Files
carbon-lang/toolchain/check/handle_binding_pattern.cpp
T
Jon Ross-Perkins 311b4ff03d Refactor AddInst-family functions to their own file (#4941)
This in particular uses free functions because it's likely to end up
more consistent with types (versus a wrapper object for InstStore).
Note, this is unlikely to have a performance impact, but if it does, we
can look into related approaches (and we've already discussed using
LTO).

Renames `PendingBlock::AddInst` to `PendingBlock::Add` because
`MakeElementAccessInst` expects the matching name to exist.
2025-02-14 19:44:36 +00:00

371 lines
16 KiB
C++

// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
#include "toolchain/check/context.h"
#include "toolchain/check/convert.h"
#include "toolchain/check/handle.h"
#include "toolchain/check/inst.h"
#include "toolchain/check/interface.h"
#include "toolchain/check/name_lookup.h"
#include "toolchain/check/return.h"
#include "toolchain/check/subpattern.h"
#include "toolchain/check/type.h"
#include "toolchain/check/type_completion.h"
#include "toolchain/diagnostics/format_providers.h"
#include "toolchain/sem_ir/ids.h"
#include "toolchain/sem_ir/inst.h"
namespace Carbon::Check {
static auto HandleAnyBindingPattern(Context& context, Parse::NodeId node_id,
Parse::NodeKind node_kind) -> bool {
// TODO: split this into smaller, more focused functions.
auto [type_node, parsed_type_id] = context.node_stack().PopExprWithNodeId();
auto [cast_type_inst_id, cast_type_id] =
ExprAsType(context, type_node, parsed_type_id);
// TODO: Handle `_` bindings.
SemIR::ExprRegionId type_expr_region_id =
EndSubpatternAsExpr(context, cast_type_inst_id);
// The name in a template binding may be wrapped in `template`.
bool is_generic = node_kind == Parse::NodeKind::CompileTimeBindingPattern;
auto is_template =
context.node_stack()
.PopAndDiscardSoloNodeIdIf<Parse::NodeKind::TemplateBindingName>();
// A non-generic template binding is diagnosed by the parser.
is_template &= is_generic;
// Every other kind of pattern binding has a name.
auto [name_node, name_id] = context.node_stack().PopNameWithNodeId();
const DeclIntroducerState& introducer =
context.decl_introducer_state_stack().innermost();
auto make_binding_pattern = [&]() -> SemIR::InstId {
auto bind_id = SemIR::InstId::None;
auto binding_pattern_id = SemIR::InstId::None;
// TODO: Eventually the name will need to support associations with other
// scopes, but right now we don't support qualified names here.
auto entity_name_id = context.entity_names().AddSymbolicBindingName(
name_id, context.scope_stack().PeekNameScopeId(),
is_generic ? context.scope_stack().AddCompileTimeBinding()
: SemIR::CompileTimeBindIndex::None,
is_template);
if (is_generic) {
bind_id = AddInstInNoBlock(
context,
SemIR::LocIdAndInst(name_node, SemIR::BindSymbolicName{
.type_id = cast_type_id,
.entity_name_id = entity_name_id,
.value_id = SemIR::InstId::None}));
binding_pattern_id = AddPatternInst<SemIR::SymbolicBindingPattern>(
context, name_node,
{.type_id = cast_type_id, .entity_name_id = entity_name_id});
} else {
bind_id = AddInstInNoBlock(
context,
SemIR::LocIdAndInst(
name_node, SemIR::BindName{.type_id = cast_type_id,
.entity_name_id = entity_name_id,
.value_id = SemIR::InstId::None}));
binding_pattern_id = AddPatternInst<SemIR::BindingPattern>(
context, name_node,
{.type_id = cast_type_id, .entity_name_id = entity_name_id});
}
// Add name to lookup immediately, so it can be used in the rest of the
// enclosing pattern.
