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Jon Ross-Perkins
7b48ac7258
In summary - some of the changes here are focused on producing the same test results for SemanticsIR, but I think the next step will be to change the SemanticsIR structure to reduce how much is added to the traversal stack.
Switching semantics to a postorder traversal is intended to be more efficient. The traversal stack is to eliminate risk of recursion limits within the semantic analysis that could come from layered code structures. However, we need to start considering the implications for type-checking and what the ParseTree looks like, as well as copying of data here.
As we start thinking about type-checking in SemanticsIR, it's helpful for a function to know its own signature in order to perform lookup recursive calls. The challenge in the post-order walk without this change is it doesn't know it's in a function definition (or similar) until it reaches the FunctionDeclaration; this restructures so that either:
1. For a declaration, the signature is a child of FunctionDeclaration(";")
2. For a definition, the signature is a child of FunctionDefinitionStart("{") which pairs with FunctionDefinition("}"), replacing CodeBlock.
This similarly reorients CodeBlock to be CodeBlockStart("{") as the first child of CodeBlock("}"). I'm not doing that with ParameterList here just because it affects a bit more, and felt like it could be delayed.
Overall, my goal is making the postorder traversal more intuitive along scope boundaries. I think we may also not need subtree_size, so I'm avoiding use of that now.
Currently the SemanticsIRFactory implementation is less clean than I might like (there are a couple comments to this point), but I was starting to feel like a more complete rewrite would be appropriate rather than trying to clean it up further: in particular, I think the node structures are off, but changing them is significant and also changes test output; in turn it may also warrant more substantial ParseTree changes. If you prefer from a reviewer POV, I can do a more complete rewrite.
43 lines
1.3 KiB
C++
43 lines
1.3 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include <cstddef>
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#include <cstdint>
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#include <cstring>
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#include "common/check.h"
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#include "llvm/ADT/StringRef.h"
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#include "toolchain/diagnostics/diagnostic_emitter.h"
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#include "toolchain/diagnostics/null_diagnostics.h"
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#include "toolchain/lexer/tokenized_buffer.h"
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#include "toolchain/parser/parse_tree.h"
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namespace Carbon::Testing {
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// NOLINTNEXTLINE: Match the documented fuzzer entry point declaration style.
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extern "C" int LLVMFuzzerTestOneInput(const unsigned char* data,
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std::size_t size) {
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// Ignore large inputs.
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// TODO: See tokenized_buffer_fuzzer.cpp.
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if (size > 100000) {
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return 0;
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}
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auto source = SourceBuffer::CreateFromText(
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llvm::StringRef(reinterpret_cast<const char*>(data), size));
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// Lex the input.
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auto tokens = TokenizedBuffer::Lex(*source, NullDiagnosticConsumer());
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if (tokens.has_errors()) {
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return 0;
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}
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// Now parse it into a tree. Note that parsing will (when asserts are enabled)
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// walk the entire tree to verify it so we don't have to do that here.
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ParseTree::Parse(tokens, NullDiagnosticConsumer());
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return 0;
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}
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} // namespace Carbon::Testing
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