plugin event for C/C++ function definitions

Hi, this patch adds two new plugin events PLUGIN_START_PARSE_FUNCTION and PLUGIN_FINISH_PARSE_FUNCTION. These events are invoked at start_function and finish_function in gcc/c/c-decl.c and gcc/cp/decl.c respectively in the C and C++ frontends. 
PLUGIN_START_PARSE_FUNCTION is called before parsing a function body.
PLUGIN_FINISH_PARSE_FUNCTION is called after parsing a function definition.
This patch has been implemented in gcc 5.1.0.

changelog:

2015-05-18 16:51 GMT-03:00  <andres.tiraboschi@tallertechnologies.com>:
> Hi, this patch adds two new plugin events PLUGIN_START_PARSE_FUNCTION and PLUGIN_FINISH_PARSE_FUNCTION. These events are invoked at start_function and finish_function in gcc/c/c-decl.c and gcc/cp/decl.c respectively in the C and C++ frontends.
> PLUGIN_START_PARSE_FUNCTION is called before parsing a function body.
> PLUGIN_FINISH_PARSE_FUNCTION is called after parsing a function definition.
> This patch has been implemented in gcc 5.1.0.
>
> changelog:
>
> diff --git a/gcc/c/c-decl.c b/gcc/c/c-decl.c
> index e28a294..fcc849d 100644
> --- a/gcc/c/c-decl.c
> +++ b/gcc/c/c-decl.c
> @@ -8235,6 +8235,7 @@ start_function (struct c_declspecs *declspecs, struct c_declarator *declarator,
>
>    decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, true, NULL,
>                           &attributes, NULL, NULL, DEPRECATED_NORMAL);
> +  invoke_plugin_callbacks (PLUGIN_START_PARSE_FUNCTION, decl1);
>
>    /* If the declarator is not suitable for a function definition,
>       cause a syntax error.  */
> @@ -9050,6 +9051,7 @@ finish_function (void)
>       It's still in DECL_STRUCT_FUNCTION, and we'll restore it in
>       tree_rest_of_compilation.  */
>    set_cfun (NULL);
> +  invoke_plugin_callbacks (PLUGIN_FINISH_PARSE_FUNCTION, current_function_decl);
>    current_function_decl = NULL;
>  }
>
> diff --git a/gcc/cp/decl.c b/gcc/cp/decl.c
> index c4731ae..bde92cc 100644
> --- a/gcc/cp/decl.c
> +++ b/gcc/cp/decl.c
> @@ -13727,6 +13727,7 @@ start_function (cp_decl_specifier_seq *declspecs,
>    tree decl1;
>
>    decl1 = grokdeclarator (declarator, declspecs, FUNCDEF, 1, &attrs);
> +  invoke_plugin_callbacks (PLUGIN_START_PARSE_FUNCTION, decl1);
>    if (decl1 == error_mark_node)
>      return false;
>    /* If the declarator is not suitable for a function definition,
> @@ -14365,6 +14366,7 @@ finish_function (int flags)
>        vec_free (deferred_mark_used_calls);
>      }
>
> +  invoke_plugin_callbacks (PLUGIN_FINISH_PARSE_FUNCTION, fndecl);
>    return fndecl;
>  }
>
> diff --git a/gcc/doc/plugins.texi b/gcc/doc/plugins.texi
> index c6caa19..d50f25c 100644
> --- a/gcc/doc/plugins.texi
> +++ b/gcc/doc/plugins.texi
> @@ -174,6 +174,8 @@ Callbacks can be invoked at the following pre-determined events:
>  @smallexample
>  enum plugin_event
>  @{
> +  PLUGIN_START_PARSE_FUNCTION,  /* Called before parsing the body of a function. */
> +  PLUGIN_FINISH_PARSE_FUNCTION, /* After finishing parsing a function. */
>    PLUGIN_PASS_MANAGER_SETUP,    /* To hook into pass manager.  */
>    PLUGIN_FINISH_TYPE,           /* After finishing parsing a type.  */
>    PLUGIN_FINISH_DECL,           /* After finishing parsing a declaration. */
> diff --git a/gcc/plugin.c b/gcc/plugin.c
> index d924438..628833f 100644
> --- a/gcc/plugin.c
> +++ b/gcc/plugin.c
> @@ -441,6 +441,8 @@ register_callback (const char *plugin_name,
>             return;
>           }
>        /* Fall through.  */
> +      case PLUGIN_START_PARSE_FUNCTION:
> +      case PLUGIN_FINISH_PARSE_FUNCTION:
>        case PLUGIN_FINISH_TYPE:
>        case PLUGIN_FINISH_DECL:
>        case PLUGIN_START_UNIT:
> @@ -519,6 +521,8 @@ invoke_plugin_callbacks_full (int event, void *gcc_data)
>         gcc_assert (event >= PLUGIN_EVENT_FIRST_DYNAMIC);
>         gcc_assert (event < event_last);
>        /* Fall through.  */
> +      case PLUGIN_START_PARSE_FUNCTION:
> +      case PLUGIN_FINISH_PARSE_FUNCTION:
>        case PLUGIN_FINISH_TYPE:
>        case PLUGIN_FINISH_DECL:
>        case PLUGIN_START_UNIT:
> diff --git a/gcc/plugin.def b/gcc/plugin.def
> index 98c988a..2a7e4c2 100644
> --- a/gcc/plugin.def
