Merge branch 'bjorn/line-numbers-in-exceptions/OTP-9468' into major

* bjorn/line-numbers-in-exceptions/OTP-9468: (51 commits)
  debugger: By default, only save non-tail-recursive calls
  debugger: Add line_number_SUITE
  debugger: Include line numbers in exceptions
  Update examples in the documentation to include line numbers
  Update documentation for erlang:raise/3 and erlang:get_stacktrace/0
  beam_lib: Retain the "Line" chunk when stripping BEAM files
  erl: Add +L to suppress loading of line number information
  compiler: Add no_line_info for suppressing line/1 instructions
  exception_SUITE: Test line numbers in exceptions
  common_test: Use line numbers in exceptions
  common_test tests: Don't do detailed testing of the stack backtrace
  test_server: Refactor init_per_testcase/3 into two functions
  Implement process_info(Pid, current_{location,stacktrace})
  beam_emu: Factor out saving of stack trace from save_stacktrace()
  compiler: Don't create filenames starting with "./"
  ops.tab: Remove line instructions before tail-recursive calls
  Lookup and include filenames and line numbers in exceptions
  Fix decrement of continuation pointers
  Refactor building of the exception stacktrace
  BEAM loader: Load the line table
  ...

1 files changed, 50 insertions, 11 deletions

diff --git a/lib/compiler/src/beam_asm.erl b/lib/compiler/src/beam_asm.erl
index 89d64834cf..6e63c4d0f2 100644
--- a/lib/compiler/src/beam_asm.erl
+++ b/lib/compiler/src/beam_asm.erl
@@ -23,7 +23,7 @@
 -export([module/4]).
 -export([encode/2]).
 
--import(lists, [map/2,member/2,keymember/3,duplicate/2]).
+-import(lists, [map/2,member/2,keymember/3,duplicate/2,splitwith/2]).
 -include("beam_opcodes.hrl").
 
 module(Code, Abst, SourceFile, Opts) ->
@@ -31,22 +31,20 @@ module(Code, Abst, SourceFile, Opts) ->
 
 assemble({Mod,Exp,Attr0,Asm0,NumLabels}, Abst, SourceFile, Opts) ->
     {1,Dict0} = beam_dict:atom(Mod, beam_dict:new()),
+    {0,Dict1} = beam_dict:fname(atom_to_list(Mod) ++ ".erl", Dict0),
     NumFuncs = length(Asm0),
     {Asm,Attr} = on_load(Asm0, Attr0),
-    {Code,Dict1} = assemble_1(Asm, Exp, Dict0, []),
-    build_file(Code, Attr, Dict1, NumLabels, NumFuncs, Abst, SourceFile, Opts).
+    {Code,Dict2} = assemble_1(Asm, Exp, Dict1, []),
+    build_file(Code, Attr, Dict2, NumLabels, NumFuncs, Abst, SourceFile, Opts).
 
 on_load(Fs0, Attr0) ->
     case proplists:get_value(on_load, Attr0) of
 	undefined ->
 	    {Fs0,Attr0};
 	[{Name,0}] ->
-	    Fs = map(fun({function,N,0,Entry,Asm0}) when N =:= Name ->
-			     [{label,_}=L,
-			      {func_info,_,_,_}=Fi,
-			      {label,_}=E|Asm1] = Asm0,
-			     Asm = [L,Fi,E,on_load|Asm1],
-			     {function,N,0,Entry,Asm};
+	    Fs = map(fun({function,N,0,Entry,Is0}) when N =:= Name ->
+			     Is = insert_on_load_instruction(Is0, Entry),
+			     {function,N,0,Entry,Is};
 			(F) ->
 			     F
 		     end, Fs0),
@@ -54,6 +52,13 @@ on_load(Fs0, Attr0) ->
 	    {Fs,Attr}
     end.
 
