Files
carbon-lang/toolchain/parse/handle_period.cpp
T
Jon Ross-Perkins f67791cfee Separate subtree size information from parse nodes. (#4174)
Move subtree sizes over to TreeAndSubtrees, using the different
structure to represent the additional parse work that occurs, as well as
making it clear which functions require the extra information. My intent
is to make it hard to use this by accident.

The subtree size is still tracked during Parse::Tree construction. I
think a lot of that can be cleaned up, although we use it during
placeholder assignment so it may take some work. I wanted to see what
people thought about this before taking action on such a change.

I'm using a 1m line source file generated by #4124 for testing. Command
is `time bazel-bin/toolchain/install/prefix_root/bin/carbon compile
--phase=check --dump-mem-usage ~/tmp/data.carbon`

At head, what I'm seeing is:

```
...
parse_tree_.node_impls_:
  used_bytes:      61516116
  reserved_bytes:  61516116
...
Total:
  used_bytes:      447814230
  reserved_bytes:  551663894
...
1.43s user 0.14s system 99% cpu 1.565 total
```

With `Tree::Verify` disabled completely, it looks like:
```
parse_tree_.node_impls_:
  used_bytes:      41010744
  reserved_bytes:  41010744
...
Total:
  used_bytes:      427308858
  reserved_bytes:  531158522
...
1.20s user 0.13s system 99% cpu 1.332 total
```

Re-enabling just the basic verification (what is now `Tree::Verify`),
I'm seeing maybe 0.05s slower, but that's within noise for my system. I
do see variability in my timing results, and overall I think this is a
0.2s +/- 0.1s improvement versus the earlier (always testing `Extract`
code) implementation. That's opt; debug builds will be unaffected,
because the same checking occurs as before.

Note, the subtree size is a third of the node representation, which is
why I'm showing the decrease in memory usage here.
2024-07-31 19:39:45 +00:00

85 lines
3.3 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/parse/context.h"
#include "toolchain/parse/handle.h"
namespace Carbon::Parse {
// Handles PeriodAs variants and ArrowExpr.
// TODO: This currently only supports identifiers on the rhs, but will in the
// future need to handle things like `object.(Interface.member)` for qualifiers.
static auto HandlePeriodOrArrow(Context& context, NodeKind node_kind,
State paren_state, bool is_arrow) -> void {
auto state = context.PopState();
// We're handling `.something` or `->something`.
auto dot = context.ConsumeChecked(is_arrow ? Lex::TokenKind::MinusGreater
: Lex::TokenKind::Period);
if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Identifier,
NodeKind::IdentifierName)) {
// OK, `.` identifier.
} else if (context.ConsumeAndAddLeafNodeIf(Lex::TokenKind::Base,
NodeKind::BaseName)) {
// OK, `.base`.
} else if (paren_state != State::Invalid &&
context.PositionIs(Lex::TokenKind::OpenParen)) {
state.state = paren_state;
context.PushState(state);
context.PushState(State::OnlyParenExpr);
return;
} else {
CARBON_DIAGNOSTIC(ExpectedIdentifierAfterDotOrArrow, Error,
"Expected identifier after `{0}`.", llvm::StringLiteral);
context.emitter().Emit(
*context.position(), ExpectedIdentifierAfterDotOrArrow,
is_arrow ? llvm::StringLiteral("->") : llvm::StringLiteral("."));
// If we see a keyword, assume it was intended to be a name.
// TODO: Should keywords be valid here?
if (context.PositionKind().is_keyword()) {
context.AddLeafNode(NodeKind::IdentifierName, context.Consume(),
/*has_error=*/true);
} else {
context.AddLeafNode(NodeKind::IdentifierName, *context.position(),
/*has_error=*/true);
// Indicate the error to the parent state so that it can avoid producing
// more errors.
context.ReturnErrorOnState();
}
}
context.AddNode(node_kind, dot, state.has_error);
}
auto HandlePeriodAsExpr(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::MemberAccessExpr,
State::CompoundMemberAccess,
/*is_arrow=*/false);
}
auto HandlePeriodAsStruct(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::StructFieldDesignator, State::Invalid,
/*is_arrow=*/false);
}
auto HandleArrowExpr(Context& context) -> void {
HandlePeriodOrArrow(context, NodeKind::PointerMemberAccessExpr,
State::CompoundPointerMemberAccess,
/*is_arrow=*/true);
}
auto HandleCompoundMemberAccess(Context& context) -> void {
auto state = context.PopState();
context.AddNode(NodeKind::MemberAccessExpr, state.token, state.has_error);
}
auto HandleCompoundPointerMemberAccess(Context& context) -> void {
auto state = context.PopState();
context.AddNode(NodeKind::PointerMemberAccessExpr, state.token,
state.has_error);
}
} // namespace Carbon::Parse