feat(parser): macro expansion, conditionals and include splicing with -I

Assisted-by: GLM 5.3 Flash

parser/parser.go

@@ -408,6 +408,18 @@ func parseImmediate(g []token.Token) ast.Immediate {
 			return imm
 		}
 	}
+	// A constant expression introduced by '(' or '~'.  Textual macro
+	// substitution leaves arithmetic such as $(32-shift) and $~63 behind,
+	// and the toolchain evaluates it in place; only shapes the ordinary
+	// paths below cannot read reach the folder, so every existing form
+	// keeps its exact parse.
+	if g[0].Kind == token.LParen || g[0].Kind == token.Tilde {
+		if v, rest, ok := foldExpr(g); ok && len(rest) == 0 {
+			imm.Val = v
+			imm.HasVal = true
+			return imm
+		}
+	}
 	i := 0
 	if g[i].Kind == token.Minus {
 		imm.Neg = true
@@ -459,6 +471,17 @@ func parseAddress(g []token.Token) ast.Address {
 	}
 
 	i := 0
+	// A parenthesised constant expression as the displacement: substituted
+	// macro bodies carry ((index*4)+0)(base) shapes.  As with the signed
+	// number path below, the value is committed only when a base group
+	// follows.
+	if i < len(g) && g[i].Kind == token.LParen {
+		if v, rest, ok := foldExpr(g[i:]); ok && len(rest) > 0 && rest[0].Kind == token.LParen {
+			addr.Offset = v
+			addr.HasOff = true
+			i = len(g) - len(rest)
+		}
+	}
 	// Optional leading displacement before a '(' base group.  A sign pushes
 	// the parenthesis one token further out: -4(DX) has it at i+2.
 	if isSignedNumber(g, i) {