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Code Issues Packages Projects Releases 10 Wiki Activity

Replace form insts with actions (#7100)

Browse Source 
See
[here](https://docs.google.com/document/d/1rWcueFwIfZox6GKVGxiUG4cBzjrZ6djXiIDGyJDtrE4/edit?tab=t.0)
for the design doc.

This also removes the default value of the `result_type_inst_id`
parameter of `HandleAction`, moves it before the action in the parameter
list, and documents it. This solves two problems:
- The default made it easy to forget, leading to unnecessary
`TypeOfInst` instructions.
- When it was present, putting it after the fairly "bulky" action
argument tended to make the callsite harder to read.
This commit is contained in:
Geoff Romer
2026-04-29 18:13:42 +00:00
committed by GitHub
parent 0124aae041
commit 4c9049346d
97 changed files with 1181 additions and 834 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/pattern_match.cpp
+104 -98
View File
@@ -12,6 +12,7 @@
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallVector.h"
#include "toolchain/base/kind_switch.h"
#include "toolchain/check/action.h"
#include "toolchain/check/context.h"
#include "toolchain/check/control_flow.h"
#include "toolchain/check/convert.h"
@@ -35,8 +36,32 @@ struct CallerState {
SemIR::SpecificId callee_specific_id;
};
// Manages the allocation of call parameter indices.
class IndexSource {
public:
// Creates an IndexSource that will allocate indices starting from
// `next_index`.
explicit IndexSource(SemIR::CallParamIndex next_index)
: next_index_(next_index) {}
// Returns the index that will be allocated next.
auto Peek() const -> SemIR::CallParamIndex { return next_index_; }
// Allocates and returns the next index.
auto Allocate() -> SemIR::CallParamIndex {
auto result = next_index_;
++next_index_.index;
return result;
}
private:
SemIR::CallParamIndex next_index_;
};
// State for callee-side pattern matching.
struct CalleeState {
IndexSource index;
// The in-progress contents of the `Call` parameters block.
llvm::SmallVector<SemIR::InstId> call_params;
@@ -158,6 +183,8 @@ class MatchContext {
SemIR::InstId scrutinee_id, WorkItem entry) -> void;
auto DoPreWork(State state, SemIR::TuplePattern tuple_pattern,
SemIR::InstId scrutinee_id, WorkItem entry) -> void;
auto DoPreWork(State state, SemIR::SpliceInst splice,
SemIR::InstId scrutinee_id, WorkItem entry) -> void;
// Do the post-work for `entry`. `entry.work` must be a `PostWork`, and
// the pattern argument must be the value of `entry.pattern_id` in `context_`.
@@ -186,8 +213,8 @@ class MatchContext {
// Performs the core logic of matching a variable pattern whose type is
// `pattern_type_id`, but returns the scrutinee that its subpattern should be
// matched with, rather than pushing it onto the worklist. This is factored
// out so it can be reused when handling a `FormBindingPattern` or
// `FormParamPattern` with an initializing form.
// out so it can be reused by `VarParamPattern`, which needs to do the
// pre-work of both a `VarPattern` and a `RefParamPattern`.
auto DoVarPreWorkImpl(State state, SemIR::TypeId pattern_type_id,
SemIR::InstId scrutinee_id, WorkItem entry) const
-> SemIR::InstId;
@@ -276,8 +303,7 @@ static auto InsertHere(Context& context, SemIR::ExprRegionId region_id)
// given pattern. Note that this returns `NoOp` for `var` patterns, because
// their conversion needs special handling, prior to any general-purpose
// conversion that would use this function.
