)
+{
+	FILE *fp;
+	char line[FILENAME_MAX];
+	unsigned char *s, *t;
+
+	if ((fp = fopen(fname, "rb")) == NULL)
+		die("ld: %s: %s", fname, strerror(errno));
+
+	while (fgets(line, sizeof(line), fp)) {
+		size_t n = strlen(line);
+		if (n == 0)
+			continue;
+		if (line[n-1] != '\n')
+			die("ld: %s: line too long", fname);
+		for (s = line; isspace(*s); ++s)
+			*s = '\0';
+		for (t = &line[n-1]; isspace(*t); --t)
+			*t = '\0';
+		newitem(list, xstrdup(s));
+	}
+
+	if (ferror(fp))
+		die("ld: %s: %s", fname, strerror(errno));
+
+	fclose(fp);
+}
+
+static void
+usage(void)
+{
+	fputs("usage: ld [options] [@file] file ...\n", stderr);
+	exit(1);
+}
+
 int
 main(int argc, char *argv[])
 {
+	unsigned i;
+	struct items flist = {.n = 0};
+
+	ARGBEGIN {
+	case 's':
+	case 'u':
+	case 'l':
+	case 'x':
+	case 'X':
+	case 'r':
+	case 'd':
+	case 'n':
+	case 'i':
+	case 'o':
+	case 'e':
+	case 'O':
+	case 'D':
+		break;
+	default:
+		usage();
+	} ARGEND
+
+
+	if (argc == 0)
+		usage();
+
+	if (*argv[0] == '@') {
+		readflist(&flist, *argv + 1);
+		++argv;
+	}
+
+	for (; *argv; ++argv)
+		newitem(&flist, *argv);
+
+	pass1(&flist);
+	pass2(&flist);
+
 	return 0;
 }