X-Git-Url: https://ruderich.org/simon/gitweb/?p=coloredstderr%2Fcoloredstderr.git;a=blobdiff_plain;f=src%2Fcoloredstderr.c;h=00de8a588b080cee6b37d968f8641df954bd0544;hp=ccefdf34a31c9da821a58e868008a303e5310c14;hb=045ca46e7929c27c3c408324aaae02499b1eae81;hpb=51377106d1bd632546fa66bc27ac1a02a647f026

diff --git a/src/coloredstderr.c b/src/coloredstderr.c
index ccefdf3..00de8a5 100644
--- a/src/coloredstderr.c
+++ b/src/coloredstderr.c
@@ -20,28 +20,58 @@
 
 #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>
 #include <stdio.h>
 #include <string.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
+#ifdef HAVE_ERR_H
+# include <err.h>
+#endif
 #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
+/* The following functions may be macros. Undefine them or they cause build
+ * failures when used in our hook macros below. */
+
+/* In glibc, real fwrite_unlocked() is called in macro. */
+#ifdef HAVE_FWRITE_UNLOCKED
+# undef fwrite_unlocked
+#endif
+/* In Clang when compiling with hardening flags (fortify) on Debian Wheezy. */
+#undef printf
+#undef fprintf
+/* On FreeBSD (9.1), __swbuf() is used instead of these macros. */
+#ifdef HAVE___SWBUF
+# undef putc
+# undef putc_unlocked
+# undef putchar
+# undef putchar_unlocked
+#endif
 
 
 /* Used by various functions, including debug(). */
-static ssize_t (*real_write)(int, const void *, size_t);
+static ssize_t (*real_write)(int, void const *, size_t);
 static int (*real_close)(int);
-static size_t (*real_fwrite)(const void *, size_t, size_t, FILE *);
+static size_t (*real_fwrite)(void const *, size_t, size_t, FILE *);
 
 /* Did we already (try to) parse the environment and setup the necessary
  * variables? */
@@ -51,7 +81,7 @@ static int force_write_to_non_tty;
 
 
 #include "constants.h"
-#ifdef DEBUG
+#ifdef WARNING
 # include "debug.h"
 #endif
 
@@ -60,36 +90,34 @@ static int force_write_to_non_tty;
 
 
 
-/* Should the "action" handler be invoked for this file descriptor? */
-static int check_handle_fd(int fd) {
-    /* Load state from environment. Only necessary once per process. */
-    if (!initialized) {
-        init_from_environment();
-    }
-    if (tracked_fds_list_count == 0) {
-        return 0;
-    }
+/* See hookmacros.h for the decision if a function call is colored. */
 
-    /* Never touch anything not going to a terminal - unless we are explicitly
-     * asked to do so. */
-    if (!force_write_to_non_tty && !isatty(fd)) {
-        return 0;
-    }
 
-    return tracked_fds_find(fd);
+/* 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
 
-    if (!initialized) {
+    assert(oldfd >= 0 && newfd >= 0);
+
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
-    if (tracked_fds_list_count == 0) {
-        return;
-    }
 
     /* We are already tracking this file descriptor, add newfd to the list as
      * it will reference the same descriptor. */
@@ -109,12 +137,11 @@ static void close_fd(int fd) {
     debug("%3d ->   .\t\t\t[%d]\n", fd, getpid());
 #endif
 
-    if (!initialized) {
+    assert(fd >= 0);
+
+    if (unlikely(!initialized)) {
         init_from_environment();
     }
-    if (tracked_fds_list_count == 0) {
-        return;
-    }
 
     tracked_fds_remove(fd);
 }
@@ -122,14 +149,14 @@ static void close_fd(int fd) {
 
 /* "Action" handlers called when a file descriptor is matched. */
 
-static char *pre_string;
+static char const *pre_string;
 static size_t pre_string_size;
-static char *post_string;
+static char const *post_string;
 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() {
+static void init_pre_post_string(void) {
     pre_string = getenv(ENV_NAME_PRE_STRING);
     if (!pre_string) {
         pre_string = DEFAULT_PRE_STRING;
@@ -143,38 +170,53 @@ inline static void init_pre_post_string() {
     post_string_size = strlen(post_string);
 }
 
-static void handle_fd_pre(int fd, int action) {
-    (void)action;
+/* 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;
 
-    if (!pre_string || !post_string) {
+    if (unlikely(!pre_string || !post_string)) {
         init_pre_post_string();
     }
 
     DLSYM_FUNCTION(real_write, "write");
     real_write(fd, pre_string, pre_string_size);
+
+    errno = saved_errno;
 }
-static void handle_fd_post(int fd, int action) {
-    (void)action;
+static void handle_fd_post(int fd) {
+    int saved_errno = errno;
 
