diff options
Diffstat (limited to 'lib/diameter/src/compiler')
| -rw-r--r-- | lib/diameter/src/compiler/diameter_exprecs.erl | 301 | ||||
| -rw-r--r-- | lib/diameter/src/compiler/modules.mk | 1 |
2 files changed, 302 insertions, 0 deletions
diff --git a/lib/diameter/src/compiler/diameter_exprecs.erl b/lib/diameter/src/compiler/diameter_exprecs.erl new file mode 100644 index 0000000000..5e120d6f44 --- /dev/null +++ b/lib/diameter/src/compiler/diameter_exprecs.erl @@ -0,0 +1,301 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2010-2011. All Rights Reserved. +%% +%% The contents of this file are subject to the Erlang Public License, +%% Version 1.1, (the "License"); you may not use this file except in +%% compliance with the License. You should have received a copy of the +%% Erlang Public License along with this software. If not, it can be +%% retrieved online at http://www.erlang.org/. +%% +%% Software distributed under the License is distributed on an "AS IS" +%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See +%% the License for the specific language governing rights and limitations +%% under the License. +%% +%% %CopyrightEnd% +%% + +%% +%% Parse transform for generating record access functions +%% +%% This parse transform can be used to reduce compile-time +%% dependencies in large systems. +%% +%% In the old days, before records, Erlang programmers often wrote +%% access functions for tuple data. This was tedious and error-prone. +%% The record syntax made this easier, but since records were implemented +%% fully in the pre-processor, a nasty compile-time dependency was +%% introduced. +%% +%% This module automates the generation of access functions for +%% records. While this method cannot fully replace the utility of +%% pattern matching, it does allow a fair bit of functionality on +%% records without the need for compile-time dependencies. +%% +%% Whenever record definitions need to be exported from a module, +%% inserting a compiler attribute, +%% +%% export_records([RecName, ...]) +%% +%% causes this transform to lay out access functions for the exported +%% records: +%% +%% -module(foo) +%% -compile({parse_transform, diameter_exprecs}). +%% +%% -record(r, {a, b, c}). +%% -export_records([a]). +%% +%% -export(['#info-'/1, '#info-'/2, +%% '#new-'/1, '#new-'/2, +%% '#get-'/2, '#set-'/2, +%% '#new-a'/0, '#new-a'/1, +%% '#get-a'/2, '#set-a'/2, +%% '#info-a'/1]). +%% +%% '#info-'(RecName) -> +%% '#info-'(RecName, fields). +%% +%% '#info-'(r, Info) -> +%% '#info-r'(Info). +%% +%% '#new-'(r) -> #r{}. +%% '#new-'(r, Vals) -> '#new-r'(Vals) +%% +%% '#new-r'() -> #r{}. +%% '#new-r'(Vals) -> '#set-r'(Vals, #r{}). +%% +%% '#get-'(Attrs, #r{} = Rec) -> +%% '#get-r'(Attrs, Rec). +%% +%% '#get-r'(Attrs, Rec) when is_list(Attrs) -> +%% ['#get-r'(A, Rec) || A <- Attrs]; +%% '#get-r'(a, Rec) -> Rec#r.a; +%% '#get-r'(b, Rec) -> Rec#r.b; +%% '#get-r'(c, Rec) -> Rec#r.c. +%% +%% '#set-'(Vals, #r{} = Rec) -> +%% '#set-r'(Vals, Rec). +%% +%% '#set-r'(Vals, Rec) when