smbd: Fix snapshot query on shares with DFS enabled

[vlendec/samba-autobuild/.git] / README.Coding

diff --git a/README.Coding b/README.Coding
index f19399e7f24adf8c819f160e701fa0aa35c2dc4e..2b011a6ae9fd6f082baa49c783479afdd5a719b6 100644 (file)
--- a/README.Coding
+++ b/README.Coding
@@ -280,8 +280,8 @@ Good Examples:
                int ret = 0;
 
                if (y < 10) {
-                       z = malloc(sizeof(int)*y);
-                       if (!z) {
+                       z = malloc(sizeof(int) * y);
+                       if (z == NULL) {
                                ret = 1;
                                goto done;
                        }
@@ -290,7 +290,7 @@ Good Examples:
                print("Allocated %d elements.\n", y);
 
         done:
-               if (z) {
+               if (z != NULL) {
                        free(z);
                }
 
@@ -312,6 +312,17 @@ lib/replace/, new code should adhere to the following conventions:
   * Boolean values are "true" and "false" (not True or False)
   * Exact width integers are of type [u]int[8|16|32|64]_t
 
+Most of the time a good name for a boolean variable is 'ok'. Here is an
+example we often use:
+
+       bool ok;
+
+       ok = foo();
+       if (!ok) {
+               /* do something */
+       }
+
+It makes the code more readable and is easy to debug.
 
 Typedefs
 --------
@@ -320,6 +331,39 @@ Samba tries to avoid "typedef struct { .. } x_t;" so we do always try to use
 "struct x { .. };". We know there are still such typedefs in the code,
 but for new code, please don't do that anymore.
 
+Initialize pointers
+-------------------
+
+All pointer variables MUST be initialized to NULL. History has
+demonstrated that uninitialized pointer variables have lead to various
+bugs and security issues.
+
+Pointers MUST be initialized even if the assignment directly follows
+the declaration, like pointer2 in the example below, because the
+instructions sequence may change over time.
+
+Good Example:
+
+       char *pointer1 = NULL;
+       char *pointer2 = NULL;
+
+       pointer2 = some_func2();
+
+       ...
+
+       pointer1 = some_func1();
+
+Bad Example:
+
+       char *pointer1;
+       char *pointer2;
+
+       pointer2 = some_func2();
+
+       ...
+
+       pointer1 = some_func1();
+
 Make use of helper variables
 ----------------------------
 
@@ -329,7 +373,8 @@ it's also easier to use the "step" command within gdb.
 
 Good Example:
 
-       char *name;
+       char *name = NULL;
+       int ret;
 
        name = get_some_name();
        if (name == NULL) {
@@ -352,7 +397,7 @@ debugger.
 Good example:
 
        x = malloc(sizeof(short)*10);
-       if (!x) {
+       if (x == NULL) {
                fprintf(stderr, "Unable to alloc memory!\n");
        }
 
@@ -384,15 +429,21 @@ The only exception is the test code that depends repeated use of calls
 like CHECK_STATUS, CHECK_VAL and others.
 
 
-Function names in DEBUG statements
-----------------------------------
+DEBUG statements
+----------------
 
-Many DEBUG statements contain the name of the function they appear in. This is
-not a good idea, as this is prone to bitrot. Function names change, code
-moves, but the DEBUG statements are not adapted. Use %s and __func__ for this:
+Use these following macros instead of DEBUG:
 
-Bad Example:
-       DEBUG(0, ("strstr_m: src malloc fail\n"));
+DBG_ERR        log level 0             error conditions
+DBG_WARNING    log level 1             warning conditions
+DBG_NOTICE     log level 3             normal, but significant, condition
+DBG_INFO       log level 5             informational message
+DBG_DEBUG      log level 10            debug-level message
 
-Good Example:
-       DEBUG(0, ("%s: src malloc fail\n", __func__));
+Example usage:
+
+DBG_ERR("Memory allocation failed\n");
+DBG_DEBUG("Received %d bytes\n", count);
+
+The messages from these macros are automatically prefixed with the
+function name.