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// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include "src/resolver/resolver.h"
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <limits>
#include <utility>
#include "src/ast/alias.h"
#include "src/ast/array.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/bitcast_expression.h"
#include "src/ast/break_statement.h"
#include "src/ast/call_statement.h"
#include "src/ast/continue_statement.h"
#include "src/ast/depth_texture.h"
#include "src/ast/disable_validation_decoration.h"
#include "src/ast/discard_statement.h"
#include "src/ast/fallthrough_statement.h"
#include "src/ast/for_loop_statement.h"
#include "src/ast/if_statement.h"
#include "src/ast/internal_decoration.h"
#include "src/ast/interpolate_decoration.h"
#include "src/ast/loop_statement.h"
#include "src/ast/matrix.h"
#include "src/ast/override_decoration.h"
#include "src/ast/pointer.h"
#include "src/ast/return_statement.h"
#include "src/ast/sampled_texture.h"
#include "src/ast/sampler.h"
#include "src/ast/storage_texture.h"
#include "src/ast/struct_block_decoration.h"
#include "src/ast/switch_statement.h"
#include "src/ast/traverse_expressions.h"
#include "src/ast/type_name.h"
#include "src/ast/unary_op_expression.h"
#include "src/ast/variable_decl_statement.h"
#include "src/ast/vector.h"
#include "src/ast/workgroup_decoration.h"
#include "src/sem/array.h"
#include "src/sem/atomic_type.h"
#include "src/sem/call.h"
#include "src/sem/depth_multisampled_texture_type.h"
#include "src/sem/depth_texture_type.h"
#include "src/sem/for_loop_statement.h"
#include "src/sem/function.h"
#include "src/sem/if_statement.h"
#include "src/sem/loop_statement.h"
#include "src/sem/member_accessor_expression.h"
#include "src/sem/multisampled_texture_type.h"
#include "src/sem/pointer_type.h"
#include "src/sem/reference_type.h"
#include "src/sem/sampled_texture_type.h"
#include "src/sem/sampler_type.h"
#include "src/sem/statement.h"
#include "src/sem/storage_texture_type.h"
#include "src/sem/struct.h"
#include "src/sem/switch_statement.h"
#include "src/sem/type_constructor.h"
#include "src/sem/type_conversion.h"
#include "src/sem/variable.h"
#include "src/utils/defer.h"
#include "src/utils/map.h"
#include "src/utils/math.h"
#include "src/utils/reverse.h"
#include "src/utils/scoped_assignment.h"
#include "src/utils/transform.h"
namespace tint {
namespace resolver {
namespace {
bool IsValidStorageTextureDimension(ast::TextureDimension dim) {
switch (dim) {
case ast::TextureDimension::k1d:
case ast::TextureDimension::k2d:
case ast::TextureDimension::k2dArray:
case ast::TextureDimension::k3d:
return true;
default:
return false;
}
}
bool IsValidStorageTextureImageFormat(ast::ImageFormat format) {
switch (format) {
case ast::ImageFormat::kR32Uint:
case ast::ImageFormat::kR32Sint:
case ast::ImageFormat::kR32Float:
case ast::ImageFormat::kRg32Uint:
case ast::ImageFormat::kRg32Sint:
case ast::ImageFormat::kRg32Float:
case ast::ImageFormat::kRgba8Unorm:
case ast::ImageFormat::kRgba8Snorm:
case ast::ImageFormat::kRgba8Uint:
case ast::ImageFormat::kRgba8Sint:
case ast::ImageFormat::kRgba16Uint:
case ast::ImageFormat::kRgba16Sint:
case ast::ImageFormat::kRgba16Float:
case ast::ImageFormat::kRgba32Uint:
case ast::ImageFormat::kRgba32Sint:
case ast::ImageFormat::kRgba32Float:
return true;
default:
return false;
}
}
// Helper to stringify a pipeline IO decoration.
std::string deco_to_str(const ast::Decoration* deco) {
std::stringstream str;
if (auto* builtin = deco->As<ast::BuiltinDecoration>()) {
str << "builtin(" << builtin->builtin << ")";
} else if (auto* location = deco->As<ast::LocationDecoration>()) {
str << "location(" << location->value << ")";
}
return str.str();
}
template <typename CALLBACK>
void TraverseCallChain(diag::List& diagnostics,
const sem::Function* from,
const sem::Function* to,
CALLBACK&& callback) {
for (auto* f : from->TransitivelyCalledFunctions()) {
if (f == to) {
callback(f);
return;
}
if (f->TransitivelyCalledFunctions().contains(to)) {
TraverseCallChain(diagnostics, f, to, callback);
callback(f);
return;
}
}
TINT_ICE(Resolver, diagnostics)
<< "TraverseCallChain() 'from' does not transitively call 'to'";
}
} // namespace
bool Resolver::ValidateAtomic(const ast::Atomic* a, const sem::Atomic* s) {
// https://gpuweb.github.io/gpuweb/wgsl/#atomic-types
// T must be either u32 or i32.
if (!s->Type()->IsAnyOf<sem::U32, sem::I32>()) {
AddError("atomic only supports i32 or u32 types",
a->type ? a->type->source : a->source);
return false;
}
return true;
}
bool Resolver::ValidateStorageTexture(const ast::StorageTexture* t) {
switch (t->access) {
case ast::Access::kWrite:
break;
case ast::Access::kUndefined:
AddError("storage texture missing access control", t->source);
return false;
default:
AddError("storage textures currently only support 'write' access control",
t->source);
return false;
}
if (!IsValidStorageTextureDimension(t->dim)) {
AddError("cube dimensions for storage textures are not supported",
t->source);
return false;
}
if (!IsValidStorageTextureImageFormat(t->format)) {
AddError(
"image format must be one of the texel formats specified for storage "
"textues in https://gpuweb.github.io/gpuweb/wgsl/#texel-formats",
t->source);
return false;
}
return true;
}
bool Resolver::ValidateVariableConstructorOrCast(
const ast::Variable* var,
ast::StorageClass storage_class,
const sem::Type* storage_ty,
const sem::Type* rhs_ty) {
auto* value_type = rhs_ty->UnwrapRef(); // Implicit load of RHS
// Value type has to match storage type
if (storage_ty != value_type) {
std::string decl = var->is_const ? "let" : "var";
AddError("cannot initialize " + decl + " of type '" +
TypeNameOf(storage_ty) + "' with value of type '" +
TypeNameOf(rhs_ty) + "'",
var->source);
return false;
}
if (!var->is_const) {
switch (storage_class) {
case ast::StorageClass::kPrivate:
case ast::StorageClass::kFunction:
break; // Allowed an initializer
default:
// https://gpuweb.github.io/gpuweb/wgsl/#var-and-let
// Optionally has an initializer expression, if the variable is in the
// private or function storage classes.
