Output of independent artefacts might differ depending on unrelated options

[nagisa]

Existence or lack of --crate-type=bin may influence output of other crate-type outputs. In general libfoo.a output by --crate-type=bin,staticlib and --crate-type=staticlib might be completely different.

For example using this foo.rs, this is the list of a few first symbols when built with --crate-type=bin,staticlib and this, when bin crate-type is absent.

This is a quirk in rust’s entry point semantics and how current middle/entry.rs is implemented.

[nagisa]

The check whether the entry point is necessary or not should occur elsewhere.

[steveklabnik]

Triage: not aware of any changes here?

[Mark-Simulacrum]

I think that not much has changed here. The individual outputs are different, but the overall diff is the same: entry points are included in staticlib with --crate-type bin.

--- no-bin      2017-04-30 18:10:53.442645721 -0600
+++ bin 2017-04-30 18:10:48.398648634 -0600
@@ -1,5 +1,8 @@

 test.0.o:
+0000000000000000 T main
+                 U std::rt::lang_start::h8126425a59d3b4a0
+0000000000000000 t test::main::hf4d700377696cbb0

 std-35ad9950c7e5074b.0.o:
                  U abort

$ nm -C libtest.a | head -n 15

test.0.o:

std-35ad9950c7e5074b.0.o:
                 U abort
                 U accept
                 U backtrace_create_state
                 U backtrace_pcinfo
                 U backtrace_syminfo
                 U bind
0000000000000000 r byte_str.3f
0000000000000000 r byte_str.3r
0000000000000000 r byte_str.4B
0000000000000000 r byte_str.4D
0000000000000000 r byte_str.4f

$ nm -C libtest-bin.a | head -n 15

test.0.o:
0000000000000000 T main
                 U std::rt::lang_start::h8126425a59d3b4a0
0000000000000000 t test::main::hf4d700377696cbb0

std-35ad9950c7e5074b.0.o:
                 U abort
                 U accept
                 U backtrace_create_state
                 U backtrace_pcinfo
                 U backtrace_syminfo
                 U bind
0000000000000000 r byte_str.3f
0000000000000000 r byte_str.3r

[jyn514]

I'm not sure why this is marked as rustbuild, it seems to affect all binaries. Going to move this to T-compiler.