[PATH, libgfortran] PR 63589 Fix find_addr2line

[PATH, libgfortran] PR 63589 Fix find_addr2line

[Janne Blomqvist]

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Hi,

Benoit Lodej reported on the fortran list a bug in find_addr2line,
namely that if the PATH string does not end in ":", the last PATH
element is not tested. Rather than fixing the current implementation,
I rewrote it in a simpler fashion by using the strtok_r function.

Tested that it fixes the original bug, and with strace & valgrind that
everything seems Ok (no regtest since we don't have anything in the
testsuite which tests the backtrace functionality, AFAIK). Ok for
trunk/4.9/4.8?

2014-10-18  Janne Blomqvist  <jb@gcc.gnu.org>

    PR libfortran/63589
    * configure.ac: Check for strtok_r.
    * runtime/main.c (gfstrtok_r): Fallback implementation of
    strtok_r.
    (find_addr2line): Use strtok_r to split PATH.
    * config.h.in: Regenerated.
    * configure: Regenerated.


-- 
Janne Blomqvist

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diff --git a/libgfortran/configure.ac b/libgfortran/configure.ac
index 9d8e05c..b3150f4 100644
--- a/libgfortran/configure.ac
+++ b/libgfortran/configure.ac
@@ -275,6 +275,7 @@ if test "x${with_newlib}" = "xyes"; then
    AC_DEFINE(HAVE_GMTIME_R, 1, [Define if you have gmtime_r.])
    AC_DEFINE(HAVE_STRNLEN, 1, [Define if you have strnlen.])
    AC_DEFINE(HAVE_STRNDUP, 1, [Define if you have strndup.])
+   AC_DEFINE(HAVE_STRTOK_R, 1, [Define if you have strtok_r.])
 
    # At some point, we should differentiate between architectures
    # like x86, which have long double versions, and alpha/powerpc/etc.,
@@ -289,7 +290,7 @@ else
    strcasestr getrlimit gettimeofday stat fstat lstat getpwuid vsnprintf dup \
    getcwd localtime_r gmtime_r getpwuid_r ttyname_r clock_gettime \
    readlink getgid getpid getppid getuid geteuid umask getegid \
-   secure_getenv __secure_getenv mkostemp strnlen strndup)
+   secure_getenv __secure_getenv mkostemp strnlen strndup strtok_r)
 fi
 
 # Check strerror_r, cannot be above as versions with two and three arguments exist
diff --git a/libgfortran/runtime/main.c b/libgfortran/runtime/main.c
index 8a572ec..448dfee 100644
--- a/libgfortran/runtime/main.c
+++ b/libgfortran/runtime/main.c
@@ -181,6 +181,16 @@ full_exe_path (void)
 }
 
 
+#ifndef HAVE_STRTOK_R
+static char*
+gfstrtok_r (char *str, const char *delim, 
+	    char **saveptr __attribute__ ((unused)))
+{
+  return strtok (str, delim);
+}
+#define strtok_r gfstrtok_r
+#endif
+
 char *addr2line_path;
 
 /* Find addr2line and store the path.  */
@@ -189,30 +199,32 @@ void
 find_addr2line (void)
 {
 #ifdef HAVE_ACCESS
-#define A2L_LEN 10
+#define A2L_LEN 11
   char *path = secure_getenv ("PATH");
   if (!path)
     return;
+  char *tp = strdup (path);
+  if (!tp)
+    return;
   size_t n = strlen (path);
-  char ap[n + 1 + A2L_LEN];
-  size_t ai = 0;
-  for (size_t i = 0; i < n; i++)
+  char *ap = xmalloc (n + A2L_LEN);
+  char *saveptr;
+  for (char *str = tp;; str = NULL)
     {
-      if (path[i] != ':')
-	ap[ai++] = path[i];
-      else
+      char *token = strtok_r (str, ":", &saveptr);
+      if (!token)
+	break;
+      size_t toklen = strlen (token);
+      memcpy (ap, token, toklen);
+      memcpy (ap + toklen, "/addr2line", A2L_LEN);
+      if (access (ap, R_OK|X_OK) == 0)
 	{
-	  ap[ai++] = '/';
-	  memcpy (ap + ai, "addr2line", A2L_LEN);
-	  if (access (ap, R_OK|X_OK) == 0)
-	    {
-	      addr2line_path = strdup (ap);
-	      return;
-	    }
-	  else
-	    ai = 0;
+	  addr2line_path = strdup (ap);
+	  break;
 	}
     }
+  free (tp);
+  free (ap);
 #endif
 }
 

Re: [PATH, libgfortran] PR 63589 Fix find_addr2line

[Steve Kargl]

On Sat, Oct 18, 2014 at 05:38:16PM +0300, Janne Blomqvist wrote:
> 
> Benoit Lodej reported on the fortran list a bug in find_addr2line,
> namely that if the PATH string does not end in ":", the last PATH
> element is not tested. Rather than fixing the current implementation,
> I rewrote it in a simpler fashion by using the strtok_r function.
> 
> Tested that it fixes the original bug, and with strace & valgrind that
> everything seems Ok (no regtest since we don't have anything in the
> testsuite which tests the backtrace functionality, AFAIK). Ok for
> trunk/4.9/4.8?
> 
> 2014-10-18  Janne Blomqvist  <jb@gcc.gnu.org>
> 
>     PR libfortran/63589
>     * configure.ac: Check for strtok_r.
>     * runtime/main.c (gfstrtok_r): Fallback implementation of
>     strtok_r.
>     (find_addr2line): Use strtok_r to split PATH.
>     * config.h.in: Regenerated.
>     * configure: Regenerated.
> 

OK.

-- 
Steve