1 files changed, 152 insertions, 0 deletions
diff --git a/script/plugins/ffi/c-parser/cdefines.lua b/script/plugins/ffi/c-parser/cdefines.lua
new file mode 100644
index 00000000..55065f2d
--- /dev/null
+++ b/script/plugins/ffi/c-parser/cdefines.lua
@@ -0,0 +1,152 @@
+
+local cdefines = {}
+
+local c99 = require("plugins.ffi.c-parser.c99")
+local cpp = require("plugins.ffi.c-parser.cpp")
+local typed = require("plugins.ffi.c-parser.typed")
+
+local function add_type(lst, name, typ)
+    lst[name] = typ
+    table.insert(lst, { name = name, type = typ })
+end
+
+local base_c_types = {
+    CONST_CHAR_PTR = { "const", "char", "*" },
+    CONST_CHAR = { "const", "char" },
+    LONG_LONG = { "long", "long" },
+    LONG = { "long" },
+    DOUBLE = { "double" },
+    INT = { "int" },
+}
+
+local function get_binop_type(e1, e2)
+    if e1[1] == "double" or e2[1] == "double" then
+        return base_c_types.DOUBLE
+    end
+    if e1[2] == "long" or e2[2] == "long" then
+        return base_c_types.LONG_LONG
+    end
+    if e1[1] == "long" or e2[1] == "long" then
+        return base_c_types.LONG
+    end
+    return base_c_types.INT
+end
+
+local binop_set = {
+    ["+"] = true,
+    ["-"] = true,
+    ["*"] = true,
+    ["/"] = true,
+    ["%"] = true,
+}
+
+local relop_set = {
+    ["<"] = true,
+    [">"] = true,
+    [">="] = true,
+    ["<="] = true,
+    ["=="] = true,
+    ["!="] = true,
+}
+
+local bitop_set = {
+    ["<<"] = true,
+    [">>"] = true,
+    ["&"] = true,
+    ["^"] = true,
+    ["|"] = true,
+}
+
+-- Best-effort assessment of the type of a #define
+local get_type_of_exp
+get_type_of_exp = typed("Exp, TypeList -> {string}?", function(exp, lst)
+    if type(exp[1]) == "string" and exp[2] == nil then
+        local val = exp[1]
+        if val:sub(1,1) == '"' or val:sub(1,2) == 'L"' then
+            return base_c_types.CONST_CHAR_PTR
+        elseif val:sub(1,1) == "'" or val:sub(1,2) == "L'" then
+            return base_c_types.CONST_CHAR
+        elseif val:match("^[0-9]*LL$") then
+            return base_c_types.LONG_LONG
+        elseif val:match("^[0-9]*L$") then
+            return base_c_types.LONG
+        elseif val:match("%.") then
+            return base_c_types.DOUBLE
+        else
+            return base_c_types.INT
+        end
+    end
+
+    if type(exp[1]) == "string" and exp[2] and exp[2].args then
+        local fn = lst[exp[1]]
+        if not fn or not fn.ret then
+            return nil -- unknown function, or not a function
+        end
+        local r = fn.ret.type
+        return table.move(r, 1, #r, 1, {}) -- shallow_copy(r)
+    end
+
+    if exp.unop == "*" then
+        local etype = get_type_of_exp(exp[1], lst)
+        if not etype then
+            return nil
+        end
+        local rem = table.remove(etype)
+        assert(rem == "*")
+        return etype
+    elseif exp.unop == "-" then
+        return get_type_of_exp(exp[1], lst)
+    elseif exp.op == "?" then
+        return get_type_of_exp(exp[2], lst)
+    elseif exp.op == "," then
+        return get_type_of_exp(exp[#exp], lst)
+    elseif binop_set[exp.op] then
+        local e1 = get_type_of_exp(exp[1], lst)
+        if not e1 then
+            return nil
+        end
+        -- some binops are also unops (e.g. - and *)
+        if exp[2] then
+            local e2 = get_type_of_exp(exp[2], lst)
+            if not e2 then
+                return nil
+            end
+            return get_binop_type(e1, e2)
+        else
+            return e1
+        end
+    elseif relop_set[exp.op] then
+        return base_c_types.INT
+    elseif bitop_set[exp.op] then
+        return get_type_of_exp(exp[1], lst) -- ...or should it be int?
+    elseif exp.op then
+        print("FIXME unsupported op", exp.op)
+    end
+    return nil
+end)
+
+function cdefines.register_define(lst, name, text, define_set)
+    local exp, err, line, col = c99.match_language_expression_grammar(text .. " ")
+    if not exp then
+        -- failed parsing expression
+        -- print(("failed parsing: %d:%d: %s\n"):format(line, col, text))
+        return
+    end
+    local typ = get_type_of_exp(exp, lst)
+    if typ then
+        add_type(lst, name, { type = typ })
+    end
+end
+
+function cdefines.register_defines(lst, define_set)
+    for name, def in pairs(define_set) do
+        if #def == 0 then
+            goto continue
+        end
+        local text = cpp.expand_macro(name, define_set)
+        cdefines.register_define(lst, name, text, define_set)
+        ::continue::
+    end
+end
+
+return cdefines