simple B compiler

asmrigs/brb/main.cpp

@@ -3,6 +3,127 @@
 #include "tier2/ifilesystem.h"
 
 
+class CTokenParser
+{
+public:
+	const char *PeekToken();
+	bool IsToken( const char *szString );
+	const char *PeekStringLiteral();
+	bool Continue();
+	
+	Token_t *m_pTokens;
+	Token_t *m_pTokensEnd;
+	Token_t *m_pCurrentToken;
+};
+
+const char *CTokenParser::PeekToken()
+{
+	if ( m_pCurrentToken->m_bIsQuoted )
+		return NULL;
+	return m_pCurrentToken->m_szValue;
+}
+
+bool CTokenParser::IsToken( const char *szString )
+{
+	if ( !V_strcmp(szString, m_pCurrentToken->m_szValue))
+		return true;
+	return false;
+};
+
+const char *CTokenParser::PeekStringLiteral()
+{
+	if ( !m_pCurrentToken->m_bIsQuoted )
+		return NULL;
+	return m_pCurrentToken->m_szValue;
+}
+
+bool CTokenParser::Continue()
+{
+	m_pCurrentToken++;
+	if ( m_pCurrentToken == m_pTokensEnd )
+		return false;
+	return true;
+}
+
+void CompileErrorExpectedToken( Token_t *pToken, const char *szToken )
+{
+	if (pToken->m_bIsQuoted)
+		V_printf("%d:%d: expected %s but got string literal\n", pToken->m_iLine, pToken->m_iCharacter, szToken);
+	else
+		V_printf("%d:%d: expected %s but got %s\n", pToken->m_iLine, pToken->m_iCharacter, szToken, pToken->m_szValue.GetString());
+	exit(1);
+}
+
+struct BExpression_t
+{
+	enum BExpressionType
+	{
+		BEXPRESSION_TYPE_NEW,
+		BEXPRESSION_TYPE_ADD,
+		BEXPRESSION_TYPE_SUBTRACT,
+	} m_eType;
+	CUtlVector<BExpression_t> m_children;
+};
+
+BExpression_t ParseVar( CTokenParser *pParser )
+{
+	const char *szToken = pParser->PeekToken();
+
+	return szToken;
+};
+
+void ParseRValue( CTokenParser *pParser )
+{
+	if (pParser->PeekToken() == "(")
+	{
+		pParser->PeekToken();
+		ParseRValue(pParser)
+	}
+	BVar_t var = ParseVar( pParser );
+}
+
+void ParseStatement( CTokenParser *pParser )
+{
+	if (pParser->IsToken("return"))
+	{
+		pParser->Continue();
+		ParseRValue( pParser );
+		if (!pParser->IsToken(";"))
+			CompileErrorExpectedToken(pParser->m_pCurrentToken, ";");
+		V_printf("  ret\n");
+		pParser->Continue();
+	}
+}
+
+void ParseGlobal( CTokenParser *pParser )
+{
+
+	const char *szObjectName = pParser->PeekToken();
+	pParser->Continue();
+	V_printf("%s:\n", szObjectName);
+
+	if (pParser->IsToken("("))
+	{
+		pParser->Continue();
+		if (!pParser->IsToken(")"))
+			CompileErrorExpectedToken(pParser->m_pCurrentToken, ")");
+		pParser->Continue();
+		if (!pParser->IsToken("{"))
+			CompileErrorExpectedToken(pParser->m_pCurrentToken, "{");
+		pParser->Continue();
+		while (!pParser->IsToken("}"))
+		{
+			ParseStatement( pParser );
+		}
+		pParser->Continue();
+	}
+	else
+	{
+		CompileErrorExpectedToken(pParser->m_pCurrentToken, "(");
+	}
+};
+
+
 int main( int argc, char **argv )
 {
 	CommandLine()->CreateCommandLine(argc, argv);
@@ -15,5 +136,13 @@ int main( int argc, char **argv )
 	filesystem->Close(pFile);
 
 
+	CUtlVector<Token_t> tokens = Tokenize(szFileContents);
+	CTokenParser parser;
+	parser.m_pTokens = tokens.GetData();
+	parser.m_pTokensEnd = tokens.GetData()+tokens.GetSize();
+	parser.m_pCurrentToken = tokens.GetData()-1;
+	parser.Continue();
+	ParseGlobal(&parser);
+
 	V_free((void*)szFileContents);
 }