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Author SHA1 Message Date
3db9fd9b8f Added object file format spec
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This is a WIP.
2025-04-03 00:49:31 +02:00
0d3881f680 Update the test input file to contain all AST nodes
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Validate the build / validate-build (push) Successful in 36s
2025-04-02 21:41:27 +02:00
5ea942024f add functionality to main to parse and print the ast 2025-04-02 20:57:02 +02:00
b4757e008c Add parse_result_wrap to wrap a result with another parent node
Use the new wrap function to wrap numbers and immediate nodes
2025-04-02 20:57:02 +02:00
b70b6896bf Partial parser implementation 2025-04-02 20:56:59 +02:00
6ca7bb3661 Fix incorrect size comparison in lexer_consume_n
The buffer length len and the requested number of tokens n are mixed up
in an invalid comparison. This causes all valid requests for n < len
tokens to be denied and all invalid requests for n > len tokens to be
accepted. This may cause a buffer overflow if the caller requests more
characters than they provide space for.
2025-04-02 20:41:49 +02:00
d424c0f886 Add a parser combinator to parse a delimited list 2025-04-02 20:41:49 +02:00
c66489dd90 Add basic parser combinators 2025-04-02 20:41:49 +02:00
44fa66c2b7 Add "primitive" parsers for all the non-trivia tokens in the lexer grammar 2025-04-02 20:41:42 +02:00
c48adb1306 Add basic parser utilities 2025-04-02 20:38:35 +02:00
13 changed files with 265 additions and 84 deletions

55
doc/object_format.md Normal file
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@ -0,0 +1,55 @@
# Linker file format
```C
struct object_file {
uint64_t magic; // ".oo-bin"
uint64_t version; // 1
uint64_t architecture; // AMD64(0)
uint64_t offsets_offset;
struct offsets {
uint64_t strings;
uint64_t sections;
uint64_t symbols;
uint64_t relocations;
} offsets;
struct string_table {
uint64_t size;
uint8_t data[static size];
} strings;
struct section_table {
uint32_t count;
struct section_entry {
uint32_t name;
uint64_t offset;
uint64_t size_on_disk;
uint64_t size_in_memory;
uint64_t flags;
} sections[static count];
} sections;
struct symbol_table {
uint32_t count;
struct symbol_entry {
uint32_t name;
uint8_t kind; // IMPORT(0) | EXPORT(1) | LOCAL(2)
uint32_t section;
uint64_t offset;
} symbols[static count];
} symbols;
struct relocation_table {
uint32_t count;
struct relocation_entry {
uint32_t section;
uint64_t offset;
uint8_t size;
uint32_t symbol;
uint8_t kind; // ABSOLUTE(0) | RELATIVE(1)
} relocations[static count];
} relocations;
};
```

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@ -1,6 +1,6 @@
#include "error.h"
#include "lexer.h"
#include "parser.h"
#include "parser/parser.h"
#include "tokenlist.h"
#include <limits.h>

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@ -1,53 +0,0 @@
#include "parser.h"
#include "ast.h"
#include "lexer.h"
#include "parser_combinators.h"
#include "parser_primitives.h"
#include "parser_util.h"
#include "tokenlist.h"
parse_result_t parse_number(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_octal, parse_decimal, parse_hexadecimal,
parse_binary, nullptr};
return parse_any(current, parsers);
}
parse_result_t parse_operand(tokenlist_entry_t *current) {
// FIXME: not the correct set of parsers
parser_t parsers[] = {parse_register, parse_number, nullptr};
return parse_any(current, parsers);
}
parse_result_t parse_operands(tokenlist_entry_t *current) {
return parse_list(current, NODE_OPERANDS, true, TOKEN_COMMA, parse_operand);
}
parse_result_t parse_label(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_identifier, parse_colon, nullptr};
return parse_consecutive(current, NODE_LABEL, parsers);
}
parse_result_t parse_section_directive(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_section, parse_identifier, nullptr};
return parse_consecutive(current, NODE_SECTION_DIRECTIVE, parsers);
}
parse_result_t parse_directive(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_dot, parse_section_directive, nullptr};
return parse_consecutive(current, NODE_DIRECTIVE, parsers);
}
parse_result_t parse_instruction(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_identifier, parse_operands, nullptr};
return parse_consecutive(current, NODE_INSTRUCTION, parsers);
}
parse_result_t parse_statement(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_label, parse_directive, parse_instruction,
nullptr};
return parse_any(current, parsers);
}
parse_result_t parse(tokenlist_entry_t *current) {
return parse_many(current, NODE_PROGRAM, true, parse_statement);
}

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@ -1,11 +0,0 @@
#ifndef INCLUDE_SRC_PARSER_H_
#define INCLUDE_SRC_PARSER_H_
#include "ast.h"
#include "error.h"
#include "parser_util.h"
#include "tokenlist.h"
parse_result_t parse(tokenlist_entry_t *current);
#endif // INCLUDE_SRC_PARSER_H_