     /* write() already loaded above in handle_fd_pre(). */
     real_write(fd, post_string, post_string_size);
+
+    errno = saved_errno;
 }
 
-static void handle_file_pre(FILE *stream, int action) {
-    (void)action;
+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();
     }
 
     DLSYM_FUNCTION(real_fwrite, "fwrite");
     real_fwrite(pre_string, pre_string_size, 1, stream);
+
+    errno = saved_errno;
 }
-static void handle_file_post(FILE *stream, int action) {
-    (void)action;
+static void handle_file_post(FILE *stream) {
+    int saved_errno = errno;
 
     /* fwrite() already loaded above in handle_file_pre(). */
     real_fwrite(post_string, post_string_size, 1, stream);
+
+    errno = saved_errno;
 }
 
 
@@ -182,13 +224,13 @@ static void handle_file_post(FILE *stream, int action) {
 /* Hook all important output functions to manipulate their output. */
 
 HOOK_FD3(ssize_t, write, fd,
-         int, fd, const void *, buf, size_t, count)
+         int, fd, void const *, buf, size_t, count)
 HOOK_FILE4(size_t, fwrite, stream,
-           const void *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+           void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
 
 /* puts(3) */
 HOOK_FILE2(int, fputs, stream,
-           const char *, s, FILE *, stream)
+           char const *, s, FILE *, stream)
 HOOK_FILE2(int, fputc, stream,
            int, c, FILE *, stream)
 HOOK_FILE2(int, putc, stream,
@@ -196,51 +238,99 @@ HOOK_FILE2(int, putc, stream,
 HOOK_FILE1(int, putchar, stdout,
            int, c)
 HOOK_FILE1(int, puts, stdout,
-           const char *, s)
+           char const *, s)
 
 /* printf(3), excluding all s*() and vs*() functions (no output) */
 HOOK_VAR_FILE1(int, printf, stdout, vprintf,
-               const char *, format)
+               char const *, format)
 HOOK_VAR_FILE2(int, fprintf, stream, vfprintf,
-               FILE *, stream, const char *, format)
+               FILE *, stream, char const *, format)
 HOOK_FILE2(int, vprintf, stdout,
-           const char *, format, va_list, ap)
+           char const *, format, va_list, ap)
 HOOK_FILE3(int, vfprintf, stream,
-           FILE *, stream, const char *, format, va_list, ap)
+           FILE *, stream, char const *, format, va_list, ap)
 /* Hardening functions (-D_FORTIFY_SOURCE=2), only functions from above */
 HOOK_VAR_FILE2(int, __printf_chk, stdout, __vprintf_chk,
-               int, flag, const char *, format)
+               int, flag, char const *, format)
 HOOK_VAR_FILE3(int, __fprintf_chk, fp, __vfprintf_chk,
-               FILE *, fp, int, flag, const char *, format)
+               FILE *, fp, int, flag, char const *, format)
 HOOK_FILE3(int, __vprintf_chk, stdout,
-           int, flag, const char *, format, va_list, ap)
+           int, flag, char const *, format, va_list, ap)
 HOOK_FILE4(int, __vfprintf_chk, stream,
-           FILE *, stream, int, flag, const char *, format, va_list, ap)
+           FILE *, stream, int, flag, char const *, format, va_list, ap)
 
 /* unlocked_stdio(3), only functions from above are hooked */
+#ifdef HAVE_FWRITE_UNLOCKED
 HOOK_FILE4(size_t, fwrite_unlocked, stream,
-           const void *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+           void const *, ptr, size_t, size, size_t, nmemb, FILE *, stream)
+#endif
+#ifdef HAVE_FPUTS_UNLOCKED
 HOOK_FILE2(int, fputs_unlocked, stream,
-           const char *, s, FILE *, stream)
+           char const *, s, FILE *, stream)
+#endif
+#ifdef HAVE_FPUTC_UNLOCKED
 HOOK_FILE2(int, fputc_unlocked, stream,
            int, c, FILE *, stream)
+#endif
 HOOK_FILE2(int, putc_unlocked, stream,
            int, c, FILE *, stream)
 HOOK_FILE1(int, putchar_unlocked, stdout,
            int, c)
-HOOK_FILE1(int, puts_unlocked, stdout,
-           const char *, s)
+/* glibc defines (_IO_)putc_unlocked() to a macro which either updates the
+ * output buffer or calls __overflow(). As this code is inlined we can't
+ * handle the first case, but if __overflow() is called we can color that
+ * part. As writes to stderr are never buffered, __overflow() is always called
+ * and everything works fine. This is only a problem if stdout is dupped to
+ * stderr (which shouldn't be the case too often). */
+#if defined(HAVE_STRUCT__IO_FILE__FILENO) && defined(HAVE___OVERFLOW)
+/* _IO_FILE is glibc's representation of FILE. */
+HOOK_FILE2(int, __overflow, f, _IO_FILE *, f, int, ch)
+#endif
+/* Same for FreeBSD's libc. However it's more aggressive: The inline writing
+ * and __swbuf() are also used for normal output (e.g. putc()). Writing to
+ * stderr is still fine; it always calls __swbuf() as stderr is always
+ * unbufferd. */
+#ifdef HAVE___SWBUF
+HOOK_FILE2(int, __swbuf, f, int, c, FILE *, f)
+#endif
 
