glsl: Fix program interface queries relating to interface blocks.

This fixes 555 dEQP tests (using the nougat-cts-dev branch), Piglit's
arb_program_interface_query/arb_program_interface_query-resource-query,
and GL45-CTS.program_interface_query.separate-programs-{tess-control,
tess-eval,geometry}.  Only one dEQP program interface failure remains.

I would have liked to split this up into several distinct changes, but
I wasn't sure how to do that given thet tangled nature of these issues.

So, the issues:

   * We need to treat interface blocks declared as an array of instances
     as a single block - removing the outer array.  The resource list
     entry's name should not include the array length.  Properties such
     as GL_ARRAY_SIZE should refer to the variable inside the block, not
     the interface block's array properties.

   * We need to do this prefixing even for structure variables.

   * We need to do this for built-ins (such as gl_PerVertex.gl_Position).

   * After interface array unwrapping, any variable which is an array
     should have [0] appended.  It doesn't matter if it's a TCS/TES/GS
     input or TCS output - that looked like an attempt to unwrap for
     per-vertex variables, but that didn't consider per-patch variables,
     and as far as I can tell there's nothing to justify this.

Several Mesa developers have suggested that Issue 16 contradicts the
main specification, but I believe that it doesn't - the main spec just
isn't terribly clear.  The main ARB_program_interface query spec says:

  "* For an active interface block not declared as an array of block
     instances, a single entry will be generated, using the block name from
     the shader source.

   * For an active interface block declared as an array of instances,
     separate entries will be generated for each active instance.  The name
     of the instance is formed by concatenating the block name, the "["
     character, an integer identifying the instance number, and the "]"
     character."

Issue 16 says that built-ins should be named "gl_PerVertex.gl_Position",
but several people suggested the second bullet above means that it
should be named "gl_PerVertex[array length].gl_Position".

There are two important things to note.  Those bullet points say
"an active interface block", while the others say "variable" or "active
shader storage block member".  They also don't mention applying the
rules recursively (unlike the other bullets).  Both suggest that
these rules apply to blocks themselves, not members of blocks.

In fact, for GL_UNIFORM_BLOCK queries, we do have "block[0]",
"block[1]", ... resource list entries - so those rules are real,
and actually used.  So if they don't apply to block members, then how
should members be named?  Unfortunately, I don't see any rules outside
of issue 16 - where the rationale is very unclear.  I hope to clarify
the spec in the future.

Signed-off-by: Kenneth Graunke <[email protected]>
Reviewed-by: Alejandro Piñeiro <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>