AddError("var of storage class '" +
std::string(ast::ToString(storage_class)) +
"' cannot have an initializer. var initializers are only "
"supported for the storage classes "
"'private' and 'function'",
var->source);
return false;
}
}
return true;
}
bool Resolver::ValidateStorageClassLayout(const sem::Struct* str,
ast::StorageClass sc) {
// https://gpuweb.github.io/gpuweb/wgsl/#storage-class-layout-constraints
auto is_uniform_struct_or_array = [sc](const sem::Type* ty) {
return sc == ast::StorageClass::kUniform &&
ty->IsAnyOf<sem::Array, sem::Struct>();
};
auto is_uniform_struct = [sc](const sem::Type* ty) {
return sc == ast::StorageClass::kUniform && ty->Is<sem::Struct>();
};
auto required_alignment_of = [&](const sem::Type* ty) {
uint32_t actual_align = ty->Align();
uint32_t required_align = actual_align;
if (is_uniform_struct_or_array(ty)) {
required_align = utils::RoundUp(16u, actual_align);
}
return required_align;
};
auto member_name_of = [this](const sem::StructMember* sm) {
return builder_->Symbols().NameFor(sm->Declaration()->symbol);
};
auto type_name_of = [this](const sem::StructMember* sm) {
return TypeNameOf(sm->Type());
};
// TODO(amaiorano): Output struct and member decorations so that this output
// can be copied verbatim back into source
auto get_struct_layout_string = [&](const sem::Struct* st) -> std::string {
std::stringstream ss;
if (st->Members().empty()) {
TINT_ICE(Resolver, diagnostics_) << "Validation should have ensured that "
"structs have at least one member";
return {};
}
const auto* const last_member = st->Members().back();
const uint32_t last_member_struct_padding_offset =
last_member->Offset() + last_member->Size();
// Compute max widths to align output
const auto offset_w =
static_cast<int>(::log10(last_member_struct_padding_offset)) + 1;
const auto size_w = static_cast<int>(::log10(st->Size())) + 1;
const auto align_w = static_cast<int>(::log10(st->Align())) + 1;
auto print_struct_begin_line = [&](size_t align, size_t size,
std::string struct_name) {
ss << "/* " << std::setw(offset_w) << " "
<< "align(" << std::setw(align_w) << align << ") size("
<< std::setw(size_w) << size << ") */ struct " << struct_name
<< " {\n";
};
auto print_struct_end_line = [&]() {
ss << "/* "
<< std::setw(offset_w + size_w + align_w) << " "
<< "*/ };";
};
auto print_member_line = [&](size_t offset, size_t align, size_t size,
std::string s) {
ss << "/* offset(" << std::setw(offset_w) << offset << ") align("
<< std::setw(align_w) << align << ") size(" << std::setw(size_w)
<< size << ") */ " << s << ";\n";
};
print_struct_begin_line(st->Align(), st->Size(), TypeNameOf(st));
for (size_t i = 0; i < st->Members().size(); ++i) {
auto* const m = st->Members()[i];
// Output field alignment padding, if any
auto* const prev_member = (i == 0) ? nullptr : str->Members()[i - 1];
if (prev_member) {
uint32_t padding =
m->Offset() - (prev_member->Offset() + prev_member->Size());
if (padding > 0) {
size_t padding_offset = m->Offset() - padding;
print_member_line(padding_offset, 1, padding,
"// -- implicit field alignment padding --");
}
}
// Output member
std::string member_name = member_name_of(m);
print_member_line(m->Offset(), m->Align(), m->Size(),
member_name_of(m) + " : " + type_name_of(m));
}
// Output struct size padding, if any
uint32_t struct_padding = st->Size() - last_member_struct_padding_offset;
if (struct_padding > 0) {
print_member_line(last_member_struct_padding_offset, 1, struct_padding,
"// -- implicit struct size padding --");
}
print_struct_end_line();
return ss.str();
};
if (!ast::IsHostShareable(sc)) {
return true;
}
for (size_t i = 0; i < str->Members().size(); ++i) {
auto* const m = str->Members()[i];
uint32_t required_align = required_alignment_of(m->Type());
// Validate that member is at a valid byte offset
if (m->Offset() % required_align != 0) {
AddError("the offset of a struct member of type '" + type_name_of(m) +
"' in storage class '" + ast::ToString(sc) +
"' must be a multiple of " + std::to_string(required_align) +
" bytes, but '" + member_name_of(m) +
"' is currently at offset " + std::to_string(m->Offset()) +
". Consider setting [[align(" +
std::to_string(required_align) + ")]] on this member",
m->Declaration()->source);
AddNote("see layout of struct:\n" + get_struct_layout_string(str),
str->Declaration()->source);
if (auto* member_str = m->Type()->As<sem::Struct>()) {
AddNote("and layout of struct member:\n" +
get_struct_layout_string(member_str),
member_str->Declaration()->source);
}
return false;
}
// For uniform buffers, validate that the number of bytes between the
// previous member of type struct and the current is a multiple of 16 bytes.
auto* const prev_member = (i == 0) ? nullptr : str->Members()[i - 1];
if (prev_member && is_uniform_struct(prev_member->Type())) {
const uint32_t prev_to_curr_offset = m->Offset() - prev_member->Offset();
if (prev_to_curr_offset % 16 != 0) {
AddError(
"uniform storage requires that the number of bytes between the "
"start of the previous member of type struct and the current "
"member be a multiple of 16 bytes, but there are currently " +
std::to_string(prev_to_curr_offset) + " bytes between '" +
member_name_of(prev_member) + "' and '" + member_name_of(m) +
"'. Consider setting [[align(16)]] on this member",
m->Declaration()->source);
AddNote("see layout of struct:\n" + get_struct_layout_string(str),
str->Declaration()->source);
auto* prev_member_str = prev_member->Type()->As<sem::Struct>();
AddNote("and layout of previous member struct:\n" +
get_struct_layout_string(prev_member_str),
prev_member_str->Declaration()->source);
return false;
}
}
// For uniform buffer array members, validate that array elements are
// aligned to 16 bytes
if (auto* arr = m->Type()->As<sem::Array>()) {
if (sc == ast::StorageClass::kUniform) {
// We already validated that this array member is itself aligned to 16
// bytes above, so we only need to validate that stride is a multiple of
// 16 bytes.
if (arr->Stride() % 16 != 0) {
AddError(
"uniform storage requires that array elements be aligned to 16 "
"bytes, but array stride of '" +
member_name_of(m) + "' is currently " +
std::to_string(arr->Stride()) +
". Consider setting [[stride(" +
std::to_string(
utils::RoundUp(required_align, arr->Stride())) +
")]] on the array type",
m->Declaration()->type->source);
AddNote("see layout of struct:\n" + get_struct_layout_string(str),
str->Declaration()->source);
return false;
}
}
}
// If member is struct, recurse
if (auto* str_member = m->Type()->As<sem::Struct>()) {
// Cache result of struct + storage class pair
if (valid_struct_storage_layouts_.emplace(str_member, sc).second) {
if (!ValidateStorageClassLayout(str_member, sc)) {
return false;
}
}
}
}
return true;
}
bool Resolver::ValidateStorageClassLayout(const sem::Variable* var) {
if (auto* str = var->Type()->UnwrapRef()->As<sem::Struct>()) {
if (!ValidateStorageClassLayout(str, var->StorageClass())) {
AddNote("see declaration of variable", var->Declaration()->source);
return false;
}
}
return true;
}
bool Resolver::ValidateGlobalVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
if (!ValidateNoDuplicateDecorations(decl->decorations)) {
return false;
}
for (auto* deco : decl->decorations) {
if (decl->is_const) {
if (auto* override_deco = deco->As<ast::OverrideDecoration>()) {
if (override_deco->has_value) {
uint32_t id = override_deco->value;
auto it = constant_ids_.find(id);
if (it != constant_ids_.end() && it->second != var) {
AddError("pipeline constant IDs must be unique", deco->source);
AddNote("a pipeline constant with an ID of " + std::to_string(id) +
" was previously declared "
"here:",
ast::GetDecoration<ast::OverrideDecoration>(
it->second->Declaration()->decorations)
->source);
return false;
}
if (id > 65535) {
AddError("pipeline constant IDs must be between 0 and 65535",
deco->source);
return false;
}
}
} else {
AddError("decoration is not valid for constants", deco->source);
return false;
}
} else {
bool is_shader_io_decoration =
deco->IsAnyOf<ast::BuiltinDecoration, ast::InterpolateDecoration,
ast::InvariantDecoration, ast::LocationDecoration>();
bool has_io_storage_class =
var->StorageClass() == ast::StorageClass::kInput ||
var->StorageClass() == ast::StorageClass::kOutput;
if (!(deco->IsAnyOf<ast::BindingDecoration, ast::GroupDecoration,
ast::InternalDecoration>()) &&
(!is_shader_io_decoration || !has_io_storage_class)) {
AddError("decoration is not valid for variables", deco->source);
return false;
}
}
}
auto binding_point = decl->BindingPoint();
switch (var->StorageClass()) {
case ast::StorageClass::kUniform:
case ast::StorageClass::kStorage:
case ast::StorageClass::kUniformConstant: {
// https://gpuweb.github.io/gpuweb/wgsl/#resource-interface
// Each resource variable must be declared with both group and binding
// attributes.
if (!binding_point) {
AddError(
"resource variables require [[group]] and [[binding]] "
"decorations",
decl->source);
return false;
}
break;
}
default:
if (binding_point.binding || binding_point.group) {
// https://gpuweb.github.io/gpuweb/wgsl/#attribute-binding
// Must only be applied to a resource variable
AddError(
"non-resource variables must not have [[group]] or [[binding]] "
"decorations",
decl->source);
return false;
}
}
// https://gpuweb.github.io/gpuweb/wgsl/#variable-declaration
// The access mode always has a default, and except for variables in the
// storage storage class, must not be written.
if (var->StorageClass() != ast::StorageClass::kStorage &&
decl->declared_access != ast::Access::kUndefined) {
AddError(
"only variables in <storage> storage class may declare an access mode",
decl->source);
return false;
}
switch (var->StorageClass()) {
case ast::StorageClass::kStorage: {
// https://gpuweb.github.io/gpuweb/wgsl/#module-scope-variables
// A variable in the storage storage class is a storage buffer variable.
// Its store type must be a host-shareable structure type with block
// attribute, satisfying the storage class constraints.
auto* str = var->Type()->UnwrapRef()->As<sem::Struct>();
if (!str) {
AddError(
"variables declared in the <storage> storage class must be of a "
"structure type",
decl->source);
return false;
}
if (!str->IsBlockDecorated()) {
AddError(
"structure used as a storage buffer must be declared with the "
"[[block]] decoration",
str->Declaration()->source);
if (decl->source.range.begin.line) {
AddNote("structure used as storage buffer here", decl->source);
}
return false;
}
break;
}
case ast::StorageClass::kUniform: {
// https://gpuweb.github.io/gpuweb/wgsl/#module-scope-variables
// A variable in the uniform storage class is a uniform buffer variable.