 /* perror(3) */
 HOOK_VOID1(void, perror, STDERR_FILENO,
-           const char *, s)
+           char const *, s)
+
+/* err(3), non standard BSD extension */
+#ifdef HAVE_ERR_H
+HOOK_VAR_VOID2(void, err, STDERR_FILENO, verr,
+               int, eval, char const *, fmt)
+HOOK_VAR_VOID2(void, errx, STDERR_FILENO, verrx,
+               int, eval, char const *, fmt)
+HOOK_VAR_VOID1(void, warn, STDERR_FILENO, vwarn,
+               char const *, fmt)
+HOOK_VAR_VOID1(void, warnx, STDERR_FILENO, vwarnx,
+               char const *, fmt)
+HOOK_FUNC_SIMPLE3(void, verr, int, eval, const char *, fmt, va_list, args) {
+    /* Can't use verr() directly as it terminates the process which prevents
+     * the post string from being printed. */
+    vwarn(fmt, args);
+    exit(eval);
+}
+HOOK_FUNC_SIMPLE3(void, verrx, int, eval, const char *, fmt, va_list, args) {
+    /* See verr(). */
+    vwarnx(fmt, args);
+    exit(eval);
+}
+HOOK_VOID2(void, vwarn, STDERR_FILENO,
+           char const *, fmt, va_list, args)
+HOOK_VOID2(void, vwarnx, STDERR_FILENO,
+           char const *, fmt, va_list, args)
+#endif
 
-/* error(3) */
+/* error(3), non-standard GNU extension */
 #ifdef HAVE_ERROR_H
-static void  error_vararg(int status, int errnum,
-                   const char *filename, unsigned int linenum,
-                   const char *format, va_list ap) {
-    static const char *last_filename;
+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;
 
     /* Skip this error message if requested and if there was already an error
@@ -286,15 +376,15 @@ static void  error_vararg(int status, int errnum,
     }
 }
 void error_at_line(int status, int errnum,
-                   const char *filename, unsigned int linenum,
-                   const char *format, ...) {
+                   char const *filename, unsigned int linenum,
+                   char const *format, ...) {
     va_list ap;
 
     va_start(ap, format);
     error_vararg(status, errnum, filename, linenum, format, ap);
     va_end(ap);
 }
-void error(int status, int errnum, const char *format, ...) {
+void error(int status, int errnum, char const *format, ...) {
     va_list ap;
 
     va_start(ap, format);
@@ -306,50 +396,44 @@ void error(int status, int errnum, const char *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");
 
     newfd = real_dup(oldfd);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     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);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     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);
     if (newfd != -1) {
-        int saved_errno = errno;
         dup_fd(oldfd, newfd);
-        errno = saved_errno;
     }
 
     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;
 
@@ -374,26 +458,30 @@ int fcntl(int fd, int cmd, ...) {
 
     /* We only care about duping fds. */
     if (cmd == F_DUPFD && result != -1) {
-        int saved_errno = errno;
         dup_fd(fd, result);
-        errno = saved_errno;
     }
 
     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);
 }
 
@@ -423,8 +511,8 @@ 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)(const char *filename, char *const argv[], char *const env[]);
-int execve(const char *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;
@@ -479,14 +567,14 @@ int execve(const char *filename, char *const argv[], char *const env[]) {
     /* Count arguments. */ \
     size_t count = 1; /* arg */ \
     va_start(ap, arg); \
-    while (va_arg(ap, const char *)) { \
+    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); \
@@ -500,41 +588,53 @@ int execve(const char *filename, char *const argv[], char *const env[]) {
     EXECL_COPY_VARARGS_START(args); \
     EXECL_COPY_VARARGS_END(args);
 
-int execl(const char *path, const char *arg, ...) {
+int execl(char const *path, char const *arg, ...) {
     EXECL_COPY_VARARGS(args);
 
-    update_environment();
+    /* execv() updates the environment. */
     return execv(path, args);
 }
-
-int execlp(const char *file, const char *arg, ...) {
+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;
 
-int execle(const char *path, const char *arg, ... /*, 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)(const char *path, char *const argv[]);
-int execv(const char *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)(const char *path, char *const argv[]);
-int execvp(const char *path, 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();
-    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;
+
+    /* execvp() updates the environment. */
+    return execvp(file, argv);
 }
+#endif