1 files changed, 60 insertions, 40 deletions

diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
index 50660141c3e..5508d588cd5 100644
--- a/src/compiler/glsl/linker.cpp
+++ b/src/compiler/glsl/linker.cpp
@@ -3735,6 +3735,65 @@ add_shader_variable(const struct gl_context *ctx,
                     bool use_implicit_location, int location,
                     const glsl_type *outermost_struct_type = NULL)
 {
+   const glsl_type *interface_type = var->get_interface_type();
+
+   if (outermost_struct_type == NULL) {
+      /* Unsized (non-patch) TCS output/TES input arrays are implicitly
+       * sized to gl_MaxPatchVertices.  Internally, we shrink them to a
+       * smaller size.
+       *
+       * This can cause trouble with SSO programs.  Since the TCS declares
+       * the number of output vertices, we can always shrink TCS output
+       * arrays.  However, the TES might not be linked with a TCS, in
+       * which case it won't know the size of the patch.  In other words,
+       * the TCS and TES may disagree on the (smaller) array sizes.  This
+       * can result in the resource names differing across stages, causing
+       * SSO validation failures and other cascading issues.
+       *
+       * Expanding the array size to the full gl_MaxPatchVertices fixes
+       * these issues.  It's also what program interface queries expect,
+       * as that is the official size of the array.
+       */
+      if (var->data.tess_varying_implicit_sized_array) {
+         type = resize_to_max_patch_vertices(ctx, type);
+         interface_type = resize_to_max_patch_vertices(ctx, interface_type);
+      }
+
+      if (var->data.from_named_ifc_block) {
+         const char *interface_name = interface_type->name;
+
+         if (interface_type->is_array()) {
+            /* Issue #16 of the ARB_program_interface_query spec says:
+             *
+             * "* If a variable is a member of an interface block without an
+             *    instance name, it is enumerated using just the variable name.
+             *
+             *  * If a variable is a member of an interface block with an
+             *    instance name, it is enumerated as "BlockName.Member", where
+             *    "BlockName" is the name of the interface block (not the
+             *    instance name) and "Member" is the name of the variable."
+             *
+             * In particular, it indicates that it should be "BlockName",
+             * not "BlockName[array length]".  The conformance suite and
+             * dEQP both require this behavior.
+             *
+             * Here, we unwrap the extra array level added by named interface
+             * block array lowering so we have the correct variable type.  We
+             * also unwrap the interface type when constructing the name.
+             *
+             * We leave interface_type the same so that ES 3.x SSO pipeline
+             * validation can enforce the rules requiring array length to
+             * match on interface blocks.
+             */
+            type = type->fields.array;
+
+            interface_name = interface_type->fields.array->name;
+         }
+
+         name = ralloc_asprintf(shProg, "%s.%s", interface_name, name);
+      }
+   }
+
    switch (type->base_type) {
    case GLSL_TYPE_STRUCT: {
       /* The ARB_program_interface_query spec says:
@@ -3766,44 +3825,6 @@ add_shader_variable(const struct gl_context *ctx,
    }
 
    default: {
-      const glsl_type *interface_type = var->get_interface_type();
-
-      /* Unsized (non-patch) TCS output/TES input arrays are implicitly
-       * sized to gl_MaxPatchVertices.  Internally, we shrink them to a
-       * smaller size.
-       *
-       * This can cause trouble with SSO programs.  Since the TCS declares
-       * the number of output vertices, we can always shrink TCS output
-       * arrays.  However, the TES might not be linked with a TCS, in
-       * which case it won't know the size of the patch.  In other words,
-       * the TCS and TES may disagree on the (smaller) array sizes.  This
-       * can result in the resource names differing across stages, causing
-       * SSO validation failures and other cascading issues.
-       *
-       * Expanding the array size to the full gl_MaxPatchVertices fixes
-       * these issues.  It's also what program interface queries expect,
-       * as that is the official size of the array.
-       */
-      if (var->data.tess_varying_implicit_sized_array) {
-         type = resize_to_max_patch_vertices(ctx, type);
-         interface_type = resize_to_max_patch_vertices(ctx, interface_type);
-      }
-
-      /* Issue #16 of the ARB_program_interface_query spec says:
-       *
-       * "* If a variable is a member of an interface block without an
-       *    instance name, it is enumerated using just the variable name.
-       *
-       *  * If a variable is a member of an interface block with an instance
-       *    name, it is enumerated as "BlockName.Member", where "BlockName" is
-       *    the name of the interface block (not the instance name) and
-       *    "Member" is the name of the variable."
-       */
-      const char *prefixed_name = (var->data.from_named_ifc_block &&
-                                   !is_gl_identifier(var->name))
-         ? ralloc_asprintf(shProg, "%s.%s", interface_type->name, name)
-         : name;
-
       /* The ARB_program_interface_query spec says:
        *
        *     "For an active variable declared as a single instance of a basic
@@ -3811,8 +3832,7 @@ add_shader_variable(const struct gl_context *ctx,
        *     from the shader source."
        */
       gl_shader_variable *sha_v =
-         create_shader_variable(shProg, var, prefixed_name, type,
-                                interface_type,
+         create_shader_variable(shProg, var, name, type, interface_type,
                                 use_implicit_location, location,
                                 outermost_struct_type);
       if (!sha_v)