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- /* Copyright (C) 2014-2015 Ben Kurtovic <ben.kurtovic@gmail.com>
- Released under the terms of the MIT License. See LICENSE for details. */
-
- #include <errno.h>
- #include <stdio.h>
- #include <string.h>
- #include <sys/stat.h>
-
- #include "assembler.h"
- #include "logging.h"
- #include "util.h"
-
- #define DEFAULT_HEADER_OFFSET 0x7FF0
- #define DEFAULT_REGION "GG Export"
-
- #define SYMBOL_TABLE_BUCKETS 128
-
- /* Internal structs */
-
- struct ASMLine {
- char *data;
- size_t length;
- const Line *original;
- const char *filename;
- struct ASMLine *next;
- };
- typedef struct ASMLine ASMLine;
-
- struct ASMInclude {
- LineBuffer *lines;
- struct ASMInclude *next;
- };
- typedef struct ASMInclude ASMInclude;
-
- struct ASMInstruction {
- size_t offset;
- uint8_t length;
- uint8_t b1, b2, b3, b4;
- uint8_t virtual_byte;
- char *symbol;
- struct ASMInstruction *next;
- };
- typedef struct ASMInstruction ASMInstruction;
-
- struct ASMSymbol {
- size_t offset;
- char *symbol;
- struct ASMSymbol *next;
- };
- typedef struct ASMSymbol ASMSymbol;
-
- typedef struct {
- ASMSymbol *buckets[SYMBOL_TABLE_BUCKETS];
- } ASMSymbolTable;
-
- typedef struct {
- size_t offset;
- bool checksum;
- uint32_t product_code;
- uint8_t version;
- uint8_t region;
- uint8_t rom_size;
- } ASMHeaderInfo;
-
- typedef struct {
- ASMHeaderInfo header;
- bool optimizer;
- size_t rom_size;
- ASMLine *lines;
- ASMInclude *includes;
- ASMInstruction *instructions;
- ASMSymbolTable *symtable;
- } AssemblerState;
-
- /*
- Deallocate a LineBuffer previously created with read_source_file().
- */
- static void free_line_buffer(LineBuffer *buffer)
- {
- Line *line = buffer->lines, *temp;
- while (line) {
- temp = line->next;
- free(line->data);
- free(line);
- line = temp;
- }
-
- free(buffer->filename);
- free(buffer);
- }
-
- /*
- Read the contents of the source file at the given path into a line buffer.
-
- Return the buffer if reading was successful; it must be freed with
- free_line_buffer() when done. Return NULL if an error occurred while
- reading. A message will be printed to stderr in this case.
- */
- static LineBuffer* read_source_file(const char *path)
- {
- FILE *fp;
- struct stat st;
-
- if (!(fp = fopen(path, "r"))) {
- ERROR_ERRNO("couldn't open source file")
- return NULL;
- }
-
- if (fstat(fileno(fp), &st)) {
- fclose(fp);
- ERROR_ERRNO("couldn't open source file")
- return NULL;
- }
- if (!(st.st_mode & S_IFREG)) {
- fclose(fp);
- ERROR("couldn't open source file: %s", st.st_mode & S_IFDIR ?
- "Is a directory" : "Is not a regular file")
- return NULL;
- }
-
- LineBuffer *source = malloc(sizeof(LineBuffer));
- if (!source)
- OUT_OF_MEMORY()
-
- source->lines = NULL;
- source->filename = malloc(sizeof(char) * (strlen(path) + 1));
- if (!source->filename)
- OUT_OF_MEMORY()
- strcpy(source->filename, path);
-
- Line dummy = {.next = NULL};
- Line *line, *prev = &dummy;
- size_t lineno = 1;
-
- while (1) {
- char *data = NULL;
- size_t cap = 0;
- ssize_t len;
-
- if ((len = getline(&data, &cap, fp)) < 0) {
- if (feof(fp))
- break;
- if (errno == ENOMEM)
- OUT_OF_MEMORY()
- ERROR_ERRNO("couldn't read source file")
- fclose(fp);
- source->lines = dummy.next;
- free_line_buffer(source);
- return NULL;
- }
-
- line = malloc(sizeof(Line));
- if (!line)
- OUT_OF_MEMORY()
-
- line->data = data;
- line->length = feof(fp) ? len : (len - 1);
- line->lineno = lineno++;
- line->next = NULL;
-
- prev->next = line;
- prev = line;
- }
-
- fclose(fp);
- source->lines = dummy.next;
- return source;
- }
-
- /*
- Write an assembled binary file to the given path.
-
- Return whether the file was written successfully. On error, a message is
- printed to stderr.
- */
- static bool write_binary_file(const char *path, const uint8_t *data, size_t size)
- {
- FILE *fp;
- if (!(fp = fopen(path, "wb"))) {
- ERROR_ERRNO("couldn't open destination file")
- return false;
- }
-
- if (!fwrite(data, size, 1, fp)) {
- fclose(fp);
- ERROR_ERRNO("couldn't write to destination file")
- return false;
- }
-
- fclose(fp);
- return true;
- }
-
- /*
- Print an ErrorInfo object returned by assemble() to the given stream.