is_list(Vals) -> +%% lists:foldl(fun '#set-r'/2, Rec, Vals); +%% '#set-r'({a,V}, Rec) -> Rec#r{a = V}; +%% '#set-r'({b,V}, Rec) -> Rec#r{b = V}; +%% '#set-r'({c,V}, Rec) -> Rec#r{c = V}. +%% +%% '#info-r'(fields) -> record_info(fields, r); +%% '#info-r'(size) -> record_info(size, r); +%% '#info-r'({index, a}) -> 1; +%% '#info-r'({index, b}) -> 2; +%% '#info-r'({index, c}) -> 3; +%% + +-module(diameter_exprecs). + +-export([parse_transform/2]). + +%% Form tag with line number. +-define(F(T), T, ?LINE). +%% Yes, that's right. The replacement is to the first unmatched ')'. + +-define(attribute, ?F(attribute)). +-define(clause, ?F(clause)). +-define(function, ?F(function)). +-define(call, ?F(call)). +-define('fun', ?F('fun')). +-define(generate, ?F(generate)). +-define(lc, ?F(lc)). +-define(match, ?F(match)). +-define(remote, ?F(remote)). +-define(record, ?F(record)). +-define(record_field, ?F(record_field)). +-define(record_index, ?F(record_index)). +-define(tuple, ?F(tuple)). + +-define(ATOM(T), {atom, ?LINE, T}). +-define(VAR(V), {var, ?LINE, V}). + +-define(CALL(F,A), {?call, ?ATOM(F), A}). +-define(APPLY(M,F,A), {?call, {?remote, ?ATOM(M), ?ATOM(F)}, A}). + +%% parse_transform/2 + +parse_transform(Forms, _Options) -> + Rs = [R || {attribute, _, record, R} <- Forms], + case lists:append([E || {attribute, _, export_records, E} <- Forms]) of + [] -> + Forms; + Es -> + {H,T} = lists:splitwith(fun is_head/1, Forms), + H ++ [a_export(Es) | f_accessors(Es, Rs)] ++ T + end. + +is_head(T) -> + not lists:member(element(1,T), [function, eof]). + +%% a_export/1 + +a_export(Exports) -> + {?attribute, export, [{fname(info), 1}, + {fname(info), 2}, + {fname(new), 1}, + {fname(new), 2}, + {fname(get), 2}, + {fname(set), 2} + | lists:flatmap(fun export/1, Exports)]}. + +export(Rname) -> + New = fname(new, Rname), + [{New, 0}, + {New, 1}, + {fname(get, Rname), 2}, + {fname(set, Rname), 2}, + {fname(info, Rname), 1}]. + +%% f_accessors/2 + +f_accessors(Es, Rs) -> + ['#info-/1'(), + '#info-/2'(Es), + '#new-/1'(Es), + '#new-/2'(Es), + '#get-/2'(Es), + '#set-/2'(Es) + | lists:flatmap(fun(N) -> accessors(N, fields(N, Rs)) end, Es)]. + +accessors(Rname, Fields) -> + ['#new-X/0'(Rname), + '#new-X/1'(Rname), + '#get-X/2'(Rname, Fields), + '#set-X/2'(Rname, Fields), + '#info-X/1'(Rname, Fields)]. + +fields(Rname, Recs) -> + {Rname, Fields} = lists:keyfind(Rname, 1, Recs), + lists:map(fun({record_field, _, {atom, _, N}}) -> N; + ({record_field, _, {atom, _, N}, _}) -> N + end, + Fields). + +fname_prefix(Op) -> + "#" ++ atom_to_list(Op) ++ "-". + +fname(Op) -> + list_to_atom(fname_prefix(Op)). + +fname(Op, Rname) -> + Prefix = fname_prefix(Op), + list_to_atom(Prefix ++ atom_to_list(Rname)). + +%% Generated functions. + +'#info-/1'() -> + Fname = fname(info), + {?function, Fname, 1, + [{?clause, [?VAR('RecName')], + [], + [?CALL(Fname, [?VAR('RecName'), ?ATOM(fields)])]}]}. + +'#info-/2'(Exports) -> + {?function, fname(info), 