From 675aadbe0da95e4023035f1ac34a784d8e217778 Mon Sep 17 00:00:00 2001
From: Sara <sara@saragerretsen.nl>
Date: Wed, 13 Sep 2023 10:39:33 +0200
Subject: [PATCH] kwil now generates a length get function and _to_json will no
 longer allocate memory

---
 src/kwil_generate.c | 48 +++++++++++++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/src/kwil_generate.c b/src/kwil_generate.c
index 55a3349..f0ed50e 100644
--- a/src/kwil_generate.c
+++ b/src/kwil_generate.c
@@ -43,13 +43,16 @@ int kwil_header_generate(struct kwil_header_t* self) {
         return 1;
     }
 
-    fprintf(file, "#include <string.h>\n"
-                  "#define KWIL_GEN_IMPL(...)\\\n");
+    fprintf(file, "#include <string.h>\n");
+
+    fprintf(file, "#define KWIL_GEN_IMPL(...)\\\n");
 
     for(int type_index = 0; type_index < self->types_len; ++type_index) {
         struct kwil_type_t* type = self->types + type_index;
+        printf("Generating functions for %s\n", type->type_name);
         switch(type->type_tag) {
             case KWIL_TYPE_STRUCT:
+                kwil_struct_generate_json_length(&type->struct_type, file, type->type_name);
                 kwil_struct_generate_to_json(&type->struct_type, file, type->type_name);
                 break;
             case KWIL_TYPE_ENUM:
@@ -67,6 +70,7 @@ int kwil_header_generate(struct kwil_header_t* self) {
 
 static
 void kwil_field_generate_to_string(struct kwil_field_t* self, FILE* file) {
+    char custom_type_prefix[48];
     switch(self->type_tag) {
         case KWIL_FIELD_CHAR:
             if(self->array_length > 0 || self->array_dynamic) {
@@ -85,12 +89,17 @@ void kwil_field_generate_to_string(struct kwil_field_t* self, FILE* file) {
         case KWIL_FIELD_UNSIGNED:
             fprintf(file, "    json_len += sprintf(json + json_len, \"%%u\", src->%s);\\\n", self->name_str);
             break;
-        default: break;
+        case KWIL_FIELD_UNKNOWN:
+        case KWIL_FIELD_CUSTOM:
+            kwil_typename_to_prefix(self->type_str, custom_type_prefix, 47);
+            fprintf(file, "    json_len += %s_to_json(&src->%s, json + json_len);\\\n", custom_type_prefix, self->name_str);
+            break;
     }
 }
 
 static
 void kwil_field_get_serialized_length(struct kwil_field_t* self, FILE* file) {
+    char custom_type_prefix[48];
     size_t len = strlen(self->name_str) + 4; // "name": ,
 
     fprintf(file, "    /* length of %s */\\\n"
@@ -116,34 +125,43 @@ void kwil_field_get_serialized_length(struct kwil_field_t* self, FILE* file) {
             break;
         case KWIL_FIELD_CUSTOM:
         case KWIL_FIELD_UNKNOWN:
-            fprintf(file, ";\\\n");
+            kwil_typename_to_prefix(self->type_str, custom_type_prefix, 47);
+            fprintf(file, " + %s_json_length(&src->%s);\\\n", custom_type_prefix, self->name_str);
             break;
     }
 }
 
+int kwil_struct_generate_json_length(struct kwil_struct_t* self, FILE* file, const char* type_name) {
+    char prefix[48];
+    kwil_typename_to_prefix(type_name, prefix, 47);
+
+    fprintf(file, "size_t %s_json_length(struct %s* src) {\\\n"
+                  "    size_t json_capacity = 2;\\\n",// allocate at least two for "{}\0"
+            prefix, type_name);
+    for(int field_index = 0; field_index < self->fields_len; ++field_index) {
+        kwil_field_get_serialized_length(self->fields + field_index, file);
+    }
+    fprintf(file, "    return json_capacity;\\\n"
+                  "}\\\n");
+    return 0;
+}
+
 int kwil_struct_generate_to_json(struct kwil_struct_t* self, FILE* file, const char* type_name) {
     char prefix[48];
     kwil_typename_to_prefix(type_name, prefix, 47);
 
-    fprintf(file, "int %s_to_json(struct %s* src, char** out_json) {\\\n"
-                  "    int json_capacity = 2; \\\n" // allocate at least two for "{}\0"
+    fprintf(file, "int %s_to_json(struct %s* src, char* json) {\\\n"
                   , prefix, type_name);
 
-    for(int field_index = 0; field_index < self->fields_len; ++field_index) {
-        kwil_field_get_serialized_length(self->fields + field_index, file);
-    }
-
-    fprintf(file, "    char* json = malloc(json_capacity);\\\n"
-                  "    int json_len = 1;\\\n"
-                  "    strcpy(json, \"{\");\\\n"
-                  "    *out_json = json;\\\n");
+    fprintf(file, "    int json_len = 1;\\\n"
+                  "    strcpy(json, \"{\");\\\n");
 
     for(int field_index = 0; field_index < self->fields_len; ++field_index) {
         kwil_field_generate_to_json(self->fields + field_index, file);
     }
 
     fprintf(file, "    strcpy(json + json_len - 1, \"}\");\\\n"
-                  "    return json_capacity;\\\n"
+                  "    return json_len;\\\n"
                   "}\\\n");
     fflush(file);