mesa: Restore functionality to dispatch sanity test

Along with a couple secondary goals, the dispatch sanity test had two
major, primary goals.

1. Ensure that all functions part of an API version are set in the
   dispatch table.

2. Ensure that functions that cannot be part of an API version are not
   set in the dispatch table.

Commit 4bdbb58 removed the tests ability to fulfill either of its
primary goals by removing anything that used _mesa_generic_nop().  It
seems like the problem on Windows could have been resolved by adding the
NULL context pointer check from nop_handler to _mesa_generic_nop().
There is, however, some debugging benefit to actually getting the
(supposed) function name logged in the "unsupported function called"
message.

The preceding commit added a function, _glapi_new_nop_table, that
allocates a table of per-entry point no-op functions.  Restore the
ability to actually validate the sanity of the dispatch table by using
_glapi_new_nop_table.

Previous to this commit removing a function from one of the
*_functions_possible lists would not cause the test to fail.  With this
commit removing such a function will result in failure, as is expected.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Brian Paul <brianp@vmware.com>

1 files changed, 43 insertions, 6 deletions

diff --git a/src/mesa/main/tests/dispatch_sanity.cpp b/src/mesa/main/tests/dispatch_sanity.cpp
index 946eabb..2a5afcd 100644
--- a/src/mesa/main/tests/dispatch_sanity.cpp
+++ b/src/mesa/main/tests/dispatch_sanity.cpp
@@ -82,6 +82,7 @@ public:
    struct dd_function_table driver_functions;
    struct gl_context share_list;
    struct gl_context ctx;
+   _glapi_proc *nop_table;
 };
 
 void
@@ -93,6 +94,9 @@ DispatchSanity_test::SetUp()
    memset(&ctx, 0, sizeof(ctx));
 
    _mesa_init_driver_functions(&driver_functions);
+
+   const unsigned size = _glapi_get_dispatch_table_size();
+   nop_table = (_glapi_proc *) _glapi_new_nop_table(size);
 }
 
 void
@@ -122,11 +126,18 @@ offset_to_proc_name_safe(unsigned offset)
  * _glapi_proc *table exist.
  */
 static void
-validate_functions(struct gl_context *ctx, const struct function *function_table)
+validate_functions(struct gl_context *ctx, const struct function *function_table,
+                   const _glapi_proc *nop_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.
+       */
+      const 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);
@@ -136,32 +147,58 @@ 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(nop_table[offset], table[offset])
+            << "Function: " << function_table[i].name
+            << " at offset " << offset;
+      }
+
+      table[offset] = nop_table[offset];
+   }
+}
+
+/* Scan through the table and ensure that there is nothing except
+ * nop functions (as set by validate_functions().
+ */
+static void
+validate_nops(struct gl_context *ctx, const _glapi_proc *nop_table)
+{
+   _glapi_proc *table = (_glapi_proc *) ctx->Exec;
+
+   const unsigned size = _glapi_get_dispatch_table_size();
+   for (unsigned i = 0; i < size; i++) {
+      EXPECT_EQ(nop_table[i], table[i])
+         << "i = " << i << " (" << offset_to_proc_name_safe(i) << ")";
    }
 }
 
 TEST_F(DispatchSanity_test, GL31_CORE)
 {
    SetUpCtx(API_OPENGL_CORE, 31);
-   validate_functions(&ctx, gl_core_functions_possible);
+   validate_functions(&ctx, gl_core_functions_possible, nop_table);
+   validate_nops(&ctx, nop_table);
 }
 
 TEST_F(DispatchSanity_test, GLES11)
 {
    SetUpCtx(API_OPENGLES, 11);
-   validate_functions(&ctx, gles11_functions_possible);
+   validate_functions(&ctx, gles11_functions_possible, nop_table);
+   validate_nops(&ctx, nop_table);
 }
 
 TEST_F(DispatchSanity_test, GLES2)
 {
    SetUpCtx(API_OPENGLES2, 20);
-   validate_functions(&ctx, gles2_functions_possible);
+   validate_functions(&ctx, gles2_functions_possible, nop_table);
+   validate_nops(&ctx, nop_table);
 }
 
 TEST_F(DispatchSanity_test, GLES3)
 {
    SetUpCtx(API_OPENGLES2, 30);
-   validate_functions(&ctx, gles2_functions_possible);
-   validate_functions(&ctx, gles3_functions_possible);
+   validate_functions(&ctx, gles2_functions_possible, nop_table);
+   validate_functions(&ctx, gles3_functions_possible, nop_table);
+   validate_nops(&ctx, nop_table);
 }
 
 const struct function gl_core_functions_possible[] = {