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/*
* Copyright © 2013 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/**
* \file link_interface_blocks.cpp
* Linker support for GLSL's interface blocks.
*/
#include "ir.h"
#include "glsl_symbol_table.h"
#include "linker.h"
#include "main/macros.h"
#include "main/mtypes.h"
#include "util/hash_table.h"
#include "util/u_string.h"
namespace {
/**
* Return true if interface members mismatch and its not allowed by GLSL.
*/
static bool
interstage_member_mismatch(struct gl_shader_program *prog,
const glsl_type *c, const glsl_type *p) {
if (c->length != p->length)
return true;
for (unsigned i = 0; i < c->length; i++) {
if (c->fields.structure[i].type != p->fields.structure[i].type)
return true;
if (strcmp(c->fields.structure[i].name,
p->fields.structure[i].name) != 0)
return true;
if (c->fields.structure[i].location !=
p->fields.structure[i].location)
return true;
if (c->fields.structure[i].patch !=
p->fields.structure[i].patch)
return true;
/* From Section 4.5 (Interpolation Qualifiers) of the GLSL 4.40 spec:
*
* "It is a link-time error if, within the same stage, the
* interpolation qualifiers of variables of the same name do not
* match."
*/
if (prog->IsES || prog->data->Version < 440)
if (c->fields.structure[i].interpolation !=
p->fields.structure[i].interpolation)
return true;
/* From Section 4.3.4 (Input Variables) of the GLSL ES 3.0 spec:
*
* "The output of the vertex shader and the input of the fragment
* shader form an interface. For this interface, vertex shader
* output variables and fragment shader input variables of the same
* name must match in type and qualification (other than precision
* and out matching to in).
*
* The table in Section 9.2.1 Linked Shaders of the GLSL ES 3.1 spec
* says that centroid no longer needs to match for varyings.
*
* The table in Section 9.2.1 Linked Shaders of the GLSL ES 3.2 spec
* says that sample need not match for varyings.
*/
if (!prog->IsES || prog->data->Version < 310)
if (c->fields.structure[i].centroid !=
p->fields.structure[i].centroid)
return true;
if (!prog->IsES)
if (c->fields.structure[i].sample !=
p->fields.structure[i].sample)
return true;
}
return false;
}
/**
* Check if two interfaces match, according to intrastage interface matching
* rules. If they do, and the first interface uses an unsized array, it will
* be updated to reflect the array size declared in the second interface.
*/
bool
intrastage_match(ir_variable *a,
ir_variable *b,
struct gl_shader_program *prog,
bool match_precision)
{
/* Types must match. */
if (a->get_interface_type() != b->get_interface_type()) {
/* Exception: if both the interface blocks are implicitly declared,
* don't force their types to match. They might mismatch due to the two
* shaders using different GLSL versions, and that's ok.
*/
if ((a->data.how_declared != ir_var_declared_implicitly ||
b->data.how_declared != ir_var_declared_implicitly) &&
(!prog->IsES ||
interstage_member_mismatch(prog, a->get_interface_type(),
b->get_interface_type())))
return false;
}
/* Presence/absence of interface names must match. */
if (a->is_interface_instance() != b->is_interface_instance())
return false;
/* For uniforms, instance names need not match. For shader ins/outs,
* it's not clear from the spec whether they need to match, but
* Mesa's implementation relies on them matching.
*/
if (a->is_interface_instance() && b->data.mode != ir_var_uniform &&
b->data.mode != ir_var_shader_storage &&
strcmp(a->name, b->name) != 0) {
return false;
}
bool type_match = (match_precision ?
a->type == b->type :
a->type->compare_no_precision(b->type));
/* If a block is an array then it must match across the shader.
* Unsized arrays are also processed and matched agaist sized arrays.
*/
if (!type_match && (b->type->is_array() || a->type->is_array()) &&
(b->is_interface_instance() || a->is_interface_instance()) &&
!validate_intrastage_arrays(prog, b, a, match_precision))
return false;
return true;
}
/**
* Check if two interfaces match, according to interstage (in/out) interface
* matching rules.
