Do not depend on some non-POSIX features.

Define/open code memrchr, rawmemchr, powerof2 and TEMP_FAILURE_RETRY if
not available through system headers.

Signed-off-by: Akihiko Odaki <akihiko.odaki.4i@stu.hosei.ac.jp>
Signed-off-by: Mark Wielaard <mjw@redhat.com>

8 files changed, 76 insertions, 8 deletions

diff --git a/ChangeLog b/ChangeLog
index 07e8f577..8d615721 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-10-11  Akihiko Odaki  <akihiko.odaki.4i@stu.hosei.ac.jp>
+
+	* configure.ac: Add memrchr, rawmemchr and powerof2 checks.
+
 2016-08-04  Mark Wielaard  <mjw@redhat.com>
 
 	* configure.ac: Set version to 0.167.
diff --git a/configure.ac b/configure.ac
index e5503f10..c02d4c2a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -245,6 +245,11 @@ zip_LIBS="$LIBS"
 LIBS="$save_LIBS"
 AC_SUBST([zip_LIBS])
 
+AC_CHECK_DECLS([memrchr, rawmemchr],[],[],
+               [#define _GNU_SOURCE
+                #include <string.h>])
+AC_CHECK_DECLS([powerof2],[],[],[#include <sys/param.h>])
+
 AC_CHECK_LIB([stdc++], [__cxa_demangle], [dnl
 AC_DEFINE([USE_DEMANGLE], [1], [Defined if demangling is enabled])])
 AM_CONDITIONAL(DEMANGLE, test "x$ac_cv_lib_stdcpp___cxa_demangle" = "xyes")
diff --git a/lib/ChangeLog b/lib/ChangeLog
index 88c71c9a..afb18b11 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,5 +1,12 @@
 2015-10-11  Akihiko Odaki  <akihiko.odaki.4i@stu.hosei.ac.jp>
 
+	* fixedsizehash.h (CONCAT): Use __CONCAT when available.
+	* system.h: Include config.h and errno.h.
+	(powerof2): Define if not already defined.
+	(TEMP_FAILURE_RETRY): Define when not yet defined.
+
+2015-10-11  Akihiko Odaki  <akihiko.odaki.4i@stu.hosei.ac.jp>
+
 	* Makefile.am (noinst_HEADERS): Add libeu.h.
 	* color.c: Remove system.h include, add libeu.h include.
 	* crc32_file.c: Likewise.
diff --git a/lib/fixedsizehash.h b/lib/fixedsizehash.h
index 18921a44..dac2a5f5 100644
--- a/lib/fixedsizehash.h
+++ b/lib/fixedsizehash.h
@@ -34,7 +34,13 @@
 
 #include <system.h>
 
+#ifdef __CONCAT
 #define CONCAT(t1,t2) __CONCAT (t1,t2)
+#else
+#define STROF(t2) t2
+#define CONCAT_EXPANDED(t1,t2) t1 ## t2
+#define CONCAT(t1,t2) CONCAT_EXPANDED(t1,t2)
+#endif
 
 /* Before including this file the following macros must be defined:
 
diff --git a/lib/system.h b/lib/system.h
index ec387c31..e1c1c698 100644
--- a/lib/system.h
+++ b/lib/system.h
@@ -29,7 +29,12 @@
 #ifndef LIB_SYSTEM_H
 #define LIB_SYSTEM_H	1
 
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
 #include <argp.h>
+#include <errno.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <sys/param.h>
@@ -59,6 +64,9 @@
 #define MIN(m, n) ((m) < (n) ? (m) : (n))
 #endif
 
+#if !HAVE_DECL_POWEROF2
+#define powerof2(x) (((x) & ((x) - 1)) == 0)
+#endif
 
 /* A special gettext function we use if the strings are too short.  */
 #define sgettext(Str) \
@@ -67,6 +75,14 @@
 
 #define gettext_noop(Str) Str
 
+#ifndef TEMP_FAILURE_RETRY
+#define TEMP_FAILURE_RETRY(expression) \
+  ({ ssize_t __res; \
+     do \
+       __res = expression; \
+     while (__res == -1 && errno == EINTR); \
+     __res; });
+#endif
 
 static inline ssize_t __attribute__ ((unused))
 pwrite_retry (int fd, const void *buf, size_t len, off_t off)
diff --git a/libelf/ChangeLog b/libelf/ChangeLog
index cf672bf2..35af7865 100644
--- a/libelf/ChangeLog
+++ b/libelf/ChangeLog
@@ -1,5 +1,13 @@
 2015-10-11  Akihiko Odaki  <akihiko.odaki.4i@stu.hosei.ac.jp>
 
