Define real_*() static variables with macros.

[coloredstderr/coloredstderr.git] / src / hookmacros.h

diff --git a/src/hookmacros.h b/src/hookmacros.h
index 9e1bd75fa6d60721bbf50a5709c14d5c9d38b46b..ebd5f7a80cdf4127da5a241fad99c6f466f5a8ea 100644 (file)
--- a/src/hookmacros.h
+++ b/src/hookmacros.h
@@ -22,56 +22,114 @@
 
 /* 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_noinline(<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) \
+#define _HOOK_PRE(type, name, fd) \
         int handle; \
-        type result; \
-        DLSYM_FUNCTION(real_ ## name, #name);
+        if (unlikely(!(real_ ## name ))) { \
+            *(void **) (&(real_ ## name)) = dlsym_function(#name); \
+            /* Initialize our data while we're at it. */ \
+            if (unlikely(!initialized)) { \
+                init_from_environment(); \
+            } \
+        } \
+        /* Check if this fd should be handled. */ \
+        if (unlikely(tracked_fds_find(fd))) { \
+            if (unlikely(force_write_to_non_tty)) { \
+                handle = 1; \
+            } else { \
+                handle = isatty_noinline(fd); \
+            } \
+        } else { \
+            handle = 0; \
+        }
 #define _HOOK_PRE_FD(type, name, fd) \
-        _HOOK_PRE(type, name) \
-        _HOOK_PRE_FD_ALONE(type, name, fd)
-#define _HOOK_PRE_FD_ALONE(type, name, fd) \
-        handle = check_handle_fd(fd); \
-        if (handle) { \
-            handle_fd_pre(fd, handle); \
+        type result; \
+        _HOOK_PRE_FD_(type, name, fd)
+#define _HOOK_PRE_FD_(type, name, fd) \
+        _HOOK_PRE(type, name, fd) \
+        if (unlikely(handle)) { \
+            handle_fd_pre(fd); \
         }
 #define _HOOK_PRE_FILE(type, name, file) \
-        _HOOK_PRE(type, name) \
-        handle = check_handle_fd(fileno(file)); \
-        if (handle) { \
-            handle_file_pre(file, handle); \
+        type result; \
+        _HOOK_PRE(type, name, fileno(file)) \
+        if (unlikely(handle)) { \
+            handle_file_pre(file); \
         }
-/* Save and restore the errno to make sure we return the errno of the original
- * function call. */
-#define _HOOK_POST_FD_ALONE(fd) \
-        if (handle) { \
-            int saved_errno = errno; \
-            handle_fd_post(fd, handle); \
-            errno = saved_errno; \
+#define _HOOK_POST_FD_(fd) \
+        if (unlikely(handle)) { \
+            handle_fd_post(fd); \
         }
 #define _HOOK_POST_FD(fd) \
-        _HOOK_POST_FD_ALONE(fd) \
+        _HOOK_POST_FD_(fd) \
         return result;
 #define _HOOK_POST_FILE(file) \
-        if (handle) { \
-            int saved_errno = errno; \
-            handle_file_post(file, handle); \
-            errno = saved_errno; \
+        if (unlikely(handle)) { \
+            handle_file_post(file); \
         } \
         return result;
 
 
+#define HOOK_FUNC_DEF1(type, name, type1, arg1) \
+    static type (*real_ ## name)(type1); \
+    type name(type1 arg1)
+#define HOOK_FUNC_DEF2(type, name, type1, arg1, type2, arg2) \
+    static type (*real_ ## name)(type1, type2); \
+    type name(type1 arg1, type2 arg2)
+#define HOOK_FUNC_DEF3(type, name, type1, arg1, type2, arg2, type3, arg3) \
+    static type (*real_ ## name)(type1, type2, type3); \
+    type name(type1 arg1, type2 arg2, type3 arg3)
+
+#define HOOK_FUNC_VAR_DEF2(type, name, type1, arg1, type2, arg2) \
+    static type (*real_ ## name)(type1, type2, ...); \
+    type name(type1 arg1, type2 arg2, ...)
+
 #define HOOK_VOID1(type, name, fd, type1, arg1) \
     static type (*real_ ## name)(type1); \
     type name(type1 arg1) { \
-        int handle; \
-        DLSYM_FUNCTION(real_ ## name, #name); \
-        _HOOK_PRE_FD_ALONE(type, name, fd) \
+        _HOOK_PRE_FD_(type, name, fd) \
         real_ ## name(arg1); \
-        _HOOK_POST_FD_ALONE(fd) \
+        _HOOK_POST_FD_(fd) \
     }
 
+#define HOOK_FD2(type, name, fd, type1, arg1, type2, arg2) \
+    static type (*real_ ## name)(type1, type2); \
+    type name(type1 arg1, type2 arg2) { \
+        _HOOK_PRE_FD(type, name, fd) \
+        result = real_ ## name(arg1, arg2); \
+        _HOOK_POST_FD(fd) \
+    }
 #define HOOK_FD3(type, name, fd, type1, arg1, type2, arg2, type3, arg3) \
     static type (*real_ ## name)(type1, type2, type3); \
     type name(type1 arg1, type2 arg2, type3 arg3) { \
@@ -131,8 +189,7 @@
     }
 #define HOOK_VAR_FILE3(type, name, file, func, type1, arg1, type2, arg2, type3, arg3) \
     static type (*real_ ## func)(type1, type2, type3, va_list); \
-    type name(type1 arg1, type2 arg2, type3 arg3, ...) \
-    { \
+    type name(type1 arg1, type2 arg2, type3 arg3, ...) { \
         va_list ap; \
         _HOOK_PRE_FILE(type, func, file) \
         va_start(ap, arg3); \