- */
- void error_info_print(const ErrorInfo *error_info, FILE *file)
- {
- // TODO
- fprintf(file, "Error: Unknown error\n");
- }
-
- /*
- Destroy an ErrorInfo object created by assemble().
- */
- void error_info_destroy(ErrorInfo *error_info)
- {
- if (!error_info)
- return;
-
- // TODO
- free(error_info);
- }
-
- /*
- Initialize default values in an AssemblerState object.
- */
- static void init_state(AssemblerState *state)
- {
- state->header.offset = DEFAULT_HEADER_OFFSET;
- state->header.checksum = true;
- state->header.product_code = 0;
- state->header.version = 0;
- state->header.region = region_string_to_code(DEFAULT_REGION);
- state->header.rom_size = 0;
- state->optimizer = false;
- state->rom_size = 0;
-
- state->lines = NULL;
- state->includes = NULL;
- state->instructions = NULL;
- state->symtable = NULL;
- }
-
- /*
- Deallocate an ASMLine list.
- */
- static void free_asm_lines(ASMLine *line)
- {
- while (line) {
- ASMLine *temp = line->next;
- free(line->data);
- free(line);
- line = temp;
- }
- }
-
- /*
- Deallocate an ASMInclude list.
- */
- static void free_asm_includes(ASMInclude *include)
- {
- while (include) {
- ASMInclude *temp = include->next;
- free_line_buffer(include->lines);
- free(include);
- include = temp;
- }
- }
-
- /*
- Deallocate an ASMInstruction list.
- */
- static void free_asm_instructions(ASMInstruction *inst)
- {
- while (inst) {
- ASMInstruction *temp = inst->next;
- if (inst->symbol)
- free(inst->symbol);
- free(inst);
- inst = temp;
- }
- }
-
- /*
- Deallocate an ASMSymbolTable.
- */
- static void free_asm_symtable(ASMSymbolTable *symtable)
- {
- if (!symtable)
- return;
-
- for (size_t bucket = 0; bucket < SYMBOL_TABLE_BUCKETS; bucket++) {
- ASMSymbol *sym = symtable->buckets[bucket], *temp;
- while (sym) {
- temp = sym->next;
- free(sym->symbol);
- free(sym);
- sym = temp;
- }
- }
- free(symtable);
- }
-
- /*
- Preprocess a single source line (source, length) into a normalized ASMLine.
-
- *Only* the data and length fields in the ASMLine object are populated. The
- normalization process converts tabs to spaces, removes runs of multiple
- spaces (outside of string literals), strips comments, and other things.
-
- Return NULL if an ASM line was not generated from the source, i.e. if it is
- blank after being stripped.
- */
- static ASMLine* normalize_line(const char *source, size_t length)
- {
- char *data = malloc(sizeof(char) * length);
- if (!data)
- OUT_OF_MEMORY()
-
- size_t si, di, slashes = 0;
- bool has_content = false, space_pending = false, in_string = false;
- for (si = di = 0; si < length; si++) {
- char c = source[si];
-
- if (c == '\\')
- slashes++;
- else
- slashes = 0;
-
- if (in_string) {
- if (c == '"' && (slashes % 2) == 0)
- in_string = false;
-
- data[di++] = c;
- } else {
- if (c == ';')
- break;
- if (c == '"' && (slashes % 2) == 0)
- in_string = true;
-
- if (c == '\t' || c == ' ')
- space_pending = true;
- else {
- if (space_pending) {
- if (has_content)
- data[di++] = ' ';
- space_pending = false;
- }
- has_content = true;
- data[di++] = c;
- }
- }
- }
-
- if (!has_content) {
- free(data);
- return NULL;
- }
-
- ASMLine *line = malloc(sizeof(ASMLine));
- if (!line)
- OUT_OF_MEMORY()
-
- data = realloc(data, sizeof(char) * di);
- if (!data)
- OUT_OF_MEMORY()
-
- line->data = data;
- line->length = di;
- return line;
- }
-
- /*
- Preprocess the LineBuffer into ASMLines. Change some state along the way.
-
- This function processes include directives, so read_source_file() may be
- called multiple times (along with the implications that has), and
- state->includes may be modified.
-
- On success, state->lines is modified and NULL is returned. On error, an
- ErrorInfo object is returned, and state->lines and state->includes are not
- modified.
