carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 22:02:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Factor out CopyOnWriteBlock. (#3785)

Browse Source 
Generalize it to also support type blocks.
This commit is contained in:
Richard Smith
2024-03-14 22:57:53 +00:00
committed by GitHub
parent 2507c555ca
commit 312d158bfc
3 changed files with 83 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/convert.cpp
+13 -43
View File
@@ -10,6 +10,7 @@
#include "common/check.h"
#include "llvm/ADT/STLExtras.h"
#include "toolchain/check/context.h"
#include "toolchain/sem_ir/copy_on_write_block.h"
#include "toolchain/sem_ir/file.h"
#include "toolchain/sem_ir/inst.h"
@@ -194,47 +195,6 @@ static auto ConvertAggregateElement(
return Convert(context, node_id, src_elem_id, target);
}
namespace {
// A handle to a new block that may be modified, with copy-on-write semantics.
//
// The constructor is given the ID of an existing block that provides the
// initial contents of the new block. The new block is lazily allocated; if no
// modifications have been made, the `id()` function will return the original
// block ID.
//
// This is intended to avoid an unnecessary block allocation in the case where
// the new block ends up being exactly the same as the original block.
class CopyOnWriteBlock {
public:
// Constructs the block. If `source_id` is valid, it is used as the initial
// value of the block. Otherwise, uninitialized storage for `size` elements
// is allocated.
CopyOnWriteBlock(SemIR::File& file, SemIR::InstBlockId source_id, size_t size)
: file_(file), source_id_(source_id) {
if (!source_id_.is_valid()) {
id_ = file_.inst_blocks().AddUninitialized(size);
}
}
auto id() const -> SemIR::InstBlockId { return id_; }
auto Set(int i, SemIR::InstId value) -> void {
if (source_id_.is_valid() && file_.inst_blocks().Get(id_)[i] == value) {
return;
}
if (id_ == source_id_) {
id_ = file_.inst_blocks().Add(file_.inst_blocks().Get(source_id_));
}
file_.inst_blocks().Get(id_)[i] = value;
}
private:
SemIR::File& file_;
SemIR::InstBlockId source_id_;
SemIR::InstBlockId id_ = source_id_;
};
} // namespace
// Performs a conversion from a tuple to an array type. This function only
// converts the type, and does not perform a final conversion to the requested
// expression category.
@@ -370,7 +330,12 @@ static auto ConvertTupleToTuple(Context& context, SemIR::TupleType src_type,
// Initialize each element of the destination from the corresponding element
// of the source.
// TODO: Annotate diagnostics coming from here with the element index.
CopyOnWriteBlock new_block(sem_ir, literal_elems_id, src_elem_types.size());
auto new_block =
literal_elems_id.is_valid()
? SemIR::CopyOnWriteInstBlock(sem_ir, literal_elems_id)
: SemIR::CopyOnWriteInstBlock(
sem_ir, SemIR::CopyOnWriteInstBlock::UninitializedBlock{
src_elem_types.size()});
for (auto [i, src_type_id, dest_type_id] :
llvm::enumerate(src_elem_types, dest_elem_types)) {
// TODO: This call recurses back into conversion. Switch to an iterative
@@ -463,7 +428,12 @@ static auto ConvertStructToStructOrClass(Context& context,
// Initialize each element of the destination from the corresponding element
// of the source.
// TODO: Annotate diagnostics coming from here with the element index.
CopyOnWriteBlock new_block(sem_ir, literal_elems_id, src_elem_fields.size());
auto new_block =
literal_elems_id.is_valid()
? SemIR::CopyOnWriteInstBlock(sem_ir, literal_elems_id)
: SemIR::CopyOnWriteInstBlock(
sem_ir, SemIR::CopyOnWriteInstBlock::UninitializedBlock{
src_elem_fields.size()});
for (auto [i, dest_field_id] : llvm::enumerate(dest_elem_fields)) {
auto dest_field =
sem_ir.insts().GetAs<SemIR::StructTypeField>(dest_field_id);