if (is_generic) {
context.scope_stack().PushCompileTimeBinding(bind_id);
}
auto name_context =
context.decl_name_stack().MakeUnqualifiedName(name_node, name_id);
context.decl_name_stack().AddNameOrDiagnose(
name_context, bind_id, introducer.modifier_set.GetAccessKind());
context.full_pattern_stack().AddBindName(name_id);
bool inserted = context.bind_name_map()
.Insert(binding_pattern_id,
{.bind_name_id = bind_id,
.type_expr_region_id = type_expr_region_id})
.is_inserted();
CARBON_CHECK(inserted);
return binding_pattern_id;
};
// A `self` binding can only appear in an implicit parameter list.
if (name_id == SemIR::NameId::SelfValue &&
!context.node_stack().PeekIs(Parse::NodeKind::ImplicitParamListStart)) {
CARBON_DIAGNOSTIC(
SelfOutsideImplicitParamList, Error,
"`self` can only be declared in an implicit parameter list");
context.emitter().Emit(node_id, SelfOutsideImplicitParamList);
}
// A `var` binding in a class scope declares a field, not a true binding,
// so we handle it separately.
if (auto parent_class_decl =
context.scope_stack().GetCurrentScopeAs<SemIR::ClassDecl>();
parent_class_decl.has_value() && !is_generic &&
node_kind == Parse::NodeKind::VarBindingPattern) {
cast_type_id = AsConcreteType(
context, cast_type_id, type_node,
[&] {
CARBON_DIAGNOSTIC(IncompleteTypeInFieldDecl, Error,
"field has incomplete type {0}", SemIR::TypeId);
return context.emitter().Build(type_node, IncompleteTypeInFieldDecl,
cast_type_id);
},
[&] {
CARBON_DIAGNOSTIC(AbstractTypeInFieldDecl, Error,
"field has abstract type {0}", SemIR::TypeId);
return context.emitter().Build(type_node, AbstractTypeInFieldDecl,
cast_type_id);
});
auto binding_id =
context.parse_tree().As<Parse::VarBindingPatternId>(node_id);
auto& class_info = context.classes().Get(parent_class_decl->class_id);
auto field_type_id =
GetUnboundElementType(context, class_info.self_type_id, cast_type_id);
auto field_id =
AddInst<SemIR::FieldDecl>(context, binding_id,
{.type_id = field_type_id,
.name_id = name_id,
.index = SemIR::ElementIndex::None});
context.field_decls_stack().AppendToTop(field_id);
context.node_stack().Push(node_id, field_id);
auto name_context =
context.decl_name_stack().MakeUnqualifiedName(node_id, name_id);
context.decl_name_stack().AddNameOrDiagnose(
name_context, field_id, introducer.modifier_set.GetAccessKind());
return true;
}
// A binding in an interface scope declares an associated constant, not a
// true binding, so we handle it separately.
if (auto parent_interface_decl =
context.scope_stack().GetCurrentScopeAs<SemIR::InterfaceDecl>();
parent_interface_decl.has_value() && is_generic) {
cast_type_id = AsCompleteType(context, cast_type_id, type_node, [&] {
CARBON_DIAGNOSTIC(IncompleteTypeInAssociatedConstantDecl, Error,
"associated constant has incomplete type {0}",
SemIR::TypeId);
return context.emitter().Build(
type_node, IncompleteTypeInAssociatedConstantDecl, cast_type_id);
});
if (is_template) {
CARBON_DIAGNOSTIC(TemplateBindingInAssociatedConstantDecl, Error,
"associated constant has `template` binding");
context.emitter().Emit(type_node,
TemplateBindingInAssociatedConstantDecl);
}
SemIR::AssociatedConstantDecl assoc_const_decl = {
.type_id = cast_type_id,
.assoc_const_id = SemIR::AssociatedConstantId::None,
.decl_block_id = SemIR::InstBlockId::None};
auto decl_id = AddPlaceholderInstInNoBlock(
context,
SemIR::LocIdAndInst(
context.parse_tree().As<Parse::CompileTimeBindingPatternId>(
node_id),
assoc_const_decl));
assoc_const_decl.assoc_const_id = context.associated_constants().Add(
{.name_id = name_id,
.parent_scope_id = context.scope_stack().PeekNameScopeId(),
.decl_id = decl_id,
.generic_id = SemIR::GenericId::None,
.default_value_id = SemIR::InstId::None});
ReplaceInstBeforeConstantUse(context, decl_id, assoc_const_decl);
context.node_stack().Push(node_id, decl_id);
return true;
}
// Allocate an instruction of the appropriate kind, linked to the name for
// error locations.
