asm: implement object file reader

asm/include/ivy/asm/reader.h

@@ -0,0 +1,46 @@
+#ifndef IVY_ASM_READER_H_
+#define IVY_ASM_READER_H_
+
+#include <ivy/misc.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+
+struct ivy_asm_object_info {
+	uint32_t obj_magic;
+	size_t obj_table_offset;
+	size_t obj_nr_sections;
+};
+
+struct ivy_asm_section_info {
+	uint32_t s_type;
+	size_t s_offset;
+	size_t s_length;
+};
+
+struct ivy_asm_reader;
+struct ivy_asm_section_reader;
+
+IVY_API enum ivy_status ivy_asm_reader_open(FILE *in, struct ivy_asm_reader **out);
+IVY_API enum ivy_status ivy_asm_reader_close(struct ivy_asm_reader *reader);
+
+IVY_API const struct ivy_asm_object_info *ivy_asm_reader_get_info(
+	struct ivy_asm_reader *reader);
+IVY_API const struct ivy_asm_section_info *ivy_asm_reader_get_sections(
+	struct ivy_asm_reader *reader);
+
+IVY_API enum ivy_status ivy_asm_reader_open_section(
+	struct ivy_asm_reader *reader, size_t index,
+	struct ivy_asm_section_reader **out);
+
+IVY_API const struct ivy_asm_section_info *ivy_asm_section_reader_get_info(
+	struct ivy_asm_section_reader *reader);
+IVY_API enum ivy_status ivy_asm_section_reader_close(
+	struct ivy_asm_section_reader *reader);
+IVY_API enum ivy_status ivy_asm_section_reader_read(
+	struct ivy_asm_section_reader *reader, size_t offset, size_t count,
+	void *p, size_t *nr_read);
+
+IVY_API bool ivy_asm_section_type_to_string(uint32_t in, char out[5]);
+
+#endif

