Store abstract code in the Dbgi chunk

The new Dbgi chunk returns data in the following format:

    {debug_info_v1, Backend, Data}

This allows compilers to store the debug info in different
formats. In order to retrieve a particular format, for
instance, Erlang Abstract Format, one may invoke:

    Backend:debug_info(erlang_v1, Module, Data, Opts)

Besides introducing the chunk above, this commit also:

  * Changes beam_lib:chunk(Beam, [:abstract_code]) to
    read from the new Dbgi chunk while keeping backwards
    compatibility with old .beams

  * Adds the {debug_info, {Backend, Data}} option to
    compile:file/2 and friends that are stored in the
    Dbgi chunk. This allows the debug info encryption
    mechanism to work across compilers

  * Improves dialyzer to work directly on Core Erlang,
    allowing languages that do not have the Erlang
    Abstract Format to be dialyzer as long as they emit
    the new chunk and their backend implementation is
    available

Backwards compatibility is kept across the board except
for those calling beam_lib:chunk(Beam, ["Abst"]), as the
old chunk is no longer available. Note however the "Abst"
chunk has always been optional.

Future OTP versions may remove parsing the "Abst" chunk
altogether from beam_lib once Erlang 19 and earlier is no
longer supported.

The current Dialyzer implementation still supports earlier
.beam files and such may also be removed in future versions.

2 files changed, 37 insertions, 9 deletions

diff --git a/lib/compiler/test/compilation_SUITE.erl b/lib/compiler/test/compilation_SUITE.erl
index cd1bc099e9..c98aa07a4f 100644
--- a/lib/compiler/test/compilation_SUITE.erl
+++ b/lib/compiler/test/compilation_SUITE.erl
@@ -319,7 +319,7 @@ self_compile_1(Config, Prefix, Opts) ->
     %% Compile the compiler. (In this node to get better coverage.)
     CompA = make_compiler_dir(Priv, Prefix++"compiler_a"),
     VsnA = Version ++ ".0",
-    compile_compiler(compiler_src(), CompA, VsnA, [clint0,clint|Opts]),
+    compile_compiler(compiler_src(), CompA, VsnA, Opts),
 
     %% Compile the compiler again using the newly compiled compiler.
     %% (In another node because reloading the compiler would disturb cover.)
diff --git a/lib/compiler/test/compile_SUITE.erl b/lib/compiler/test/compile_SUITE.erl
index 474c3e2ca0..11a62ce753 100644
--- a/lib/compiler/test/compile_SUITE.erl
+++ b/lib/compiler/test/compile_SUITE.erl
@@ -27,6 +27,7 @@
 -export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
 	 init_per_group/2,end_per_group/2,
 	 app_test/1,appup_test/1,
+	 debug_info/4, custom_debug_info/1,
 	 file_1/1, forms_2/1, module_mismatch/1, big_file/1, outdir/1,
 	 binary/1, makedep/1, cond_and_ifdef/1, listings/1, listings_big/1,
 	 other_output/1, kernel_listing/1, encrypted_abstr/1,
@@ -51,7 +52,7 @@ all() ->
      strict_record, utf8_atoms, extra_chunks,
      cover, env, core, core_roundtrip, asm, optimized_guards,
      sys_pre_attributes, dialyzer, warnings, pre_load_check,
-     env_compiler_options].
+     env_compiler_options, custom_debug_info].
 
 groups() -> 
     [].
@@ -504,17 +505,23 @@ encrypted_abstr_1(Simple, Target) ->
     {ok,simple} = compile:file(Simple,
 				     [debug_info,{debug_info_key,Key},
 				      {outdir,TargetDir}]),
-    verify_abstract(Target),
+    verify_abstract(Target, erl_abstract_code),
 
     {ok,simple} = compile:file(Simple,
 				     [{debug_info_key,Key},
 				      {outdir,TargetDir}]),
-    verify_abstract(Target),
+    verify_abstract(Target, erl_abstract_code),
 
     {ok,simple} = compile:file(Simple,
 				     [debug_info,{debug_info_key,{des3_cbc,Key}},
 				      {outdir,TargetDir}]),
-    verify_abstract(Target),
+    verify_abstract(Target, erl_abstract_code),
+
+    {ok,simple} = compile:file(Simple,
+				     [{debug_info,{?MODULE,ok}},
+				      {debug_info_key,Key},
+				      {outdir,TargetDir}]),
+    verify_abstract(Target, ?MODULE),
 
     {ok,{simple,[{compile_info,CInfo}]}} =
 	beam_lib:chunks(Target, [compile_info]),
@@ -539,7 +546,7 @@ encrypted_abstr_1(Simple, Target) ->
     NewKey = "better use another key here",
     write_crypt_file(["[{debug_info,des3_cbc,simple,\"",NewKey,"\"}].\n"]),
     {ok,simple} = compile:file(Simple, [encrypt_debug_info,report]),
-    verify_abstract("simple.beam"),
+    verify_abstract("simple.beam", erl_abstract_code),
     ok = file:delete(".erlang.crypt"),
     beam_lib:clear_crypto_key_fun(),
     {error,beam_lib,{key_missing_or_invalid,"simple.beam",abstract_code}} =
@@ -572,9 +579,10 @@ encrypted_abstr_no_crypto(Simple, Target) ->
 				{outdir,TargetDir},report]),
     ok.
     
-verify_abstract(Target) ->
-    {ok,{simple,[Chunk]}} = beam_lib:chunks(Target, [abstract_code]),
-    {abstract_code,{raw_abstract_v1,_}} = Chunk.
+verify_abstract(Beam, Backend) ->
+    {ok,{simple,[Abst, Dbgi]}} = beam_lib:chunks(Beam, [abstract_code, debug_info]),
+    {abstract_code,{raw_abstract_v1,_}} = Abst,
+    {debug_info,{debug_info_v1,Backend,_}} = Dbgi.
 
 has_crypto() ->
     try
@@ -593,6 +601,26 @@ install_crypto_key(Key) ->
     ok = beam_lib:crypto_key_fun(F).
 
 %% Miscellanous tests, mainly to get better coverage.
+debug_info(erlang_v1, Module, ok, _Opts) ->
+    {ok, [Module]};
+debug_info(erlang_v1, Module, error, _Opts) ->
+    {error, unknown_format}.
+
+custom_debug_info(Config) when is_list(Config) ->
+    {Simple,_} = get_files(Config, simple, "file_1"),
+
+    {ok,simple,OkBin} = compile:file(Simple, [binary, {debug_info,{?MODULE,ok}}]), %Coverage
+    {ok,{simple,[{abstract_code,{raw_abstract_v1,[simple]}}]}} =
+	beam_lib:chunks(OkBin, [abstract_code]),
+    {ok,{simple,[{debug_info,{debug_info_v1,?MODULE,ok}}]}} =
+	beam_lib:chunks(OkBin, [debug_info]),
+
+    {ok,simple,ErrorBin} = compile:file(Simple, [binary, {debug_info,{?MODULE,error}}]), %Coverage
+    {ok,{simple,[{abstract_code,no_abstract_code}]}} =
+	beam_lib:chunks(ErrorBin, [abstract_code]),
+    {ok,{simple,[{debug_info,{debug_info_v1,?MODULE,error}}]}} =
+	beam_lib:chunks(ErrorBin, [debug_info]).
+
 cover(Config) when is_list(Config) ->
     io:format("~p\n", [compile:options()]),
     ok.