M xywasm.c → xywasm.c

@@ -2,8 +2,8 @@ #include <stdio.h>
 #include "xyw.h"
 
 #define TOKEN_MAX_LENGTH 32
-#define DIRECTIVE_MAX_LENGTH 256
-#define COMMENT_MAX_LENGTH 256
+#define DIRECTIVE_CONTENT_MAX_LENGTH 256
+#define COMMENT_CONTENT_MAX_LENGTH 256
 
 #define MODE_X 0x20
 #define MODE_Y 0x40
@@ -11,6 +11,7 @@ #define MODE_W 0x80
 
 #define error(msg) fprintf(stderr, "Error - %s [%s]\n", msg, ctx->file)
 #define token_error(msg) fprintf(stderr, "Error - %s: %s [%s - Ln %d, Col %d]\n", token, msg, ctx->file, ctx->line, ctx->column)
+#define symbol_error(symbol, msg) fprintf(stderr, "Error - %s: %s [%s - Ln %d, Col %d]\n", symbol, msg, ctx->file, ctx->line, ctx->column)
 
 typedef struct
 {
@@ -35,6 +36,10 @@ // The token being processed
 static char token[TOKEN_MAX_LENGTH];
 static unsigned int token_length = 0;
 
+// Directive data
+static char directive_data[DIRECTIVE_CONTENT_MAX_LENGTH];
+static unsigned int directive_data_length = 0;
+
 // Bytecode to be written
 xyw_byte data[0xffff - 0x0100];
 
@@ -67,12 +72,44 @@ }
     str[8] = '\0';
 }
 
+static int validate_symbol(xyw_context *ctx, char *str, unsigned int start_index, unsigned int length)
+{
+    // symbols must start with a letter or underscore,
+    // and they can contain letters, numbers, underscores, dashes, or dots.
+    if (!((str[start_index] >= 'A' && str[start_index] <= 'Z') || (str[start_index] >= 'a' && str[start_index] <= 'z') || str[start_index] == '_'))
+    {
+        symbol_error(str, "symbol must start with a letter or underscore");
+        return -1;
+    }
+    for (unsigned int i = start_index + 1; i < length; i++)
+    {
+        char c = str[i];
+        if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '_' || c == '-' || c == '.'))
+        {
+            symbol_error(str, "symbol can only contain letters, numbers, underscores, dashes, or dots");
+            return -1;
+        }
+    }
+    return 0;
+}
+
+//// Directive handlers
+
+static int directive_label(xyw_context *ctx)
+{
+    if (validate_symbol(ctx, directive_data, 1, directive_data_length) != 0)
+    {
+        return -1;
+    }
+    return 0;
+}
+
 //// Parsing functions
 
 static int parse_comment(xyw_context *ctx)
 {
     char c;
-    char comment_data[COMMENT_MAX_LENGTH];
+    char comment_data[COMMENT_CONTENT_MAX_LENGTH];
     unsigned int comment_length = 0;
     // Process single-line comment
     while (fread(&c, 1, 1, ctx->fp) == 1)
@@ -84,7 +121,7 @@ ctx->column = 1;
             break;
         }
         ctx->column++;
-        if (comment_length < COMMENT_MAX_LENGTH - 1)
+        if (comment_length < COMMENT_CONTENT_MAX_LENGTH - 1)
         {
             comment_data[comment_length++] = c;
             comment_data[comment_length] = '\0';
@@ -243,30 +280,9 @@ }
     return -1;
 }
 
-static int validate_identifier(xyw_context *ctx, unsigned int start_index)
-{
-    // Identifiers must start with a letter or underscore,
-    // and they can contain letters, numbers, underscores, dashes, or dots.
-    if (!((token[start_index] >= 'A' && token[start_index] <= 'Z') || (token[start_index] >= 'a' && token[start_index] <= 'z') || token[start_index] == '_'))
-    {
-        token_error("Invalid start character for identifier");
-        return -1;
-    }
-    for (unsigned int i = start_index + 1; i < token_length; i++)
-    {
-        char c = token[i];
-        if (!((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || (c >= '0' && c <= '9') || c == '_' || c == '-' || c == '.'))
-        {
-            token_error("Invalid contains invalid characters");
-            return -1;
-        }
-    }
-    return 0;
-}
-
 static int parse_symbol(xyw_context *ctx)
 {
-    if (validate_identifier(ctx, 0) != 0)
+    if (validate_symbol(ctx, token, 0, token_length) != 0)
     {
         return -1;
     }
@@ -278,27 +294,23 @@ }
 
 static int parse_directive(xyw_context *ctx)
 {
-    if (validate_identifier(ctx, 1) != 0)
+    if (validate_symbol(ctx, token, 1, token_length) != 0)
     {
         return -1;
     }
     // Parse labels starting with . until end of line
     char c;
-    char directive_data[DIRECTIVE_MAX_LENGTH];
-    unsigned int directive_length = 0;
     while (fread(&c, 1, 1, ctx->fp) == 1)
     {
+        ctx->column++;
         if (c == '\n')
         {
-            ctx->line++;
-            ctx->column = 1;
             break;
         }
-        ctx->column++;
-        if (directive_length < DIRECTIVE_MAX_LENGTH - 1)
+        if (directive_data_length < DIRECTIVE_CONTENT_MAX_LENGTH - 1)
         {
-            directive_data[directive_length++] = c;
-            directive_data[directive_length] = '\0';
+            directive_data[directive_data_length++] = c;
+            directive_data[directive_data_length] = '\0';
         }
         else
         {
@@ -309,7 +321,18 @@ }
     // TODO: Remove
     printf("Directive:\t%s\t(%s)\n", token, directive_data);
     // TODO: Process directive
-    return 0;
+    int result = 0;
+    if (strcmpn(token, ".label", 6) == 0)
+    {
+        result = directive_label(ctx);
+    }
+    // Advance to next line
+    ctx->line++;
+    ctx->column = 1;
+    // Reset directive data
+    directive_data_length = 0;
+    directive_data[0] = '\0';
+    return result;
 }
 
 static int parse_token(xyw_context *ctx)
@@ -346,6 +369,7 @@ token_error("Unrecognized token");
     return -1;
 }
 
+// Read a file and process its tokens
 static int process_file(xyw_context *ctx)
 {
     ctx->fp = fopen(ctx->file, "r");