*
* If \c extra_array_level is true, the consumer interface is required to be
* an array and the producer interface is required to be a non-array.
* This is used for tessellation control and geometry shader consumers.
*/
static bool
interstage_match(struct gl_shader_program *prog, ir_variable *producer,
ir_variable *consumer, bool extra_array_level)
{
/* Types must match. */
if (consumer->get_interface_type() != producer->get_interface_type()) {
/* Exception: if both the interface blocks are implicitly declared,
* don't force their types to match. They might mismatch due to the two
* shaders using different GLSL versions, and that's ok.
*
* Also we store some member information such as interpolation in
* glsl_type that doesn't always have to match across shader stages.
* Therefore we make a pass over the members glsl_struct_field to make
* sure we don't reject shaders where fields don't need to match.
*/
if ((consumer->data.how_declared != ir_var_declared_implicitly ||
producer->data.how_declared != ir_var_declared_implicitly) &&
interstage_member_mismatch(prog, consumer->get_interface_type(),
producer->get_interface_type()))
return false;
}
/* Ignore outermost array if geom shader */
const glsl_type *consumer_instance_type;
if (extra_array_level) {
consumer_instance_type = consumer->type->fields.array;
} else {
consumer_instance_type = consumer->type;
}
/* If a block is an array then it must match across shaders.
* Since unsized arrays have been ruled out, we can check this by just
* making sure the types are equal.
*/
if ((consumer->is_interface_instance() &&
consumer_instance_type->is_array()) ||
(producer->is_interface_instance() &&
producer->type->is_array())) {
if (consumer_instance_type != producer->type)
return false;
}
return true;
}
/**
* This class keeps track of a mapping from an interface block name to the
* necessary information about that interface block to determine whether to
* generate a link error.
*
* Note: this class is expected to be short lived, so it doesn't make copies
* of the strings it references; it simply borrows the pointers from the
* ir_variable class.
*/
class interface_block_definitions
{
public:
interface_block_definitions()
: mem_ctx(ralloc_context(NULL)),
ht(_mesa_hash_table_create(NULL, _mesa_hash_string,
_mesa_key_string_equal))
{
}
~interface_block_definitions()
{
ralloc_free(mem_ctx);
_mesa_hash_table_destroy(ht, NULL);
}
/**
* Lookup the interface definition. Return NULL if none is found.
*/
ir_variable *lookup(ir_variable *var)
{
if (var->data.explicit_location &&
var->data.location >= VARYING_SLOT_VAR0) {
char location_str[11];
snprintf(location_str, 11, "%d", var->data.location);
const struct hash_entry *entry =
_mesa_hash_table_search(ht, location_str);
return entry ? (ir_variable *) entry->data : NULL;
} else {
const struct hash_entry *entry =
_mesa_hash_table_search(ht,
var->get_interface_type()->without_array()->name);
return entry ? (ir_variable *) entry->data : NULL;
}
}
/**
* Add a new interface definition.
*/
void store(ir_variable *var)
{
if (var->data.explicit_location &&
var->data.location >= VARYING_SLOT_VAR0) {
/* If explicit location is given then lookup the variable by location.
* We turn the location into a string and use this as the hash key
* rather than the name. Note: We allocate enough space for a 32-bit
* unsigned location value which is overkill but future proof.
*/
char location_str[11];
snprintf(location_str, 11, "%d", var->data.location);
_mesa_hash_table_insert(ht, ralloc_strdup(mem_ctx, location_str), var);
} else {
_mesa_hash_table_insert(ht,
var->get_interface_type()->without_array()->name, var);
}
}
private:
/**
* Ralloc context for data structures allocated by this class.
*/
void *mem_ctx;
/**
* Hash table mapping interface block name to an \c
* ir_variable.
