X-Git-Url: https://ruderich.org/simon/gitweb/?a=blobdiff_plain;f=src%2Fhookmacros.h;h=35e64703ddcc1933891ea8645d155c6edea9282f;hb=9862b8c8f13fe3d5a6012a8d67562bdaef48b8af;hp=469886978e3a6048d8943f92f7a516c6bc7be4ae;hpb=fe3f7d4c635b265c58efd5bc420d32135ec7903e;p=coloredstderr%2Fcoloredstderr.git

diff --git a/src/hookmacros.h b/src/hookmacros.h
index 4698869..35e6470 100644
--- a/src/hookmacros.h
+++ b/src/hookmacros.h
@@ -22,46 +22,89 @@
 
 /* Hook the function by creating a function with the same name. With
  * LD_PRELOAD our function will be preferred. The original function is stored
- * in a static variable (real_*). */
+ * in a static variable (real_*). Any function called in these macros must
+ * make sure to restore the errno if it changes it.
+ *
+ * "Pseudo code" for the following macros. <name> is the name of the hooked
+ * function, <fd> is either a file descriptor or a FILE pointer.
+ *
+ *     if (!real_<name>) {
+ *         real_<name> = dlsym_function(<name>);
+ *         if (!initialized) {
+ *             init_from_environment();
+ *         }
+ *     }
+ *     if (tracked_fds_find(<fd>)) {
+ *         if (force_write_to_non_tty) {
+ *             handle = 1;
+ *         } else {
+ *             handle = isatty(<fd>);
+ *         }
+ *     } else {
+ *         handle = 0;
+ *     }
+ *
+ *     if (handle) {
+ *         handle_<fd>_pre(<fd>);
+ *     }
+ *     <type> result = real_<name>(<args>);
+ *     if (handle) {
+ *         handle_<fd>_post(<fd>);
+ *     }
+ *     return result;
+ */
 
 #define _HOOK_PRE(type, name) \
         int handle; \
-        int saved_errno = errno; \
-        DLSYM_FUNCTION(real_ ## name, #name);
+        if (!(real_ ## name )) { \
+            *(void **) (&(real_ ## name)) = dlsym_function(#name); \
+            /* Initialize our data while we're at it. */ \
+            if (!initialized) { \
+                init_from_environment(); \
+            } \
+        }
 #define _HOOK_PRE_FD(type, name, fd) \
         type result; \
         _HOOK_PRE_FD_(type, name, fd)
 #define _HOOK_PRE_FD_(type, name, fd) \
         _HOOK_PRE(type, name) \
-        handle = check_handle_fd(fd); \
+        if (tracked_fds_find(fd)) { \
+            if (force_write_to_non_tty) { \
+                handle = 1; \
+            } else { \
+                handle = isatty(fd); \
+            } \
+        } else { \
+            handle = 0; \
+        } \
         if (handle) { \
             handle_fd_pre(fd); \
-        } \
-        errno = saved_errno;
+        }
 #define _HOOK_PRE_FILE(type, name, file) \
         type result; \
         _HOOK_PRE(type, name) \
-        handle = check_handle_fd(fileno(file)); \
+        if (tracked_fds_find(fileno(file))) { \
+            if (force_write_to_non_tty) { \
+                handle = 1; \
+            } else { \
+                handle = isatty(fileno(file)); \
+            } \
+        } else { \
+            handle = 0; \
+        } \
         if (handle) { \
             handle_file_pre(file); \
-        } \
-        errno = saved_errno;
-/* Save and restore the errno to make sure we return the errno of the original
- * function call. */
+        }
 #define _HOOK_POST_FD_(fd) \
         if (handle) { \
-            saved_errno = errno; \
             handle_fd_post(fd); \
-            errno = saved_errno; \
         }
 #define _HOOK_POST_FD(fd) \
         _HOOK_POST_FD_(fd) \
         return result;
 #define _HOOK_POST_FILE(file) \
         if (handle) { \
-            saved_errno = errno; \
             handle_file_post(file); \
-            errno = saved_errno; \
         } \
         return result;