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authorBjörn Gustavsson <[email protected]>2012-08-22 14:54:45 +0200
committerBjörn Gustavsson <[email protected]>2012-08-22 16:16:26 +0200
commite4e5d08621137473674cf3cdce0b36a43a8d6d15 (patch)
treebe27bd18de935d599efa2b48363d9df6d0edc766 /lib/compiler/test/bs_construct_SUITE.erl
parent064b42237d891d5fdcb6c1a351980b8291437618 (diff)
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compiler: Warn if the size of a binary segment is invalid
The compiler would silently accept and Dialyzer would crash on code like: <<X:(2.5)>> It is never acceptable for Dialyzer to crash. The compiler should at least generate a warning for such code. It is tempting to let the compiler generate an error, but that would mean that code like: Sz = 42.0, <<X:Sz>>. would be possible to compile with optimizations disabled, but not with optimizations enabled. Dialyzer crashes because it calls cerl:bitstr_bitsize/1, which crashes if the type of size for the segment is invalid. The easiest way to avoid that crash is to extend the sanity checks in v3_core to also include the size field of binary segments. That will cause the compiler to issue a warning and to replace the bad binary construction with a call to erlang:error/1. (It also means that Dialyzer will not issue a warning for bad size fields.)
Diffstat (limited to 'lib/compiler/test/bs_construct_SUITE.erl')
-rw-r--r--lib/compiler/test/bs_construct_SUITE.erl4
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/compiler/test/bs_construct_SUITE.erl b/lib/compiler/test/bs_construct_SUITE.erl
index 31c7890f26..e8b30f44ce 100644
--- a/lib/compiler/test/bs_construct_SUITE.erl
+++ b/lib/compiler/test/bs_construct_SUITE.erl
@@ -468,6 +468,10 @@ opt(Config) when is_list(Config) ->
?line {'EXIT',_} = (catch <<<<23,56,0,2>>:64/float>>),
?line {'EXIT',_} = (catch <<<<23,56,0,2:7>>/binary>>),
+ %% Test constant propagation - there should be a warning.
+ BadSz = 2.5,
+ {'EXIT',_} = (catch <<<<N,56,0,2>>:BadSz/binary>>),
+
case id(false) of
true -> ?line opt_dont_call_me();
false -> ok