Minor documentation update.

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

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index db6cb27e9f14771a70581222ece7704b816c8d7e..eb9d92cc3c1148d6160e87c4aade4171d8fd2c91 100644 (file)
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -25,6 +25,12 @@
 /* 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>
@@ -78,6 +84,8 @@ static int force_write_to_non_tty;
  * 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;
@@ -91,6 +99,8 @@ static void dup_fd(int oldfd, int newfd) {
     debug("%3d -> %3d\t\t\t[%d]\n", oldfd, newfd, getpid());
 #endif
 
+    assert(oldfd >= 0 && newfd >= 0);
+
     if (unlikely(!initialized)) {
         init_from_environment();
     }
@@ -113,6 +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();
     }
@@ -253,7 +265,7 @@ HOOK_FD2(int, __overflow, f->_fileno, _IO_FILE *, f, int, ch)
 HOOK_VOID1(void, perror, STDERR_FILENO,
            char const *, s)
 
-/* error(3) */
+/* error(3), non-standard GNU extension */
 #ifdef HAVE_ERROR_H
 static void error_vararg(int status, int errnum,
                          char const *filename, unsigned int linenum,
@@ -324,10 +336,8 @@ void error(int status, int errnum, char const *format, ...) {
 
 /* Hook functions which duplicate file descriptors to track them. */
 
-static int (*real_dup)(int);
-static int (*real_dup2)(int, int);
-static int (*real_dup3)(int, int, int);
-int dup(int oldfd) {
+/* int dup(int) */
+HOOK_FUNC_DEF1(int, dup, int, oldfd) {
     int newfd;
 
     DLSYM_FUNCTION(real_dup, "dup");
@@ -339,7 +349,8 @@ int dup(int oldfd) {
 
     return newfd;
 }
-int dup2(int oldfd, int newfd) {
+/* int dup2(int, int) */
+HOOK_FUNC_DEF2(int, dup2, int, oldfd, int, newfd) {
     DLSYM_FUNCTION(real_dup2, "dup2");
 
     newfd = real_dup2(oldfd, newfd);
@@ -349,7 +360,8 @@ int dup2(int oldfd, int newfd) {
 
     return newfd;
 }
-int dup3(int oldfd, int newfd, int flags) {
+/* int dup3(int, int, int) */
+HOOK_FUNC_DEF3(int, dup3, int, oldfd, int, newfd, int, flags) {
     DLSYM_FUNCTION(real_dup3, "dup3");
 
     newfd = real_dup3(oldfd, newfd, flags);
@@ -360,8 +372,8 @@ int dup3(int oldfd, int newfd, int flags) {
     return newfd;
 }
 
-static int (*real_fcntl)(int, int, ...);
-int fcntl(int fd, int cmd, ...) {
+/* int fcntl(int, int, ...) */
+HOOK_FUNC_VAR_DEF2(int, fcntl, int, fd, int, cmd /*, ... */) {
     int result;
     va_list ap;
 
@@ -392,18 +404,24 @@ int fcntl(int fd, int cmd, ...) {
     return result;
 }
 
-static int (*real_close)(int);
-int close(int fd) {
+/* int close(int) */
+HOOK_FUNC_DEF1(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 fclose(FILE *) */
+HOOK_FUNC_DEF1(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);
 }
 
@@ -433,8 +451,8 @@ pid_t vfork(void) {
  * ENV_NAME_FDS. It's also faster to update the environment only when
  * necessary, right before the exec() to pass it to the new process. */
 
-static int (*real_execve)(char const *filename, char * const argv[], char * const env[]);
-int execve(char const *filename, char * const argv[], char * const env[]) {
+/* int execve(char const *, char * const [], char * const []) */
+HOOK_FUNC_DEF3(int, execve, char const *, filename, char * const *, argv, char * const *, env) {
     DLSYM_FUNCTION(real_execve, "execve");
 
     int found = 0;
@@ -489,14 +507,14 @@ int execve(char const *filename, char * const argv[], char * const env[]) {
     /* Count arguments. */ \
     size_t count = 1; /* arg */ \
     va_start(ap, arg); \
-    while (va_arg(ap, char const *)) { \
+    while (va_arg(ap, char *)) { \
         count++; \
     } \
     va_end(ap); \
     \
     /* Copy varargs. */ \
     char *args[count + 1 /* terminating NULL */]; \
-    args[0] = (char *)arg; \
+    args[0] = (char *)arg; /* there's no other way around the cast */ \
     \
     size_t i = 1; \
     va_start(ap, arg); \
@@ -513,36 +531,37 @@ int execve(char const *filename, char * const argv[], char * const env[]) {
 int execl(char const *path, char const *arg, ...) {
     EXECL_COPY_VARARGS(args);
 
-    update_environment();
+    /* execv() updates the environment. */
     return execv(path, args);
 }
-
 int execlp(char const *file, char const *arg, ...) {
     EXECL_COPY_VARARGS(args);
 
-    update_environment();
+    /* execvp() updates the environment. */
     return execvp(file, args);
 }
-
 int execle(char const *path, char const *arg, ... /*, char * const envp[] */) {
+    char * const *envp;
+
     EXECL_COPY_VARARGS_START(args);
     /* Get envp[] located after arguments. */
-    char * const *envp = va_arg(ap, char * const *);
+    envp = va_arg(ap, char * const *);
     EXECL_COPY_VARARGS_END(args);
 
+    /* execve() updates the environment. */
     return execve(path, args, envp);
 }
 
-static int (*real_execv)(char const *path, char * const argv[]);
-int execv(char const *path, char * const argv[]) {
+/* int execv(char const *, char * const []) */
+HOOK_FUNC_DEF2(int, execv, char const *, path, char * const *, argv) {
     DLSYM_FUNCTION(real_execv, "execv");
 
     update_environment();
     return real_execv(path, argv);
 }
 
-static int (*real_execvp)(char const *path, char * const argv[]);
-int execvp(char const *file, char * const argv[]) {
+/* int execvp(char const *, char * const []) */
+HOOK_FUNC_DEF2(int, execvp, char const *, file, char * const *, argv) {
     DLSYM_FUNCTION(real_execvp, "execvp");
 
     update_environment();
@@ -555,6 +574,7 @@ int execvpe(char const *file, char * const argv[], char * const envp[]) {
     /* Fake the environment so we can reuse execvp(). */
     environ = (char **)envp;
 
+    /* execvp() updates the environment. */
     return execvp(file, argv);
 }
 #endif