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@ -1,4 +1,4 @@
#include "parser_combinators.h"
#include "combinators.h"
// Parse a list of the given parser delimited by the given token id. Does not
// store the delimiters in the parent node

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@ -1,4 +1,7 @@
#include "parser_util.h"
#ifndef INCLUDE_PARSER_COMBINATORS_H_
#define INCLUDE_PARSER_COMBINATORS_H_
#include "util.h"
typedef parse_result_t (*parser_t)(tokenlist_entry_t *);
@ -18,3 +21,5 @@ parse_result_t parse_list(tokenlist_entry_t *current, node_id_t id,
// wraps the parsed nodes in a new parent node.
parse_result_t parse_consecutive(tokenlist_entry_t *current, node_id_t id,
parser_t parsers[]);
#endif // INCLUDE_PARSER_COMBINATORS_H_

140
src/parser/parser.c Normal file
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@ -0,0 +1,140 @@
#include "parser.h"
#include "../ast.h"
#include "../lexer.h"
#include "../tokenlist.h"
#include "combinators.h"
#include "primitives.h"
#include "util.h"
parse_result_t parse_number(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_octal, parse_decimal, parse_hexadecimal,
parse_binary, nullptr};
parse_result_t result = parse_any(current, parsers);
return parse_result_wrap(NODE_NUMBER, result);
}
parse_result_t parse_plus_or_minus(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_plus, parse_minus, nullptr};
return parse_any(current, parsers);
}
parse_result_t parse_register_index(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_plus, parse_register, parse_asterisk,
parse_number, nullptr};
return parse_consecutive(current, NODE_REGISTER_INDEX, parsers);
}
parse_result_t parse_register_offset(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_plus_or_minus, parse_number, nullptr};
return parse_consecutive(current, NODE_REGISTER_OFFSET, parsers);
}
parse_result_t parse_register_expression(tokenlist_entry_t *current) {
parse_result_t result;
ast_node_t *expr;
error_t *err = ast_node_alloc(&expr);
if (err)
return parse_error(err);
expr->id = NODE_REGISTER_EXPRESSION;
// <register>
result = parse_register(current);
if (result.err) {
ast_node_free(expr);
return result;
}
err = ast_node_add_child(expr, result.node);
if (err) {
ast_node_free(result.node);
ast_node_free(expr);
return parse_error(err);
}
current = result.next;
// <register_index>?
result = parse_register_index(current);
if (result.err) {
error_free(result.err);
} else {
err = ast_node_add_child(expr, result.node);
if (err) {
ast_node_free(result.node);
ast_node_free(expr);
return parse_error(err);
}
current = result.next;
}
// <register_offset>?
result = parse_register_offset(current);
if (result.err) {
error_free(result.err);
} else {
err = ast_node_add_child(expr, result.node);
if (err) {
ast_node_free(result.node);
ast_node_free(expr);
return parse_error(err);
}
current = result.next;
}
return parse_success(expr, current);
}
parse_result_t parse_immediate(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_number, parse_identifier, nullptr};
parse_result_t result = parse_any(current, parsers);
return parse_result_wrap(NODE_IMMEDIATE, result);
}
parse_result_t parse_memory_expression(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_register_expression, parse_identifier, nullptr};
return parse_any(current, parsers);
}
parse_result_t parse_memory(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_lbracket, parse_memory_expression,
parse_rbracket, nullptr};
return parse_consecutive(current, NODE_MEMORY, parsers);
}
parse_result_t parse_operand(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_register, parse_memory, parse_immediate,
nullptr};
return parse_any(current, parsers);
}
parse_result_t parse_operands(tokenlist_entry_t *current) {
return parse_list(current, NODE_OPERANDS, true, TOKEN_COMMA, parse_operand);
}
parse_result_t parse_label(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_identifier, parse_colon, nullptr};
return parse_consecutive(current, NODE_LABEL, parsers);
}
parse_result_t parse_section_directive(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_section, parse_identifier, nullptr};
return parse_consecutive(current, NODE_SECTION_DIRECTIVE, parsers);
}
parse_result_t parse_directive(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_dot, parse_section_directive, nullptr};
return parse_consecutive(current, NODE_DIRECTIVE, parsers);
}
parse_result_t parse_instruction(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_identifier, parse_operands, nullptr};
return parse_consecutive(current, NODE_INSTRUCTION, parsers);
}
parse_result_t parse_statement(tokenlist_entry_t *current) {
parser_t parsers[] = {parse_label, parse_directive, parse_instruction,
nullptr};
return parse_any(current, parsers);
}
parse_result_t parse(tokenlist_entry_t *current) {
return parse_many(current, NODE_PROGRAM, true, parse_statement);
}

9
src/parser/parser.h Normal file
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@ -0,0 +1,9 @@
#ifndef INCLUDE_PARSER_PARSER_H_
#define INCLUDE_PARSER_PARSER_H_
#include "../tokenlist.h"
#include "util.h"
parse_result_t parse(tokenlist_entry_t *current);
#endif // INCLUDE_PARSER_PARSER_H_

