Copy in libbacktrace from gcc

This copies in libbacktrace from the gcc repository as it was in the
commit 62e420293a293608f383d9b9c7f2debd666e9fc9.  GDB is going to
start using this library soon.

A dependency between GDB and libbacktrace has already been added to
the top level Makefile, so, after this commit, when building GDB,
libbacktrace will be built first.  However, libbacktrace is not yet
linked into GDB, or used by GDB in any way.

It is possible to stop libbacktrace being built by configuring the
tree with --disable-libbacktrace.

This commit does NOT update src-release.sh, that will be done in the
next commit, this commit ONLY imports libbacktrace from gcc.  This
means that if you try to make a release of GDB from exactly this
commit then the release tar file will not include libbacktrace.
However, as libbacktrace is an optional dependency this is fine.

1 files changed, 110 insertions, 0 deletions

diff --git a/libbacktrace/testlib.h b/libbacktrace/testlib.h
new file mode 100644
index 0000000..29542a5
--- /dev/null
+++ b/libbacktrace/testlib.h
@@ -0,0 +1,110 @@
+/* testlib.h -- Header for test functions for libbacktrace library
+   Copyright (C) 2012-2021 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.  */
+
+#ifndef LIBBACKTRACE_TESTLIB_H
+#define LIBBACKTRACE_TESTLIB_H
+
+/* Portable attribute syntax.  Actually some of these tests probably
+   won't work if the attributes are not recognized.  */
+
+#ifndef GCC_VERSION
+# define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
+#endif
+
+#if (GCC_VERSION < 2007)
+# define __attribute__(x)
+#endif
+
+#ifndef ATTRIBUTE_UNUSED
+# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
+#endif
+
+/* Used to collect backtrace info.  */
+
+struct info
+{
+  char *filename;
+  int lineno;
+  char *function;
+};
+
+/* Passed to backtrace callback function.  */
+
+struct bdata
+{
+  struct info *all;
+  size_t index;
+  size_t max;
+  int failed;
+};
+
+/* Passed to backtrace_simple callback function.  */
+
+struct sdata
+{
+  uintptr_t *addrs;
+  size_t index;
+  size_t max;
+  int failed;
+};
+
+/* Passed to backtrace_syminfo callback function.  */
+
+struct symdata
+{
+  const char *name;
+  uintptr_t val, size;
+  int failed;
+};
+
+/* The backtrace state.  */
+
+extern void *state;
+
+/* The number of failures.  */
+
+extern int failures;
+
+extern const char *base (const char *p);
+extern void check (const char *name, int index, const struct info *all,
+		   int want_lineno, const char *want_function,
+		   const char *want_file, int *failed);
+extern int callback_one (void *, uintptr_t, const char *, int, const char *);
+extern void error_callback_one (void *, const char *, int);
+extern int callback_two (void *, uintptr_t);
+extern void error_callback_two (void *, const char *, int);
+extern void callback_three (void *, uintptr_t, const char *, uintptr_t,
+			    uintptr_t);
+extern void error_callback_three (void *, const char *, int);
+extern void error_callback_create (void *, const char *, int);
+
+#endif /* !defined(LIBBACKTRACE_TESTLIB_H) */