Add lexer and parser sources

source/CommandLineInterface.elna

@@ -0,0 +1,89 @@
+module;
+
+from SYSTEM import ADR, TSIZE;
+
+from Args import GetArg, Narg;
+from FIO import WriteString, WriteChar, WriteLine, StdErr;
+from Storage import ALLOCATE;
+from Strings import CompareStr, Length;
+from MemUtils import MemZero;
+
+from Common import ShortString;
+
+proc parse_command_line() -> PCommandLine;
+var
+  parameter: ShortString;
+  i: CARDINAL;
+  result: PCommandLine;
+  parsed: BOOLEAN;
+begin
+  i := 1;
+  NEW(result);
+  result^.lex := false;
+  result^.parse := false;
+  MemZero(ADR(result^.input), 256);
+  result^.output[1] := CHAR(0);
+
+  while (i < Narg()) & (result <> nil) do
+    parsed := GetArg(parameter, i);
+    parsed := false;
+
+    if CompareStr(parameter, '--lex') = 0 then
+      parsed := true;
+      result^.lex := true
+    end;
+    if CompareStr(parameter, '--parse') = 0 then
+      parsed := true;
+      result^.parse := true
+    end;
+    if CompareStr(parameter, '-o') = 0 then
+      INC(i);
+
+      if i = Narg() then
+        WriteString(StdErr, 'Fatal error: expecting a file name following -o.');
+        result := nil
+      end;
+      if i < Narg() then
+        parsed := GetArg(parameter, i);
+        result^.output := parameter
+      end;
+      parsed := true
+    end;
+    if (parameter[1] <> '-') & (parsed = false) then
+      parsed := true;
+
+      if Length(result^.input) > 0 then
+        WriteString(StdErr, 'Fatal error: only one source file can be compiled at once. First given "');
+        WriteString(StdErr, result^.input);
+        WriteString(StdErr, '", then "');
+        WriteString(StdErr, parameter);
+        WriteString(StdErr, '".');
+        WriteLine(StdErr);
+        result := nil
+      end;
+      if result <> nil then
+        result^.input := parameter
+      end
+    end;
+    if parsed = false then
+      WriteString(StdErr, 'Fatal error: unknown command line options: ');
+
+      WriteString(StdErr, parameter);
+      WriteChar(StdErr, '.');
+      WriteLine(StdErr);
+
+      result := nil
+    end;
+
+    i := i + 1
+  end;
+  if (result <> nil) & (Length(result^.input) = 0) then
+    WriteString(StdErr, 'Fatal error: no input files.');
+    WriteLine(StdErr);
+    result := nil
+  end;
+
+  return result
+end;
+
+end.