diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 39bd297ea..7822a6edf 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,11 @@
+2007-06-27  Eric Blake  <ebb9@byu.net>
+
+	Support __func__ in assert, as required by C99.
+	* libc/stdlib/assert.c (__assert_func): New function.
+	(__assert): Use __assert_func.
+	* libc/include/assert.h (assert) [!NDEBUG]: Use __assert_func when
+	possible.
+
 2007-06-20  Patrick Mansfield  <patmans@us.ibm.com>
 
 	* libc/machine/spu/perror.c: Pass errno as the second argument to
@@ -11,7 +19,7 @@
 2007-06-20  Patrick Mansfield  <patmans@us.ibm.com>
 
 	* libc/include/sys/unistd.h[__SPU__]: Make fchdir prototype visible.
-	* libc/include/sys/stat.h[__SPU__]: Make mknod and lstat prototypes 
+	* libc/include/sys/stat.h[__SPU__]: Make mknod and lstat prototypes
 	visible.
 
 2007-06-15  Patrick Mansfield  <patmans@us.ibm.com>
@@ -23,7 +31,7 @@
 2007-06-13  Patrick Mansfield  <patmans@us.ibm.com>
 
 	* libc/machine/spu/creat.c: New file copied from libc/posix/creat.c,
-	it just calls open with appropriate arguments. 
+	it just calls open with appropriate arguments.
 	* libc/machine/spu/Makefile.am: Add creat.c.
 	* libc/machine/spu/Makefile.in: Regenerate.
 
@@ -77,7 +85,7 @@
 
 2007-06-05  Christian Groessler  <chris@groessler.org>
 
-	* libc/argz/argz_insert.c (argz_insert): Move delta variable 
+	* libc/argz/argz_insert.c (argz_insert): Move delta variable
 	declaration to top of function in keeping with C89 standard.
 
 2007-06-04  Eric Blake  <ebb9@byu.net>
diff --git a/newlib/libc/include/assert.h b/newlib/libc/include/assert.h
index b681a8518..ed14928ba 100644
--- a/newlib/libc/include/assert.h
+++ b/newlib/libc/include/assert.h
@@ -11,18 +11,31 @@ extern "C" {
 #undef assert
 
 #ifdef NDEBUG           /* required by ANSI standard */
-#define assert(p)  	((void)0)
+# define assert(__e) ((void)0)
 #else
+# define assert(__e) ((__e) ? (void)0 : __assert_func (__FILE__, __LINE__, \
+						       __ASSERT_FUNC, #__e))
 
-#ifdef __STDC__
-#define assert(e)       ((e) ? (void)0 : __assert(__FILE__, __LINE__, #e))
-#else   /* PCC */
-#define assert(e)       ((e) ? (void)0 : __assert(__FILE__, __LINE__, "e"))
-#endif
+# ifndef __ASSERT_FUNC
+  /* Use g++'s demangled names in C++.  */
+#  if defined __cplusplus && defined __GNUC__
+#   define __ASSERT_FUNC __PRETTY_FUNCTION__
 
-#endif /* NDEBUG */
+  /* C99 requires the use of __func__, gcc also supports it.  */
+#  elif defined __GNUC__ || __STDC_VERSION__ >= 199901L
+#   define __ASSERT_FUNC __func__
 
-void _EXFUN(__assert,(const char *, int, const char *));
+  /* failed to detect __func__ support.  */
+#  else
+#   define __ASSERT_FUNC ((char *) 0)
+#  endif
+# endif /* !__ASSERT_FUNC */
+#endif /* !NDEBUG */
+
+void _EXFUN(__assert, (const char *, int, const char *)
+	    _ATTRIBUTE ((__noreturn__)));
+void _EXFUN(__assert_func, (const char *, int, const char *, const char *)
+	    _ATTRIBUTE ((__noreturn__)));
 
 #ifdef __cplusplus
 }
diff --git a/newlib/libc/stdlib/assert.c b/newlib/libc/stdlib/assert.c
index c9887da5c..2da329815 100644
--- a/newlib/libc/stdlib/assert.c
+++ b/newlib/libc/stdlib/assert.c
@@ -9,11 +9,6 @@ ANSI_SYNOPSIS
 	#include <assert.h>
 	void assert(int <[expression]>);
 
-TRAD_SYNOPSIS
-	#include <assert.h>
-	assert(<[expression]>)
-	int <[expression]>;
-
 DESCRIPTION
 	Use this macro to embed debuggging diagnostic statements in
 	your programs.  The argument <[expression]> should be an
@@ -24,7 +19,11 @@ DESCRIPTION
 	calls <<abort>>, after first printing a message showing what
 	failed and where:
 
-. Assertion failed: <[expression]>, file <[filename]>, line <[lineno]>
+. Assertion failed: <[expression]>, file <[filename]>, line <[lineno]>, function: <[func]>
+
+	If the name of the current function is not known (for example,
+	when using a C89 compiler that does not understand __func__),
+	the function location is omitted.
 
 	The macro is defined to permit you to turn off all uses of
 	<<assert>> at compile time by defining <<NDEBUG>> as a
@@ -48,15 +47,28 @@ Supporting OS subroutines required (only if enabled): <<close>>, <<fstat>>,
 #include <stdlib.h>
 #include <stdio.h>
 
+/* func can be NULL, in which case no function information is given.  */
+void
+_DEFUN (__assert_func, (file, line, func, failedexpr),
+	const char *file _AND
+	int line _AND
+	const char *func _AND
+	const char *failedexpr)
+{
+  fiprintf(stderr,
+	   "assertion \"%s\" failed: file \"%s\", line %d%s%s\n",
+	   failedexpr, file, line,
+	   func ? ", function: " : "", func ? func : "");
+  abort();
+  /* NOTREACHED */
+}
+
 void
 _DEFUN (__assert, (file, line, failedexpr),
 	const char *file _AND
 	int line _AND
 	const char *failedexpr)
 {
-  (void)fiprintf(stderr,
-	"assertion \"%s\" failed: file \"%s\", line %d\n",
-	failedexpr, file, line);
-  abort();
+   __assert_func (file, line, NULL, failedexpr);
   /* NOTREACHED */
 }