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Diffstat (limited to 'tools/dump_cinit.lua')
-rw-r--r-- | tools/dump_cinit.lua | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/tools/dump_cinit.lua b/tools/dump_cinit.lua new file mode 100644 index 0000000..1447d58 --- /dev/null +++ b/tools/dump_cinit.lua @@ -0,0 +1,414 @@ +--[[ + + upb - a minimalist implementation of protocol buffers. + + Copyright (c) 2012 Google Inc. See LICENSE for details. + Author: Josh Haberman <jhaberman@gmail.com> + + Routines for dumping internal data structures into C initializers + that can be compiled into a .o file. + +--]] + +local upbtable = require "upbtable" +local upb = require "upb" +local export = {} + +-- A tiny little abstraction that decouples the dump_* functions from +-- what they're writing to (appending to a string, writing to file I/O, etc). +-- This could possibly matter since naive string building is O(n^2) in the +-- number of appends. +function export.str_appender() + local str = "" + local function append(fmt, ...) + str = str .. string.format(fmt, ...) + end + local function get() + return str + end + return append, get +end + +function export.file_appender(file) + local f = file + local function append(fmt, ...) + f:write(string.format(fmt, ...)) + end + return append +end + +-- const(f, label) -> UPB_LABEL_REPEATED, where f:label() == upb.LABEL_REPEATED +function const(obj, name) + local val = obj[name](obj) + for k, v in pairs(upb) do + if v == val and string.find(k, "^" .. string.upper(name)) then + return "UPB_" .. k + end + end + assert(false, "Couldn't find constant") +end + +--[[ + + LinkTable: an object that tracks all linkable objects and their offsets to + facilitate linking. + +--]] + +local LinkTable = {} +function LinkTable:new(basename, types) + local linktab = { + basename = basename, + types = types, + table = {}, -- ptr -> {type, 0-based offset} + obj_arrays = {} -- Establishes the ordering for each object type + } + for type, _ in pairs(types) do + linktab.obj_arrays[type] = {} + end + setmetatable(linktab, {__index = LinkTable}) -- Inheritance + return linktab +end + +-- Adds a new object to the sequence of objects of this type. +function LinkTable:add(objtype, ptr, obj) + obj = obj or ptr + assert(self.table[obj] == nil) + assert(self.types[objtype]) + local arr = self.obj_arrays[objtype] + self.table[ptr] = {objtype, #arr} + arr[#arr + 1] = obj +end + +-- Returns a C symbol name for the given objtype and offset. +function LinkTable:csym(objtype, offset) + local typestr = assert(self.types[objtype]) + return string.format("%s_%s[%d]", self.basename, typestr, offset) +end + +-- Returns the address of the given C object. +function LinkTable:addr(obj) + if obj == upbtable.NULL then + return "NULL" + else + local tabent = assert(self.table[obj], "unknown object") + return "&" .. self:csym(tabent[1], tabent[2]) + end +end + +-- Returns an array declarator indicating how many objects have been added. +function LinkTable:cdecl(objtype) + return self:csym(objtype, #self.obj_arrays[objtype]) +end + +function LinkTable:objs(objtype) + -- Return iterator function, allowing use as: + -- for obj in linktable:objs(type) do + -- -- ... + -- done + local array = self.obj_arrays[objtype] + local i = 0 + return function() + i = i + 1 + if array[i] then return array[i] end + end +end + +--[[ + + Dumper: an object that can dump C initializers for several constructs. + Uses a LinkTable to resolve references when necessary. + +--]] + +local Dumper = {} +function Dumper:new(linktab) + local obj = {linktab = linktab} + setmetatable(obj, {__index = Dumper}) -- Inheritance + return obj +end + +-- Dumps a upb_value, eg: +-- UPB_VALUE_INIT_INT32(5) +function Dumper:value(val, upbtype) + if type(val) == "nil" then + return "UPB_VALUE_INIT_NONE" + elseif type(val) == "number" then + -- Use upbtype to disambiguate what kind of number it is. + if upbtype == upbtable.CTYPE_INT32 then + return string.format("UPB_VALUE_INIT_INT32(%d)", val) + else + -- TODO(haberman): add support for these so we can properly support + -- default values. + error("Unsupported number type " .. upbtype) + end + elseif type(val) == "string" then + return