static auto ConversionKindFor(Context& context, SemIR::Inst pattern,
MatchContext::WorkItem entry)
static auto ConversionKindFor(SemIR::Inst pattern, MatchContext::WorkItem entry)
-> ConversionTarget::Kind {
CARBON_KIND_SWITCH(pattern) {
case SemIR::VarParamPattern::Kind:
@@ -298,48 +324,6 @@ static auto ConversionKindFor(Context& context, SemIR::Inst pattern,
case SemIR::ValueBindingPattern::Kind:
case SemIR::ValueParamPattern::Kind:
return ConversionTarget::Value;
case CARBON_KIND(SemIR::FormBindingPattern form_binding_pattern): {
auto form_id = context.entity_names()
.Get(form_binding_pattern.entity_name_id)
.form_id;
auto form_inst = context.insts().Get(form_id);
switch (form_inst.kind()) {
case SemIR::InitForm::Kind:
context.TODO(entry.pattern_id, "Support local initializing forms");
[[fallthrough]];
case SemIR::RefForm::Kind:
return ConversionTarget::DurableRef;
case SemIR::SymbolicBinding::Kind:
context.TODO(entry.pattern_id, "Support symbolic form bindings");
[[fallthrough]];
case SemIR::ValueForm::Kind:
case SemIR::ErrorInst::Kind:
return ConversionTarget::Value;
default:
CARBON_FATAL("Unexpected form {0}", form_inst);
}
}
case CARBON_KIND(SemIR::FormParamPattern form_param_pattern): {
auto form_inst = context.insts().Get(form_param_pattern.form_id);
switch (form_inst.kind()) {
case SemIR::InitForm::Kind:
return ConversionTarget::NoOp;
case SemIR::RefForm::Kind:
// TODO: Figure out rules for when the argument must have a `ref` tag.
return entry.allow_unmarked_ref ? ConversionTarget::UnmarkedRefParam
: ConversionTarget::RefParam;
case SemIR::SymbolicBinding::Kind:
context.TODO(entry.pattern_id, "Support symbolic form params");
[[fallthrough]];
case SemIR::ErrorInst::Kind:
case SemIR::ValueForm::Kind:
return ConversionTarget::Value;
default:
CARBON_FATAL("Unexpected form {0}", form_inst);
}
}
default:
CARBON_FATAL("Unexpected pattern kind in {0}", pattern);
}
@@ -388,7 +372,7 @@ auto MatchContext::DoPostWork(State state,
auto value_id = PopResult();
if (value_id.has_value()) {
auto conversion_kind = ConversionKindFor(context_, binding_pattern, entry);
auto conversion_kind = ConversionKindFor(binding_pattern, entry);
if (!bind_name_id.has_value()) {
// TODO: Is this appropriate, or should we perform a conversion based on
// the category of the `_` binding first, and then separately discard the
@@ -417,8 +401,7 @@ auto MatchContext::DoPostWork(State state,
// Returns the inst kind to use for the parameter corresponding to the given
// parameter pattern.
static auto ParamKindFor(Context& context, SemIR::Inst param_pattern,
MatchContext::WorkItem entry) -> SemIR::InstKind {
static auto ParamKindFor(SemIR::Inst param_pattern) -> SemIR::InstKind {
CARBON_KIND_SWITCH(param_pattern) {
case SemIR::OutParamPattern::Kind:
return SemIR::OutParam::Kind;
@@ -427,22 +410,6 @@ static auto ParamKindFor(Context& context, SemIR::Inst param_pattern,
return SemIR::RefParam::Kind;
case SemIR::ValueParamPattern::Kind:
return SemIR::ValueParam::Kind;
case CARBON_KIND(SemIR::FormParamPattern form_param_pattern): {
auto form_inst = context.insts().Get(form_param_pattern.form_id);
switch (form_inst.kind()) {
case SemIR::InitForm::Kind:
case SemIR::RefForm::Kind:
return SemIR::RefParam::Kind;
case SemIR::SymbolicBinding::Kind:
context.TODO(entry.pattern_id, "Support symbolic form params");
[[fallthrough]];
case SemIR::ErrorInst::Kind:
case SemIR::ValueForm::Kind:
return SemIR::ValueParam::Kind;
default:
CARBON_FATAL("Unexpected form {0}", form_inst);
}
}
default:
CARBON_FATAL("Unexpected param pattern kind: {0}", param_pattern);
}
@@ -471,25 +438,12 @@ auto MatchContext::DoPreWork(State state, SemIR::AnyParamPattern param_pattern,
auto pattern_type_id =
GetSpecificPatternTypeId(state, entry.pattern_id, param_pattern.type_id);
// If `param_pattern` has initializing form, match it as a `VarPattern`
// before matching it as a parameter pattern.
