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https://github.com/JakeHillion/drgn.git
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75c3679147
The current mixed Python/C implementation works well, but it has a couple of important limitations: - It's too slow for some common use cases, like iterating over large data structures. - It can't be reused in utilities written in other languages. This replaces the internals with a new library written in C, libdrgn. It includes Python bindings with mostly the same public interface as before, with some important improvements: - Types are now represented by a single Type class rather than the messy polymorphism in the Python implementation. - Qualifiers are a bitmask instead of a set of strings. - Bit fields are not considered a separate type. - The lvalue/rvalue terminology is replaced with reference/value. - Structure, union, and array values are better supported. - Function objects are supported. - Program distinguishes between lookups of variables, constants, and functions. The C rewrite is about 6x as fast as the original Python when using the Python bindings, and about 8x when using the C API directly. Currently, the exposed API in C is fairly conservative. In the future, the memory reader, type index, and object index APIs will probably be exposed for more flexibility.
60 lines
1.3 KiB
C
60 lines
1.3 KiB
C
// Copyright 2018-2019 - Omar Sandoval
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// SPDX-License-Identifier: GPL-3.0+
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#include "internal.h"
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#include "lexer.h"
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void drgn_lexer_init(struct drgn_lexer *lexer, drgn_lexer_func func,
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const char *str)
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{
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lexer->func = func;
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lexer->p = str;
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lexer->stack = NULL;
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lexer->stack_len = 0;
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lexer->stack_capacity = 0;
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}
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void drgn_lexer_deinit(struct drgn_lexer *lexer)
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{
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free(lexer->stack);
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}
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struct drgn_error *drgn_lexer_pop(struct drgn_lexer *lexer,
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struct drgn_token *token)
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{
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if (lexer->stack_len) {
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*token = lexer->stack[--lexer->stack_len];
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return NULL;
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}
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return lexer->func(lexer, token);
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}
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struct drgn_error *drgn_lexer_push(struct drgn_lexer *lexer,
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const struct drgn_token *token)
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{
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if (lexer->stack_len >= lexer->stack_capacity) {
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size_t new_capacity;
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new_capacity = (lexer->stack_capacity ?
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2 * lexer->stack_capacity : 2);
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if (!resize_array(&lexer->stack, new_capacity))
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return &drgn_enomem;
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lexer->stack_capacity = new_capacity;
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}
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lexer->stack[lexer->stack_len++] = *token;
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return NULL;
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}
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struct drgn_error *drgn_lexer_peek(struct drgn_lexer *lexer,
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struct drgn_token *token)
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{
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struct drgn_error *err;
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err = drgn_lexer_pop(lexer, token);
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if (!err)
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err = drgn_lexer_push(lexer, token);
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return err;
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}
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