[Intel-gfx] [PATCH i-g-t v2 1/3] lib/core: Avoid unused result in backtrace printing

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Add helpers for direct write to stderr to consolidate the code
and avoid the unused result warning in build.

This also stops fatal_sig_handler from using igt_assert making the
fatal exit path more conceptually correct.

v2: Use igt_ignore_warn since it is questionable whether igt_assert
    should be used on the exit paths. (Chris Wilson)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 lib/igt_core.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/lib/igt_core.c b/lib/igt_core.c
index 538a4472e209..e866bf995872 100644
--- a/lib/igt_core.c
+++ b/lib/igt_core.c
@@ -1239,7 +1239,7 @@ static const char hex[] = "0123456789abcdef";
 static void
 xputch(int c)
 {
-	write(STDERR_FILENO, (const void *) &c, 1);
+	igt_ignore_warn(write(STDERR_FILENO, (const void *) &c, 1));
 }
 
 static int
@@ -1384,13 +1384,23 @@ xprintf(const char *fmt, ...)
 	va_end(ap);
 }
 
+static void __write_stderr(const char *str, size_t len)
+{
+	igt_ignore_warn(write(STDERR_FILENO, str, len));
+}
+
+static void write_stderr(const char *str)
+{
+	__write_stderr(str, strlen(str));
+}
+
 static void print_backtrace_sig_safe(void)
 {
 	unw_cursor_t cursor;
 	unw_context_t uc;
 	int stack_num = 0;
 
-	write(STDERR_FILENO, "Stack trace: \n", 15);
+	write_stderr("Stack trace: \n");
 
 	unw_getcontext(&uc);
 	unw_init_local(&cursor, &uc);
@@ -1899,11 +1909,10 @@ static void fatal_sig_handler(int sig)
 			continue;
 
 		if (handled_signals[i].name_len) {
-			igt_assert_eq(write(STDERR_FILENO, "Received signal ", 16),
-                                      16);
-			igt_assert_eq(write(STDERR_FILENO, handled_signals[i].name, handled_signals[i].name_len),
-                                      handled_signals[i].name_len);
-			igt_assert_eq(write(STDERR_FILENO, ".\n", 2), 2);
+			write_stderr("Received signal ");
+			__write_stderr(handled_signals[i].name,
+				       handled_signals[i].name_len);
+			write_stderr(".\n");
 		}
 
 		if (crash_signal(sig)) {
-- 
2.9.5