// Its store type must be a host-shareable structure type with block
// attribute, satisfying the storage class constraints.
auto* str = var->Type()->UnwrapRef()->As<sem::Struct>();
if (!str) {
AddError(
"variables declared in the <uniform> storage class must be of a "
"structure type",
decl->source);
return false;
}
if (!str->IsBlockDecorated()) {
AddError(
"structure used as a uniform buffer must be declared with the "
"[[block]] decoration",
str->Declaration()->source);
if (decl->source.range.begin.line) {
AddNote("structure used as uniform buffer here", decl->source);
}
return false;
}
for (auto* member : str->Members()) {
if (auto* arr = member->Type()->As<sem::Array>()) {
if (arr->IsRuntimeSized()) {
AddError(
"structure containing a runtime sized array "
"cannot be used as a uniform buffer",
decl->source);
AddNote("structure is declared here", str->Declaration()->source);
return false;
}
}
}
break;
}
default:
break;
}
if (!decl->is_const) {
if (!ValidateAtomicVariable(var)) {
return false;
}
}
return ValidateVariable(var);
}
// https://gpuweb.github.io/gpuweb/wgsl/#atomic-types
// Atomic types may only be instantiated by variables in the workgroup storage
// class or by storage buffer variables with a read_write access mode.
bool Resolver::ValidateAtomicVariable(const sem::Variable* var) {
auto sc = var->StorageClass();
auto* decl = var->Declaration();
auto access = var->Access();
auto* type = var->Type()->UnwrapRef();
auto source = decl->type ? decl->type->source : decl->source;
if (type->Is<sem::Atomic>()) {
if (sc != ast::StorageClass::kWorkgroup) {
AddError(
"atomic variables must have <storage> or <workgroup> storage class",
source);
return false;
}
} else if (type->IsAnyOf<sem::Struct, sem::Array>()) {
auto found = atomic_composite_info_.find(type);
if (found != atomic_composite_info_.end()) {
if (sc != ast::StorageClass::kStorage &&
sc != ast::StorageClass::kWorkgroup) {
AddError(
"atomic variables must have <storage> or <workgroup> storage class",
source);
AddNote(
"atomic sub-type of '" + TypeNameOf(type) + "' is declared here",
found->second);
return false;
} else if (sc == ast::StorageClass::kStorage &&
access != ast::Access::kReadWrite) {
AddError(
"atomic variables in <storage> storage class must have read_write "
"access mode",
source);
AddNote(
"atomic sub-type of '" + TypeNameOf(type) + "' is declared here",
found->second);
return false;
}
}
}
return true;
}
bool Resolver::ValidateVariable(const sem::Variable* var) {
auto* decl = var->Declaration();
auto* storage_ty = var->Type()->UnwrapRef();
if (var->Is<sem::GlobalVariable>()) {
auto name = builder_->Symbols().NameFor(decl->symbol);
if (sem::ParseIntrinsicType(name) != sem::IntrinsicType::kNone) {
auto* kind = var->Declaration()->is_const ? "let" : "var";
AddError(
"'" + name +
"' is a builtin and cannot be redeclared as a module-scope " +
kind,
decl->source);
return false;
}
}
if (!decl->is_const && !IsStorable(storage_ty)) {
AddError(TypeNameOf(storage_ty) + " cannot be used as the type of a var",
decl->source);
return false;
}
if (decl->is_const && !var->Is<sem::Parameter>() &&
!(storage_ty->IsConstructible() || storage_ty->Is<sem::Pointer>())) {
AddError(TypeNameOf(storage_ty) + " cannot be used as the type of a let",
decl->source);
return false;
}
if (auto* r = storage_ty->As<sem::Array>()) {
if (r->IsRuntimeSized()) {
AddError("runtime arrays may only appear as the last member of a struct",
decl->source);
return false;
}
}
if (auto* r = storage_ty->As<sem::MultisampledTexture>()) {
if (r->dim() != ast::TextureDimension::k2d) {
AddError("only 2d multisampled textures are supported", decl->source);
return false;
}
if (!r->type()->UnwrapRef()->is_numeric_scalar()) {
AddError("texture_multisampled_2d<type>: type must be f32, i32 or u32",
decl->source);
return false;
}
}
if (var->Is<sem::LocalVariable>() && !decl->is_const &&
IsValidationEnabled(decl->decorations,
ast::DisabledValidation::kIgnoreStorageClass)) {
if (!var->Type()->UnwrapRef()->IsConstructible()) {
AddError("function variable must have a constructible type",
decl->type ? decl->type->source : decl->source);
return false;
}
}
if (storage_ty->is_handle() &&
decl->declared_storage_class != ast::StorageClass::kNone) {
// https://gpuweb.github.io/gpuweb/wgsl/#module-scope-variables
// If the store type is a texture type or a sampler type, then the
// variable declaration must not have a storage class decoration. The
// storage class will always be handle.
AddError("variables of type '" + TypeNameOf(storage_ty) +
"' must not have a storage class",
decl->source);
return false;
}
if (IsValidationEnabled(decl->decorations,
ast::DisabledValidation::kIgnoreStorageClass) &&
(decl->declared_storage_class == ast::StorageClass::kInput ||
decl->declared_storage_class == ast::StorageClass::kOutput)) {
AddError("invalid use of input/output storage class", decl->source);
return false;
}
return true;
}
bool Resolver::ValidateFunctionParameter(const ast::Function* func,
const sem::Variable* var) {
if (!ValidateVariable(var)) {
return false;
}
auto* decl = var->Declaration();
for (auto* deco : decl->decorations) {
if (!func->IsEntryPoint() && !deco->Is<ast::InternalDecoration>()) {
AddError(
"decoration is not valid for non-entry point function parameters",
deco->source);
return false;
} else if (!deco->IsAnyOf<ast::BuiltinDecoration, ast::InvariantDecoration,
ast::LocationDecoration,
ast::InterpolateDecoration,
ast::InternalDecoration>() &&
(IsValidationEnabled(
decl->decorations,
ast::DisabledValidation::kEntryPointParameter) &&
IsValidationEnabled(
decl->decorations,
ast::DisabledValidation::
kIgnoreConstructibleFunctionParameter))) {
AddError("decoration is not valid for function parameters", deco->source);
return false;
}
}
if (auto* ref = var->Type()->As<sem::Pointer>()) {
auto sc = ref->StorageClass();
if (!(sc == ast::StorageClass::kFunction ||
sc == ast::StorageClass::kPrivate ||
sc == ast::StorageClass::kWorkgroup) &&
IsValidationEnabled(decl->decorations,
ast::DisabledValidation::kIgnoreStorageClass)) {
std::stringstream ss;
ss << "function parameter of pointer type cannot be in '" << sc
<< "' storage class";
AddError(ss.str(), decl->source);
return false;
}
}
if (IsPlain(var->Type())) {
if (!var->Type()->IsConstructible() &&
IsValidationEnabled(
decl->decorations,
ast::DisabledValidation::kIgnoreConstructibleFunctionParameter)) {
AddError("store type of function parameter must be a constructible type",
decl->source);
return false;
}
} else if (!var->Type()
->IsAnyOf<sem::Texture, sem::Sampler, sem::Pointer>()) {
AddError(
"store type of function parameter cannot be " + TypeNameOf(var->Type()),
decl->source);
return false;
}
return true;
}
bool Resolver::ValidateBuiltinDecoration(const ast::BuiltinDecoration* deco,
const sem::Type* storage_ty,
const bool is_input) {
auto* type = storage_ty->UnwrapRef();
const auto stage = current_function_
? current_function_->Declaration()->PipelineStage()
: ast::PipelineStage::kNone;
std::stringstream stage_name;
stage_name << stage;
bool is_stage_mismatch = false;
bool is_output = !is_input;
switch (deco->builtin) {
case ast::Builtin::kPosition:
if (stage != ast::PipelineStage::kNone &&
!((is_input && stage == ast::PipelineStage::kFragment) ||
(is_output && stage == ast::PipelineStage::kVertex))) {
is_stage_mismatch = true;
}
if (!(type->is_float_vector() && type->As<sem::Vector>()->Width() == 4)) {
AddError("store type of " + deco_to_str(deco) + " must be 'vec4<f32>'",
deco->source);
return false;
}
break;
case ast::Builtin::kGlobalInvocationId:
case ast::Builtin::kLocalInvocationId:
case ast::Builtin::kNumWorkgroups:
case ast::Builtin::kWorkgroupId:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kCompute && is_input)) {
is_stage_mismatch = true;
}
if (!(type->is_unsigned_integer_vector() &&
type->As<sem::Vector>()->Width() == 3)) {
AddError("store type of " + deco_to_str(deco) + " must be 'vec3<u32>'",
deco->source);
return false;
}
break;
case ast::Builtin::kFragDepth:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && !is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::F32>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'f32'",
deco->source);
return false;
}
break;
case ast::Builtin::kFrontFacing:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::Bool>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'bool'",
deco->source);
return false;
}
break;
case ast::Builtin::kLocalInvocationIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kCompute && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::U32>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'u32'",
deco->source);
return false;
}
break;
case ast::Builtin::kVertexIndex:
