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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.
105 lines
2.1 KiB
C
105 lines
2.1 KiB
C
// Copyright 2018-2019 - Omar Sandoval
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// SPDX-License-Identifier: GPL-3.0+
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#include <errno.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include "internal.h"
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#include "string_builder.h"
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struct drgn_error *string_builder_init(struct string_builder *sb)
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{
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sb->len = 0;
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sb->capacity = 16;
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sb->str = malloc(sb->capacity);
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if (!sb->str)
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return &drgn_enomem;
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sb->str[0] = '\0';
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return NULL;
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}
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struct drgn_error *string_builder_reserve(struct string_builder *sb,
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size_t capacity)
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{
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size_t new_capacity = sb->capacity;
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char *tmp;
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if (capacity < new_capacity)
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return NULL;
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while (capacity >= new_capacity)
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new_capacity *= 2;
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tmp = realloc(sb->str, new_capacity);
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if (!tmp)
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return &drgn_enomem;
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sb->str = tmp;
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sb->capacity = new_capacity;
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return NULL;
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}
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struct drgn_error *string_builder_appendc(struct string_builder *sb, char c)
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{
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struct drgn_error *err;
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err = string_builder_reserve(sb, sb->len + 1);
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if (err)
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return err;
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sb->str[sb->len++] = c;
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sb->str[sb->len] = '\0';
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return NULL;
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}
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struct drgn_error *string_builder_appendn(struct string_builder *sb,
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const char *str,
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size_t len)
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{
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struct drgn_error *err;
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err = string_builder_reserve(sb, sb->len + len);
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if (err)
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return err;
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memcpy(&sb->str[sb->len], str, len);
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sb->len += len;
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sb->str[sb->len] = '\0';
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return NULL;
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}
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struct drgn_error *string_builder_vappendf(struct string_builder *sb,
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const char *format,
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va_list ap)
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{
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struct drgn_error *err;
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va_list aq;
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int len;
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again:
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va_copy(aq, ap);
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len = vsnprintf(&sb->str[sb->len], sb->capacity - sb->len, format, aq);
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va_end(aq);
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if (len < 0)
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return drgn_error_create_os(errno, NULL, "vsnprintf");
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if (sb->len + len < sb->capacity) {
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sb->len += len;
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sb->str[sb->len] = '\0';
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return NULL;
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}
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err = string_builder_reserve(sb, sb->len + len);
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if (err)
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return err;
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goto again;
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}
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struct drgn_error *string_builder_appendf(struct string_builder *sb,
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const char *format, ...)
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{
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struct drgn_error *err;
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va_list ap;
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va_start(ap, format);
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err = string_builder_vappendf(sb, format, ap);
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va_end(ap);
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return err;
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}
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