From: Simon Ruderich <simon@ruderich.org>
Date: Mon, 10 Jun 2013 04:19:00 +0000 (+0200)
Subject: Fix save/restore of errno for isatty().
X-Git-Tag: 0.1~88
X-Git-Url: https://ruderich.org/simon/gitweb/?a=commitdiff_plain;h=86352712fdc5fa08777eca1458f4ef6bbe579e7b;p=coloredstderr%2Fcoloredstderr.git

Fix save/restore of errno for isatty().
---

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index 72a881f..727c580 100644
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -64,6 +64,19 @@ 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());
diff --git a/src/hookmacros.h b/src/hookmacros.h
index 0eb47cd..6b52293 100644
--- a/src/hookmacros.h
+++ b/src/hookmacros.h
@@ -38,7 +38,7 @@
  *         if (force_write_to_non_tty) {
  *             handle = 1;
  *         } else {
- *             handle = isatty(<fd>);
+ *             handle = isatty_noinline(<fd>);
  *         }
  *     } else {
  *         handle = 0;
@@ -72,7 +72,7 @@
             if (unlikely(force_write_to_non_tty)) { \
                 handle = 1; \
             } else { \
-                handle = isatty(fd); \
+                handle = isatty_noinline(fd); \
             } \
         } else { \
             handle = 0; \
@@ -87,7 +87,7 @@
             if (unlikely(force_write_to_non_tty)) { \
                 handle = 1; \
             } else { \
-                handle = isatty(fileno(file)); \
+                handle = isatty_noinline(fileno(file)); \
             } \
         } else { \
             handle = 0; \