switch (param_pattern.kind) {
case SemIR::FormParamPattern::Kind: {
auto form_param_pattern =
context_.insts().GetAs<SemIR::FormParamPattern>(entry.pattern_id);
if (!context_.insts().Is<SemIR::InitForm>(form_param_pattern.form_id)) {
break;
}
[[fallthrough]];
}
case SemIR::VarParamPattern::Kind: {
scrutinee_id =
DoVarPreWorkImpl(state, pattern_type_id, scrutinee_id, entry);
entry.allow_unmarked_ref = true;
break;
}
default:
break;
// If `param_pattern` is a `VarParamPattern`, match it as a `VarPattern` here,
// and then as a `RefParamPattern` below.
if (param_pattern.kind == SemIR::VarParamPattern::Kind) {
scrutinee_id =
DoVarPreWorkImpl(state, pattern_type_id, scrutinee_id, entry);
entry.allow_unmarked_ref = true;
}
CARBON_KIND_SWITCH(state) {
@@ -500,7 +454,7 @@ auto MatchContext::DoPreWork(State state, SemIR::AnyParamPattern param_pattern,
} else {
caller_state->call_args.push_back(
Convert(context_, SemIR::LocId(scrutinee_id), scrutinee_id,
{.kind = ConversionKindFor(context_, param_pattern, entry),
{.kind = ConversionKindFor(param_pattern, entry),
.type_id = pattern_type_id}));
}
// Do not traverse farther or schedule PostWork, because the caller side
@@ -508,13 +462,13 @@ auto MatchContext::DoPreWork(State state, SemIR::AnyParamPattern param_pattern,
break;
}
case CARBON_KIND(CalleeState* callee_state): {
SemIR::Inst param = SemIR::AnyParam{
.kind = ParamKindFor(context_, param_pattern, entry),
.type_id =
ExtractScrutineeType(context_.sem_ir(), param_pattern.type_id),
.index = SemIR::CallParamIndex(callee_state->call_params.size()),
.pretty_name_id = SemIR::GetPrettyNameFromPatternId(
context_.sem_ir(), entry.pattern_id)};
SemIR::Inst param =
SemIR::AnyParam{.kind = ParamKindFor(param_pattern),
.type_id = ExtractScrutineeType(
context_.sem_ir(), param_pattern.type_id),
.index = callee_state->index.Allocate(),
.pretty_name_id = SemIR::GetPrettyNameFromPatternId(
context_.sem_ir(), entry.pattern_id)};
auto loc_id = SemIR::LocId(entry.pattern_id);
auto param_id = SemIR::InstId::None;
// TODO: find a way to avoid this boilerplate.
@@ -592,7 +546,8 @@ auto MatchContext::DoPreWork(State state,
AddAsPostWork(entry);
}
AddWork({.pattern_id = return_slot_pattern.subpattern_id,
.work = PreWork{.scrutinee_id = scrutinee_id}});
.work = PreWork{.scrutinee_id = scrutinee_id},
.allow_unmarked_ref = entry.allow_unmarked_ref});
}
auto MatchContext::DoPostWork(State state,
@@ -719,7 +674,8 @@ auto MatchContext::DoPreWork(State state, SemIR::TuplePattern tuple_pattern,
for (auto [subpattern_id, subscrutinee_id] :
llvm::reverse(llvm::zip_equal(subpattern_ids, subscrutinee_ids))) {
AddWork({.pattern_id = subpattern_id,
.work = PreWork{.scrutinee_id = subscrutinee_id}});
.work = PreWork{.scrutinee_id = subscrutinee_id},
.allow_unmarked_ref = entry.allow_unmarked_ref});
}
};
if (!scrutinee_id.has_value()) {
@@ -729,7 +685,8 @@ auto MatchContext::DoPreWork(State state, SemIR::TuplePattern tuple_pattern,
// pattern, so the subpatterns don't have a scrutinee either.
