1 files changed, 122 insertions, 0 deletions
diff --git a/libtest/libtest_print_backtrace.c b/libtest/libtest_print_backtrace.c
new file mode 100644
index 0000000..8fa0fd5
--- /dev/null
+++ b/libtest/libtest_print_backtrace.c
@@ -0,0 +1,122 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#ifndef TEST
+
+
+#if defined(__linux__)
+# define HAVE_LINE_INFO
+#endif
+
+
+void
+libtest_print_backtrace(FILE *fp, const char *indent, size_t first, const struct backtrace *backtrace)
+{
+	static _Thread_local int recursion_guard = 0;
+	int saved_errno;
+        unw_word_t rip;
+        unw_cursor_t cursor;
+        unw_context_t context;
+        Dwarf_Addr ip;
+	size_t i;
+#if defined(HAVE_LINE_INFO)
+	Dwfl_Callbacks callbacks;
+	char *debuginfo_path = NULL;
+	Dwfl *dwfl = NULL;
+	Dwfl_Line *line = NULL;
+	Dwfl_Module *module = NULL;
+	int lineno = 0; /* initialised for compiler happiness */
+        const char *filename = NULL;
+        const char *funcname = NULL;
+#endif
+
+	if (recursion_guard)
+		return;
+	saved_errno = errno;
+	recursion_guard = 1;
+	libtest_malloc_internal_usage++;
+
+	if (!backtrace) {
+		if (unw_getcontext(&context))
+			goto out;
+		if (unw_init_local(&cursor, &context))
+			goto out;
+	}
+
+#if defined(__linux__)
+        memset(&callbacks, 0, sizeof(callbacks));
+        callbacks.find_elf        = &dwfl_linux_proc_find_elf;
+        callbacks.find_debuginfo  = &dwfl_standard_find_debuginfo;
+        callbacks.section_address = NULL;
+        callbacks.debuginfo_path  = &debuginfo_path;
+
+	dwfl = dwfl_begin(&callbacks);
+	if (dwfl) {
+		if (dwfl_linux_proc_report(dwfl, getpid()) ||
+		    dwfl_report_end(dwfl, NULL, NULL)) {
+			dwfl_end(dwfl);
+			dwfl = NULL;
+		}
+	}
+#endif
+
+	for (i = 0u; backtrace ? i < backtrace->n : unw_step(&cursor) > 0; i++) {
+		if (backtrace) {
+			ip = backtrace->trace[i];
+		} else {
+			if (unw_get_reg(&cursor, UNW_REG_IP, &rip))
+				break;
+			ip = (Dwarf_Addr)rip;
+		}
+		if (i < first)
+			continue;
+
+#if defined(HAVE_LINE_INFO)
+		if (dwfl) {
+			module   = dwfl_addrmodule(dwfl, ip);
+			funcname = module ? dwfl_module_addrname(module, ip) : NULL;
+			line     = dwfl_getsrc(dwfl, ip);
+			if (line) {
+				filename = dwfl_lineinfo(line, &(Dwarf_Addr){0}, &lineno, NULL, NULL, NULL);
+# ifdef USE_BASENAMES_IN_BACKTRACES
+				if (strrchr(filename, '/'))
+					filename = &strrchr(filename, '/')[1];
+# endif
+			}
+		}
+#endif
+
+#if defined(HAVE_LINE_INFO)
+		fprintf(fp, "%s0x%016"PRIxPTR": %s", indent, (uintptr_t)ip, funcname ? funcname : "???");
+		if (line)
+			fprintf(fp, " (%s:%i)\n", filename, lineno);
+		else
+			fprintf(fp, "\n");
+#else
+		fprintf(fp, "%s0x%016"PRIxPTR"\n", indent, (uintptr_t)ip);
+#endif
+	}
+
+#if defined(HAVE_LINE_INFO)
+	if (dwfl)
+		dwfl_end(dwfl);
+#endif
+
+out:
+	libtest_malloc_internal_usage--;
+	recursion_guard = 0;
+	errno = saved_errno;
+}
+
+
+#else
+
+
+CONST int
+main(void)
+{
+	/* How would one even test this, and what would be the point? */
+	return 0;
+}
+
+
+#endif