improve handling of API calls provided by loaded modules through use of some GCC features; this makes app_stack's usage of AGI APIs even cleaner, and will allow it to work 'as expected' either with or without res_agi being loaded

reviewed at http://reviewboard.digium.com/r/62



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@159631 65c4cc65-6c06-0410-ace0-fbb531ad65f3

1 files changed, 41 insertions, 19 deletions

diff --git a/include/asterisk/agi.h b/include/asterisk/agi.h
index c92ab3c66..9c7759576 100644
--- a/include/asterisk/agi.h
+++ b/include/asterisk/agi.h
@@ -28,6 +28,7 @@ extern "C" {
 #endif
 
 #include "asterisk/cli.h"
+#include "asterisk/optional_api.h"
 
 typedef struct agi_state {
 	int fd;		        /*!< FD for general output */
@@ -60,26 +61,31 @@ typedef struct agi_command {
 	AST_LIST_ENTRY(agi_command) list;
 } agi_command;
 
-#if defined(ASTERISK_AGI_OPTIONAL)
-#define AGI_WEAK attribute_weak
-#else
-#define AGI_WEAK
-#endif
+/*!
+ * \brief
+ *
+ * Registers an AGI command.
+ *
+ * \param mod Pointer to the module_info structure for the module that is registering the command
+ * \param cmd Pointer to the descriptor for the command
+ * \return 1 on success, 0 if the command is already registered
+ *
+ */
+AST_OPTIONAL_API(int, ast_agi_register, (struct ast_module *mod, agi_command *cmd),
+		 { return AST_OPTIONAL_API_UNAVAILABLE; });
 
 /*!
  * \brief
  *
- * Sends a string of text to an application connected via AGI.
+ * Unregisters an AGI command.
  *
- * \param fd The file descriptor for the AGI session (from struct agi_state)
- * \param chan Pointer to an associated Asterisk channel, if any
- * \param fmt printf-style format string
- * \return 0 for success, -1 for failure
+ * \param mod Pointer to the module_info structure for the module that is unregistering the command
+ * \param cmd Pointer to the descriptor for the command
+ * \return 1 on success, 0 if the command was not already registered
  *
  */
-int AGI_WEAK ast_agi_send(int fd, struct ast_channel *chan, char *fmt, ...) __attribute__((format(printf, 3, 4)));
-int AGI_WEAK ast_agi_register(struct ast_module *mod, agi_command *cmd);
-int AGI_WEAK ast_agi_unregister(struct ast_module *mod, agi_command *cmd);
+AST_OPTIONAL_API(int, ast_agi_unregister, (struct ast_module *mod, agi_command *cmd),
+		 { return AST_OPTIONAL_API_UNAVAILABLE; });
 
 /*!
  * \brief
@@ -88,15 +94,16 @@ int AGI_WEAK ast_agi_unregister(struct ast_module *mod, agi_command *cmd);
  * entries.
  *
  * \param mod Pointer to the module_info structure for the module that is registering the commands
- * \param cmd Pointer to the first entry in the array of commands
+ * \param cmd Pointer to the first entry in the array of command descriptors
  * \param len Length of the array (use the ARRAY_LEN macro to determine this easily)
- * \return 0 on success, -1 on failure
+ * \return 0 on success, -1 on failure, AST_OPTIONAL_API_UNAVAILABLE if res_agi is not loaded
  *
  * \note If any command fails to register, all commands previously registered during the operation
  * will be unregistered. In other words, this function registers all the provided commands, or none
  * of them.
  */
-int AGI_WEAK ast_agi_register_multiple(struct ast_module *mod, struct agi_command *cmd, unsigned int len);
+AST_OPTIONAL_API(int, ast_agi_register_multiple, (struct ast_module *mod, struct agi_command *cmd, unsigned int len),
+		 { return AST_OPTIONAL_API_UNAVAILABLE; });
 
 /*!
  * \brief
@@ -105,14 +112,29 @@ int AGI_WEAK ast_agi_register_multiple(struct ast_module *mod, struct agi_comman
  * entries.
  *
  * \param mod Pointer to the module_info structure for the module that is unregistering the commands
- * \param cmd Pointer to the first entry in the array of commands
+ * \param cmd Pointer to the first entry in the array of command descriptors
  * \param len Length of the array (use the ARRAY_LEN macro to determine this easily)
- * \return 0 on success, -1 on failure
+ * \return 0 on success, -1 on failure, AST_OPTIONAL_API_UNAVAILABLE if res_agi is not loaded
  *
  * \note If any command fails to unregister, this function will continue to unregister the
  * remaining commands in the array; it will not reregister the already-unregistered commands.
  */
-int AGI_WEAK ast_agi_unregister_multiple(struct ast_module *mod, struct agi_command *cmd, unsigned int len);
+AST_OPTIONAL_API(int, ast_agi_unregister_multiple, (struct ast_module *mod, struct agi_command *cmd, unsigned int len),
+		 { return AST_OPTIONAL_API_UNAVAILABLE; });
+
+/*!
+ * \brief
+ *
+ * Sends a string of text to an application connected via AGI.
+ *
+ * \param fd The file descriptor for the AGI session (from struct agi_state)
+ * \param chan Pointer to an associated Asterisk channel, if any
+ * \param fmt printf-style format string
+ * \return 0 for success, -1 for failure, AST_OPTIONAL_API_UNAVAILABLE if res_agi is not loaded
+ *
+ */
+AST_OPTIONAL_API_ATTR(int, format(printf, 3, 4), ast_agi_send, (int fd, struct ast_channel *chan, char *fmt, ...),
+		      { return AST_OPTIONAL_API_UNAVAILABLE; });
 
 #if defined(__cplusplus) || defined(c_plusplus)
 }