scc

commit 5fa52cf167cadda288c71b4f083da38481698159
parent bea50a9fb4635fd90859754cd31e8756c21479b0
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sun, 19 Jan 2025 10:32:26 +0100

objdump: Add support for -j option

The -j allows to select a set of sections to filter the output of
objdump in commands like for example -h.

Diffstat:
M
src/cmd/scc-objdump/coff32.c
 | 
6
+++++-
M
src/cmd/scc-objdump/main.c
 | 
32
+++++++++++++++++++++++++++++---
M
src/cmd/scc-objdump/objdump.h
 | 
1
+

3 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/src/cmd/scc-objdump/coff32.c b/src/cmd/scc-objdump/coff32.c
@@ -74,12 +74,16 @@ void
 coff32scns(Obj *obj)
 {
 	int i;
+	char *name;
 	SCNHDR *scn;
 	struct coff32 *coff = obj->data;
 	FILHDR *hdr = &coff->hdr;
 
 	for (i = 0; i < hdr->f_nscns; i++) {
 		scn = &coff->scns[i];
+		name = coff32str(coff, scn);
+		if (!selected(name))
+			continue;
 		printf("\nscnhdr: %d\n"
 		       "\tname: %s\n"
 		       "\ts_paddr: 0x%04lx\n"
@@ -92,7 +96,7 @@ coff32scns(Obj *obj)
 		       "\ts_nlnno: %u\n"
 		       "\ts_flags: %#lx\n",
 		       i,
-		       coff32str(coff, scn),
+		       name,
 		       scn->s_paddr,
 		       scn->s_vaddr,
 		       scn->s_size,
diff --git a/src/cmd/scc-objdump/main.c b/src/cmd/scc-objdump/main.c
@@ -15,8 +15,8 @@
 int tflag, fflag, hflag, pflag, aflag, rflag;
 char *argv0;
 
-static int status;
-static char *filename, *membname;
+static int status, nsecs;
+static char *filename, *membname, **secs;
 
 void
 error(char *fmt, ...)
@@ -132,6 +132,22 @@ logb2(unsigned val)
 	return n;
 }
 
+int
+selected(char *secname)
+{
+	int i;
+
+	if (nsecs == 0)
+		return 1;
+
+	for (i = 0; i < nsecs; i++) {
+		if (strcmp(secname, secs[i]) == 0)
+			return 1;
+	}
+
+	return 0;
+}
+
 static void
 dumpscns(Obj *obj)
 {
@@ -142,6 +158,9 @@ dumpscns(Obj *obj)
 	puts("Sections:");
 	puts("Idx Name          Size      VMA       LMA       File off  Algn");
 	for (i = 0; getsec(obj, &i, &sec); i++) {
+		if (!selected(sec.name))
+			continue;
+
 		printf("%3d %-13s %08llx  %08llx  %08llx  %08llx  2**%d\n",
 		       sec.index,
 		       sec.name,
@@ -317,13 +336,15 @@ objdump(char *fname)
 static void
 usage(void)
 {
-	fputs("usage: objdump [-afhpt] file...\n", stderr);
+	fputs("usage: objdump [-afhpt][-j section] file...\n", stderr);
 	exit(EXIT_FAILURE);
 }
 
 int
 main(int argc, char *argv[])
 {
+	char *s;
+
 	ARGBEGIN {
 	case 'a':
 		aflag = 1;
@@ -340,6 +361,11 @@ main(int argc, char *argv[])
 	case 't':
 		tflag = 1;
 		break;
+	case 'j':
+		s = EARGF(usage());
+		secs = xrealloc(secs, (nsecs + 1) * sizeof(char *));
+		secs[nsecs++] = s;
+		break;		
 	default:
 		usage();
 	} ARGEND
diff --git a/src/cmd/scc-objdump/objdump.h b/src/cmd/scc-objdump/objdump.h
@@ -29,6 +29,7 @@ extern unsigned coff32fhdr(Obj *, unsigned long long *);
 /* main.c */
 extern void error(char *, ...);
 extern void setflag(unsigned *, int, int);
+extern int selected(char *);
 
 /* globals */
 extern int pflag;