- */
- static ErrorInfo* preprocess(AssemblerState *state, const LineBuffer *source)
- {
- // TODO
-
- // state->header.offset <-- check in list of acceptable values
- // state->header.checksum <-- boolean check
- // state->header.product_code <-- range check
- // state->header.version <-- range check
- // state->header.region <-- string conversion, check
- // state->header.rom_size <-- value/range check
- // state->optimizer <-- boolean check
- // state->rom_size <-- value check
-
- // if giving rom size, check header offset is in rom size range
- // if giving reported and actual rom size, check reported is <= actual
- // ensure no duplicate explicit assignments
-
- ASMLine dummy = {.next = NULL};
- ASMLine *line, *prev = &dummy;
- const Line *orig = source->lines;
-
- while (orig) {
- if ((line = normalize_line(orig->data, orig->length))) {
- line->original = orig;
- line->filename = source->filename;
- line->next = NULL;
-
- prev->next = line;
- prev = line;
- }
- orig = orig->next;
- }
-
- state->lines = dummy.next;
-
- #ifdef DEBUG_MODE
- DEBUG("Dumping ASMLines:")
- const ASMLine *temp = state->lines;
- while (temp) {
- DEBUG("- %-40.*s [%s:%02zu]", (int) temp->length, temp->data,
- temp->filename, temp->original->lineno)
- temp = temp->next;
- }
- #endif
-
- return NULL;
- }
-
- /*
- Tokenize ASMLines into ASMInstructions.
-
- On success, state->instructions is modified and NULL is returned. On error,
- an ErrorInfo object is returned and state->instructions is not modified.
- state->symtable may or may not be modified regardless of success.
- */
- static ErrorInfo* tokenize(AssemblerState *state)
- {
- // TODO
-
- // verify no instructions clash with header offset
- // if rom size is set, verify nothing overflows
-
- return NULL;
- }
-
- /*
- Resolve default placeholder values in assembler state, such as ROM size.
-
- On success, no new heap objects are allocated. On error, an ErrorInfo
- object is returned.
- */
- static ErrorInfo* resolve_defaults(AssemblerState *state)
- {
- // TODO
-
- // if (!state.rom_size)
- // set to max possible >= 32 KB, or error if too many instructions
- // if (state.header.rom_size)
- // check reported rom size is <= actual rom size
-
- // if (!state.header.rom_size)
- // set to actual rom size
-
- return NULL;
- }
-
- /*
- Resolve symbol placeholders in instructions such as jumps and branches.
-
- On success, no new heap objects are allocated. On error, an ErrorInfo
- object is returned.
- */
- static ErrorInfo* resolve_symbols(AssemblerState *state)
- {
- // TODO
-
- return NULL;
- }
-
- /*
- Convert finalized ASMInstructions into a binary data block.
-
- This function should never fail.
- */
- static void serialize_binary(AssemblerState *state, uint8_t *binary)
- {
- // TODO
-
- for (size_t i = 0; i < state->rom_size; i++)
- binary[i] = 'X';
- }
-
- /*
- Assemble the z80 source code in the source code buffer into binary data.
-
- If successful, return the size of the assembled binary data and change
- *binary_ptr to point to the assembled ROM data buffer. *binary_ptr must be
- free()'d when finished.
-
- If an error occurred, return 0 and update *ei_ptr to point to an ErrorInfo
- object which can be shown to the user with error_info_print(). The
- ErrorInfo object must be destroyed with error_info_destroy() when finished.
-
- In either case, only one of *binary_ptr and *ei_ptr is modified.
- */
- size_t assemble(const LineBuffer *source, uint8_t **binary_ptr, ErrorInfo **ei_ptr)
- {
- AssemblerState state;
- ErrorInfo *error_info;
- size_t retval = 0;
-
- init_state(&state);
-
- if ((error_info = preprocess(&state, source)))
- goto error;
-
- if (!(state.symtable = malloc(sizeof(ASMSymbolTable))))
- OUT_OF_MEMORY()
- for (size_t bucket = 0; bucket < SYMBOL_TABLE_BUCKETS; bucket++)
- state.symtable->buckets[bucket] = NULL;
-
- if ((error_info = tokenize(&state)))
- goto error;
-
- if ((error_info = resolve_defaults(&state)))
- goto error;
-
- if ((error_info = resolve_symbols(&state)))
- goto error;
-
- uint8_t *binary = malloc(sizeof(uint8_t) * state.rom_size);
- if (!binary)
- OUT_OF_MEMORY()
-
- serialize_binary(&state, binary);
- *binary_ptr = binary;
- retval = state.rom_size;
- goto cleanup;
-
- error:
- *ei_ptr = error_info;
-
- cleanup:
- free_asm_lines(state.lines);
- free_asm_includes(state.includes);
- free_asm_instructions(state.instructions);
- free_asm_symtable(state.symtable);
- return retval;
- }
-
- /*
- Assemble the z80 source code at the input path into a binary file.
-
- Return true if the operation was a success and false if it was a failure.
- Errors are printed to STDOUT; if the operation was successful then nothing
- is printed.
- */
- bool assemble_file(const char *src_path, const char *dst_path)
- {
- LineBuffer *source = read_source_file(src_path);
- if (!source)
- return false;
-
- uint8_t *binary;
- ErrorInfo *error_info;
- size_t size = assemble(source, &binary, &error_info);
- free_line_buffer(source);
-
- if (!size) {
- error_info_print(error_info, stderr);
- error_info_destroy(error_info);
- return false;
- }
-
- bool success = write_binary_file(dst_path, binary, size);
- free(binary);
- return success;
- }
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