[Mesa-dev] [PATCH 2/4] mesa: reimplement dispatch table no-op function handling
Brian Paul
brianp at vmware.com
Fri Mar 13 12:22:33 PDT 2015
Use the new _glapi_new_nop_table() and _glapi_set_nop_handler() to
improve how we handle calling no-op GL functions.
If there's a current context for the calling thread, generate a
GL_INVALID_OPERATION error. This will happen if the app calls an
unimplemented extension function or it calls an illegal function
between glBegin/glEnd.
If there's no current context, print an error to stdout if it's a debug
build.
The dispatch_sanity.cpp file has some previous checks removed since
the _mesa_generic_nop() function no longer exists.
This fixes the piglit gl-1.0-dlist-begin-end and gl-1.0-beginend-coverage
tests on Windows.
---
src/mesa/main/context.c | 66 +++++++++++++++++----------------
src/mesa/main/context.h | 3 --
src/mesa/main/tests/dispatch_sanity.cpp | 35 +----------------
3 files changed, 37 insertions(+), 67 deletions(-)
diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 22c2341..e7d1f4d 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -882,18 +882,35 @@ update_default_objects(struct gl_context *ctx)
/**
- * This is the default function we plug into all dispatch table slots
- * This helps prevents a segfault when someone calls a GL function without
- * first checking if the extension's supported.
+ * This function is called by the glapi no-op functions. For each OpenGL
+ * function/entrypoint there's a simple no-op function. These "no-op"
+ * functions call this function.
+ *
+ * If there's a current OpenGL context for the calling thread, we record a
+ * GL_INVALID_OPERATION error. This can happen either because the app's
+ * calling an unsupported extension function, or calling an illegal function
+ * (such as glClear between glBegin/glEnd).
+ *
+ * If there's no current OpenGL context for the calling thread, we can
+ * print a message to stderr.
+ *
+ * \param name the name of the OpenGL function, without the "gl" prefix
*/
-int
-_mesa_generic_nop(void)
+static void
+nop_handler(const char *name)
{
GET_CURRENT_CONTEXT(ctx);
- _mesa_error(ctx, GL_INVALID_OPERATION,
- "unsupported function called "
- "(unsupported extension or deprecated function?)");
- return 0;
+ if (ctx) {
+ _mesa_error(ctx, GL_INVALID_OPERATION, "gl%s(invalid call)", name);
+ }
+#if defined(DEBUG)
+ else if (getenv("MESA_DEBUG") || getenv("LIBGL_DEBUG")) {
+ fprintf(stderr,
+ "GL User Error: gl%s called without a rendering context\n",
+ name);
+ fflush(stderr);
+ }
+#endif
}
@@ -909,13 +926,10 @@ nop_glFlush(void)
#endif
-extern void (*__glapi_noop_table[])(void);
-
-
/**
- * Allocate and initialize a new dispatch table. All the dispatch
- * function pointers will point at the _mesa_generic_nop() function
- * which raises GL_INVALID_OPERATION.
+ * Allocate and initialize a new dispatch table. The table will be
+ * populated with pointers to "no-op" functions. In turn, the no-op
+ * functions will call nop_handler() above.
*/
struct _glapi_table *
_mesa_alloc_dispatch_table(void)
@@ -926,23 +940,10 @@ _mesa_alloc_dispatch_table(void)
* DRI drivers.
*/
GLint numEntries = MAX2(_glapi_get_dispatch_table_size(), _gloffset_COUNT);
- struct _glapi_table *table;
-
- table = malloc(numEntries * sizeof(_glapi_proc));
- if (table) {
- _glapi_proc *entry = (_glapi_proc *) table;
- GLint i;
- for (i = 0; i < numEntries; i++) {
-#if defined(_WIN32)
- /* FIXME: This will not generate an error, but at least it won't
- * corrupt the stack like _mesa_generic_nop does. */
- entry[i] = __glapi_noop_table[i];
-#else
- entry[i] = (_glapi_proc) _mesa_generic_nop;
-#endif
- }
+ struct _glapi_table *table = _glapi_new_nop_table(numEntries);
#if defined(_WIN32)
+ if (table) {
/* This is a special case for Windows in the event that
* wglGetProcAddress is called between glBegin/End().