> +++ b/gcc/plugin.def
> @@ -17,6 +17,11 @@ You should have received a copy of the GNU General Public License
>  along with GCC; see the file COPYING3.  If not see
>  <http://www.gnu.org/licenses/>.  */
>
> +/* Called before parsing the body of a function.  */
> +DEFEVENT (PLUGIN_START_PARSE_FUNCTION)
> +
> +/* After finishing parsing a function. */
> +DEFEVENT (PLUGIN_FINISH_PARSE_FUNCTION)
>
>  /* To hook into pass manager.  */
>  DEFEVENT (PLUGIN_PASS_MANAGER_SETUP)
> diff --git a/gcc/testsuite/g++.dg/plugin/def-plugin-test.C b/gcc/testsuite/g++.dg/plugin/def-plugin-test.C
> new file mode 100644
> index 0000000..b7f2d3d
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/plugin/def-plugin-test.C
> @@ -0,0 +1,13 @@
> +int global = 12;
> +
> +int function1(void);
> +
> +int function2(int a) // { dg-warning "Start fndef function2" }
> +{
> +  return function1() + a;
> +} //  { dg-warning "Finish fndef function2" }
> +
> +int function1(void) // { dg-warning "Start fndef function1" }
> +{
> +  return global + 1;
> +} //  { dg-warning "Finish fndef function1" }
> diff --git a/gcc/testsuite/g++.dg/plugin/def_plugin.c b/gcc/testsuite/g++.dg/plugin/def_plugin.c
> new file mode 100644
> index 0000000..63983c5
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/plugin/def_plugin.c
> @@ -0,0 +1,45 @@
> +/* A plugin example that shows which function definitions are caught by PLUGIN_START_FUNCTION and PLUGIN_FINISH_FUNCTION */
> +
> +#include "gcc-plugin.h"
> +#include <stdlib.h>
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "tree.h"
> +#include "tree-pass.h"
> +#include "intl.h"
> +#include "diagnostic.h"
> +
> +int plugin_is_GPL_compatible;
> +
> +/* Callback function to invoke when GCC starts a function definition*/
> +
> +void plugin_start_parse_function (void *event_data, void *data)
> +{
> +  tree fndef = (tree) event_data;
> +  warning (0, G_("Start fndef %s"),
> +           IDENTIFIER_POINTER (DECL_NAME (fndef)));
> +}
> +
> +/* Callback function to invoke after GCC finishes a function definition. */
> +
> +void plugin_finish_parse_function (void *event_data, void *data)
> +{
> +  tree fndef = (tree) event_data;
> +  warning (0, G_("Finish fndef %s"),
> +           IDENTIFIER_POINTER (DECL_NAME (fndef)));
> +}
> +
> +int
> +plugin_init (struct plugin_name_args *plugin_info,
> +             struct plugin_gcc_version *version)
> +{
> +  const char *plugin_name = plugin_info->base_name;
> +
> +  register_callback (plugin_name, PLUGIN_START_PARSE_FUNCTION,
> +                     plugin_start_parse_function, NULL);
> +
> +  register_callback (plugin_name, PLUGIN_FINISH_PARSE_FUNCTION,
> +                     plugin_finish_parse_function, NULL);
> +  return 0;
> +}
> diff --git a/gcc/testsuite/g++.dg/plugin/plugin.exp b/gcc/testsuite/g++.dg/plugin/plugin.exp
> index 1051207..3ed1397 100644
> --- a/gcc/testsuite/g++.dg/plugin/plugin.exp
> +++ b/gcc/testsuite/g++.dg/plugin/plugin.exp
> @@ -61,7 +61,8 @@ set plugin_test_list [list \
>      { selfassign.c self-assign-test-1.C self-assign-test-2.C self-assign-test-3.C } \
>      { dumb_plugin.c dumb-plugin-test-1.C } \
>      { header_plugin.c header-plugin-test.C } \
> -    { decl_plugin.c decl-plugin-test.C } ]
> +    { decl_plugin.c decl-plugin-test.C } \
> +    { def_plugin.c def-plugin-test.C } ]
>
>  foreach plugin_test $plugin_test_list {
>      # Replace each source file with its full-path name

Hi, I forgot to say that I have legal clearence.
Please someone with writing privileges submit this for me

On 05/18/2015 01:51 PM, andres.tiraboschi@tallertechnologies.com wrote:
> Hi, this patch adds two new plugin events PLUGIN_START_PARSE_FUNCTION and PLUGIN_FINISH_PARSE_FUNCTION. These events are invoked at start_function and finish_function in gcc/c/c-decl.c and gcc/cp/decl.c respectively in the C and C++ frontends.
> PLUGIN_START_PARSE_FUNCTION is called before parsing a function body.
> PLUGIN_FINISH_PARSE_FUNCTION is called after parsing a function definition.
> This patch has been implemented in gcc 5.1.0.
THanks.  I've bootstrapped and regression tested this patch on 
x86-linux-gnu.  I also wrote a ChangeLog and installed it on the trunk.

jeff