*/
hash_table *ht;
};
}; /* anonymous namespace */
void
validate_intrastage_interface_blocks(struct gl_shader_program *prog,
const gl_shader **shader_list,
unsigned num_shaders)
{
interface_block_definitions in_interfaces;
interface_block_definitions out_interfaces;
interface_block_definitions uniform_interfaces;
interface_block_definitions buffer_interfaces;
for (unsigned int i = 0; i < num_shaders; i++) {
if (shader_list[i] == NULL)
continue;
foreach_in_list(ir_instruction, node, shader_list[i]->ir) {
ir_variable *var = node->as_variable();
if (!var)
continue;
const glsl_type *iface_type = var->get_interface_type();
if (iface_type == NULL)
continue;
interface_block_definitions *definitions;
switch (var->data.mode) {
case ir_var_shader_in:
definitions = &in_interfaces;
break;
case ir_var_shader_out:
definitions = &out_interfaces;
break;
case ir_var_uniform:
definitions = &uniform_interfaces;
break;
case ir_var_shader_storage:
definitions = &buffer_interfaces;
break;
default:
/* Only in, out, and uniform interfaces are legal, so we should
* never get here.
*/
assert(!"illegal interface type");
continue;
}
ir_variable *prev_def = definitions->lookup(var);
if (prev_def == NULL) {
/* This is the first time we've seen the interface, so save
* it into the appropriate data structure.
*/
definitions->store(var);
} else if (!intrastage_match(prev_def, var, prog,
true /* match_precision */)) {
linker_error(prog, "definitions of interface block `%s' do not"
" match\n", iface_type->name);
return;
}
}
}
}
static bool
is_builtin_gl_in_block(ir_variable *var, int consumer_stage)
{
return !strcmp(var->name, "gl_in") &&
(consumer_stage == MESA_SHADER_TESS_CTRL ||
consumer_stage == MESA_SHADER_TESS_EVAL ||
consumer_stage == MESA_SHADER_GEOMETRY);
}
void
validate_interstage_inout_blocks(struct gl_shader_program *prog,
const gl_linked_shader *producer,
const gl_linked_shader *consumer)
{
interface_block_definitions definitions;
/* VS -> GS, VS -> TCS, VS -> TES, TES -> GS */
const bool extra_array_level = (producer->Stage == MESA_SHADER_VERTEX &&
consumer->Stage != MESA_SHADER_FRAGMENT) ||
consumer->Stage == MESA_SHADER_GEOMETRY;
/* Check that block re-declarations of gl_PerVertex are compatible
* across shaders: From OpenGL Shading Language 4.5, section
* "7.1 Built-In Language Variables", page 130 of the PDF:
*
* "If multiple shaders using members of a built-in block belonging
* to the same interface are linked together in the same program,
* they must all redeclare the built-in block in the same way, as
* described in section 4.3.9 “Interface Blocks” for interface-block
* matching, or a link-time error will result."
*
* This is done explicitly outside of iterating the member variable
* declarations because it is possible that the variables are not used and
* so they would have been optimised out.
*/
const glsl_type *consumer_iface =
consumer->symbols->get_interface("gl_PerVertex",
ir_var_shader_in);
const glsl_type *producer_iface =
producer->symbols->get_interface("gl_PerVertex",
ir_var_shader_out);
if (producer_iface && consumer_iface &&
interstage_member_mismatch(prog, consumer_iface, producer_iface)) {
linker_error(prog, "Incompatible or missing gl_PerVertex re-declaration "
"in consecutive shaders");
return;
}
/* Desktop OpenGL requires redeclaration of the built-in interfaces for
* SSO programs. Passes above implement following rules:
*
* From Section 7.4 (Program Pipeline Objects) of the OpenGL 4.6 Core
* spec:
*
* "To use any built-in input or output in the gl_PerVertex and
* gl_PerFragment blocks in separable program objects, shader code
* must redeclare those blocks prior to use. A separable program
* will fail to link if:
*
* it contains multiple shaders of a single type with different
* redeclarations of these built-in input and output blocks; or
*
* any shader uses a built-in block member not found in the
* redeclaration of that block."
