libbacktrace/:

	* Initial implementation.

./:
	* MAINTAINERS (Various Maintainers): Add libbacktrace.
	* configure.ac (host_libs): Add libbacktrace.
	(target_libraries): Add libbacktrace.
	* Makefile.def (host_modules): Add libbacktrace.
	(target_modules): Likewise.
	* configure, Makefile.in: Rebuild.

gcc/go:
	* config-lang.in (target_libs): Add target-libbacktrace.

From-SVN: r191397

1 files changed, 154 insertions, 0 deletions

diff --git a/libbacktrace/fileline.c b/libbacktrace/fileline.c
new file mode 100644
index 0000000..de2a589
--- /dev/null
+++ b/libbacktrace/fileline.c
@@ -0,0 +1,154 @@
+/* fileline.c -- Get file and line number information in a backtrace.
+   Copyright (C) 2012 Free Software Foundation, Inc.
+   Written by Ian Lance Taylor, Google.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    (1) Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer. 
+
+    (2) Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.  
+    
+    (3) The name of the author may not be used to
+    endorse or promote products derived from this software without
+    specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
+INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.  */
+
+#include "config.h"
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "backtrace.h"
+#include "internal.h"
+
+/* Initialize the fileline information from the executable.  Returns 1
+   on success, 0 on failure.  */
+
+static int
+fileline_initialize (struct backtrace_state *state,
+		     backtrace_error_callback error_callback, void *data)
+{
+  int failed;
+  fileline fileline_fn;
+  int descriptor;
+
+  failed = state->fileline_initialization_failed;
+
+  if (state->threaded)
+    {
+      /* Use __sync_bool_compare_and_swap to do an atomic load.  */
+      while (!__sync_bool_compare_and_swap
+	     (&state->fileline_initialization_failed, failed, failed))
+	failed = state->fileline_initialization_failed;
+    }
+
+  if (failed)
+    {
+      error_callback (data, "failed to read executable information", 0);
+      return 0;
+    }
+
+  fileline_fn = state->fileline_fn;
+  if (state->threaded)
+    {
+      while (!__sync_bool_compare_and_swap (&state->fileline_fn, fileline_fn,
+					    fileline_fn))
+	fileline_fn = state->fileline_fn;
+    }
+  if (fileline_fn != NULL)
+    return 1;
+
+  /* We have not initialized the information.  Do it now.  */
+
+  if (state->filename != NULL)
+    descriptor = backtrace_open (state->filename, error_callback, data);
+  else
+    descriptor = backtrace_open ("/proc/self/exe", error_callback, data);
+  if (descriptor < 0)
+    failed = 1;
+
+  if (!failed)
+    {
+      if (!backtrace_initialize (state, descriptor, error_callback, data,
+				 &fileline_fn))
+	failed = 1;
+    }
+
+  if (failed)
+    {
+      if (!state->threaded)
+	state->fileline_initialization_failed = 1;
+      else
+	__sync_bool_compare_and_swap (&state->fileline_initialization_failed,
+				      0, failed);
+      return 0;
+    }
+
+  if (!state->threaded)
+    state->fileline_fn = fileline_fn;
+  else
+    {
+      __sync_bool_compare_and_swap (&state->fileline_fn, NULL, fileline_fn);
+
+      /* At this point we know that state->fileline_fn is not NULL.
+	 Either we stored our value, or some other thread stored its
+	 value.  If some other thread stored its value, we leak the
+	 one we just initialized.  Either way, state->fileline_fn is
+	 initialized.  The compare_and_swap is a full memory barrier,
+	 so we should have full access to that value even if it was
+	 created by another thread.  */
+    }
+
+  return 1;
+}
+
+/* Given a PC, find the file name, line number, and function name.  */
+
+int
+backtrace_pcinfo (struct backtrace_state *state, uintptr_t pc,
+		  backtrace_full_callback callback,
+		  backtrace_error_callback error_callback, void *data)
+{
+  if (!fileline_initialize (state, error_callback, data))
+    return 0;
+
+  if (state->fileline_initialization_failed)
+    return 0;
+
+  return state->fileline_fn (state, pc, callback, error_callback, data);
+}
+
+/* Given a PC, find the symbol for it, and its value.  */
+
+int
+backtrace_syminfo (struct backtrace_state *state, uintptr_t pc,
+		   backtrace_syminfo_callback callback,
+		   backtrace_error_callback error_callback, void *data)
+{
+  if (!fileline_initialize (state, error_callback, data))
+    return 0;
+
+  if (state->fileline_initialization_failed)
+    return 0;
+
+  state->syminfo_fn (state, pc, callback, error_callback, data);
+  return 1;
+}