case ast::Builtin::kInstanceIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kVertex && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::U32>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'u32'",
deco->source);
return false;
}
break;
case ast::Builtin::kSampleMask:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::U32>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'u32'",
deco->source);
return false;
}
break;
case ast::Builtin::kSampleIndex:
if (stage != ast::PipelineStage::kNone &&
!(stage == ast::PipelineStage::kFragment && is_input)) {
is_stage_mismatch = true;
}
if (!type->Is<sem::U32>()) {
AddError("store type of " + deco_to_str(deco) + " must be 'u32'",
deco->source);
return false;
}
break;
default:
break;
}
if (is_stage_mismatch) {
AddError(deco_to_str(deco) + " cannot be used in " +
(is_input ? "input of " : "output of ") + stage_name.str() +
" pipeline stage",
deco->source);
return false;
}
return true;
}
bool Resolver::ValidateInterpolateDecoration(
const ast::InterpolateDecoration* deco,
const sem::Type* storage_ty) {
auto* type = storage_ty->UnwrapRef();
if (type->is_integer_scalar_or_vector() &&
deco->type != ast::InterpolationType::kFlat) {
AddError(
"interpolation type must be 'flat' for integral user-defined IO types",
deco->source);
return false;
}
if (deco->type == ast::InterpolationType::kFlat &&
deco->sampling != ast::InterpolationSampling::kNone) {
AddError("flat interpolation attribute must not have a sampling parameter",
deco->source);
return false;
}
return true;
}
bool Resolver::ValidateFunction(const sem::Function* func) {
auto* decl = func->Declaration();
auto name = builder_->Symbols().NameFor(decl->symbol);
if (sem::ParseIntrinsicType(name) != sem::IntrinsicType::kNone) {
AddError(
"'" + name + "' is a builtin and cannot be redeclared as a function",
decl->source);
return false;
}
auto workgroup_deco_count = 0;
for (auto* deco : decl->decorations) {
if (deco->Is<ast::WorkgroupDecoration>()) {
workgroup_deco_count++;
if (decl->PipelineStage() != ast::PipelineStage::kCompute) {
AddError(
"the workgroup_size attribute is only valid for compute stages",
deco->source);
return false;
}
} else if (!deco->IsAnyOf<ast::StageDecoration,
ast::InternalDecoration>()) {
AddError("decoration is not valid for functions", deco->source);
return false;
}
}
if (decl->params.size() > 255) {
AddError("functions may declare at most 255 parameters", decl->source);
return false;
}
for (size_t i = 0; i < decl->params.size(); i++) {
if (!ValidateFunctionParameter(decl, func->Parameters()[i])) {
return false;
}
}
if (!func->ReturnType()->Is<sem::Void>()) {
if (!func->ReturnType()->IsConstructible()) {
AddError("function return type must be a constructible type",
decl->return_type->source);
return false;
}
if (decl->body) {
if (!decl->body->Last() ||
!decl->body->Last()->Is<ast::ReturnStatement>()) {
AddError("non-void function must end with a return statement",
decl->source);
return false;
}
} else if (IsValidationEnabled(
decl->decorations,
ast::DisabledValidation::kFunctionHasNoBody)) {
TINT_ICE(Resolver, diagnostics_)
<< "Function " << builder_->Symbols().NameFor(decl->symbol)
<< " has no body";
}
for (auto* deco : decl->return_type_decorations) {
if (!decl->IsEntryPoint()) {
AddError(
"decoration is not valid for non-entry point function return types",
deco->source);
return false;
}
if (!deco->IsAnyOf<ast::BuiltinDecoration, ast::InternalDecoration,
ast::LocationDecoration, ast::InterpolateDecoration,
ast::InvariantDecoration>() &&
(IsValidationEnabled(decl->decorations,
ast::DisabledValidation::kEntryPointParameter) &&
IsValidationEnabled(decl->decorations,
ast::DisabledValidation::
kIgnoreConstructibleFunctionParameter))) {
AddError("decoration is not valid for entry point return types",
deco->source);
return false;
}
}
}
if (decl->IsEntryPoint()) {
if (!ValidateEntryPoint(func)) {
return false;
}
}
return true;
}
bool Resolver::ValidateEntryPoint(const sem::Function* func) {
auto* decl = func->Declaration();
// Use a lambda to validate the entry point decorations for a type.
// Persistent state is used to track which builtins and locations have
// already been seen, in order to catch conflicts.
// TODO(jrprice): This state could be stored in sem::Function instead, and
// then passed to sem::Function since it would be useful there too.
std::unordered_set<ast::Builtin> builtins;
std::unordered_set<uint32_t> locations;
enum class ParamOrRetType {
kParameter,
kReturnType,
};
// Inner lambda that is applied to a type and all of its members.
auto validate_entry_point_decorations_inner = [&](const ast::DecorationList&
decos,
const sem::Type* ty,
Source source,
ParamOrRetType param_or_ret,
bool is_struct_member) {
// Scan decorations for pipeline IO attributes.
// Check for overlap with attributes that have been seen previously.
const ast::Decoration* pipeline_io_attribute = nullptr;
const ast::InterpolateDecoration* interpolate_attribute = nullptr;
const ast::InvariantDecoration* invariant_attribute = nullptr;
for (auto* deco : decos) {
auto is_invalid_compute_shader_decoration = false;
if (auto* builtin = deco->As<ast::BuiltinDecoration>()) {
if (pipeline_io_attribute) {
AddError("multiple entry point IO attributes", deco->source);
AddNote("previously consumed " + deco_to_str(pipeline_io_attribute),
pipeline_io_attribute->source);
return false;
}
pipeline_io_attribute = deco;
if (builtins.count(builtin->builtin)) {
AddError(deco_to_str(builtin) +
" attribute appears multiple times as pipeline " +
(param_or_ret == ParamOrRetType::kParameter ? "input"
: "output"),
decl->source);
return false;
}
if (!ValidateBuiltinDecoration(
builtin, ty,
/* is_input */ param_or_ret == ParamOrRetType::kParameter)) {
return false;
}
builtins.emplace(builtin->builtin);
} else if (auto* location = deco->As<ast::LocationDecoration>()) {
if (pipeline_io_attribute) {
AddError("multiple entry point IO attributes", deco->source);
AddNote("previously consumed " + deco_to_str(pipeline_io_attribute),
pipeline_io_attribute->source);
return false;
}
pipeline_io_attribute = deco;
bool is_input = param_or_ret == ParamOrRetType::kParameter;
if (!ValidateLocationDecoration(location, ty, locations, source,
is_input)) {
return false;
}
} else if (auto* interpolate = deco->As<ast::InterpolateDecoration>()) {
if (decl->PipelineStage() == ast::PipelineStage::kCompute) {
is_invalid_compute_shader_decoration = true;
} else if (!ValidateInterpolateDecoration(interpolate, ty)) {
return false;
}
interpolate_attribute = interpolate;
} else if (auto* invariant = deco->As<ast::InvariantDecoration>()) {
if (decl->PipelineStage() == ast::PipelineStage::kCompute) {
is_invalid_compute_shader_decoration = true;
}
invariant_attribute = invariant;
}
if (is_invalid_compute_shader_decoration) {
std::string input_or_output =
param_or_ret == ParamOrRetType::kParameter ? "inputs" : "output";
AddError(
"decoration is not valid for compute shader " + input_or_output,
deco->source);
return false;
}
}
if (IsValidationEnabled(decos,
ast::DisabledValidation::kEntryPointParameter)) {
if (is_struct_member && ty->Is<sem::Struct>()) {
AddError("nested structures cannot be used for entry point IO", source);
return false;
}
if (!ty->Is<sem::Struct>() && !pipeline_io_attribute) {
std::string err = "missing entry point IO attribute";
if (!is_struct_member) {
err +=
(param_or_ret == ParamOrRetType::kParameter ? " on parameter"
: " on return type");
}
AddError(err, source);
return false;
}
if (pipeline_io_attribute &&
pipeline_io_attribute->Is<ast::LocationDecoration>()) {
if (ty->is_integer_scalar_or_vector() && !interpolate_attribute) {
// TODO(crbug.com/tint/1224): Make these errors once downstream
// usages have caught up (no sooner than M99).
if (decl->PipelineStage() == ast::PipelineStage::kVertex &&
param_or_ret == ParamOrRetType::kReturnType) {
AddWarning(
"integral user-defined vertex outputs must have a flat "
"interpolation attribute",
source);
}
if (decl->PipelineStage() == ast::PipelineStage::kFragment &&
param_or_ret == ParamOrRetType::kParameter) {
AddWarning(
"integral user-defined fragment inputs must have a flat "
"interpolation attribute",
source);
}
}
}
if (interpolate_attribute) {
if (!pipeline_io_attribute ||
!pipeline_io_attribute->Is<ast::LocationDecoration>()) {
AddError("interpolate attribute must only be used with [[location]]",
interpolate_attribute->source);
return false;
}
}
if (invariant_attribute) {
bool has_position = false;
if (pipeline_io_attribute) {
if (auto* builtin =
pipeline_io_attribute->As<ast::BuiltinDecoration>()) {
has_position = (builtin->builtin == ast::Builtin::kPosition);
}
}
if (!has_position) {
AddError(
"invariant attribute must only be applied to a position "
"builtin",
invariant_attribute->source);
return false;
}
}
}
return true;
};
// Outer lambda for validating the entry point decorations for a type.
