public static LNode CompileMacro(LNode pattern, LNode body, IMacroContext context, LNodeList attrs)
{
var modeNodes = attrs.Where(a => Enum.TryParse(a.Name.Name, out MacroMode _));
// unwrap braces (they're not part of the pattern, they just enable statement syntax in EC#)
var pattern_apos = pattern.UnwrapBraces();
MacroMode modes = GetMacroMode(ref attrs, pattern_apos);
// compileTime {...} can recognize macro method definitions.
// Take advantage of this by generating a macro method which it will register for us.
LNode macroName = pattern_apos.Target ?? pattern_apos;
LNode syntax = F.Literal(pattern_apos.ToString());
LNode description = attrs.FirstOrDefault(a => a.Value is string) ?? F.Literal("User-defined macro at {0}".Localized(pattern.Range.Start));
attrs = attrs.SmartWhere(a => !(a.Value is string)); // remove docstring, if any
var extraArgs = LNode.List();
if (macroName.IsId)
{
extraArgs.Add(F.Literal(macroName.Name.Name));
}
else
{
Debug.Assert((modes & (MacroMode.MatchEveryCall | MacroMode.MatchEveryIdentifier | MacroMode.MatchEveryLiteral)) != 0);
}
// ensure operator macros like `'+` are not printed as `operator+` which C# will reject
if (EcsValidators.IsOperator(macroName.Name))
{
macroName = F.Id(EcsValidators.SanitizeIdentifier(macroName.Name.Name));
}
LNode modesExpr = null;
foreach (LNode mode in modeNodes)
{
modesExpr = LNode.MergeBinary(modesExpr, LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.ColonColon, LNode.List(LNode.Id((Symbol)"global"), LNode.Id((Symbol)"LeMP"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"MacroMode"))).SetStyle(NodeStyle.Operator), mode)).SetStyle(NodeStyle.Operator), S.OrBits);
}
if (modesExpr != null)
{
extraArgs.Add(LNode.Call(CodeSymbols.Assign, LNode.List(LNode.Id((Symbol)"Mode"), modesExpr)).SetStyle(NodeStyle.Operator));
}
LNode lmAttribute = LNode.Call(LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.ColonColon, LNode.List(LNode.Id((Symbol)"global"), LNode.Id((Symbol)"LeMP"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"LexicalMacroAttribute"))).SetStyle(NodeStyle.Operator), LNode.List().Add(syntax).Add(description).AddRange(extraArgs));
if (!body.Calls(S.Braces))
{
body = LNode.Call(CodeSymbols.Braces, LNode.List(LNode.Call(CodeSymbols.Return, LNode.List(body)))).SetStyle(NodeStyle.StatementBlock);
}
body = context.PreProcess(body);
// Look for "using" statements above the macro() call
LNodeList usingDirectives = LNode.List(context.PreviousSiblings.Where(n => n.Calls(S.Import)));
// Look for "using" and "#r" statements at the beginning of the body
if (body.Calls(S.Braces))
{
var bodyUsings = body.Args.TakeNowWhile(stmt => stmt.Calls(S.Import) || stmt.Calls(S.CsiReference));
usingDirectives.AddRange(bodyUsings);
body = body.WithArgs(body.Args.Slice(bodyUsings.Count));
}
// Create a matchCode statement unless the pattern is MacroName($(.._)), which always matches
if (!(pattern_apos.HasSimpleHeadWithoutPAttrs() && pattern_apos.Target.IsId &&
pattern_apos.ArgCount == 1 && pattern_apos[0].Equals(LNode.Call(CodeSymbols.Substitute, LNode.List(LNode.Call(CodeSymbols.DotDot, LNode.List(LNode.Id((Symbol)"_"))).SetStyle(NodeStyle.Operator))).SetStyle(NodeStyle.Operator))))
{
// Note: the body is already preprocessed; #noLexicalMacros prevents double-processing
body = LNode.Call(CodeSymbols.Braces, LNode.List(LNode.Call((Symbol)"matchCode", LNode.List(LNode.Id((Symbol)"#node"), LNode.Call(CodeSymbols.Braces, LNode.List(LNode.Call(CodeSymbols.Case, LNode.List(pattern)), LNode.Call((Symbol)"#noLexicalMacros", LNode.List(body.AsList(S.Braces))))).SetStyle(NodeStyle.StatementBlock))).SetStyle(NodeStyle.Special), LNode.Call(CodeSymbols.Return, LNode.List(LNode.Literal(null))))).SetStyle(NodeStyle.StatementBlock);
}
return(LNode.Call((Symbol)"compileTime", LNode.List(LNode.Call(CodeSymbols.Braces, LNode.List().AddRange(usingDirectives).Add(LNode.Call(LNode.List().Add(lmAttribute).AddRange(attrs).Add(LNode.Id(CodeSymbols.Public)).Add(LNode.Id(CodeSymbols.Static)), CodeSymbols.Fn, LNode.List(LNode.Id((Symbol)"LNode"), macroName, LNode.Call(CodeSymbols.AltList, LNode.List(LNode.Call(CodeSymbols.Var, LNode.List(LNode.Id((Symbol)"LNode"), LNode.Id((Symbol)"#node"))), LNode.Call(CodeSymbols.Var, LNode.List(LNode.Call(CodeSymbols.Dot, LNode.List(LNode.Call(CodeSymbols.ColonColon, LNode.List(LNode.Id((Symbol)"global"), LNode.Id((Symbol)"LeMP"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"IMacroContext"))).SetStyle(NodeStyle.Operator), LNode.Id((Symbol)"#context"))))), body)))).SetStyle(NodeStyle.StatementBlock))).SetStyle(NodeStyle.Special));
}