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2017-05-12Warn for potentially unsafe use of get_stacktrace/0Björn Gustavsson
erlang:get_stacktrace/0 returns the stacktrace for the latest exception. The problem is that the stacktrace is kept until the next exception occurs. If the last exception was a 'function_clause' or a 'badarg', the arguments for the call are also kept forever. The arguments can be terms of any size (potentially huge). In a future release, we would like to only allow erlang:get_stacktrace/0 from within a 'try' expression. That would make it possible to clear the stacktrace when the 'try' expression is exited. The 'catch' expression has no natural end where the stacktrace could be cleared. The stacktrace could be cleared at the end of the function that the 'catch' occurs in, but that would cause problems in the following scenario (from real life, but simplified): try ... catch _:_ -> io:format(...), io:format("~p\n", [erlang:get_stacktrace()]) end. %% In io.erl. format(Fmt, Args) -> Res = case ... of SomePattern -> catch... ...; SomeOtherPattern -> %% Output the formatted string here ... end, clear_stacktrace(), %% Inserted by compiler. Res. The call to io:format() would always clear the stacktrace before it could be retrieved. That problem could be solved by tightning the scope in which the stacktrace is kept, but the rules for how long erlang:get_stacktrace/0 would work would become complicated. Therefore, the solution we suggest for a future major release of OTP is that erlang:get_stacktrace/0 will return [] if it is called outside the 'catch' part of a 'try' expression. To help users prepare, introduce a warning when it is likely that erlang:get_stacktrace/0 will always return an empty list, for example in this code: catch error(foo), Stk = erlang:get_stacktrace() or in this code: try Expr catch _:_ -> ok end, Stk = erlang:get_stacktrace()
2017-04-24stdlib: Add Unicode modifier t to control sequences w and WHans Bolinder
As of the introduction of Unicode characters in atoms, the control sequences 'w' and 'W' can return non-Latin-1 characters, unless some measure is taken. This commit makes sure that '~w' and '~W' always return Latin-1 characters, or bytes, which can be output to ports or written to raw files. The Unicode translation modifier 't' is needed to return non-Latin-1 characters.
2017-04-13stdlib: Add checks of the dialyzer attribute to the linterHans Bolinder
The same checks are also performed by the Dialyzer.
2017-03-16Don't allow module names with non-latin1 charactersBjörn Gustavsson
In OTP 20, all Unicode characters are allowed in atoms. However, we have decided that we will not allow non-latin1 characters in module names in OTP 20. This restriction may be lifted in a future major release of OTP. Enforce the restriction in erl_lint, so that it will be a compilation error to have a module name containing non-latin1 characters. That means that tools such as debugger, xref, dialyzer, syntax_tools, and so on, do not have to be modified to handle non-latin1 module names.
2017-03-08stdlib: Fix handling of locations and annotationsHans Bolinder
2016-11-29Make warn_export_all the defaultRichard Carlsson
2016-09-02Fix overridden BIFsBjörn Gustavsson
The filters in a list comprehension can be guard expressions or an ordinary expressions. If a guard expression is used as a filter, an exception will basically mean the same as 'false': t() -> L = [{some_tag,42},an_atom], [X || X <- L, element(1, X) =:= some_tag] %% Returns [{some_tag,42}] On the other hand, if an ordinary expression is used as a filter, there will be an exception: my_element(N, T) -> element(N, T). t() -> L = [{some_tag,42},an_atom], [X || X <- L, my_element(1, X) =:= some_tag] %% Causes a 'badarg' exception when element(1, an_atom) is evaluated It has been allowed for several releases to override a BIF with a local function. Thus, if we define a function called element/2, it will be called instead of the BIF element/2 within the module. We must use the "erlang:" prefix to call the BIF. Therefore, the following code is expected to work the same way as in our second example above: -compile({no_auto_import,[element/2]}). element(N, T) -> erlang:element(N, T). t() -> L = [{some_tag,42},an_atom], [X || X <- L, element(1, X) =:= some_tag]. %% Causes a 'badarg' exception when element(1, an_atom) is evaluated But the compiler refuses to compile the code with the following diagnostic: call to local/imported function element/2 is illegal in guard
2016-09-02Don't crash when obsolete guard overrides local functionBjörn Gustavsson
The compiler would crash in v3_codegen when trying to compile the following code: is_port(_) -> false. foo(P) when port(P) -> ok. We *could* have the compiler interpret the code as: is_port(_) -> false. foo(P) when erlang:is_port(P) -> ok. But that would encourage using the obsolete form of the guard tests. Note that the following code is illegal: is_port(_) -> false. foo(P) when is_port(P) -> ok. It produces the following diagnostic: call to local/imported function is_port/1 is illegal in guard Therefore, we should refuse to compile the code.
2016-06-09stdlib: Correct types and specsHans Bolinder
2016-06-09stdlib: Correct types and specsHans Bolinder
2016-05-02stdlib: Fix linting of map key variablesBjörn-Egil Dahlberg
Map keys cannot be bound and then used in parallel matching. Example: #{ K := V } = #{ k := K } = M. This is illegal if 'K' is not already bound.