+insert_on_load_instruction(Is0, Entry) ->
+    {Bef,[{label,Entry}=El|Is]} =
+	splitwith(fun({label,L}) when L =:= Entry -> false;
+		     (_) -> true
+		  end, Is0),
+    Bef ++ [El,on_load|Is].
+
 assemble_1([{function,Name,Arity,Entry,Asm}|T], Exp, Dict0, Acc) ->
     Dict1 = case member({Name,Arity}, Exp) of
 		true ->
@@ -132,7 +137,10 @@ build_file(Code, Attr, Dict, NumLabels, NumFuncs, Abst, SourceFile, Opts) ->
 			   LitTab = iolist_to_binary(zlib:compress(LitTab2)),
 			   chunk(<<"LitT">>, <<(byte_size(LitTab2)):32>>, LitTab)
 		   end,
+
+    %% Create the line chunk.
     
+    LineChunk = chunk(<<"Line">>, build_line_table(Dict)),
 
     %% Create the attributes and compile info chunks.
 
@@ -150,8 +158,11 @@ build_file(Code, Attr, Dict, NumLabels, NumFuncs, Abst, SourceFile, Opts) ->
     %% Create IFF chunk.
 
     Chunks = case member(slim, Opts) of
-		 true -> [Essentials,AttrChunk,AbstChunk];
-		 false -> [Essentials,LocChunk,AttrChunk,CompileChunk,AbstChunk]
+		 true ->
+		     [Essentials,AttrChunk,AbstChunk];
+		 false ->
+		     [Essentials,LocChunk,AttrChunk,
+		      CompileChunk,AbstChunk,LineChunk]
 	     end,
     build_form(<<"BEAM">>, Chunks).
 
@@ -201,6 +212,31 @@ build_attributes(Opts, SourceFile, Attr, Essentials) ->
     Compile = [{options,Opts},{version,?COMPILER_VSN}|Misc],
     {term_to_binary(calc_vsn(Attr, Essentials)),term_to_binary(Compile)}.
 
+build_line_table(Dict) ->
+    {NumLineInstrs,NumFnames0,Fnames0,NumLines,Lines0} =
+	beam_dict:line_table(Dict),
+    NumFnames = NumFnames0 - 1,
+    [_|Fnames1] = Fnames0,
+    Fnames2 = [unicode:characters_to_binary(F) || F <- Fnames1],
+    Fnames = << <<(byte_size(F)):16,F/binary>> || F <- Fnames2 >>,
+    Lines1 = encode_line_items(Lines0, 0),
+    Lines = iolist_to_binary(Lines1),
+    Ver = 0,
+    Bits = 0,
+    <<Ver:32,Bits:32,NumLineInstrs:32,NumLines:32,NumFnames:32,
+     Lines/binary,Fnames/binary>>.
+
+%% encode_line_items([{FnameIndex,Line}], PrevFnameIndex)
+%%  Encode the line items compactly. Tag the FnameIndex with
+%%  an 'a' tag (atom) and only include it when it has changed.
+%%  Tag the line numbers with an 'i' (integer) tag.
+
+encode_line_items([{F,L}|T], F) ->
+    [encode(?tag_i, L)|encode_line_items(T, F)];
+encode_line_items([{F,L}|T], _) ->
+    [encode(?tag_a, F),encode(?tag_i, L)|encode_line_items(T, F)];
+encode_line_items([], _) -> [].
+
 %%
 %% If the attributes contains no 'vsn' attribute, we'll insert one
 %% with an MD5 "checksum" calculated on the code as its value.
@@ -243,6 +279,9 @@ bif_type(_, 2)      -> bif2.
 
 make_op({'%',_}, Dict) ->
     {[],Dict};
+make_op({line,Location}, Dict0) ->
+    {Index,Dict} = beam_dict:line(Location, Dict0),
+    encode_op(line, [Index], Dict);
 make_op({bif, Bif, {f,_}, [], Dest}, Dict) ->
     %% BIFs without arguments cannot fail.
     encode_op(bif0, [{extfunc, erlang, Bif, 0}, Dest], Dict);