switch (context.full_pattern_stack().CurrentKind()) {
case FullPatternStack::Kind::ImplicitParamList:
case FullPatternStack::Kind::ExplicitParamList: {
// Parameters can have incomplete types in a function declaration, but not
// in a function definition. We don't know which kind we have here.
// TODO: A tuple pattern can appear in other places than function
// parameters.
auto param_pattern_id = SemIR::InstId::None;
bool had_error = false;
switch (introducer.kind) {
case Lex::TokenKind::Fn: {
if (context.full_pattern_stack().CurrentKind() ==
FullPatternStack::Kind::ImplicitParamList &&
!(is_generic || name_id == SemIR::NameId::SelfValue)) {
CARBON_DIAGNOSTIC(
ImplictParamMustBeConstant, Error,
"implicit parameters of functions must be constant or `self`");
context.emitter().Emit(node_id, ImplictParamMustBeConstant);
had_error = true;
}
break;
}
case Lex::TokenKind::Class:
case Lex::TokenKind::Impl:
case Lex::TokenKind::Interface: {
if (name_id == SemIR::NameId::SelfValue) {
CARBON_DIAGNOSTIC(SelfParameterNotAllowed, Error,
"`self` parameter only allowed on functions");
context.emitter().Emit(node_id, SelfParameterNotAllowed);
had_error = true;
} else if (!is_generic) {
CARBON_DIAGNOSTIC(GenericParamMustBeConstant, Error,
"parameters of generic types must be constant");
context.emitter().Emit(node_id, GenericParamMustBeConstant);
had_error = true;
}
break;
}
default:
break;
}
if (had_error) {
AddNameToLookup(context, name_id, SemIR::ErrorInst::SingletonInstId);
// Replace the parameter with `ErrorInst` so that we don't try
// constructing a generic based on it.
param_pattern_id = SemIR::ErrorInst::SingletonInstId;
} else {
auto pattern_inst_id = make_binding_pattern();
param_pattern_id = AddPatternInst<SemIR::ValueParamPattern>(
context, node_id,
{
.type_id = context.insts().Get(pattern_inst_id).type_id(),
.subpattern_id = pattern_inst_id,
.runtime_index = is_generic ? SemIR::RuntimeParamIndex::None
: SemIR::RuntimeParamIndex::Unknown,
});
}
context.node_stack().Push(node_id, param_pattern_id);
break;
}
case FullPatternStack::Kind::NameBindingDecl: {
auto incomplete_diagnoser = [&] {
CARBON_DIAGNOSTIC(IncompleteTypeInBindingDecl, Error,
"binding pattern has incomplete type {0} in name "
"binding declaration",
InstIdAsType);
return context.emitter().Build(type_node, IncompleteTypeInBindingDecl,
cast_type_inst_id);
};
if (node_kind == Parse::NodeKind::VarBindingPattern) {
cast_type_id = AsConcreteType(
context, cast_type_id, type_node, incomplete_diagnoser, [&] {
CARBON_DIAGNOSTIC(
AbstractTypeInVarPattern, Error,
"binding pattern has abstract type {0} in `var` "
"pattern",
SemIR::TypeId);
return context.emitter().Build(
type_node, AbstractTypeInVarPattern, cast_type_id);
});
} else {
cast_type_id = AsCompleteType(context, cast_type_id, type_node,
incomplete_diagnoser);
}
auto binding_pattern_id = make_binding_pattern();
if (node_kind == Parse::NodeKind::VarBindingPattern) {
CARBON_CHECK(!is_generic);
if (introducer.modifier_set.HasAnyOf(KeywordModifierSet::Returned)) {
// TODO: Should we check this for the `var` as a whole, rather than
// for the name binding?