auto validate_entry_point_decorations = [&](const ast::DecorationList& decos,
const sem::Type* ty,
Source source,
ParamOrRetType param_or_ret) {
if (!validate_entry_point_decorations_inner(decos, ty, source, param_or_ret,
/*is_struct_member*/ false)) {
return false;
}
if (auto* str = ty->As<sem::Struct>()) {
for (auto* member : str->Members()) {
if (!validate_entry_point_decorations_inner(
member->Declaration()->decorations, member->Type(),
member->Declaration()->source, param_or_ret,
/*is_struct_member*/ true)) {
AddNote("while analysing entry point '" +
builder_->Symbols().NameFor(decl->symbol) + "'",
decl->source);
return false;
}
}
}
return true;
};
for (auto* param : func->Parameters()) {
auto* param_decl = param->Declaration();
if (!validate_entry_point_decorations(param_decl->decorations,
param->Type(), param_decl->source,
ParamOrRetType::kParameter)) {
return false;
}
}
// Clear IO sets after parameter validation. Builtin and location attributes
// in return types should be validated independently from those used in
// parameters.
builtins.clear();
locations.clear();
if (!func->ReturnType()->Is<sem::Void>()) {
if (!validate_entry_point_decorations(decl->return_type_decorations,
func->ReturnType(), decl->source,
ParamOrRetType::kReturnType)) {
return false;
}
}
if (decl->PipelineStage() == ast::PipelineStage::kVertex &&
builtins.count(ast::Builtin::kPosition) == 0) {
// Check module-scope variables, as the SPIR-V sanitizer generates these.
bool found = false;
for (auto* global : func->TransitivelyReferencedGlobals()) {
if (auto* builtin = ast::GetDecoration<ast::BuiltinDecoration>(
global->Declaration()->decorations)) {
if (builtin->builtin == ast::Builtin::kPosition) {
found = true;
break;
}
}
}
if (!found) {
AddError(
"a vertex shader must include the 'position' builtin in its return "
"type",
decl->source);
return false;
}
}
if (decl->PipelineStage() == ast::PipelineStage::kCompute) {
if (!ast::HasDecoration<ast::WorkgroupDecoration>(decl->decorations)) {
AddError(
"a compute shader must include 'workgroup_size' in its "
"attributes",
decl->source);
return false;
}
}
// Validate there are no resource variable binding collisions
std::unordered_map<sem::BindingPoint, const ast::Variable*> binding_points;
for (auto* var : func->TransitivelyReferencedGlobals()) {
auto* var_decl = var->Declaration();
if (!var_decl->BindingPoint()) {
continue;
}
auto bp = var->BindingPoint();
auto res = binding_points.emplace(bp, var_decl);
if (!res.second &&
IsValidationEnabled(decl->decorations,
ast::DisabledValidation::kBindingPointCollision) &&
IsValidationEnabled(res.first->second->decorations,
ast::DisabledValidation::kBindingPointCollision)) {
// https://gpuweb.github.io/gpuweb/wgsl/#resource-interface
// Bindings must not alias within a shader stage: two different
// variables in the resource interface of a given shader must not have
// the same group and binding values, when considered as a pair of
// values.
auto func_name = builder_->Symbols().NameFor(decl->symbol);
AddError("entry point '" + func_name +
"' references multiple variables that use the "
"same resource binding [[group(" +
std::to_string(bp.group) + "), binding(" +
std::to_string(bp.binding) + ")]]",
var_decl->source);
AddNote("first resource binding usage declared here",
res.first->second->source);
return false;
}
}
return true;
}
bool Resolver::ValidateStatements(const ast::StatementList& stmts) {
bool unreachable = false;
for (auto* stmt : stmts) {
if (unreachable) {
AddError("code is unreachable", stmt->source);
return false;
}
auto* nested_stmt = stmt;
while (auto* block = nested_stmt->As<ast::BlockStatement>()) {
if (block->Empty()) {
break;
}
nested_stmt = block->statements.back();
}
if (nested_stmt->IsAnyOf<ast::ReturnStatement, ast::BreakStatement,
ast::ContinueStatement, ast::DiscardStatement>()) {
unreachable = true;
}
}
return true;
}
bool Resolver::ValidateBreakStatement(const sem::Statement* stmt) {
if (!stmt->FindFirstParent<sem::LoopBlockStatement>() &&
!stmt->FindFirstParent<sem::CaseStatement>()) {
AddError("break statement must be in a loop or switch case",
stmt->Declaration()->source);
return false;
}
return true;
}
bool Resolver::ValidateContinueStatement(const sem::Statement* stmt) {
if (auto* block =
stmt->FindFirstParent<sem::LoopBlockStatement,
sem::LoopContinuingBlockStatement>()) {
if (block->Is<sem::LoopContinuingBlockStatement>()) {
AddError("continuing blocks must not contain a continue statement",
stmt->Declaration()->source);
return false;
}
} else {
AddError("continue statement must be in a loop",
stmt->Declaration()->source);
return false;
}
return true;
}
bool Resolver::ValidateDiscardStatement(const sem::Statement* stmt) {
if (auto* continuing =
stmt->FindFirstParent<sem::LoopContinuingBlockStatement>()) {
AddError("continuing blocks must not contain a discard statement",
stmt->Declaration()->source);
if (continuing != stmt->Parent()) {
AddNote("see continuing block here", continuing->Declaration()->source);
}
return false;
}
return true;
}
bool Resolver::ValidateFallthroughStatement(const sem::Statement* stmt) {
if (auto* block = As<sem::BlockStatement>(stmt->Parent())) {
if (auto* c = As<sem::CaseStatement>(block->Parent())) {
if (block->Declaration()->Last() == stmt->Declaration()) {
if (auto* s = As<sem::SwitchStatement>(c->Parent())) {
if (c->Declaration() != s->Declaration()->body.back()) {
return true;
}
AddError(
"a fallthrough statement must not be used in the last switch "
"case",
stmt->Declaration()->source);
return false;
}
}
}
}
AddError(
"fallthrough must only be used as the last statement of a case block",
stmt->Declaration()->source);
return false;
}
bool Resolver::ValidateElseStatement(const sem::ElseStatement* stmt) {
if (auto* cond = stmt->Condition()) {
auto* cond_ty = cond->Type()->UnwrapRef();
if (!cond_ty->Is<sem::Bool>()) {
AddError(
"else statement condition must be bool, got " + TypeNameOf(cond_ty),
stmt->Condition()->Declaration()->source);
return false;
}
}
return true;
}
bool Resolver::ValidateForLoopStatement(const sem::ForLoopStatement* stmt) {
if (auto* cond = stmt->Condition()) {
auto* cond_ty = cond->Type()->UnwrapRef();
if (!cond_ty->Is<sem::Bool>()) {
AddError("for-loop condition must be bool, got " + TypeNameOf(cond_ty),
stmt->Condition()->Declaration()->source);
return false;
}
}
return true;
}
bool Resolver::ValidateIfStatement(const sem::IfStatement* stmt) {
auto* cond_ty = stmt->Condition()->Type()->UnwrapRef();
if (!cond_ty->Is<sem::Bool>()) {
AddError("if statement condition must be bool, got " + TypeNameOf(cond_ty),
stmt->Condition()->Declaration()->source);
return false;
}
return true;
}
bool Resolver::ValidateIntrinsicCall(const sem::Call* call) {
if (call->Type()->Is<sem::Void>()) {
bool is_call_statement = false;
if (auto* call_stmt = As<ast::CallStatement>(call->Stmt()->Declaration())) {
if (call_stmt->expr == call->Declaration()) {
is_call_statement = true;
}
}
if (!is_call_statement) {
// https://gpuweb.github.io/gpuweb/wgsl/#function-call-expr
// If the called function does not return a value, a function call
// statement should be used instead.
auto* ident = call->Declaration()->target.name;
auto name = builder_->Symbols().NameFor(ident->symbol);
AddError("intrinsic '" + name + "' does not return a value",
call->Declaration()->source);
return false;
}
}
return true;
}
bool Resolver::ValidateTextureIntrinsicFunction(const sem::Call* call) {
auto* intrinsic = call->Target()->As<sem::Intrinsic>();
if (!intrinsic) {
return false;
}
std::string func_name = intrinsic->str();
auto& signature = intrinsic->Signature();
auto index = signature.IndexOf(sem::ParameterUsage::kOffset);
if (index > -1) {
auto* arg = call->Arguments()[index];
if (auto values = arg->ConstantValue()) {
// Assert that the constant values are of the expected type.
if (!values.Type()->Is<sem::Vector>() ||
!values.ElementType()->Is<sem::I32>()) {
TINT_ICE(Resolver, diagnostics_)
<< "failed to resolve '" + func_name + "' offset parameter type";
return false;
}
// Currently const_expr is restricted to literals and type constructors.
