diff options
Diffstat (limited to 'gcc/doc/plugins.texi')
| -rw-r--r-- | gcc/doc/plugins.texi | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/gcc/doc/plugins.texi b/gcc/doc/plugins.texi index 4a839b8..96df506 100644 --- a/gcc/doc/plugins.texi +++ b/gcc/doc/plugins.texi @@ -185,7 +185,6 @@ enum plugin_event PLUGIN_GGC_MARKING, /* Extend the GGC marking. */ PLUGIN_GGC_END, /* Called at end of GGC. */ PLUGIN_REGISTER_GGC_ROOTS, /* Register an extra GGC root table. */ - PLUGIN_REGISTER_GGC_CACHES, /* Register an extra GGC cache table. */ PLUGIN_ATTRIBUTES, /* Called during attribute registration */ PLUGIN_START_UNIT, /* Called before processing a translation unit. */ PLUGIN_PRAGMAS, /* Called during pragma registration. */ @@ -233,10 +232,9 @@ the arguments: @item @code{void *user_data}: Pointer to plugin-specific data. @end itemize -For the @i{PLUGIN_PASS_MANAGER_SETUP}, @i{PLUGIN_INFO}, -@i{PLUGIN_REGISTER_GGC_ROOTS} and @i{PLUGIN_REGISTER_GGC_CACHES} -pseudo-events the @code{callback} should be null, and the -@code{user_data} is specific. +For the @i{PLUGIN_PASS_MANAGER_SETUP}, @i{PLUGIN_INFO}, and +@i{PLUGIN_REGISTER_GGC_ROOTS} pseudo-events the @code{callback} should be null, +and the @code{user_data} is specific. When the @i{PLUGIN_PRAGMAS} event is triggered (with a null pointer as data from GCC), plugins may register their own pragmas. Notice that @@ -321,21 +319,22 @@ done by registering a callback (called with a null @code{gcc_data}) for the @code{PLUGIN_GGC_MARKING} event. Such callbacks can call the @code{ggc_set_mark} routine, preferably through the @code{ggc_mark} macro (and conversely, these routines should usually not be used in plugins -outside of the @code{PLUGIN_GGC_MARKING} event). +outside of the @code{PLUGIN_GGC_MARKING} event). Plugins that wish to hold +weak references to gc data may also use this event to drop weak references when +the object is about to be collected. The @code{ggc_marked_p} function can be +used to tell if an object is marked, or is about to be collected. The +@code{gt_clear_cache} overloads which some types define may also be of use in +managing weak references. Some plugins may need to add extra GGC root tables, e.g. to handle their own @code{GTY}-ed data. This can be done with the @code{PLUGIN_REGISTER_GGC_ROOTS} pseudo-event with a null callback and the extra root table (of type @code{struct -ggc_root_tab*}) as @code{user_data}. Plugins that want to use the -@code{if_marked} hash table option can add the extra GGC cache tables generated -by @code{gengtype} using the @code{PLUGIN_REGISTER_GGC_CACHES} pseudo-event with -a null callback and the extra cache table (of type @code{struct ggc_cache_tab*}) -as @code{user_data}. Running the @code{gengtype -p @var{source-dir} -@var{file-list} @var{plugin*.c} ...} utility generates these extra root tables. +ggc_root_tab*}) as @code{user_data}. Running the + @code{gengtype -p @var{source-dir} @var{file-list} @var{plugin*.c} ...} +utility generates these extra root tables. You should understand the details of memory management inside GCC -before using @code{PLUGIN_GGC_MARKING}, @code{PLUGIN_REGISTER_GGC_ROOTS} -or @code{PLUGIN_REGISTER_GGC_CACHES}. +before using @code{PLUGIN_GGC_MARKING} or @code{PLUGIN_REGISTER_GGC_ROOTS}. @node Plugins description |