From c758fa81e1c48c56ff20ef2a95e6424c1e69033a Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Tue, 12 May 2015 06:34:54 +0200 Subject: sys_core_fold: Eliminate warnings for unused terms The optimization introduced in 0a0d39d351fc would cause spurious warnings of the type: "a term is constructed, but never used". To avoid the warning, we must mark not only tuples and lists as compiler_generated, but also each element. We must also propagate compiler_generated annotations in lets. For example, if we have: let = 42 in X + 1 we must propagate the compiler_generated annotation to the literal when do constant propagation: 42 -| ['compiler_generated'] + 1 --- lib/compiler/test/warnings_SUITE.erl | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'lib/compiler/test') diff --git a/lib/compiler/test/warnings_SUITE.erl b/lib/compiler/test/warnings_SUITE.erl index f6ba75577d..471ded219f 100644 --- a/lib/compiler/test/warnings_SUITE.erl +++ b/lib/compiler/test/warnings_SUITE.erl @@ -739,6 +739,14 @@ no_warnings(Config) when is_list(Config) -> case R0 of {r,V1,_V2,V3} -> {r,V1,\"def\",V3} end. + + d(In0, Bool) -> + {In1,Int} = case id(Bool) of + false -> {In0,0} + end, + [In1,Int]. + + id(I) -> I. ">>, [], []}], -- cgit v1.2.3