// Check that that's all we have for the offset parameter.
bool is_const_expr = true;
ast::TraverseExpressions(
arg->Declaration(), diagnostics_, [&](const ast::Expression* e) {
if (e->IsAnyOf<ast::LiteralExpression, ast::CallExpression>()) {
return ast::TraverseAction::Descend;
}
is_const_expr = false;
return ast::TraverseAction::Stop;
});
if (is_const_expr) {
for (auto offset : values.Elements()) {
auto offset_value = offset.i32;
if (offset_value < -8 || offset_value > 7) {
AddError("each offset component of '" + func_name +
"' must be at least -8 and at most 7. "
"found: '" +
std::to_string(offset_value) + "'",
arg->Declaration()->source);
return false;
}
}
return true;
}
}
AddError("'" + func_name + "' offset parameter must be a const_expression",
arg->Declaration()->source);
return false;
}
return true;
}
bool Resolver::ValidateFunctionCall(const sem::Call* call) {
auto* decl = call->Declaration();
auto* target = call->Target()->As<sem::Function>();
auto sym = decl->target.name->symbol;
auto name = builder_->Symbols().NameFor(sym);
if (target->Declaration()->IsEntryPoint()) {
// https://www.w3.org/TR/WGSL/#function-restriction
// An entry point must never be the target of a function call.
AddError("entry point functions cannot be the target of a function call",
decl->source);
return false;
}
if (decl->args.size() != target->Parameters().size()) {
bool more = decl->args.size() > target->Parameters().size();
AddError("too " + (more ? std::string("many") : std::string("few")) +
" arguments in call to '" + name + "', expected " +
std::to_string(target->Parameters().size()) + ", got " +
std::to_string(call->Arguments().size()),
decl->source);
return false;
}
for (size_t i = 0; i < call->Arguments().size(); ++i) {
const sem::Variable* param = target->Parameters()[i];
const ast::Expression* arg_expr = decl->args[i];
auto* param_type = param->Type();
auto* arg_type = TypeOf(arg_expr)->UnwrapRef();
if (param_type != arg_type) {
AddError("type mismatch for argument " + std::to_string(i + 1) +
" in call to '" + name + "', expected '" +
TypeNameOf(param_type) + "', got '" + TypeNameOf(arg_type) +
"'",
arg_expr->source);
return false;
}
if (param_type->Is<sem::Pointer>()) {
auto is_valid = false;
if (auto* ident_expr = arg_expr->As<ast::IdentifierExpression>()) {
auto* var = ResolvedSymbol<sem::Variable>(ident_expr);
if (!var) {
TINT_ICE(Resolver, diagnostics_) << "failed to resolve identifier";
return false;
}
if (var->Is<sem::Parameter>()) {
is_valid = true;
}
} else if (auto* unary = arg_expr->As<ast::UnaryOpExpression>()) {
if (unary->op == ast::UnaryOp::kAddressOf) {
if (auto* ident_unary =
unary->expr->As<ast::IdentifierExpression>()) {
auto* var = ResolvedSymbol<sem::Variable>(ident_unary);
if (!var) {
TINT_ICE(Resolver, diagnostics_)
<< "failed to resolve identifier";
return false;
}
if (var->Declaration()->is_const) {
TINT_ICE(Resolver, diagnostics_)
<< "Resolver::FunctionCall() encountered an address-of "
"expression of a constant identifier expression";
return false;
}
is_valid = true;
}
}
}
if (!is_valid &&
IsValidationEnabled(
param->Declaration()->decorations,
ast::DisabledValidation::kIgnoreInvalidPointerArgument)) {
AddError(
"expected an address-of expression of a variable identifier "
"expression or a function parameter",
arg_expr->source);
return false;
}
}
}
if (call->Type()->Is<sem::Void>()) {
bool is_call_statement = false;
if (auto* call_stmt = As<ast::CallStatement>(call->Stmt()->Declaration())) {
if (call_stmt->expr == call->Declaration()) {
is_call_statement = true;
}
}
if (!is_call_statement) {
// https://gpuweb.github.io/gpuweb/wgsl/#function-call-expr
// If the called function does not return a value, a function call
// statement should be used instead.
AddError("function '" + name + "' does not return a value", decl->source);
return false;
}
}
return true;
}
bool Resolver::ValidateStructureConstructorOrCast(
const ast::CallExpression* ctor,
const sem::Struct* struct_type) {
if (!struct_type->IsConstructible()) {
AddError("struct constructor has non-constructible type", ctor->source);
return false;
}
if (ctor->args.size() > 0) {
if (ctor->args.size() != struct_type->Members().size()) {
std::string fm =
ctor->args.size() < struct_type->Members().size() ? "few" : "many";
AddError("struct constructor has too " + fm + " inputs: expected " +
std::to_string(struct_type->Members().size()) + ", found " +
std::to_string(ctor->args.size()),
ctor->source);
return false;
}
for (auto* member : struct_type->Members()) {
auto* value = ctor->args[member->Index()];
auto* value_ty = TypeOf(value);
if (member->Type() != value_ty->UnwrapRef()) {
AddError(
"type in struct constructor does not match struct member type: "
"expected '" +
TypeNameOf(member->Type()) + "', found '" +
TypeNameOf(value_ty) + "'",
value->source);
return false;
}
}
}
return true;
}
bool Resolver::ValidateArrayConstructorOrCast(const ast::CallExpression* ctor,
const sem::Array* array_type) {
auto& values = ctor->args;
auto* elem_ty = array_type->ElemType();
for (auto* value : values) {
auto* value_ty = TypeOf(value)->UnwrapRef();
if (value_ty != elem_ty) {
AddError(
"type in array constructor does not match array type: "
"expected '" +
TypeNameOf(elem_ty) + "', found '" + TypeNameOf(value_ty) + "'",
value->source);
return false;
}
}
if (array_type->IsRuntimeSized()) {
AddError("cannot init a runtime-sized array", ctor->source);
return false;
} else if (!elem_ty->IsConstructible()) {
AddError("array constructor has non-constructible element type",
ctor->source);
return false;
} else if (!values.empty() && (values.size() != array_type->Count())) {
std::string fm = values.size() < array_type->Count() ? "few" : "many";
AddError("array constructor has too " + fm + " elements: expected " +
std::to_string(array_type->Count()) + ", found " +
std::to_string(values.size()),
ctor->source);
return false;
} else if (values.size() > array_type->Count()) {
AddError("array constructor has too many elements: expected " +
std::to_string(array_type->Count()) + ", found " +
std::to_string(values.size()),
ctor->source);
return false;
}
return true;
}
bool Resolver::ValidateVectorConstructorOrCast(const ast::CallExpression* ctor,
const sem::Vector* vec_type) {
auto& values = ctor->args;
auto* elem_ty = vec_type->type();
size_t value_cardinality_sum = 0;
for (auto* value : values) {
auto* value_ty = TypeOf(value)->UnwrapRef();
if (value_ty->is_scalar()) {
if (elem_ty != value_ty) {
AddError(
"type in vector constructor does not match vector type: "
"expected '" +
TypeNameOf(elem_ty) + "', found '" + TypeNameOf(value_ty) + "'",
value->source);
return false;
}
value_cardinality_sum++;
} else if (auto* value_vec = value_ty->As<sem::Vector>()) {
auto* value_elem_ty = value_vec->type();
// A mismatch of vector type parameter T is only an error if multiple
// arguments are present. A single argument constructor constitutes a
// type conversion expression.
if (elem_ty != value_elem_ty && values.size() > 1u) {
AddError(
"type in vector constructor does not match vector type: "
"expected '" +
TypeNameOf(elem_ty) + "', found '" + TypeNameOf(value_elem_ty) +
"'",
value->source);
return false;
}
value_cardinality_sum += value_vec->Width();
} else {
// A vector constructor can only accept vectors and scalars.
