[Elftoolchain-developers] Ticket #379 readelf -p should accept section names

[Sunil N. <su...@su...>]

Here is an attempt to implement solution for this ticket. Tested with
limited knowledge about elf.

Index: readelf.c
===================================================================
--- readelf.c	(revision 2487)
+++ readelf.c	(working copy)
@@ -118,6 +118,7 @@
 	size_t		 sn;		/* section index */
 #define HEX_DUMP	0x0001
 #define STR_DUMP	0x0002
+	const char	 *sname;	/* section name */
 	int		 op;		/* dump op type */
 	STAILQ_ENTRY(dumpop) dumpop_list;
 };
@@ -196,6 +197,7 @@
 };
 
 static void add_dumpop(struct readelf *re, size_t sn, int op);
+static void addstr_dumpop(struct readelf *re, const char *sname, int op);
 static const char *aeabi_adv_simd_arch(uint64_t simd);
 static const char *aeabi_align_needed(uint64_t an);
 static const char *aeabi_align_preserved(uint64_t ap);
@@ -270,6 +272,7 @@
 static void dump_verneed(struct readelf *re, int dump);
 static void dump_versym(struct readelf *re);
 static struct dumpop *find_dumpop(struct readelf *re, size_t sn, int op);
+static struct dumpop *findstr_dumpop(struct readelf *re, const char *sname, int op);
 static const char *get_string(struct readelf *re, int strtab, size_t off);
 static const char *get_symbol_name(struct readelf *re, int symtab, int i);
 static uint64_t get_symbol_value(struct readelf *re, int symtab, int i);
@@ -5961,7 +5964,8 @@
 	int i, j, elferr, found;
 
 	for (i = 1; (size_t) i < re->shnum; i++) {
-		if (find_dumpop(re, (size_t) i, STR_DUMP) == NULL)
+		if ((find_dumpop(re, (size_t) i, STR_DUMP) == NULL) &&
+		    (findstr_dumpop(re, re->sl[i].name, STR_DUMP) == NULL))
 			continue;
 		s = &re->sl[i];
 		(void) elf_errno();
@@ -6314,12 +6318,28 @@
 		if ((d = malloc(sizeof(*d))) == NULL)
 			err(EXIT_FAILURE, "malloc failed");
 		d->sn = sn;
+		d->sname = NULL;
 		d->op = op;
 		STAILQ_INSERT_TAIL(&re->v_dumpop, d, dumpop_list);
 	} else
 		d->op |= op;
 }
 
+static void
+addstr_dumpop(struct readelf *re, const char *sname, int op)
+{
+	struct dumpop *d;
+
+	if ((d = findstr_dumpop(re, sname, 0)) == NULL) {
+		if ((d = malloc(sizeof(*d))) == NULL)
+			err(EXIT_FAILURE, "malloc failed");
+		d->sname = sname;
+		d->op = op;
+		STAILQ_INSERT_TAIL(&re->v_dumpop, d, dumpop_list);
+	} else
+		d->op |= op;
+}
+
 static struct dumpop *
 find_dumpop(struct readelf *re, size_t sn, int op)
 {
@@ -6333,6 +6353,19 @@
 	return (NULL);
 }
 
+static struct dumpop *
+findstr_dumpop(struct readelf *re, const char *sname, int op)
+{
+	struct dumpop *d;
+
+	STAILQ_FOREACH(d, &re->v_dumpop, dumpop_list) {
+		if ( d->sname && (strcmp(d->sname, sname) == 0) &&
+		    (op == 0 || op & d->op))
+			return (d);
+	}
+
+	return (NULL);
+}
 static struct {
 	const char *ln;
 	char sn;
@@ -6626,6 +6659,7 @@
 	struct readelf	*re, re_storage;
 	unsigned long	 sn;
 	int		 opt, i;
+	char		*ep;
 
 	re = &re_storage;
 	memset(re, 0, sizeof(*re));
@@ -6682,7 +6716,11 @@
 			break;
 		case 'p':
 			re->options |= RE_P;
-			sn = strtoul(optarg, NULL, 10);
+			sn = strtoul(optarg, &ep, 10);
+			if (optarg[0] == '\0' || *ep != '\0') {
+				addstr_dumpop(re, optarg, STR_DUMP);
+				break;
+			}
 			add_dumpop(re, (size_t) sn, STR_DUMP);
 			break;
 		case 'r':