2016-04-19stdlib: Fix warningsHans Bolinder
2016-04-18stdlib: The type map() is built-inHans Bolinder
2016-02-17stdlib: Let the linter detect old typed recordsHans Bolinder
2016-02-17stdlib: Update the linter to handle typed record fieldsHans Bolinder
2016-02-17Merge branch 'maint'Hans Bolinder
* maint: xmerl: Remove 'no_return' Dialyzer warnings xmerl: Add suppression of Dialyzer warnings eunit: Add suppression of Dialyzer warnings debugger: Add suppression of Dialyzer warnings kernel: Add suppression of Dialyzer warnings mnesia: Add suppression of Dialyzer warnings observer: Add suppression of Dialyzer warnings runtime_tools: Add suppression of Dialyzer warnings stdlib: Add suppression of Dialyzer warnings test_server: Add suppression of Dialyzer warnings tools: Add suppression of Dialyzer warnings Conflicts: lib/stdlib/src/erl_lint.erl lib/stdlib/src/otp_internal.erl
2016-02-17stdlib: Add suppression of Dialyzer warningsHans Bolinder
2016-01-20stdlib: Update erl_parse(3)Hans Bolinder
Calls to map_anno(), fold_anno(), and mapfold_anno() with lists of erl_parse trees have been replaced. Those functions accept lists of erl_parse trees, but it was not the intention when the functions were introduced, and it is not documented.
2016-01-13Merge branch 'maint'Hans Bolinder
* maint: stdlib: Fix linter crash due to missing -module declaration Conflicts: lib/stdlib/test/erl_lint_SUITE.erl
2016-01-13stdlib: Fix linter crash due to missing -module declarationHans Bolinder
The Erlang Code Linter no longer crashes if there is a -deprecated() attribute but no -module() declaration. See also ERL-62 at bugs.erlang.org.
2015-12-15stdlib: Remove undocumented function specification syntaxHans Bolinder
The syntax -spec/callback F/A :: FunctionType; has been removed. No deprecation was deemed necessary.
2015-12-04Merge branch 'maint'Björn Gustavsson
* maint: Extend erl_lint:format_error/1 to handle bittype mismatches erl_lint_SUITE: Add smoke test of format_error/1
2015-12-03Extend erl_lint:format_error/1 to handle bittype mismatchesBjörn Gustavsson
erl_lint:format_error/1 would crash with a function error if conflicting types were given. That was most easily noticed in the shell: Eshell V7.0.3 (abort with ^G) 1> <<0/integer-binary>>. *** ERROR: Shell process terminated! *** Noticed-by: Aleksei Magusev
2015-11-27Forbid bytes modifier for unsized part of binary generatorAleksei Magusev
This type modifier was missed in 90efeaf21147505b1e8207822e606027f94183cc.
2015-09-15stdlib: Remove deprecated functions in erl_parse and erl_scanHans Bolinder
The recently added module erl_anno can no longer handle negative line numbers.
2015-06-18Change license text to APLv2Bruce Yinhe
2015-06-02Merge branch 'josevalim/jv-annotate-form-type'Henrik Nord
* josevalim/jv-annotate-form-type: Annotate used types in erl_lint OTP-12800
2015-05-27Annotate used types in erl_lintJosé Valim
This is a follow up to commit b5ee5c6. Similar to function calls, we also need to annotate used types on call site since this information is used later on when showing undefined type errors. Notice we don't need to annotate the type export because it is an attribute and those are always properly annotated.
2015-05-26Merge branch 'josevalim/jv-annotate-form'Henrik Nord
* josevalim/jv-annotate-form: Only annotate forms when linting in the compiler OTP-12772
2015-05-22Only annotate forms when linting in the compilerJosé Valim
A lot of time spent on linting is due to eval_file_attribute/2 function that recursively traverses all the AST, annotating the file name on the AST nodes. This traversal happens so it is easier to add errors and warnings later on by simply introspecting the node. This patch changes eval_file_attribute/2 to only annotate forms (i.e. attributes and functions) and rely on the #lint record to keep the proper file information (which it already did before this patch). To summarize, both pre scan and pos scan will use the annotated file attribute in forms, however form/2 already maintains the proper file in #lint, which we pass around when retrieving the location information. After this patch, linting of a regular erlang module with 500LOC became twice faster when measured with eprof.
2015-05-21Remove final (?) vestiges of support for parameterized modulesBjörn Gustavsson
Parameterized modules were removed in cdf8060868575, but a few vestiges still remained in erl_lint.
2015-05-14Cache nowarn_bif_clash functions in erl_lintJosé Valim
When compiling parser files, because they rely heavily on inline annotations, retrieving the nowarn_bif_clash information from the compiler options is expensive. This patch stores nowarn_bif_clash in the lint record. By using erlc +'{eprof,lint_module}' when compiling the erlang parser, we noticed the time spent on nowarn_function/2 reduced from 30% to 0.01%.