AddError("expected vector or scalar type in vector constructor; found: " +
TypeNameOf(value_ty),
value->source);
return false;
}
}
// A correct vector constructor must either be a zero-value expression,
// a single-value initializer (splat) expression, or the number of components
// of all constructor arguments must add up to the vector cardinality.
if (value_cardinality_sum > 1 && value_cardinality_sum != vec_type->Width()) {
if (values.empty()) {
TINT_ICE(Resolver, diagnostics_)
<< "constructor arguments expected to be non-empty!";
}
const Source& values_start = values[0]->source;
const Source& values_end = values[values.size() - 1]->source;
AddError("attempted to construct '" + TypeNameOf(vec_type) + "' with " +
std::to_string(value_cardinality_sum) + " component(s)",
Source::Combine(values_start, values_end));
return false;
}
return true;
}
bool Resolver::ValidateVector(const sem::Vector* ty, const Source& source) {
if (!ty->type()->is_scalar()) {
AddError("vector element type must be 'bool', 'f32', 'i32' or 'u32'",
source);
return false;
}
return true;
}
bool Resolver::ValidateMatrix(const sem::Matrix* ty, const Source& source) {
if (!ty->is_float_matrix()) {
AddError("matrix element type must be 'f32'", source);
return false;
}
return true;
}
bool Resolver::ValidateMatrixConstructorOrCast(const ast::CallExpression* ctor,
const sem::Matrix* matrix_ty) {
auto& values = ctor->args;
// Zero Value expression
if (values.empty()) {
return true;
}
if (!ValidateMatrix(matrix_ty, ctor->source)) {
return false;
}
auto* elem_type = matrix_ty->type();
auto num_elements = matrix_ty->columns() * matrix_ty->rows();
// Print a generic error for an invalid matrix constructor, showing the
// available overloads.
auto print_error = [&]() {
const Source& values_start = values[0]->source;
const Source& values_end = values[values.size() - 1]->source;
auto type_name = TypeNameOf(matrix_ty);
auto elem_type_name = TypeNameOf(elem_type);
std::stringstream ss;
ss << "invalid constructor for " + type_name << std::endl << std::endl;
ss << "3 candidates available:" << std::endl;
ss << " " << type_name << "()" << std::endl;
ss << " " << type_name << "(" << elem_type_name << ",...,"
<< elem_type_name << ")"
<< " // " << std::to_string(num_elements) << " arguments" << std::endl;
ss << " " << type_name << "(";
for (uint32_t c = 0; c < matrix_ty->columns(); c++) {
if (c > 0) {
ss << ", ";
}
ss << VectorPretty(matrix_ty->rows(), elem_type);
}
ss << ")" << std::endl;
AddError(ss.str(), Source::Combine(values_start, values_end));
};
const sem::Type* expected_arg_type = nullptr;
if (num_elements == values.size()) {
// Column-major construction from scalar elements.
expected_arg_type = matrix_ty->type();
} else if (matrix_ty->columns() == values.size()) {
// Column-by-column construction from vectors.
expected_arg_type = matrix_ty->ColumnType();
} else {
print_error();
return false;
}
for (auto* value : values) {
if (TypeOf(value)->UnwrapRef() != expected_arg_type) {
print_error();
return false;
}
}
return true;
}
bool Resolver::ValidateScalarConstructorOrCast(const ast::CallExpression* ctor,
const sem::Type* ty) {
if (ctor->args.size() == 0) {
return true;
}
if (ctor->args.size() > 1) {
AddError("expected zero or one value in constructor, got " +
std::to_string(ctor->args.size()),
ctor->source);
return false;
}
// Validate constructor
auto* value = ctor->args[0];
auto* value_ty = TypeOf(value)->UnwrapRef();
using Bool = sem::Bool;
using I32 = sem::I32;
using U32 = sem::U32;
using F32 = sem::F32;
const bool is_valid = (ty->Is<Bool>() && value_ty->is_scalar()) ||
(ty->Is<I32>() && value_ty->is_scalar()) ||
(ty->Is<U32>() && value_ty->is_scalar()) ||
(ty->Is<F32>() && value_ty->is_scalar());
if (!is_valid) {
AddError("cannot construct '" + TypeNameOf(ty) +
"' with a value of type '" + TypeNameOf(value_ty) + "'",
ctor->source);
return false;
}
return true;
}
bool Resolver::ValidatePipelineStages() {
auto check_workgroup_storage = [&](const sem::Function* func,
const sem::Function* entry_point) {
auto stage = entry_point->Declaration()->PipelineStage();
if (stage != ast::PipelineStage::kCompute) {
for (auto* var : func->DirectlyReferencedGlobals()) {
if (var->StorageClass() == ast::StorageClass::kWorkgroup) {
std::stringstream stage_name;
stage_name << stage;
for (auto* user : var->Users()) {
if (func == user->Stmt()->Function()) {
AddError("workgroup memory cannot be used by " +
stage_name.str() + " pipeline stage",
user->Declaration()->source);
break;
}
}
AddNote("variable is declared here", var->Declaration()->source);
if (func != entry_point) {
TraverseCallChain(diagnostics_, entry_point, func,
[&](const sem::Function* f) {
AddNote("called by function '" +
builder_->Symbols().NameFor(
f->Declaration()->symbol) +
"'",
f->Declaration()->source);
});
AddNote("called by entry point '" +
builder_->Symbols().NameFor(
entry_point->Declaration()->symbol) +
"'",
entry_point->Declaration()->source);
}
return false;
}
}
}
return true;
};
for (auto* entry_point : entry_points_) {
if (!check_workgroup_storage(entry_point, entry_point)) {
return false;
}
for (auto* func : entry_point->TransitivelyCalledFunctions()) {
if (!check_workgroup_storage(func, entry_point)) {
return false;
}
}
}
auto check_intrinsic_calls = [&](const sem::Function* func,
const sem::Function* entry_point) {
auto stage = entry_point->Declaration()->PipelineStage();
for (auto* intrinsic : func->DirectlyCalledIntrinsics()) {
if (!intrinsic->SupportedStages().Contains(stage)) {
auto* call = func->FindDirectCallTo(intrinsic);
std::stringstream err;
err << "built-in cannot be used by " << stage << " pipeline stage";
AddError(err.str(), call ? call->Declaration()->source
: func->Declaration()->source);
if (func != entry_point) {
TraverseCallChain(
diagnostics_, entry_point, func, [&](const sem::Function* f) {
AddNote(
"called by function '" +
builder_->Symbols().NameFor(f->Declaration()->symbol) +
"'",
f->Declaration()->source);
});
AddNote("called by entry point '" +
builder_->Symbols().NameFor(
entry_point->Declaration()->symbol) +
"'",
entry_point->Declaration()->source);
}
return false;
}
}
return true;
};
for (auto* entry_point : entry_points_) {
if (!check_intrinsic_calls(entry_point, entry_point)) {
return false;
}
for (auto* func : entry_point->TransitivelyCalledFunctions()) {
if (!check_intrinsic_calls(func, entry_point)) {
return false;
}
}
}
return true;
}
bool Resolver::ValidateArray(const sem::Array* arr, const Source& source) {
auto* el_ty = arr->ElemType();
if (auto* el_str = el_ty->As<sem::Struct>()) {
if (el_str->IsBlockDecorated()) {
// https://gpuweb.github.io/gpuweb/wgsl/#attributes
// A structure type with the block attribute must not be:
// * the element type of an array type
// * the member type in another structure
AddError(
"A structure type with a [[block]] decoration cannot be used as an "
"element of an array",
source);
return false;
}
}
return true;
}
bool Resolver::ValidateArrayStrideDecoration(const ast::StrideDecoration* deco,
uint32_t el_size,
uint32_t el_align,
const Source& source) {
auto stride = deco->stride;
bool is_valid_stride =
(stride >= el_size) && (stride >= el_align) && (stride % el_align == 0);
if (!is_valid_stride) {
// https://gpuweb.github.io/gpuweb/wgsl/#array-layout-rules
// Arrays decorated with the stride attribute must have a stride that is
// at least the size of the element type, and be a multiple of the
// element type's alignment value.