asm/reader.c

@@ -0,0 +1,181 @@
+#include "reader.h"
+
+#include <ctype.h>
+#include <ivy/asm/bin.h>
+#include <ivy/asm/reader.h>
+#include <ivy/status.h>
+#include <stdlib.h>
+#include <string.h>
+
+static enum ivy_status decode_header(
+	const struct ivy_bin_header *hdr, struct ivy_asm_object_info *out)
+{
+	out->obj_magic = b_i32_btoh(hdr->h_magic);
+	out->obj_nr_sections = b_i16_btoh(hdr->h_table_len);
+	out->obj_table_offset = b_i64_btoh(hdr->h_table_offset);
+
+	return IVY_OK;
+}
+
+static enum ivy_status decode_table_entry(
+	const struct ivy_bin_table_entry *entry, struct ivy_asm_section_info *out)
+{
+	out->s_type = b_i32_btoh(entry->e_type);
+	out->s_offset = b_i64_btoh(entry->e_offset);
+	out->s_length = b_i32_btoh(entry->e_size);
+
+	return IVY_OK;
+}
+
+enum ivy_status ivy_asm_reader_open(FILE *in, struct ivy_asm_reader **out)
+{
+	struct ivy_asm_reader *reader = malloc(sizeof *reader);
+	if (!reader) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(reader, 0x0, sizeof *reader);
+
+	reader->r_fp = in;
+
+	fseek(in, 0, SEEK_SET);
+
+	struct ivy_bin_header hdr;
+	size_t r = fread(&hdr, sizeof hdr, 1, in);
+
+	if (r != 1) {
+		free(reader);
+		return IVY_ERR_IO_FAILURE;
+	}
+
+	enum ivy_status status = decode_header(&hdr, &reader->r_info);
+	if (status != IVY_OK) {
+		free(reader);
+		return status;
+	}
+
+	if (reader->r_info.obj_magic != IVY_BIN_MAGIC) {
+		free(reader);
+		return IVY_ERR_BAD_FORMAT;
+	}
+
+	fseek(in, reader->r_info.obj_table_offset, SEEK_SET);
+
+	size_t nr_sections = reader->r_info.obj_nr_sections;
+	struct ivy_bin_table_entry *table = calloc(nr_sections, sizeof *table);
+	if (!table) {
+		free(reader);
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	r = fread(table, sizeof *table, nr_sections, in);
+	if (r != nr_sections) {
+		free(table);
+		free(reader);
+		return IVY_ERR_IO_FAILURE;
+	}
+
+	struct ivy_asm_section_info *sections
+		= calloc(nr_sections, sizeof *sections);
+	for (size_t i = 0; i < nr_sections; i++) {
+		status = decode_table_entry(&table[i], &sections[i]);
+
+		if (status != IVY_OK) {
+			free(table);
+			free(sections);
+			free(reader);
+
+			return status;
+		}
+	}
+
+	free(table);
+
+	reader->r_sections = sections;
+
+	*out = reader;
+	return IVY_OK;
+}
+
+enum ivy_status ivy_asm_reader_close(struct ivy_asm_reader *reader)
+{
+	free(reader);
+	return IVY_OK;
+}
+
+const struct ivy_asm_object_info *ivy_asm_reader_get_info(
+	struct ivy_asm_reader *reader)
+{
+	return &reader->r_info;
+}
+
+const struct ivy_asm_section_info *ivy_asm_reader_get_sections(
+	struct ivy_asm_reader *reader)
+{
+	return reader->r_sections;
+}
+
+enum ivy_status ivy_asm_reader_open_section(
+	struct ivy_asm_reader *reader, size_t index,
+	struct ivy_asm_section_reader **out)
+{
+	if (index >= reader->r_info.obj_nr_sections) {
+		return IVY_ERR_NO_ENTRY;
+	}
+
+	struct ivy_asm_section_reader *sect = malloc(sizeof *sect);
+	if (!sect) {
+		return IVY_ERR_NO_MEMORY;
+	}
+
+	memset(sect, 0x0, sizeof *sect);
+
+	sect->r_parent = reader;
+	sect->r_info = &reader->r_sections[index];
+
+	*out = sect;
+	return IVY_OK;
+}
+
+const struct ivy_asm_section_info *ivy_asm_section_reader_get_info(
+	struct ivy_asm_section_reader *reader)
+{
+	return reader->r_info;
+}
+
+enum ivy_status ivy_asm_section_reader_close(struct ivy_asm_section_reader *reader)
+{
+	free(reader);
+	return IVY_OK;
+}
+
+enum ivy_status ivy_asm_section_reader_read(
+	struct ivy_asm_section_reader *reader, size_t offset, size_t count,
+	void *p, size_t *nr_read)
+{
+	size_t object_offset = reader->r_info->s_offset + offset;
+	FILE *fp = reader->r_parent->r_fp;
+	fseek(fp, object_offset, SEEK_SET);
+	size_t r = fread(p, 1, count, fp);
+
+	*nr_read = r;
+
+	return ferror(fp) ? IVY_ERR_IO_FAILURE : IVY_OK;
+}
+
+bool ivy_asm_section_type_to_string(uint32_t in, char out[5])
+{
+	b_i32 v = b_i32_htob(in);
+
+	for (size_t i = 0; i < sizeof in; i++) {
+		char c = v.i_bytes[i];
+		if (!isgraph(c)) {
+			return false;
+		}
+
+		out[i] = c;
+	}
+
+	out[4] = 0;
+	return true;
+}

asm/reader.h

@@ -0,0 +1,18 @@
+#ifndef _ASM_READER_H_
+#define _ASM_READER_H_
+
+#include <ivy/asm/reader.h>
+#include <stdio.h>
+
+struct ivy_asm_reader {
+	FILE *r_fp;
+	struct ivy_asm_object_info r_info;
+	struct ivy_asm_section_info *r_sections;
+};
+
+struct ivy_asm_section_reader {
+	struct ivy_asm_reader *r_parent;
+	const struct ivy_asm_section_info *r_info;
+};
+
+#endif