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authorUlrich Drepper <drepper@redhat.com>1998-06-12 07:36:49 +0000
committerUlrich Drepper <drepper@redhat.com>1998-06-12 07:36:49 +0000
commitecdc196cac5e9e4b783cd77bb709eb6742a0184e (patch)
treede17c14556d0a4ffbeff5649a27ef2283fff60c7 /sysdeps/generic
parentb07d03e000b5c073e7768a6ca2e30578ac51f318 (diff)
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Update.
1998-06-11 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/generic/getenv.c: Fix last change. 1998-06-10 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/generic/backtrace.c: Provide generic implementation. 1998-06-10 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * configure.in: Give visual feedback of the default directories we added. 1998-06-11 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * io/fts.c (fts_build): Define oflag only if needed. 1998-06-11 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * sysdeps/libm-ieee754/w_exp10.c: Add missing close comment.
Diffstat (limited to 'sysdeps/generic')
-rw-r--r--sysdeps/generic/backtrace.c59
-rw-r--r--sysdeps/generic/getenv.c2
2 files changed, 55 insertions, 6 deletions
diff --git a/sysdeps/generic/backtrace.c b/sysdeps/generic/backtrace.c
index 26bf9d4..7ac1d5f 100644
--- a/sysdeps/generic/backtrace.c
+++ b/sysdeps/generic/backtrace.c
@@ -1,4 +1,4 @@
-/* Return backtrace of current program state.
+/* Return backtrace of current program state. Generic version.
Copyright (C) 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
@@ -21,14 +21,63 @@
#include <execinfo.h>
+/* This is a global variable set at program start time. It marks the
+ highest used stack address. */
+extern void *__libc_stack_end;
+
+
+/* This implementation assumes a stack layout that matches the defaults
+ used by gcc's `__builtin_frame_address' and `__builtin_return_address'
+ (FP is the frame pointer register):
+
+ +-----------------+ +-----------------+
+ FP -> | previous FP --------> | previous FP ------>...
+ | | | |
+ | return address | | return address |
+ +-----------------+ +-----------------+
+
+ */
+
+/* Get some notion of the current stack. Need not be exactly the top
+ of the stack, just something somewhere in the current frame. */
+#ifndef CURRENT_STACK_FRAME
+# define CURRENT_STACK_FRAME ({ char __csf; &__csf; })
+#endif
+
+struct layout
+{
+ struct layout *next;
+ void *return_address;
+};
+
int
__backtrace (array, size)
void **array;
int size;
{
- /* We don't generally have the possibility to determine the stack
- trace. Even gcc's `__builtin_return_address' feature cannot help
- since it requires a constant argument. */
- return 0;
+ struct layout *current;
+ void *top_frame;
+ void *top_stack;
+ int cnt = 0;
+
+ top_frame = __builtin_frame_address (0);
+ top_stack = CURRENT_STACK_FRAME;
+
+ /* We skip the call to this function, it makes no sense to record it. */
+ current = (struct layout *) top_frame;
+ while (cnt < size)
+ {
+ if ((void *) current < top_stack || (void *) current > __libc_stack_end)
+ /* This means the address is out of range. Note that for the
+ toplevel we see a frame pointer with value NULL which clearly is
+ out of range. */
+ break;
+
+ array[cnt++] = current->return_address;
+
+ current = current->next;
+ }
+
+ return cnt;
}
weak_alias (__backtrace, backtrace)
diff --git a/sysdeps/generic/getenv.c b/sysdeps/generic/getenv.c
index b6f405d..584b120 100644
--- a/sysdeps/generic/getenv.c
+++ b/sysdeps/generic/getenv.c
@@ -37,7 +37,7 @@ char *
getenv (name)
const char *name;
{
- const size_t len = strlen (name);
+ size_t len = strlen (name);
char **ep;
uint16_t name_start;