string.format('UPB_VALUE_INIT_CONSTPTR("%s")', val) + else + -- We take this as an object reference that has an entry in the link table. + return string.format("UPB_VALUE_INIT_CONSTPTR(%s)", self.linktab:addr(val)) + end +end + +-- Dumps a table key. +function Dumper:tabkey(key) + if type(key) == "nil" then + return "UPB_TABKEY_NONE" + elseif type(key) == "string" then + return string.format('UPB_TABKEY_STR("%s")', key) + else + return string.format("UPB_TABKEY_NUM(%d)", key) + end +end + +-- Dumps a table entry. +function Dumper:tabent(ent) + local key = self:tabkey(ent.key) + local val = self:value(ent.value, ent.valtype) + local next = self.linktab:addr(ent.next) + return string.format(' {%s, %s, %s},\n', key, val, next) +end + +-- Dumps an inttable array entry. This is almost the same as value() above, +-- except that nil values have a special value to indicate "empty". +function Dumper:arrayval(val) + if val.val then + return string.format(" %s,\n", self:value(val.val, val.valtype)) + else + return " UPB_ARRAY_EMPTYENT,\n" + end +end + +-- Dumps an initializer for the given strtable/inttable (respectively). Its +-- entries must have previously been added to the linktable. +function Dumper:strtable(t) + -- UPB_STRTABLE_INIT(count, mask, type, size_lg2, entries) + return string.format( + "UPB_STRTABLE_INIT(%d, %d, %d, %d, %s)", + t.count, t.mask, t.type, t.size_lg2, self.linktab:addr(t.entries[1].ptr)) +end + +function Dumper:inttable(t) + local lt = assert(self.linktab) + -- UPB_INTTABLE_INIT(count, mask, type, size_lg2, ent, a, asize, acount) + local entries = "NULL" + if #t.entries > 0 then + entries = lt:addr(t.entries[1].ptr) + end + return string.format( + "UPB_INTTABLE_INIT(%d, %d, %d, %d, %s, %s, %d, %d)", + t.count, t.mask, t.type, t.size_lg2, entries, + lt:addr(t.array[1].ptr), t.array_size, t.array_count) +end + +-- A visitor for visiting all tables of a def. Used first to count entries +-- and later to dump them. +local function gettables(def) + if def:def_type() == upb.DEF_MSG then + return {int = upbtable.msgdef_itof(def), str = upbtable.msgdef_ntof(def)} + elseif def:def_type() == upb.DEF_ENUM then + return {int = upbtable.enumdef_iton(def), str = upbtable.enumdef_ntoi(def)} + end +end + +local function emit_file_warning(append) + append('// This file was generated by upbc (the upb compiler).\n') + append('// Do not edit -- your changes will be discarded when the file is\n') + append('// regenerated.\n\n') +end + +--[[ + + Top-level, exported dumper functions + +--]] + +local function dump_defs_c(symtab, basename, append) + -- Add fielddefs for any msgdefs passed in. + local fielddefs = {} + for _, def in ipairs(symtab:getdefs(upb.DEF_MSG)) do + for field in def:fields() do + fielddefs[#fielddefs + 1] = field + end + end + + -- Get a list of all defs and add fielddefs to it. + local defs = symtab:getdefs(upb.DEF_ANY) + for _, fielddef in ipairs(fielddefs) do + defs[#defs + 1] = fielddef + end + + -- Sort all defs by (type, name). + -- This gives us a linear ordering that we can use to create offsets into + -- shared arrays like REFTABLES, hash table entries, and arrays. + table.sort(defs, function(a, b) + if a:def_type() ~= b:def_type() then + return a:def_type() < b:def_type() + else + return a:full_name() < b:full_name() end + end + ) + + -- Perform pre-pass to build the link table. + local linktab = LinkTable:new(basename, { + [upb.DEF_MSG] = "msgs", + [upb.DEF_FIELD] = "fields", + [upb.DEF_ENUM] = "enums", + intentries = "intentries", + strentries = "strentries", + arrays = "arrays", + }) + for _, def in ipairs(defs) do + assert(def:is_frozen(), "can only dump frozen defs.") + linktab:add(def:def_type(), def) + local tables = gettables(def) + if tables then + for _, e in ipairs(tables.str.entries) do + linktab:add("strentries", e.ptr, e) + end + for _, e in ipairs(tables.int.entries) do + linktab:add("intentries", e.ptr, e) + end + for _, e in ipairs(tables.int.array) do + linktab:add("arrays", e.ptr, e) + end + end + end + + -- Emit forward declarations. + emit_file_warning(append) + append('#include "upb/def.h"\n\n') + append("const upb_msgdef %s;\n", linktab:cdecl(upb.DEF_MSG)) + append("const upb_fielddef %s;\n", linktab:cdecl(upb.DEF_FIELD)) + append("const upb_enumdef %s;\n", linktab:cdecl(upb.DEF_ENUM)) + append("const upb_tabent %s;\n", linktab:cdecl("strentries")) + append("const upb_tabent %s;\n", linktab:cdecl("intentries")) + append("const upb_value %s;\n", linktab:cdecl("arrays")) + append("\n") + + -- Emit defs. + local dumper = Dumper:new(linktab) + + append("const upb_msgdef %s = {\n", linktab:cdecl(upb.DEF_MSG)) + for m in linktab:objs(upb.DEF_MSG) do + local tables = gettables(m) + -- UPB_MSGDEF_INIT(name, itof, ntof) + append(' UPB_MSGDEF_INIT("%s", %s, %s, %s),\n', + m:full_name(), + dumper:inttable(tables.int), + dumper:strtable(tables.str), + m:_selector_count()) + end + append("};\n\n") + + append("const upb_fielddef %s = {\n", linktab:cdecl(upb.DEF_FIELD)) + for f in linktab:objs(upb.DEF_FIELD) do + local subdef = "NULL" + if f:has_subdef() then + subdef = string.format("upb_upcast(%s)", linktab:addr(f:subdef())) + end + -- UPB_FIELDDEF_INIT(label, type, name, num, msgdef, subdef, + -- selector_base, default_value) + append(' UPB_FIELDDEF_INIT(%s, %s, "%s", %d, %s, %s, %d, %s),\n', + const(f, "label"), const(f, "type"), f:name(), + f:number(), linktab:addr(f:msgdef()), subdef, + f:_selector_base(), + dumper:value(nil) -- TODO + ) + end + append("};\n\n") + + append("const upb_enumdef %s = {\n", linktab:cdecl(upb.DEF_ENUM)) + for e in linktab:objs(upb.DEF_ENUM) do + local tables = gettables(e) + -- UPB_ENUMDEF_INIT(name, ntoi, iton, defaultval) + append(' UPB_ENUMDEF_INIT("%s", %s, %s, %d),\n', + e:full_name(), + dumper:strtable(tables.str), + dumper:inttable(tables.int), + --e:default()) + 0) + end + append("};\n\n") + + append("const upb_tabent %s = {\n", linktab:cdecl("strentries")) + for ent in linktab:objs("strentries") do + append(dumper:tabent(ent)) + end + append("};\n\n"); + + append("const upb_tabent %s = {\n", linktab:cdecl("intentries")) + for ent in linktab:objs("intentries") do + append(dumper:tabent(ent)) + end + append("};\n\n"); + + append("const upb_value %s = {\n", linktab:cdecl("arrays")) + for ent in linktab:objs("arrays") do + append(dumper:arrayval(ent)) + end + append("};\n\n"); + + return linktab +end + +local function join(...) + return table.concat({...}, ".") +end + +local function to_cident(...) + return string.gsub(join(...), "%.", "_") +end + +local function to_preproc(...) + return string.upper(to_cident(...)) +end + +local function dump_defs_h(symtab, basename, append, linktab) + local ucase_basename = string.upper(basename) + emit_file_warning(append) + append('#ifndef %s_UPB_H_\n', ucase_basename) + append('#define %s_UPB_H_\n\n', ucase_basename) + append('#include "upb/def.h"\n\n') + append('#ifdef __cplusplus\n') + append('extern "C" {\n') + append('#endif\n\n') + + -- Dump C enums for proto enums. + append("// Enums\n\n") + for _, def in ipairs(symtab:getdefs(upb.DEF_ENUM)) do + local cident = to_cident(def:full_name()) + append('typedef enum {\n') + for k, v in def:values() do + append(' %s = %d,\n', to_preproc(cident, k), v) + end + append('} %s;\n\n', cident) + end + + -- Dump macros for referring to specific defs. + append("// Do not refer to these forward declarations; use the constants\n") + append("// below.\n") + append("extern const upb_msgdef %s;\n", linktab:cdecl(upb.DEF_MSG)) + append("extern const upb_fielddef %s;\n", linktab:cdecl(upb.DEF_FIELD)) + append("extern const upb_enumdef %s;\n\n", linktab:cdecl(upb.DEF_ENUM)) + append("// Constants for references to defs.\n") + append("// We hide these behind macros to decouple users from the\n") + append("// details of how we have statically defined them (ie. whether\n") + append("// each def has its own symbol or lives in an array of defs).\n") + for def in linktab:objs(upb.DEF_MSG) do + append("#define %s %s\n", to_preproc(def:full_name()), linktab:addr(def)) + end + append("\n") + + append('#ifdef __cplusplus\n') + append('}; // extern "C"\n') + append('#endif\n\n') + append('#endif // %s_UPB_H_\n', ucase_basename) +end + +function export.dump_defs(symtab, basename, append_h, append_c) + local linktab = dump_defs_c(symtab, basename, append_c) + dump_defs_h(symtab, basename, append_h, linktab) +end + +return export |