*
@@ -960,8 +961,11 @@ _mesa_alloc_dispatch_table(void)
* assertion passes and the test continues.
*/
SET_Flush(table, nop_glFlush);
-#endif
}
+#endif
+
+ _glapi_set_nop_handler(nop_handler);
+
return table;
}
diff --git a/src/mesa/main/context.h b/src/mesa/main/context.h
index d565087..1cd89a8 100644
--- a/src/mesa/main/context.h
+++ b/src/mesa/main/context.h
@@ -175,9 +175,6 @@ _mesa_finish(struct gl_context *ctx);
extern void
_mesa_flush(struct gl_context *ctx);
-extern int
-_mesa_generic_nop(void);
-
extern void GLAPIENTRY
_mesa_Finish( void );
diff --git a/src/mesa/main/tests/dispatch_sanity.cpp b/src/mesa/main/tests/dispatch_sanity.cpp
index 8f7f69e..26664ed 100644
--- a/src/mesa/main/tests/dispatch_sanity.cpp
+++ b/src/mesa/main/tests/dispatch_sanity.cpp
@@ -119,20 +119,14 @@ offset_to_proc_name_safe(unsigned offset)
}
/* Scan through the dispatch table and check that all the functions in
- * _glapi_proc *table exist. When found, set their pointers in the table
- * to _mesa_generic_nop. */
+ * _glapi_proc *table exist.
+ */
static void
validate_functions(struct gl_context *ctx, const struct function *function_table)
{
_glapi_proc *table = (_glapi_proc *) ctx->Exec;
for (unsigned i = 0; function_table[i].name != NULL; i++) {
- /* The context version is >= the GL version where the
- function was introduced. Therefore, the function cannot
- be set to the nop function.
- */
- bool cant_be_nop = ctx->Version >= function_table[i].Version;
-
const int offset = (function_table[i].offset != -1)
? function_table[i].offset
: _glapi_get_proc_offset(function_table[i].name);
@@ -142,27 +136,6 @@ validate_functions(struct gl_context *ctx, const struct function *function_table
ASSERT_EQ(offset,
_glapi_get_proc_offset(function_table[i].name))
<< "Function: " << function_table[i].name;
- if (cant_be_nop) {
- EXPECT_NE((_glapi_proc) _mesa_generic_nop, table[offset])
- << "Function: " << function_table[i].name
- << " at offset " << offset;
- }
-
- table[offset] = (_glapi_proc) _mesa_generic_nop;
- }
-}
-
-/* Scan through the table and ensure that there is nothing except
- * _mesa_generic_nop (as set by validate_functions(). */
-static void
-validate_nops(struct gl_context *ctx)
-{
- _glapi_proc *table = (_glapi_proc *) ctx->Exec;
-
- const unsigned size = _glapi_get_dispatch_table_size();
- for (unsigned i = 0; i < size; i++) {
- EXPECT_EQ((_glapi_proc) _mesa_generic_nop, table[i])
- << "i = " << i << " (" << offset_to_proc_name_safe(i) << ")";
}
}
@@ -170,21 +143,18 @@ TEST_F(DispatchSanity_test, GL31_CORE)
{
SetUpCtx(API_OPENGL_CORE, 31);
validate_functions(&ctx, gl_core_functions_possible);
- validate_nops(&ctx);
}
TEST_F(DispatchSanity_test, GLES11)
{
SetUpCtx(API_OPENGLES, 11);
validate_functions(&ctx, gles11_functions_possible);
- validate_nops(&ctx);
}
TEST_F(DispatchSanity_test, GLES2)
{
SetUpCtx(API_OPENGLES2, 20);
validate_functions(&ctx, gles2_functions_possible);
- validate_nops(&ctx);
}
TEST_F(DispatchSanity_test, GLES3)
@@ -192,7 +162,6 @@ TEST_F(DispatchSanity_test, GLES3)
SetUpCtx(API_OPENGLES2, 30);
validate_functions(&ctx, gles2_functions_possible);
validate_functions(&ctx, gles3_functions_possible);
- validate_nops(&ctx);
}
const struct function gl_core_functions_possible[] = {
--
1.9.1
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