From f846bf70b0c97ce66f29b0ff88a50316924bf34e Mon Sep 17 00:00:00 2001 From: Anthony Ramine Date: Thu, 6 Jun 2013 01:34:25 +0200 Subject: Fix variable usage tracking in erl_lint When analyzing complex expressions (i.e. comprehensions, cases, tries, ifs and receives), erl_lint does not forget about old unused variables when returning the updated variable table. This causes a bug where old unused variables are not recorded as such: t(X, Y) -> #r{a=[ K || K <- Y ],b=[ K || K <- Y ]}. As erl_lint uses vtmerge_pat/2 to merge the results of the analysis of the two list comprehensions, X is marked as used and the warning is not emitted. The function vtmerge_pat/2 is used instead of the similar vtmerge/2 which does not mark multiple occurrences of a variable as usage to handle cases like the following one: t(X, Y) -> #r{a=A=X,b=A=Y}. Other simpler expressions like conses, tuples and external fun references do not correctly follow this behaviour, e.g. A is not marked as used in the following code: t(X, Y) -> {A=X,A=Y}. This commit fixes both issues and makes erl_lint not return old unused variables in updated tables and makes all compound expressions use vtmerge_pat/2. Reported-by: Anders Ramsell --- lib/stdlib/test/erl_lint_SUITE.erl | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'lib/stdlib/test/erl_lint_SUITE.erl') diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl index 4dc7a44064..0bcf9b3e01 100644 --- a/lib/stdlib/test/erl_lint_SUITE.erl +++ b/lib/stdlib/test/erl_lint_SUITE.erl @@ -151,7 +151,16 @@ unused_vars_warn_basic(Config) when is_list(Config) -> {22,erl_lint,{unused_var,'N'}}, {23,erl_lint,{shadowed_var,'N','fun'}}, {28,erl_lint,{unused_var,'B'}}, - {29,erl_lint,{unused_var,'B'}}]}}], + {29,erl_lint,{unused_var,'B'}}]}}, + {basic2, + <<"-record(r, {x,y}). + f({X,Y}) -> {Z=X,Z=Y}; + f([H|T]) -> [Z=H|Z=T]; + f(#r{x=X,y=Y}) -> #r{x=A=X,y=A=Y}. + g({M, F}) -> (Z=M):(Z=F)(); + g({M, F, Arg}) -> (Z=M):F(Z=Arg). + h(X, Y) -> (Z=X) + (Z=Y).">>, + [warn_unused_vars], []}], ?line [] = run(Config, Ts), ok. @@ -537,7 +546,21 @@ unused_vars_warn_rec(Config) when is_list(Config) -> end. ">>, [warn_unused_vars], - {warnings,[{22,erl_lint,{unused_var,'Same'}}]}}], + {warnings,[{22,erl_lint,{unused_var,'Same'}}]}}, + {rec2, + <<"-record(r, {a,b}). + f(X, Y) -> #r{a=[K || K <- Y], b=[K || K <- Y]}. + g(X, Y) -> #r{a=lists:map(fun (K) -> K end, Y), + b=lists:map(fun (K) -> K end, Y)}. + h(X, Y) -> #r{a=case Y of _ when is_list(Y) -> Y end, + b=case Y of _ when is_list(Y) -> Y end}. + i(X, Y) -> #r{a=if is_list(Y) -> Y end, b=if is_list(Y) -> Y end}. + ">>, + [warn_unused_vars], + {warnings,[{2,erl_lint,{unused_var,'X'}}, + {3,erl_lint,{unused_var,'X'}}, + {5,erl_lint,{unused_var,'X'}}, + {7,erl_lint,{unused_var,'X'}}]}}], ?line [] = run(Config, Ts), ok. -- cgit v1.2.3 From 9ce148b1059e4da746a11f1d80a653340216c468 Mon Sep 17 00:00:00 2001 From: Anthony Ramine Date: Mon, 22 Jul 2013 21:41:31 +0200 Subject: Fix unsafe variable tracking in try expressions Variables used in the body of a try expression were marked as unsafe *and* used, which makes no sense as an unsafe variable can't be used. Function vtsubtract/2 is used to forget usage of such unsafe variables. Reported-by: Paul Davis --- lib/stdlib/test/erl_lint_SUITE.erl | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'lib/stdlib/test/erl_lint_SUITE.erl') diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl index 0bcf9b3e01..a1a9839bae 100644 --- a/lib/stdlib/test/erl_lint_SUITE.erl +++ b/lib/stdlib/test/erl_lint_SUITE.erl @@ -1098,7 +1098,24 @@ unsafe_vars_try(Config) when is_list(Config) -> {10,erl_lint,{unsafe_var,'Ra',{'try',3}}}, {10,erl_lint,{unsafe_var,'Rc',{'try',3}}}, {10,erl_lint,{unsafe_var,'Ro',{'try',3}}}], - []}}], + []}}, + {unsafe_try5, + <<"bang() -> + case 1 of + nil -> + Acc = 2; + _ -> + try + Acc = 3, + Acc + catch _:_ -> + ok + end + end, + Acc. + ">>, + [], + {errors,[{13,erl_lint,{unsafe_var,'Acc',{'try',6}}}],[]}}], ?line [] = run(Config, Ts), ok. -- cgit v1.2.3 From 92460f4035e369be8726c88a72055d0fd6c7cdfe Mon Sep 17 00:00:00 2001 From: Anthony Ramine Date: Wed, 31 Jul 2013 10:31:51 +0200 Subject: Fix variable usage tracking in some record errors When reporting a field redefinition in a record, erl_lint can forget about some old unused variables. f() -> X = 1, #r{a=foo,a=bar,a=qux}. --- lib/stdlib/test/erl_lint_SUITE.erl | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'lib/stdlib/test/erl_lint_SUITE.erl') diff --git a/lib/stdlib/test/erl_lint_SUITE.erl b/lib/stdlib/test/erl_lint_SUITE.erl index a1a9839bae..48ddeac478 100644 --- a/lib/stdlib/test/erl_lint_SUITE.erl +++ b/lib/stdlib/test/erl_lint_SUITE.erl @@ -560,7 +560,15 @@ unused_vars_warn_rec(Config) when is_list(Config) -> {warnings,[{2,erl_lint,{unused_var,'X'}}, {3,erl_lint,{unused_var,'X'}}, {5,erl_lint,{unused_var,'X'}}, - {7,erl_lint,{unused_var,'X'}}]}}], + {7,erl_lint,{unused_var,'X'}}]}}, + {rec3, + <<"-record(r, {a}). + t() -> X = 1, #r{a=foo, a=bar, a=qux}. + ">>, + [warn_unused_vars], + {error,[{2,erl_lint,{redefine_field,r,a}}, + {2,erl_lint,{redefine_field,r,a}}], + [{2,erl_lint,{unused_var,'X'}}]}}], ?line [] = run(Config, Ts), ok. -- cgit v1.2.3