for (auto subpattern_id : llvm::reverse(subpattern_ids)) {
AddWork({.pattern_id = subpattern_id,
.work = PreWork{.scrutinee_id = SemIR::InstId::None}});
.work = PreWork{.scrutinee_id = SemIR::InstId::None},
.allow_unmarked_ref = entry.allow_unmarked_ref});
}
return;
}
@@ -791,6 +748,34 @@ auto MatchContext::DoPostWork(State /*state*/,
results_stack_.AppendToTop(tuple_value_id);
}
auto MatchContext::DoPreWork(State state, SemIR::SpliceInst splice,
SemIR::InstId scrutinee_id, WorkItem entry)
-> void {
CARBON_KIND_SWITCH(state) {
case CARBON_KIND(CallerState* _): {
CARBON_FATAL("TODO: support caller-side matching of pattern splices");
}
case CARBON_KIND(ThunkState* _): {
CARBON_FATAL("TODO: support thunk matching of pattern splices");
}
case CARBON_KIND(LocalState* _): {
CARBON_FATAL("TODO: support local matching of pattern splices");
}
case CARBON_KIND(CalleeState* callee_state): {
CARBON_CHECK(!scrutinee_id.has_value());
auto result_id = HandleAction<SemIR::CalleePatternMatchAction>(
context_, SemIR::LocId(entry.pattern_id),
context_.types().GetTypeInstId(splice.type_id),
{.type_id = SemIR::InstType::TypeId,
.pattern_id = entry.pattern_id,
.parent_index = callee_state->index.Allocate()});
callee_state->call_param_patterns.push_back(entry.pattern_id);
callee_state->call_params.push_back(result_id);
results_stack_.AppendToTop(result_id);
}
}
}
auto MatchContext::DoPreWork(State state,
SemIR::AnyReturnPattern return_pattern,
SemIR::InstId /*scrutinee_id*/, WorkItem entry)
@@ -861,6 +846,10 @@ auto MatchContext::Dispatch(State state, WorkItem entry) -> void {
DoPreWork(state, tuple_pattern, work.scrutinee_id, entry);
break;
}
case CARBON_KIND(SemIR::SpliceInst splice_inst): {
DoPreWork(state, splice_inst, work.scrutinee_id, entry);
break;
}
default: {
CARBON_FATAL("Inst kind not handled: {0}", pattern.kind());
}
@@ -914,7 +903,7 @@ auto CalleePatternMatch(Context& context,
.param_ranges = SemIR::Function::CallParamIndexRanges::Empty};
}
CalleeState state;
CalleeState state = {.index = IndexSource(SemIR::CallParamIndex(0))};
MatchContext match(context);
// We add work to the stack in reverse so that the results will be produced
@@ -969,20 +958,37 @@ auto ThunkPatternMatch(Context& context, SemIR::InstId self_pattern_id,
inner_args.push_back(match.MatchWithResult(
&state,
{.pattern_id = self_pattern_id,
.work = MatchContext::PreWork{.scrutinee_id = SemIR::InstId::None}}));
.work = MatchContext::PreWork{.scrutinee_id = SemIR::InstId::None},
.allow_unmarked_ref = true}));
}
for (SemIR::InstId inst_id : param_pattern_ids) {
inner_args.push_back(match.MatchWithResult(
&state,
{.pattern_id = inst_id,
.work = MatchContext::PreWork{.scrutinee_id = SemIR::InstId::None}}));
.work = MatchContext::PreWork{.scrutinee_id = SemIR::InstId::None},
.allow_unmarked_ref = true}));
}
return {.syntactic_args = std::move(inner_args),
.ignored_call_args = state.outer_call_args};
}
auto PerformAction(Context& context, SemIR::LocId /*loc_id*/,
SemIR::CalleePatternMatchAction action) -> SemIR::InstId {
CalleeState state = {.index = IndexSource(action.parent_index)};
MatchContext match(context);
auto result_id = match.MatchWithResult(
&state,
{.pattern_id = action.pattern_id,
.work = MatchContext::PreWork{.scrutinee_id = SemIR::InstId::None},
.allow_unmarked_ref = true});
CARBON_CHECK(state.index.Peek().index <= action.parent_index.index + 1,
"TODO: add support for composite forms");
return result_id;
}
auto CallerPatternMatch(Context& context, SemIR::SpecificId specific_id,
SemIR::InstId self_pattern_id,
SemIR::InstBlockId param_patterns_id,