Add assert()s.

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

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index 72a881fb866ab12e0e92188c58456e4e2979c1a7..7c4a5f5010cc42163ca10e8de75a34cb1ea32da1 100644 (file)
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -20,9 +20,17 @@
 
 #include <config.h>
 
+#include "compiler.h"
+
 /* Must be loaded before the following headers. */
 #include "ldpreload.h"
 
+/* Disable assert()s if not compiled with --enable-debug. */
+#ifndef DEBUG
+# define NDEBUG
+#endif
+
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdarg.h>
@@ -33,9 +41,17 @@
 #ifdef HAVE_ERROR_H
 # include <error.h>
 #endif
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+# include <libio.h>
+#endif
 
 /* Conflicting declaration in glibc. */
 #undef fwrite_unlocked
+/* These functions may be macros when compiling with hardening flags (fortify)
+ * which cause build failures when used in our hook macros below. Observed
+ * with Clang on Debian Wheezy. */
+#undef printf
+#undef fprintf
 
 
 /* Used by various functions, including debug(). */
@@ -51,8 +67,7 @@ static int force_write_to_non_tty;
 
 
 #include "constants.h"
-#include "compiler.h"
-#ifdef DEBUG
+#ifdef WARNING
 # include "debug.h"
 #endif
 
@@ -64,11 +79,28 @@ 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) {
+    assert(fd >= 0);
+
+    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
 
+    assert(oldfd >= 0 && newfd >= 0);
+
     if (unlikely(!initialized)) {
         init_from_environment();
     }
@@ -91,6 +123,8 @@ static void close_fd(int fd) {
     debug("%3d ->   .\t\t\t[%d]\n", fd, getpid());
 #endif
 
+    assert(fd >= 0);
+
     if (unlikely(!initialized)) {
         init_from_environment();
     }
@@ -108,7 +142,7 @@ static size_t post_string_size;
 
 /* Load alternative pre/post strings from the environment if available, fall
  * back to default values. */
-inline static void init_pre_post_string(void) {
+static void init_pre_post_string(void) {
     pre_string = getenv(ENV_NAME_PRE_STRING);
     if (!pre_string) {
         pre_string = DEFAULT_PRE_STRING;
@@ -122,6 +156,13 @@ inline static void init_pre_post_string(void) {
     post_string_size = strlen(post_string);
 }
 
+/* Don't inline any of the pre/post functions. Keep the hook function as small
+ * as possible for speed reasons. */
+static void handle_fd_pre(int fd) noinline;
+static void handle_fd_post(int fd) noinline;
+static void handle_file_pre(FILE *stream) noinline;
+static void handle_file_post(FILE *stream) noinline;
+
 static void handle_fd_pre(int fd) {
     int saved_errno = errno;
 
@@ -215,6 +256,10 @@ HOOK_FILE2(int, putc_unlocked, stream,
            int, c, FILE *, stream)
 HOOK_FILE1(int, putchar_unlocked, stdout,
            int, c)
+/* glibc defines (_IO_)putc_unlocked() to __overflow() in some cases. */
+#ifdef HAVE_STRUCT__IO_FILE__FILENO
+HOOK_FD2(int, __overflow, f->_fileno, _IO_FILE *, f, int, ch)
+#endif
 
 /* perror(3) */
 HOOK_VOID1(void, perror, STDERR_FILENO,
@@ -222,9 +267,9 @@ HOOK_VOID1(void, perror, STDERR_FILENO,
 
 /* error(3) */
 #ifdef HAVE_ERROR_H
-static void  error_vararg(int status, int errnum,
-                   char const *filename, unsigned int linenum,
-                   char const *format, va_list ap) {
+static void error_vararg(int status, int errnum,
+                         char const *filename, unsigned int linenum,
+                         char const *format, va_list ap) {
     static char const *last_filename;
     static unsigned int last_linenum;
 
@@ -363,14 +408,20 @@ static int (*real_close)(int);
 int close(int fd) {
     DLSYM_FUNCTION(real_close, "close");
 
-    close_fd(fd);
+    if (fd >= 0) {
+        close_fd(fd);
+    }
     return real_close(fd);
 }
 static int (*real_fclose)(FILE *);
 int fclose(FILE *fp) {
+    int fd;
+
     DLSYM_FUNCTION(real_fclose, "fclose");
 
-    close_fd(fileno(fp));
+    if (fp != NULL && (fd = fileno(fp)) >= 0) {
+        close_fd(fd);
+    }
     return real_fclose(fp);
 }
 
@@ -509,9 +560,19 @@ int execv(char const *path, char * const argv[]) {
 }
 
 static int (*real_execvp)(char const *path, char * const argv[]);
-int execvp(char const *path, char * const argv[]) {
+int execvp(char const *file, char * const argv[]) {
     DLSYM_FUNCTION(real_execvp, "execvp");
 
     update_environment();
-    return real_execvp(path, argv);
+    return real_execvp(file, argv);
+}
+
+#ifdef HAVE_EXECVPE
+extern char **environ;
+int execvpe(char const *file, char * const argv[], char * const envp[]) {
+    /* Fake the environment so we can reuse execvp(). */
+    environ = (char **)envp;
+
+    return execvp(file, argv);
 }
+#endif