From e348250942a3d3fe1c96a6f2e1bfac9b442c9585 Mon Sep 17 00:00:00 2001 From: Jing Peng Date: Fri, 9 Dec 2016 21:42:45 -0500 Subject: Allow escripts with only two lines The current implementation assumes that escripts all have at least three lines. But according to the escript documentation, comments on the second line and emulator flags on the third line are all optional. Thus escripts with only two lines -- shebang on the first line and code on the second line -- will not run. This commit fixes the problem by rearranging the escript header parsing logic, and recognize the escript body on the second line if the header only contains a line of shebang. --- lib/stdlib/src/escript.erl | 83 ++++++++++++++-------------- lib/stdlib/test/escript_SUITE.erl | 15 ++++- lib/stdlib/test/escript_SUITE_data/two_lines | 2 + 3 files changed, 59 insertions(+), 41 deletions(-) create mode 100755 lib/stdlib/test/escript_SUITE_data/two_lines (limited to 'lib') diff --git a/lib/stdlib/src/escript.erl b/lib/stdlib/src/escript.erl index 7f5ef4df42..c42ae981e7 100644 --- a/lib/stdlib/src/escript.erl +++ b/lib/stdlib/src/escript.erl @@ -481,46 +481,49 @@ find_first_body_line(Fd, HeaderSz0, LineNo, KeepFirst, Sections) -> %% Look for special comment on second line Line2 = get_line(Fd), {ok, HeaderSz2} = file:position(Fd, cur), - case classify_line(Line2) of - emu_args -> - %% Skip special comment on second line - Line3 = get_line(Fd), - {HeaderSz2, LineNo + 2, Fd, - Sections#sections{type = guess_type(Line3), - comment = undefined, - emu_args = Line2}}; - Line2Type -> - %% Look for special comment on third line - Line3 = get_line(Fd), - {ok, HeaderSz3} = file:position(Fd, cur), - Line3Type = classify_line(Line3), - if - Line3Type =:= emu_args -> - %% Skip special comment on third line - Line4 = get_line(Fd), - {HeaderSz3, LineNo + 3, Fd, - Sections#sections{type = guess_type(Line4), - comment = Line2, - emu_args = Line3}}; - Sections#sections.shebang =:= undefined, - KeepFirst =:= true -> - %% No shebang. Use the entire file - {HeaderSz0, LineNo, Fd, - Sections#sections{type = guess_type(Line2)}}; - Sections#sections.shebang =:= undefined -> - %% No shebang. Skip the first line - {HeaderSz1, LineNo, Fd, - Sections#sections{type = guess_type(Line2)}}; - Line2Type =:= comment -> - %% Skip shebang on first line and comment on second - {HeaderSz2, LineNo + 2, Fd, - Sections#sections{type = guess_type(Line3), - comment = Line2}}; - true -> - %% Just skip shebang on first line - {HeaderSz1, LineNo + 1, Fd, - Sections#sections{type = guess_type(Line2)}} - end + if + Sections#sections.shebang =:= undefined, + KeepFirst =:= true -> + %% No shebang. Use the entire file + {HeaderSz0, LineNo, Fd, + Sections#sections{type = guess_type(Line2)}}; + Sections#sections.shebang =:= undefined -> + %% No shebang. Skip the first line + {HeaderSz1, LineNo, Fd, + Sections#sections{type = guess_type(Line2)}}; + true -> + case classify_line(Line2) of + emu_args -> + %% Skip special comment on second line + Line3 = get_line(Fd), + {HeaderSz2, LineNo + 2, Fd, + Sections#sections{type = guess_type(Line3), + comment = undefined, + emu_args = Line2}}; + comment -> + %% Look for special comment on third line + Line3 = get_line(Fd), + {ok, HeaderSz3} = file:position(Fd, cur), + Line3Type = classify_line(Line3), + if + Line3Type =:= emu_args -> + %% Skip special comment on third line + Line4 = get_line(Fd), + {HeaderSz3, LineNo + 3, Fd, + Sections#sections{type = guess_type(Line4), + comment = Line2, + emu_args = Line3}}; + true -> + %% Skip shebang on first line and comment on second + {HeaderSz2, LineNo + 2, Fd, + Sections#sections{type = guess_type(Line3), + comment = Line2}} + end; + _ -> + %% Just skip shebang on first line + {HeaderSz1, LineNo + 1, Fd, + Sections#sections{type = guess_type(Line2)}} + end end. classify_line(Line) -> diff --git a/lib/stdlib/test/escript_SUITE.erl b/lib/stdlib/test/escript_SUITE.erl index 28d69232a0..0b9106a99c 100644 --- a/lib/stdlib/test/escript_SUITE.erl +++ b/lib/stdlib/test/escript_SUITE.erl @@ -28,6 +28,7 @@ strange_name/1, emulator_flags/1, emulator_flags_no_shebang/1, + two_lines/1, module_script/1, beam_script/1, archive_script/1, @@ -49,7 +50,7 @@ suite() -> all() -> [basic, errors, strange_name, emulator_flags, - emulator_flags_no_shebang, + emulator_flags_no_shebang, two_lines, module_script, beam_script, archive_script, epp, create_and_extract, foldl, overflow, archive_script_file_access, unicode]. @@ -153,6 +154,18 @@ emulator_flags(Config) when is_list(Config) -> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +two_lines(Config) when is_list(Config) -> + Data = proplists:get_value(data_dir, Config), + Dir = filename:absname(Data), %Get rid of trailing slash. + run(Dir, "two_lines -arg1 arg2 arg3", + [<<"main:[\"-arg1\",\"arg2\",\"arg3\"]\n" + "ERL_FLAGS=false\n" + "unknown:[]\n" + "ExitCode:0">>]), + ok. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + emulator_flags_no_shebang(Config) when is_list(Config) -> Data = proplists:get_value(data_dir, Config), Dir = filename:absname(Data), %Get rid of trailing slash. diff --git a/lib/stdlib/test/escript_SUITE_data/two_lines b/lib/stdlib/test/escript_SUITE_data/two_lines new file mode 100755 index 0000000000..cf4e99639c --- /dev/null +++ b/lib/stdlib/test/escript_SUITE_data/two_lines @@ -0,0 +1,2 @@ +#! /usr/bin/env escript +main(MainArgs) -> io:format("main:~p\n", [MainArgs]), ErlArgs = init:get_arguments(), io:format("ERL_FLAGS=~p\n", [os:getenv("ERL_FLAGS")]), io:format("unknown:~p\n",[[E || E <- ErlArgs, element(1, E) =:= unknown]]). -- cgit v1.2.3