AddError(
"arrays decorated with the stride attribute must have a stride "
"that is at least the size of the element type, and be a multiple "
"of the element type's alignment value.",
source);
return false;
}
return true;
}
bool Resolver::ValidateAlias(const ast::Alias* alias) {
auto name = builder_->Symbols().NameFor(alias->name);
if (sem::ParseIntrinsicType(name) != sem::IntrinsicType::kNone) {
AddError("'" + name + "' is a builtin and cannot be redeclared as an alias",
alias->source);
return false;
}
return true;
}
bool Resolver::ValidateStructure(const sem::Struct* str) {
auto name = builder_->Symbols().NameFor(str->Declaration()->name);
if (sem::ParseIntrinsicType(name) != sem::IntrinsicType::kNone) {
AddError("'" + name + "' is a builtin and cannot be redeclared as a struct",
str->Declaration()->source);
return false;
}
if (str->Members().empty()) {
AddError("structures must have at least one member",
str->Declaration()->source);
return false;
}
std::unordered_set<uint32_t> locations;
for (auto* member : str->Members()) {
if (auto* r = member->Type()->As<sem::Array>()) {
if (r->IsRuntimeSized()) {
if (member != str->Members().back()) {
AddError(
"runtime arrays may only appear as the last member of a struct",
member->Declaration()->source);
return false;
}
if (!str->IsBlockDecorated()) {
AddError(
"a struct containing a runtime-sized array "
"requires the [[block]] attribute: '" +
builder_->Symbols().NameFor(str->Declaration()->name) + "'",
member->Declaration()->source);
return false;
}
}
}
auto has_location = false;
auto has_position = false;
const ast::InvariantDecoration* invariant_attribute = nullptr;
const ast::InterpolateDecoration* interpolate_attribute = nullptr;
for (auto* deco : member->Declaration()->decorations) {
if (!deco->IsAnyOf<ast::BuiltinDecoration, //
ast::InternalDecoration, //
ast::InterpolateDecoration, //
ast::InvariantDecoration, //
ast::LocationDecoration, //
ast::StructMemberOffsetDecoration, //
ast::StructMemberSizeDecoration, //
ast::StructMemberAlignDecoration>()) {
if (deco->Is<ast::StrideDecoration>() &&
IsValidationDisabled(
member->Declaration()->decorations,
ast::DisabledValidation::kIgnoreStrideDecoration)) {
continue;
}
AddError("decoration is not valid for structure members", deco->source);
return false;
}
if (auto* invariant = deco->As<ast::InvariantDecoration>()) {
invariant_attribute = invariant;
} else if (auto* location = deco->As<ast::LocationDecoration>()) {
has_location = true;
if (!ValidateLocationDecoration(location, member->Type(), locations,
member->Declaration()->source)) {
return false;
}
} else if (auto* builtin = deco->As<ast::BuiltinDecoration>()) {
if (!ValidateBuiltinDecoration(builtin, member->Type(),
/* is_input */ false)) {
return false;
}
if (builtin->builtin == ast::Builtin::kPosition) {
has_position = true;
}
} else if (auto* interpolate = deco->As<ast::InterpolateDecoration>()) {
interpolate_attribute = interpolate;
if (!ValidateInterpolateDecoration(interpolate, member->Type())) {
return false;
}
}
}
if (invariant_attribute && !has_position) {
AddError("invariant attribute must only be applied to a position builtin",
invariant_attribute->source);
return false;
}
if (interpolate_attribute && !has_location) {
AddError("interpolate attribute must only be used with [[location]]",
interpolate_attribute->source);
return false;
}
if (auto* member_struct_type = member->Type()->As<sem::Struct>()) {
if (auto* member_struct_type_block_decoration =
ast::GetDecoration<ast::StructBlockDecoration>(
member_struct_type->Declaration()->decorations)) {
AddError("structs must not contain [[block]] decorated struct members",
member->Declaration()->source);
AddNote("see member's struct decoration here",
member_struct_type_block_decoration->source);
return false;
}
}
}
for (auto* deco : str->Declaration()->decorations) {
if (!(deco->Is<ast::StructBlockDecoration>())) {
AddError("decoration is not valid for struct declarations", deco->source);
return false;
}
}
return true;
}
bool Resolver::ValidateLocationDecoration(
const ast::LocationDecoration* location,
const sem::Type* type,
std::unordered_set<uint32_t>& locations,
const Source& source,
const bool is_input) {
std::string inputs_or_output = is_input ? "inputs" : "output";
if (current_function_ && current_function_->Declaration()->PipelineStage() ==
ast::PipelineStage::kCompute) {
AddError("decoration is not valid for compute shader " + inputs_or_output,
location->source);
return false;
}
if (!type->is_numeric_scalar_or_vector()) {
std::string invalid_type = TypeNameOf(type);
AddError("cannot apply 'location' attribute to declaration of type '" +
invalid_type + "'",
source);
AddNote(
"'location' attribute must only be applied to declarations of "
"numeric scalar or numeric vector type",
location->source);
return false;
}
if (locations.count(location->value)) {
AddError(deco_to_str(location) + " attribute appears multiple times",
location->source);
return false;
}
locations.emplace(location->value);
return true;
}
bool Resolver::ValidateReturn(const ast::ReturnStatement* ret) {
auto* func_type = current_function_->ReturnType();
auto* ret_type = ret->value ? TypeOf(ret->value)->UnwrapRef()
: builder_->create<sem::Void>();
if (func_type->UnwrapRef() != ret_type) {
AddError(
"return statement type must match its function "
"return type, returned '" +
TypeNameOf(ret_type) + "', expected '" + TypeNameOf(func_type) +
"'",
ret->source);
return false;
}
auto* sem = Sem(ret);
if (auto* continuing =
sem->FindFirstParent<sem::LoopContinuingBlockStatement>()) {
AddError("continuing blocks must not contain a return statement",
ret->source);
if (continuing != sem->Parent()) {
AddNote("see continuing block here", continuing->Declaration()->source);
}
return false;
}
return true;
}
bool Resolver::ValidateSwitch(const ast::SwitchStatement* s) {
auto* cond_ty = TypeOf(s->condition)->UnwrapRef();
if (!cond_ty->is_integer_scalar()) {
AddError(
"switch statement selector expression must be of a "
"scalar integer type",
s->condition->source);
return false;
}
bool has_default = false;
std::unordered_map<uint32_t, Source> selectors;
for (auto* case_stmt : s->body) {
if (case_stmt->IsDefault()) {
if (has_default) {
// More than one default clause
AddError("switch statement must have exactly one default clause",
case_stmt->source);
return false;
}
has_default = true;
}
for (auto* selector : case_stmt->selectors) {
if (cond_ty != TypeOf(selector)) {
AddError(
"the case selector values must have the same "
"type as the selector expression.",
case_stmt->source);
return false;
}
auto v = selector->ValueAsU32();
auto it = selectors.find(v);
if (it != selectors.end()) {
auto val = selector->Is<ast::IntLiteralExpression>()
? std::to_string(selector->ValueAsI32())
: std::to_string(selector->ValueAsU32());
AddError("duplicate switch case '" + val + "'", selector->source);
AddNote("previous case declared here", it->second);
return false;
}
selectors.emplace(v, selector->source);
}
}
if (!has_default) {
// No default clause
AddError("switch statement must have a default clause", s->source);
return false;
}
return true;
}
bool Resolver::ValidateAssignment(const ast::AssignmentStatement* a) {
auto const* rhs_ty = TypeOf(a->rhs);
if (a->lhs->Is<ast::PhonyExpression>()) {
// https://www.w3.org/TR/WGSL/#phony-assignment-section
auto* ty = rhs_ty->UnwrapRef();
if (!ty->IsConstructible() &&
!ty->IsAnyOf<sem::Pointer, sem::Texture, sem::Sampler>()) {
AddError(
"cannot assign '" + TypeNameOf(rhs_ty) +
"' to '_'. '_' can only be assigned a constructible, pointer, "
"texture or sampler type",
a->rhs->source);
return false;
}
return true; // RHS can be anything.
}
// https://gpuweb.github.io/gpuweb/wgsl/#assignment-statement
auto const* lhs_ty = TypeOf(a->lhs);
if (auto* var = ResolvedSymbol<sem::Variable>(a->lhs)) {
auto* decl = var->Declaration();
if (var->Is<sem::Parameter>()) {
AddError("cannot assign to function parameter", a->lhs->source);
AddNote("'" + builder_->Symbols().NameFor(decl->symbol) +
"' is declared here:",
decl->source);
return false;
}
if (decl->is_const) {
AddError("cannot assign to const", a->lhs->source);
AddNote("'" + builder_->Symbols().NameFor(decl->symbol) +
"' is declared here:",
decl->source);
return false;
}
}
auto* lhs_ref = lhs_ty->As<sem::Reference>();
if (!lhs_ref) {
// LHS is not a reference, so it has no storage.
AddError("cannot assign to value of type '" + TypeNameOf(lhs_ty) + "'",
a->lhs->source);
return false;
}
auto* storage_ty = lhs_ref->StoreType();
auto* value_type = rhs_ty->UnwrapRef(); // Implicit load of RHS
// Value type has to match storage type
if (storage_ty != value_type) {
AddError("cannot assign '" + TypeNameOf(rhs_ty) + "' to '" +
TypeNameOf(lhs_ty) + "'",
a->source);
return false;
}
if (!storage_ty->IsConstructible()) {
AddError("storage type of assignment must be constructible", a->source);
return false;
}
if (lhs_ref->Access() == ast::Access::kRead) {
AddError(
"cannot store into a read-only type '" + RawTypeNameOf(lhs_ty) + "'",
a->source);
return false;
}
return true;
}
bool Resolver::ValidateNoDuplicateDecorations(
const ast::DecorationList& decorations) {
std::unordered_map<const TypeInfo*, Source> seen;
for (auto* d : decorations) {
auto res = seen.emplace(&d->TypeInfo(), d->source);
if (!res.second && !d->Is<ast::InternalDecoration>()) {
AddError("duplicate " + d->Name() + " decoration", d->source);
AddNote("first decoration declared here", res.first->second);
return false;
}
}
return true;
}
bool Resolver::IsValidationDisabled(const ast::DecorationList& decorations,
ast::DisabledValidation validation) const {
for (auto* decoration : decorations) {
if (auto* dv = decoration->As<ast::DisableValidationDecoration>()) {
if (dv->validation == validation) {
return true;
}
}
}
return false;
}
bool Resolver::IsValidationEnabled(const ast::DecorationList& decorations,
ast::DisabledValidation validation) const {
return !IsValidationDisabled(decorations, validation);
}
} // namespace resolver
} // namespace tint