auto bind_id = context.bind_name_map()
.Lookup(binding_pattern_id)
.value()
.bind_name_id;
RegisterReturnedVar(context,
introducer.modifier_node_id(ModifierOrder::Decl),
type_node, cast_type_id, bind_id);
}
}
context.node_stack().Push(node_id, binding_pattern_id);
break;
}
}
return true;
}
auto HandleParseNode(Context& context, Parse::LetBindingPatternId node_id)
-> bool {
return HandleAnyBindingPattern(context, node_id,
Parse::NodeKind::LetBindingPattern);
}
auto HandleParseNode(Context& context, Parse::VarBindingPatternId node_id)
-> bool {
return HandleAnyBindingPattern(context, node_id,
Parse::NodeKind::VarBindingPattern);
}
auto HandleParseNode(Context& context,
Parse::CompileTimeBindingPatternId node_id) -> bool {
auto node_kind = Parse::NodeKind::CompileTimeBindingPattern;
if (context.decl_introducer_state_stack().innermost().kind ==
Lex::TokenKind::Let) {
// Disallow `let` outside of function and interface definitions.
// TODO: Find a less brittle way of doing this. A `scope_inst_id` of `None`
// can represent a block scope, but is also used for other kinds of scopes
// that aren't necessarily part of an interface or function decl.
auto scope_inst_id = context.scope_stack().PeekInstId();
if (scope_inst_id.has_value()) {
auto scope_inst = context.insts().Get(scope_inst_id);
if (!scope_inst.Is<SemIR::InterfaceDecl>() &&
!scope_inst.Is<SemIR::FunctionDecl>()) {
context.TODO(
node_id,
"`let` compile time binding outside function or interface");
node_kind = Parse::NodeKind::LetBindingPattern;
}
}
}
return HandleAnyBindingPattern(context, node_id, node_kind);
}
auto HandleParseNode(Context& context, Parse::AddrId node_id) -> bool {
auto param_pattern_id = context.node_stack().PopPattern();
if (SemIR::Function::GetNameFromPatternId(
context.sem_ir(), param_pattern_id) == SemIR::NameId::SelfValue) {
auto pointer_type = context.types().TryGetAs<SemIR::PointerType>(
context.insts().Get(param_pattern_id).type_id());
if (pointer_type) {
auto addr_pattern_id = AddPatternInst<SemIR::AddrPattern>(
context, node_id,
{.type_id = SemIR::AutoType::SingletonTypeId,
.inner_id = param_pattern_id});
context.node_stack().Push(node_id, addr_pattern_id);
} else {
CARBON_DIAGNOSTIC(
AddrOnNonPointerType, Error,
"`addr` can only be applied to a binding with a pointer type");
context.emitter().Emit(node_id, AddrOnNonPointerType);
context.node_stack().Push(node_id, param_pattern_id);
}
} else {
CARBON_DIAGNOSTIC(AddrOnNonSelfParam, Error,
"`addr` can only be applied to a `self` parameter");
context.emitter().Emit(TokenOnly(node_id), AddrOnNonSelfParam);
context.node_stack().Push(node_id, param_pattern_id);
}
return true;
}
auto HandleParseNode(Context& context, Parse::TemplateBindingNameId node_id)
-> bool {
context.node_stack().Push(node_id);
return true;
}
} // namespace Carbon::Check