2, + lists:map(fun 'info-'/1, Exports)}. + +'info-'(R) -> + {?clause, [?ATOM(R), ?VAR('Info')], + [], + [?CALL(fname(info, R), [?VAR('Info')])]}. + +'#new-/1'(Exports) -> + {?function, fname(new), 1, + lists:map(fun 'new-'/1, Exports)}. + +'new-'(R) -> + {?clause, [?ATOM(R)], + [], + [{?record, R, []}]}. + +'#new-/2'(Exports) -> + {?function, fname(new), 2, + lists:map(fun 'new--'/1, Exports)}. + +'new--'(R) -> + {?clause, [?ATOM(R), ?VAR('Vals')], + [], + [?CALL(fname(new, R), [?VAR('Vals')])]}. + +'#get-/2'(Exports) -> + {?function, fname(get), 2, + lists:map(fun 'get-'/1, Exports)}. + +'get-'(R) -> + {?clause, [?VAR('Attrs'), + {?match, {?record, R, []}, ?VAR('Rec')}], + [], + [?CALL(fname(get, R), [?VAR('Attrs'), ?VAR('Rec')])]}. + +'#set-/2'(Exports) -> + {?function, fname(set), 2, + lists:map(fun 'set-'/1, Exports)}. + +'set-'(R) -> + {?clause, [?VAR('Vals'), {?match, {?record, R, []}, ?VAR('Rec')}], + [], + [?CALL(fname(set, R), [?VAR('Vals'), ?VAR('Rec')])]}. + +'#new-X/0'(Rname) -> + {?function, fname(new, Rname), 0, + [{?clause, [], + [], + [{?record, Rname, []}]}]}. + +'#new-X/1'(Rname) -> + {?function, fname(new, Rname), 1, + [{?clause, [?VAR('Vals')], + [], + [?CALL(fname(set, Rname), [?VAR('Vals'), {?record, Rname, []}])]}]}. + +'#set-X/2'(Rname, Fields) -> + {?function, fname(set, Rname), 2, + [{?clause, [?VAR('Vals'), ?VAR('Rec')], + [[?CALL(is_list, [?VAR('Vals')])]], + [?APPLY(lists, foldl, [{?'fun', {function, fname(set, Rname), 2}}, + ?VAR('Rec'), + ?VAR('Vals')])]} + | lists:map(fun(A) -> 'set-X'(Rname, A) end, Fields)]}. + +'set-X'(Rname, Attr) -> + {?clause, [{?tuple, [?ATOM(Attr), ?VAR('V')]}, ?VAR('Rec')], + [], + [{?record, ?VAR('Rec'), Rname, + [{?record_field, ?ATOM(Attr), ?VAR('V')}]}]}. + +'#get-X/2'(Rname, Fields) -> + FName = fname(get, Rname), + {?function, FName, 2, + [{?clause, [?VAR('Attrs'), ?VAR('Rec')], + [[?CALL(is_list, [?VAR('Attrs')])]], + [{?lc, ?CALL(FName, [?VAR('A'), ?VAR('Rec')]), + [{?generate, ?VAR('A'), ?VAR('Attrs')}]}]} + | lists:map(fun(A) -> 'get-X'(Rname, A) end, Fields)]}. + +'get-X'(Rname, Attr) -> + {?clause, [?ATOM(Attr), ?VAR('Rec')], + [], + [{?record_field, ?VAR('Rec'), Rname, ?ATOM(Attr)}]}. + +'#info-X/1'(Rname, Fields) -> + {?function, fname(info, Rname), 1, + [{?clause, [?ATOM(fields)], + [], + [?CALL(record_info, [?ATOM(fields), ?ATOM(Rname)])]}, + {?clause, [?ATOM(size)], + [], + [?CALL(record_info, [?ATOM(size), ?ATOM(Rname)])]} + | lists:map(fun(A) -> 'info-X'(Rname, A) end, Fields)]}. + +'info-X'(Rname, Attr) -> + {?clause, [{?tuple, [?ATOM(index), ?ATOM(Attr)]}], + [], + [{?record_index, Rname, ?ATOM(Attr)}]}. diff --git a/lib/diameter/src/compiler/modules.mk b/lib/diameter/src/compiler/modules.mk index 4b40e99a3e..6fbc8fa8d4 100644 --- a/lib/diameter/src/compiler/modules.mk +++ b/lib/diameter/src/compiler/modules.mk @@ -19,6 +19,7 @@ MODULES = \ diameter_codegen \ + diameter_exprecs \ diameter_spec_scan \ diameter_spec_util \ diameter_make |