feat: Initial parsing of instructions

Initial ability to parse basic instructions. Currently hex numbers are
broken and immediates with labels (movl $str, %ecx) are broken.

1 files changed, 28 insertions, 0 deletions

diff --git a/src/lexer.l b/src/lexer.l
new file mode 100644
index 0000000..46f6bc6
--- /dev/null
+++ b/src/lexer.l
@@ -0,0 +1,28 @@
+%{
+#include <string.h>
+#include <stdlib.h>
+#include "parser.tab.h"
+extern int yylex();
+extern size_t line_number;
+%}
+%option noyywrap
+%%
+^[a-zA-Z]+                      { yylval.symbol = strdup(yytext); return T_INSTRUCTION; }
+%*[a-zA-Z\_\-]+[a-zA-Z0-9\_\-]* { yylval.symbol = strdup(yytext); return T_LABEL; }
+0x[0-9A-Fa-f]+                  { yylval.i_val = atoi(yytext); return T_INTEGER; }
+[0-9]+                          { yylval.i_val = atoi(yytext); return T_INTEGER; }
+-*[0-9]*\.*[0-9]*               { yylval.i_val = atof(yytext); return T_FLOAT; }
+\".*\"                          {
+    yylval.s_val = strdup(yytext+1);
+    char *const close_paren = strrchr(yylval.s_val, '"');
+    if (close_paren != NULL) {
+        *close_paren = '\0';
+    }
+    return T_STRING;
+}
+,                               { return T_COMMA; }
+\$                              { return T_IMMEDIATE; }
+[ \t]                           ;
+\n                              { ++line_number; return T_ENDL; }
+.                               ;
+%%