feat: parse all structs in file and generate cmeta.h file

Makefile

@@ -3,7 +3,7 @@ all: build/cmeta
 build:
 	mkdir -p build
 
-build/cmeta: build third_party/stb_c_lexer.h src/main.c
+build/cmeta: build third_party/stb_c_lexer.h src/cmeta.h src/main.c
 	gcc -Wall -Wextra -pedantic -o build/cmeta -isystem third_party/ third_party/stb_c_lexer.h src/main.c
 
 run: build/cmeta

src/cmeta.h

@@ -0,0 +1,19 @@
+#ifndef CMETA_H
+#define CMETA_H
+
+#include <stddef.h>
+
+typedef struct {
+    char* type;
+    char* name;
+} Field_Info;
+
+typedef struct {
+    char* name;
+    size_t fields_count;
+    Field_Info *fields;
+} Struct_Info;
+
+// GENERATE_HERE //
+
+#endif // CMETA_H

src/main.c

@@ -1,4 +1,5 @@
 #include <ctype.h>
+#include <errno.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
@@ -6,6 +7,8 @@
 #define STB_C_LEXER_IMPLEMENTATION
 #include "stb_c_lexer.h"
 
+#include "cmeta.h"
+
 stb_lexer lexer = {0};
 
 bool lexer_expect_keyword(const char* expected) {
@@ -41,16 +44,18 @@ bool lexer_expect(long expected, const char* expected_str) {
     return true;
 }
 
-typedef struct {
-    char* type;
-    char* name;
-} Field_Info;
+long lexer_peek() {
+    char* mark = lexer.parse_point;
+    if (!stb_c_lexer_get_token(&lexer)) {
+        lexer.parse_point = mark;
+        return CLEX_eof;
+    }
 
-typedef struct {
-    char* name;
-    size_t fields_count;
-    Field_Info *fields;
-} Struct_Info;
+    long token = lexer.token;
+    lexer.parse_point = mark;
+
+    return token;
+}
 
 // parses typedef struct { FIELDS } TYPE_NAME
 bool parse_struct(Struct_Info* info) {
@@ -148,18 +153,112 @@ void generate_struct_info(FILE* stream, Struct_Info info) {
     free(lowercase_name);
 }
 
-int main(void)
-{
-    const char *source = "typedef struct { int int_field; bool bool_field; } My_Struct;";
-    char string_store[1024];
-    stb_c_lexer_init(&lexer, source, source + strlen(source), string_store, sizeof(string_store) / sizeof(char));
+bool read_entire_file(const char* file_path, char** content) {
+    bool result = false;
+    FILE* file = fopen(file_path, "rb");
+    if(file == NULL) goto fail;
 
-    Struct_Info info = {0};
-    if (!parse_struct(&info)) return 1;
-    printf("--- Parsed ------------\n");
-    print_struct(info);
-    printf("--- Generated ---------\n");
-    generate_struct_info(stdout, info);
+    if(fseek(file, 0, SEEK_END) < 0) goto fail;
+    
+    long length = ftell(file);
+    if(length < 0) goto fail;
+
+    if(fseek(file, 0, SEEK_SET) < 0) goto fail;
+
+    *content = (char*) malloc((length + 1) * sizeof(char));
+    fread(*content, 1, length, file);
+
+    // TODO: will not set errno
+    if (ferror(file)) goto fail;
+
+    (*content)[length] = '\0';
+
+    result = true;
+fail:
+    if (!result) {
+        free(content);
+        fprintf(stderr, "ERROR: Could not read `%s`: %s\n", file_path, strerror(errno));
+    }
+    if (file) fclose(file);
+    return result;
+}
+
+bool generate_output_file(const char* output_path, Struct_Info *struct_infos, size_t struct_infos_count) {
+    bool result = false;
+    
+    char* header_content;
+    if (!read_entire_file("src/cmeta.h", &header_content)) goto fail;
+
+    char* generate_at = strstr(header_content, "// GENERATE_HERE //");
+    if (generate_at == NULL) {
+        fprintf(stderr, "ERROR: could not found generation mark in cmeta.h\n");
+        goto fail;
+    }
+
+    FILE* output_file = fopen(output_path, "wb");
+    if (!output_file) {
+        fprintf(stderr, "ERROR: could not write to %s: %s\n", output_path, strerror(errno));
+        goto fail;
+    }
+
+    FILE* stream = output_file;
+
+    // write up to the generation mark
+    fwrite(header_content, generate_at - header_content, 1, stream);
+
+    gen("// Generated by cmeta");
+    for (size_t i = 0; i < struct_infos_count; i += 1) {
+        generate_struct_info(stream, struct_infos[i]);
+    }
+
+    // write the rest after the \n
+    generate_at = strchr(generate_at, '\n');
+    fwrite(generate_at, strlen(generate_at), 1, stream);
+
+    result = true;
+fail:
+    free(header_content);
+    if (output_file) fclose(output_file);
+
+    return result;
+}
+
+int main(int argc, char** argv)
+{
+    const char* program_name = argv[0];
+    if(argc == 1) {
+        fprintf(stderr, "ERROR: missing required argument <input_file>\n");
+        fprintf(stderr, "Usage: %s <input_file>\n", program_name);
+        return 1;
+    }
+
+    // read input file
+    char* input_content;
+    if(!read_entire_file(argv[1], &input_content)) return 1;
+
+    // init lexer
+    char string_store[1024];
+    stb_c_lexer_init(&lexer, input_content, input_content + strlen(input_content), string_store, sizeof(string_store) / sizeof(char));
+
+    // find and parse all structs
+    size_t struct_infos_count = 0;
+    Struct_Info struct_infos[16]; // TODO: use dynamic array
+
+    while (true) {
+        char* mark = lexer.parse_point;
+
+        if (!stb_c_lexer_get_token(&lexer)) break;
+
+        if (lexer.token == CLEX_id && strcmp(lexer.string, "typedef") == 0) {
+            lexer.parse_point = mark;
+
+            if (parse_struct(&struct_infos[struct_infos_count])) {
+                struct_infos_count += 1;  
+            }
+        }    
+    }
+
+    if (!generate_output_file("test/01_simple_struct/cmeta.h", struct_infos, struct_infos_count)) return 1;
 
     return 0;
 }