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@ -1,5 +1,5 @@
#include "parser_primitives.h"
#include "ast.h"
#include "primitives.h"
#include "../ast.h"
#include <string.h>
parse_result_t parse_identifier(tokenlist_entry_t *current) {
@ -62,6 +62,11 @@ parse_result_t parse_dot(tokenlist_entry_t *current) {
return parse_token(current, TOKEN_DOT, NODE_DOT, nullptr);
}
parse_result_t parse_label_reference(tokenlist_entry_t *current) {
return parse_token(current, TOKEN_IDENTIFIER, NODE_LABEL_REFERENCE,
nullptr);
}
const char *registers[] = {
// 64-bit registers
"rax", "rcx", "rdx", "rbx", "rsp", "rbp", "rsi", "rdi", "r8", "r9", "r10",
@ -75,6 +80,7 @@ const char *registers[] = {
// 8-bit low registers
"al", "cl", "dl", "bl", "spl", "bpl", "sil", "dil", "r8b", "r9b", "r10b",
"r11b", "r12b", "r13b", "r14b", "r15b", nullptr};
bool is_register_token(lexer_token_t *token) {
for (size_t i = 0; registers[i] != nullptr; ++i)
if (strcmp(token->value, registers[i]) == 0)

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@ -1,7 +1,7 @@
#ifndef INCLUDE_SRC_PARSER_PRIMITIVES_H_
#define INCLUDE_SRC_PARSER_PRIMITIVES_H_
#ifndef INCLUDE_PARSER_PRIMITIVES_H_
#define INCLUDE_PARSER_PRIMITIVES_H_
#include "parser_util.h"
#include "util.h"
parse_result_t parse_identifier(tokenlist_entry_t *current);
parse_result_t parse_decimal(tokenlist_entry_t *current);
@ -18,6 +18,7 @@ parse_result_t parse_plus(tokenlist_entry_t *current);
parse_result_t parse_minus(tokenlist_entry_t *current);
parse_result_t parse_asterisk(tokenlist_entry_t *current);
parse_result_t parse_dot(tokenlist_entry_t *current);
parse_result_t parse_label_reference(tokenlist_entry_t *current);
/* These are "primitives" with a different name and some extra validation on top
* for example, register is just an identifier but it only matches a limited set
@ -26,4 +27,4 @@ parse_result_t parse_dot(tokenlist_entry_t *current);
parse_result_t parse_register(tokenlist_entry_t *current);
parse_result_t parse_section(tokenlist_entry_t *current);
#endif // INCLUDE_SRC_PARSER_PRIMITIVES_H_
#endif // INCLUDE_PARSER_PRIMITIVES_H_

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@ -1,5 +1,5 @@
#include "parser_util.h"
#include "tokenlist.h"
#include "util.h"
#include "../tokenlist.h"
error_t *err_parse_no_match =
&(error_t){.message = "parsing failed to find the correct token sequence"};
@ -33,3 +33,24 @@ parse_result_t parse_token(tokenlist_entry_t *current,
return parse_success(node, current->next);
}
parse_result_t parse_result_wrap(node_id_t id, parse_result_t result) {
if (result.err)
return result;
ast_node_t *node;
error_t *err = ast_node_alloc(&node);
if (err) {
ast_node_free(result.node);
return parse_error(err);
}
node->id = id;
err = ast_node_add_child(node, result.node);
if (err) {
ast_node_free(result.node);
return parse_error(err);
}
return parse_success(node, result.next);
}

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@ -1,9 +1,9 @@
#ifndef INCLUDE_SRC_PARSER_UTIL_H_
#define INCLUDE_SRC_PARSER_UTIL_H_
#ifndef INCLUDE_PARSER_UTIL_H_
#define INCLUDE_PARSER_UTIL_H_
#include "ast.h"
#include "error.h"
#include "tokenlist.h"
#include "../ast.h"
#include "../error.h"
#include "../tokenlist.h"
typedef struct parse_result {
error_t *err;
@ -19,9 +19,8 @@ parse_result_t parse_success(ast_node_t *ast, tokenlist_entry_t *next);
parse_result_t parse_token(tokenlist_entry_t *current,
lexer_token_id_t token_id, node_id_t ast_id,
token_validator_t is_valid);
tokenlist_entry_t *skip_insignificant(tokenlist_entry_t *);
parse_result_t parse_result_wrap(node_id_t id, parse_result_t result);
extern error_t *err_parse_no_match;
#endif // INCLUDE_SRC_PARSER_UTIL_H_
#endif // INCLUDE_PARSER_UTIL_H_

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@ -1,8 +1,17 @@
.section text
; Small valid code snippet that should contain all different AST nodes
_start:
mov eax, ebx
mov eax, 555 ; move 555 into eax
lea eax, [eax + ebx * 4 + 8]
lea eax, [eax + 8]
lea eax, [eax + ebx * 8]
lea eax, [esp - 24]
lea eax, [eax + ebx * 4 - 8]
lea eax, [_start]
mov eax, _start
mov eax, 555
push 0o777
xor eax, 0xDEADBEEF
and ecx, 0o770