+	* elf_getarsym.c (elf_getarsym): Open code rawmemchr when not
+	available.
+	* elf_strptr.c: Include stdbool.h.
+	(validate_str): New function.
+	(elf_strptr): Use validate_str instead of memrchr.
+
+2015-10-11  Akihiko Odaki  <akihiko.odaki.4i@stu.hosei.ac.jp>
+
 	* elf32_updatefile.c: Remove sys/param.h include.
 	* elf32_updatenull.c: Likewise. Add system.h include.
 	* elf_begin.c: Remove sys/param.h.
diff --git a/libelf/elf_getarsym.c b/libelf/elf_getarsym.c
index 65c67cc8..d5f0ba43 100644
--- a/libelf/elf_getarsym.c
+++ b/libelf/elf_getarsym.c
@@ -297,7 +297,15 @@ elf_getarsym (Elf *elf, size_t *ptr)
 		arsym[cnt].as_off = (*u32)[cnt];
 
 	      arsym[cnt].as_hash = _dl_elf_hash (str_data);
+#if HAVE_DECL_RAWMEMCHR
 	      str_data = rawmemchr (str_data, '\0') + 1;
+#else
+	      char c;
+	      do {
+		c = *str_data;
+		str_data++;
+	      } while (c);
+#endif
 	    }
 
 	  /* At the end a special entry.  */
diff --git a/libelf/elf_strptr.c b/libelf/elf_strptr.c
index ea210459..e72a3a36 100644
--- a/libelf/elf_strptr.c
+++ b/libelf/elf_strptr.c
@@ -32,6 +32,7 @@
 #endif
 
 #include <libelf.h>
+#include <stdbool.h>
 #include <stddef.h>
 
 #include "libelfP.h"
@@ -52,6 +53,22 @@ get_zdata (Elf_Scn *strscn)
   return zdata;
 }
 
+static bool validate_str (const char *str, size_t from, size_t to)
+{
+#if HAVE_DECL_MEMRCHR
+  return memrchr (&str[from], '\0', to - from) != NULL;
+#else
+  do {
+    if (to <= from)
+      return false;
+
+    to--;
+  } while (str[to]);
+
+  return true;
+#endif
+}
+
 char *
 elf_strptr (Elf *elf, size_t idx, size_t offset)
 {
@@ -166,8 +183,7 @@ elf_strptr (Elf *elf, size_t idx, size_t offset)
     {
       /* Make sure the string is NUL terminated.  Start from the end,
          which very likely is a NUL char.  */
-      if (likely (memrchr (&strscn->zdata_base[offset],
-			   '\0', sh_size - offset) != NULL))
+      if (likely (validate_str (strscn->zdata_base, offset, sh_size)))
         result = &strscn->zdata_base[offset];
       else
         __libelf_seterrno (ELF_E_INVALID_INDEX);
@@ -185,8 +201,7 @@ elf_strptr (Elf *elf, size_t idx, size_t offset)
 
       /* Make sure the string is NUL terminated.  Start from the end,
 	 which very likely is a NUL char.  */
-      if (likely (memrchr (&strscn->rawdata_base[offset],
-			  '\0', sh_size - offset) != NULL))
+      if (likely (validate_str (strscn->rawdata_base, offset, sh_size)))
 	result = &strscn->rawdata_base[offset];
       else
 	__libelf_seterrno (ELF_E_INVALID_INDEX);
@@ -203,10 +218,9 @@ elf_strptr (Elf *elf, size_t idx, size_t offset)
 	    {
 	      /* Make sure the string is NUL terminated.  Start from
 		 the end, which very likely is a NUL char.  */
-	      if (likely (memrchr ((char *) dl->data.d.d_buf
-				   + (offset - dl->data.d.d_off), '\0',
-				   (dl->data.d.d_size
-				    - (offset - dl->data.d.d_off))) != NULL))
+	      if (likely (validate_str ((char *) dl->data.d.d_buf,
+					offset - dl->data.d.d_off,
+					dl->data.d.d_size)))
 		result = ((char *) dl->data.d.d_buf
 			  + (offset - dl->data.d.d_off));
 	      else