Fix save/restore of errno for isatty().

[coloredstderr/coloredstderr.git] / src / coloredstderr.c

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index a95486dc4be6bbf865aaef66718ab8eefdf7b061..727c580895b7814d18bba43ec832e905ba7ff6b4 100644 (file)
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -51,6 +51,7 @@ static int force_write_to_non_tty;
 
 
 #include "constants.h"
+#include "compiler.h"
 #ifdef DEBUG
 # include "debug.h"
 #endif
@@ -63,12 +64,25 @@ static int force_write_to_non_tty;
 /* See hookmacros.h for the decision if a function call is colored. */
 
 
+/* Prevent inlining into hook functions because it may increase the number of
+ * spilled registers unnecessarily. As it's not called very often accept the
+ * additional call. */
+static int isatty_noinline(int fd) __noinline;
+static int isatty_noinline(int fd) {
+    int saved_errno = errno;
+    int result = isatty(fd);
+    errno = saved_errno;
+
+    return result;
+}
+
+
 static void dup_fd(int oldfd, int newfd) {
 #ifdef DEBUG
     debug("%3d -> %3d\t\t\t[%d]\n", oldfd, newfd, getpid());
 #endif
 
-    if (!initialized) {
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
 
@@ -90,7 +104,7 @@ static void close_fd(int fd) {
     debug("%3d ->   .\t\t\t[%d]\n", fd, getpid());
 #endif
 
-    if (!initialized) {
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
 
@@ -124,7 +138,7 @@ inline static void init_pre_post_string(void) {
 static void handle_fd_pre(int fd) {
     int saved_errno = errno;
 
-    if (!pre_string || !post_string) {
+    if (unlikely(!pre_string || !post_string)) {
         init_pre_post_string();
     }
 
@@ -145,7 +159,7 @@ static void handle_fd_post(int fd) {
 static void handle_file_pre(FILE *stream) {
     int saved_errno = errno;
 
-    if (!pre_string || !post_string) {
+    if (unlikely(!pre_string || !post_string)) {
         init_pre_post_string();
     }