From 201e36e77d6ca616f75f14d5f1c31f0062ae4366 Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Fri, 13 Mar 2015 10:20:29 -0600 Subject: mapi: add new _glapi_new_nop_table() and _glapi_set_nop_handler() _glapi_new_nop_table() creates a new dispatch table populated with pointers to no-op functions. _glapi_set_nop_handler() is used to register a callback function which will be called from each of the no-op functions. Now we always generate a separate no-op function for each GL entrypoint. This allows us to do proper stack clean-up for Windows __stdcall and lets us report the actual function name in error messages. Before this change, for non-Windows release builds we used a single no-op function for all entrypoints. Reviewed-by: Jose Fonseca --- src/mapi/glapi/glapi_nop.c | 84 ++++++++++++++++++++++++++-------------------- 1 file changed, 48 insertions(+), 36 deletions(-) (limited to 'src/mapi/glapi/glapi_nop.c') diff --git a/src/mapi/glapi/glapi_nop.c b/src/mapi/glapi/glapi_nop.c index 628276e932b..0041ed5a876 100644 --- a/src/mapi/glapi/glapi_nop.c +++ b/src/mapi/glapi/glapi_nop.c @@ -30,14 +30,21 @@ * This file defines a special dispatch table which is loaded with no-op * functions. * - * When there's no current rendering context, calling a GL function like - * glBegin() is a no-op. Apps should never normally do this. So as a - * debugging aid, each of the no-op functions will emit a warning to - * stderr if the MESA_DEBUG or LIBGL_DEBUG env var is set. + * Mesa can register a "no-op handler function" which will be called in + * the event that a no-op function is called. + * + * In the past, the dispatch table was loaded with pointers to a single + * no-op function. But that broke on Windows because the GL entrypoints + * use __stdcall convention. __stdcall means the callee cleans up the + * stack. So one no-op function can't properly clean up the stack. This + * would lead to crashes. + * + * Another benefit of unique no-op functions is we can accurately report + * the function's name in an error message. */ - +#include #include "glapi/glapi_priv.h" @@ -51,25 +58,32 @@ _glapi_set_warning_func(_glapi_proc func) { } -/* - * When GLAPIENTRY is __stdcall (i.e. Windows), the stack is popped by the - * callee making the number/type of arguments significant. + +/** + * We'll jump though this function pointer whenever a no-op function + * is called. */ -#if defined(_WIN32) || defined(DEBUG) +static _glapi_nop_handler_proc nop_handler = NULL; + + +/** + * Register the no-op handler call-back function. + */ +void +_glapi_set_nop_handler(_glapi_nop_handler_proc func) +{ + nop_handler = func; +} + /** * Called by each of the no-op GL entrypoints. */ -static int -Warn(const char *func) +static void +nop(const char *func) { -#if defined(DEBUG) - if (getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG")) { - fprintf(stderr, "GL User Error: gl%s called without a rendering context\n", - func); - } -#endif - return 0; + if (nop_handler) + nop_handler(func); } @@ -79,7 +93,8 @@ Warn(const char *func) static GLint NoOpUnused(void) { - return Warn(" function"); + nop("unused GL entry point"); + return 0; } /* @@ -89,31 +104,28 @@ NoOpUnused(void) #define KEYWORD1_ALT static #define KEYWORD2 GLAPIENTRY #define NAME(func) NoOp##func -#define DISPATCH(func, args, msg) Warn(#func); -#define RETURN_DISPATCH(func, args, msg) Warn(#func); return 0 +#define DISPATCH(func, args, msg) nop(#func); +#define RETURN_DISPATCH(func, args, msg) nop(#func); return 0 /* * Defines for the table of no-op entry points. */ #define TABLE_ENTRY(name) (_glapi_proc) NoOp##name +#define DISPATCH_TABLE_NAME __glapi_noop_table +#define UNUSED_TABLE_NAME __unused_noop_functions + +#include "glapi/glapitemp.h" -#else -static int -NoOpGeneric(void) +/** Return pointer to new dispatch table filled with no-op functions */ +struct _glapi_table * +_glapi_new_nop_table(unsigned num_entries) { - if (getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG")) { - fprintf(stderr, "GL User Error: calling GL function without a rendering context\n"); + struct _glapi_table *table = malloc(num_entries * sizeof(_glapi_proc)); + if (table) { + memcpy(table, __glapi_noop_table, + num_entries * sizeof(_glapi_proc)); } - return 0; + return table; } - -#define TABLE_ENTRY(name) (_glapi_proc) NoOpGeneric - -#endif - -#define DISPATCH_TABLE_NAME __glapi_noop_table -#define UNUSED_TABLE_NAME __unused_noop_functions - -#include "glapi/glapitemp.h" -- cgit v1.2.3