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-rw-r--r--lib/compiler/src/v3_core.erl69
1 files changed, 42 insertions, 27 deletions
diff --git a/lib/compiler/src/v3_core.erl b/lib/compiler/src/v3_core.erl
index 2da24b2908..e1a593fffa 100644
--- a/lib/compiler/src/v3_core.erl
+++ b/lib/compiler/src/v3_core.erl
@@ -1820,7 +1820,21 @@ upattern_list([], _, St) -> {[],[],[],[],St}.
%% upat_bin([Pat], [KnownVar], State) ->
%% {[Pat],[GuardTest],[NewVar],[UsedVar],State}.
upat_bin(Es0, Ks, St0) ->
- upat_bin(Es0, Ks, [], St0).
+ {Es1,Pg,Pv,Pu0,St1} = upat_bin(Es0, Ks, [], St0),
+
+ %% In a clause such as <<Sz:8,V:Sz>> in a function head, Sz will both
+ %% be new and used; a situation that is not handled properly by
+ %% uclause/4. (Basically, since Sz occurs in two sets that are
+ %% subtracted from each other, Sz will not be added to the list of
+ %% known variables and will seem to be new the next time it is
+ %% used in a match.)
+ %% Since the variable Sz really is new (it does not use a
+ %% value bound prior to the binary matching), Sz should only be
+ %% included in the set of new variables. Thus we should take it
+ %% out of the set of used variables.
+
+ Pu1 = subtract(Pu0, intersection(Pv, Pu0)),
+ {Es1,Pg,Pv,Pu1,St1}.
%% upat_bin([Pat], [KnownVar], [LocalVar], State) ->
%% {[Pat],[GuardTest],[NewVar],[UsedVar],State}.
@@ -1832,35 +1846,36 @@ upat_bin([], _, _, St) -> {[],[],[],[],St}.
%% upat_element(Segment, [KnownVar], [LocalVar], State) ->
-%% {Segment,[GuardTest],[NewVar],[UsedVar],[LocalVar],State}
-upat_element(#c_bitstr{val=H0,size=Sz}=Seg, Ks, Bs, St0) ->
- {H1,Hg,Hv,[],St1} = upattern(H0, Ks, St0),
- Bs1 = case H0 of
- #c_var{name=Hname} ->
- case H1 of
+%% {Segment,[GuardTest],[NewVar],[UsedVar],[LocalVar],State}
+upat_element(#c_bitstr{val=H0,size=Sz0}=Seg, Ks, Bs0, St0) ->
+ {H1,Hg,Hv,[],St1} = upattern(H0, Ks, St0),
+ Bs1 = case H0 of
#c_var{name=Hname} ->
- Bs;
- #c_var{name=Other} ->
- [{Hname, Other}|Bs]
- end;
- _ ->
- Bs
- end,
- {Sz1, Us} = case Sz of
- #c_var{name=Vname} ->
- rename_bitstr_size(Vname, Bs);
- _Other -> {Sz, []}
- end,
- {Seg#c_bitstr{val=H1, size=Sz1},Hg,Hv,Us,Bs1,St1}.
-
-rename_bitstr_size(V, [{V, N}|_]) ->
- New = #c_var{name=N},
- {New, [N]};
+ case H1 of
+ #c_var{name=Hname} ->
+ Bs0;
+ #c_var{name=Other} ->
+ [{Hname,Other}|Bs0]
+ end;
+ _ ->
+ Bs0
+ end,
+ {Sz1,Us} = case Sz0 of
+ #c_var{name=Vname} ->
+ rename_bitstr_size(Vname, Bs0);
+ _Other ->
+ {Sz0,[]}
+ end,
+ {Seg#c_bitstr{val=H1,size=Sz1},Hg,Hv,Us,Bs1,St1}.
+
+rename_bitstr_size(V, [{V,N}|_]) ->
+ New = #c_var{name=N},
+ {New,[N]};
rename_bitstr_size(V, [_|Rest]) ->
- rename_bitstr_size(V, Rest);
+ rename_bitstr_size(V, Rest);
rename_bitstr_size(V, []) ->
- Old = #c_var{name=V},
- {Old, [V]}.
+ Old = #c_var{name=V},
+ {Old,[V]}.
used_in_any(Les) ->
foldl(fun (Le, Ns) -> union((get_anno(Le))#a.us, Ns) end,