2015-04-30stdlib: Use module erl_annoHans Bolinder
2015-02-25Merge branch 'nox/stdlib/erl_lint-maps/OTP-12515'Björn Gustavsson
* nox/stdlib/erl_lint-maps/OTP-12515: Properly lint map expressions in erl_lint
2015-02-25Merge branch 'nox/stdlib/erl_lint-expr_list'Björn Gustavsson
* nox/stdlib/erl_lint-expr_list: Remove a few superfluous vt operations in erl_lint
2015-02-22Remove a few superfluous vt operations in erl_lintAnthony Ramine
Given any Vt1 and Vt2 values, vtmerge(vtnew(Vt1, Vt2), vtold(Vt1, Vt2)) is always equal to Vt1.
2015-02-16Properly lint map expressions in erl_lintAnthony Ramine
The returned variable table when linting a map expression shouldn't include variables that didn't appear in the expression. Reported-By: Alexei Sholik
2015-01-14dialyzer: Introduce module local suppression of warningsHans Bolinder
The -dialyzer() attribute can be used for suppressing warnings in a module by specifying functions or warning options. It can also be used for requesting warnings in a module.
2014-11-20stdlib: remove the last traces of Mnemosyne RulesHans Bolinder
Robert has OK'ed the removal of the token ':-'.
2014-10-03Merge branch 'egil/maps/variable-keys/OTP-12218'Björn-Egil Dahlberg
* egil/maps/variable-keys/OTP-12218: (22 commits) compiler: Update test for Maps aliasing compiler: Properly support Map aliasing compiler: Refactor Map pairs aliasing compiler: Fix harmless need_heap error for Maps stdlib: Update Map tests stdlib: Use environment bindings for Maps keys in erl_eval matching debugger: Update Map tests compiler: Update Map tests compiler: Fix v3_core Maps pair chains compiler: Use expressions in core patterns compiler: Use variables in Map cerl inliner compiler: Reintroduce binary limit for Map keys compiler: Shameless v3_core hack for variables compiler: Use variables in Map beam assmebler compiler: Use variables in Map kernel pass compiler: Use variables in Map core pass compiler: Normalize unary ops on Maps key literals stdlib: Update Map tests stdlib: erl_lint Map key variables compiler: Maps are always patterns never values in matching ...
2014-09-22Merge branch 'nox/fix-exporting-rules/OTP-12186'Marcus Arendt
* nox/fix-exporting-rules/OTP-12186: Rewrite merge of clause variable tables (in case, try, etc)
2014-08-22stdlib: erl_lint Map key variablesBjörn-Egil Dahlberg
2014-08-02Rewrite merge of clause variable tables (in case, try, etc)Anthony Ramine
erl_lint:icrt_export/4 has been rewritten to make the code really follow the scoping rules of Erlang, and not just in most situations by accident. * The function should not depend on calling unused_vars/3 because that function does not return variables which begins with an underscore, something that only matters when emitting warnings. This could cause a compiler crash if such a variable was reused afterwards. * The variable tables from each clause are first merged together, lists:merge/1 is safe to use because they are orddicts and thus already sorted. This list is then traversed parallelly to the old variable table, again taking advantage of their sorted order. * The function does not emit warnings itself, there is no need to pass around the lint state. In the same vein, vtunsafe/3 has been rewritten to do more things by itself, given that all of its calls were similar. Finally, compiled-out code has been removed. * This reverts the code in 9ce148b1059e4da746a11f1d80a653340216c468, which fixed the compiler crash and made erl_lint remember unsafe variables, but forget about unused variables in the process. * Other places of the code which relied on the old clunky behaviour were also updated: unused and unsafe old variables are forgotten when merging fun clauses and boolean shortcircuiting operators do not rely on icrt_export/3 anymore.
2014-05-05Remove pre-defined types dict(), digraph(), &cHans Bolinder
The pre-defined types array(), dict(), digraph(), gb_set(), gb_tree(), queue(), set(), and tid() have been removed.
2014-04-29[stdlib] Simplify some linter warnings about specsHans Bolinder
Use F/A rather than M:F/A for local functions.
2014-04-29Modify representation of the map typeHans Bolinder
Types are represented by quadruples {type, LINE, Name, Args}, but maps were represented by five-tuples {type, LINE, map_field_assoc, Dom, Range}. Note: this is *not* about the quadruples used for representing expressions, {map_field_assoc,L,K,V}.
2014-04-29Fix a -callback attribute bugHans Bolinder
sys_pre_expand used to crash. There is no known reason to allow -callback attributes with explicit module.
2014-04-29Allow more type namesHans Bolinder
product/_, union/_, range/2 as well as tuple/N (N > 0), map/N (N > 0), atom/1, integer/1, binary/2, record/_, and 'fun'/_ can now be used as type names.
2014-04-28Introduce the attribute -optional_callbacks in the context of behavioursHans Bolinder
2014-04-16stdlib: Fix error message when exporting (redefined) map() typeHans Bolinder
When redefining and exporting the type map() erl_lint erroneously emitted an error. This bug has been fixed.