*
* ARB_separate_shader_objects issues section (issue #28) states that
* redeclaration is not required for GLSL shaders using #version 140 or
* earlier (since interface blocks are not possible with older versions).
*
* From Section 7.4.1 (Shader Interface Matching) of the OpenGL ES 3.1
* spec:
*
* "Built-in inputs or outputs do not affect interface matching."
*
* GL_OES_shader_io_blocks adds following:
*
* "When using any built-in input or output in the gl_PerVertex block
* in separable program objects, shader code may redeclare that block
* prior to use. If the shader does not redeclare the block, the
* intrinsically declared definition of that block will be used."
*/
/* Add output interfaces from the producer to the symbol table. */
foreach_in_list(ir_instruction, node, producer->ir) {
ir_variable *var = node->as_variable();
if (!var || !var->get_interface_type() || var->data.mode != ir_var_shader_out)
continue;
/* Built-in interface redeclaration check. */
if (prog->SeparateShader && !prog->IsES && prog->data->Version >= 150 &&
var->data.how_declared == ir_var_declared_implicitly &&
var->data.used && !producer_iface) {
linker_error(prog, "missing output builtin block %s redeclaration "
"in separable shader program",
var->get_interface_type()->name);
return;
}
definitions.store(var);
}
/* Verify that the consumer's input interfaces match. */
foreach_in_list(ir_instruction, node, consumer->ir) {
ir_variable *var = node->as_variable();
if (!var || !var->get_interface_type() || var->data.mode != ir_var_shader_in)
continue;
ir_variable *producer_def = definitions.lookup(var);
/* Built-in interface redeclaration check. */
if (prog->SeparateShader && !prog->IsES && prog->data->Version >= 150 &&
var->data.how_declared == ir_var_declared_implicitly &&
var->data.used && !producer_iface) {
linker_error(prog, "missing input builtin block %s redeclaration "
"in separable shader program",
var->get_interface_type()->name);
return;
}
/* The producer doesn't generate this input: fail to link. Skip built-in
* 'gl_in[]' since that may not be present if the producer does not
* write to any of the pre-defined outputs (e.g. if the vertex shader
* does not write to gl_Position, etc), which is allowed and results in
* undefined behavior.
*
* From Section 4.3.4 (Inputs) of the GLSL 1.50 spec:
*
* "Only the input variables that are actually read need to be written
* by the previous stage; it is allowed to have superfluous
* declarations of input variables."
*/
if (producer_def == NULL &&
!is_builtin_gl_in_block(var, consumer->Stage) && var->data.used) {
linker_error(prog, "Input block `%s' is not an output of "
"the previous stage\n", var->get_interface_type()->name);
return;
}
if (producer_def &&
!interstage_match(prog, producer_def, var, extra_array_level)) {
linker_error(prog, "definitions of interface block `%s' do not "
"match\n", var->get_interface_type()->name);
return;
}
}
}
void
validate_interstage_uniform_blocks(struct gl_shader_program *prog,
gl_linked_shader **stages)
{
interface_block_definitions definitions;
for (int i = 0; i < MESA_SHADER_STAGES; i++) {
if (stages[i] == NULL)
continue;
const gl_linked_shader *stage = stages[i];
foreach_in_list(ir_instruction, node, stage->ir) {
ir_variable *var = node->as_variable();
if (!var || !var->get_interface_type() ||
(var->data.mode != ir_var_uniform &&
var->data.mode != ir_var_shader_storage))
continue;
ir_variable *old_def = definitions.lookup(var);
if (old_def == NULL) {
definitions.store(var);
} else {
/* Interstage uniform matching rules are the same as intrastage
* uniform matchin rules (for uniforms, it is as though all
* shaders are in the same shader stage).
*/
if (!intrastage_match(old_def, var, prog, false /* precision */)) {
linker_error(prog, "definitions of uniform block `%s' do not "
"match\n", var->get_interface_type()->name);
return;
}
}
}
}
}