update lips

Lua/lib/lips/Dumper.lua

@@ -243,6 +243,10 @@ function Dumper:load(statements)
         self.fn = s.fn
         self.line = s.line
         if s.type:sub(1, 1) == '!' then
+            if s[1] and s[1].tt == 'EXPR' then
+                self:error('unevaluated expression')
+            end
+
             if s.type == '!LABEL' then
                 self.labels[s[1].tok] = self:pc()
             elseif s.type == '!DATA' then
@@ -255,6 +259,7 @@ function Dumper:load(statements)
             elseif s.type == '!BASE' then
                 self.base = s[1].tok
                 insert(new_statements, s)
+
             elseif s.type == '!PUSH' or s.type == '!POP' then
                 local thistype = s.type:sub(2):lower()
                 for i, t in ipairs(s) do
@@ -300,6 +305,7 @@ function Dumper:load(statements)
                         insert(new_statements, s)
                     end
                 end
+
             elseif s.type == '!ALIGN' or s.type == '!SKIP' then
                 local length, content
                 if s.type == '!ALIGN' then
@@ -332,6 +338,7 @@ function Dumper:load(statements)
                 else
                     -- length is 0, noop
                 end
+
             else
                 error('Internal Error: unknown statement, got '..s.type)
             end

Lua/lib/lips/Lexer.lua

@@ -329,6 +329,38 @@ function Lexer:lex_include_binary(_yield)
     end
 end
 
+function Lexer:lex_expression(yield)
+    if self.chr ~= '(' then
+        self:error('expected opening parenthesis for expression')
+    end
+    self:nextc()
+
+    local expr = ""
+    local depth = 1
+    while true do
+        if self.chr == '\n' then
+            self:error('unexpected newline; incomplete expression')
+        elseif self.ord == self.EOF then
+            self:nextc()
+            self:error('unexpected EOF; incomplete expression')
+        elseif self.chr == '(' then
+            depth = depth + 1
+            self:nextc()
+            expr = expr..'('
+        elseif self.chr == ')' then
+            depth = depth - 1
+            self:nextc()
+            if depth == 0 then break end
+            expr = expr..')'
+        else
+            expr = expr..self.chr
+            self:nextc()
+        end
+    end
+
+    yield('EXPR', expr)
+end
+
 function Lexer:lex(_yield)
     local function yield(tt, tok)
         return _yield(tt, tok, self.fn, self.line)
@@ -410,6 +442,8 @@ function Lexer:lex(_yield)
                 end
             elseif self.chr:find('[01]') then
                 yield('NUM', self:read_binary())
+            elseif self.chr == '(' then
+                self:lex_expression(yield)
             else
                 self:error('unknown % syntax')
             end

Lua/lib/lips/Muncher.lua

@@ -115,7 +115,13 @@ function Muncher:deref()
 end
 
 function Muncher:const(relative, no_label)
-    if self.tt ~= 'NUM' and self.tt ~= 'VARSYM' and self.tt ~= 'LABELSYM' then
+    local good = {
+        NUM = true,
+        EXPR = true,
+        VARSYM = true,
+        LABELSYM = true,
+    }
+    if not good[self.tt] then
         self:error('expected constant', self.tt)
     end
     if no_label and self.tt == 'LABELSYM' then

Lua/lib/lips/Preproc.lua

@@ -5,6 +5,7 @@ local data = require(path.."data")
 local overrides = require(path.."overrides")
 local Statement = require(path.."Statement")
 local Reader = require(path.."Reader")
+local Expression = require(path.."Expression")
 
 local abs = math.abs
 
@@ -172,6 +173,24 @@ function Preproc:process(statements)
         end
     end
 
+    -- third pass: evaluate constant expressions
+    for i=1, #new_statements do
+        local s = new_statements[i]
+        self.fn = s.fn
+        self.line = s.line
+        for j, t in ipairs(s) do
+            if t.tt == 'EXPR' then
+                local expr = Expression()
+                local result, err = expr:eval(t.tok)
+                if err then
+                    self:error('failed to evaulate ('..t.tok..')', err)
+                end
+                t.tt = 'NUM'
+                t.tok = result
+            end
+        end
+    end
+
     return new_statements
 end
 
@@ -214,7 +233,7 @@ function Preproc:pop(kind)
 end
 
 function Preproc:expand(statements)
-    -- third pass: expand pseudo-instructions and register arguments
+    -- fourth pass: expand pseudo-instructions and register arguments
     self.statements = {}
     for i=1, #statements do
         local s = statements[i]