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diff --git a/lib/compiler/doc/src/notes.xml b/lib/compiler/doc/src/notes.xml index 449453bf88..f11444137d 100644 --- a/lib/compiler/doc/src/notes.xml +++ b/lib/compiler/doc/src/notes.xml @@ -4,7 +4,7 @@ <chapter> <header> <copyright> - <year>2004</year><year>2016</year> + <year>2004</year><year>2018</year> <holder>Ericsson AB. All Rights Reserved.</holder> </copyright> <legalnotice> @@ -32,6 +32,1062 @@ <p>This document describes the changes made to the Compiler application.</p> +<section><title>Compiler 7.4.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a compiler crash introduced in <c>22.0.6</c> + (OTP-15952).</p> + <p> + Own Id: OTP-15953 Aux Id: ERL-999 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.4.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed an unsafe optimization when matching + <c>tuple_size/1</c> outside of guards, which could crash + the emulator if the argument was not a tuple.</p> + <p> + Own Id: OTP-15945</p> + </item> + <item> + <p>Fixed a rare bug that could cause the wrong kind of + exception to be thrown when a BIF failed in a function + that matched bitstrings.</p> + <p> + Own Id: OTP-15946</p> + </item> + <item> + <p>Fixed a bug where receive statements inside try/catch + blocks could return incorrect results.</p> + <p> + Own Id: OTP-15952</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.4.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed an incorrect type determination for constructed + binaries, which could cause <c>is_binary</c> checks to + succeed when they shouldn't have.</p> + <p> + Own Id: OTP-15872</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.4.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The type optimization pass of the compiler could hang + or loop for a long time when analyzing a + <c>setelement/3</c> call with a varible position.</p> + <p> + Own Id: OTP-15828 Aux Id: ERL-948 </p> + </item> + <item> + <p>Certain complex receive statements would result in an + internal compiler failure.</p> + <p> + Own Id: OTP-15832 Aux Id: ERL-950 </p> + </item> + <item> + <p>Fixed an unsafe type optimization.</p> + <p> + Own Id: OTP-15838</p> + </item> + <item> + <p>Fixed a crash when optimizing compiler-generated + exceptions (like badmatch) whose offending term was a + constructed binary.</p> + <p> + Own Id: OTP-15839 Aux Id: ERL-954 </p> + </item> + <item> + <p>Fixed a bad optimization related to the <c>++/2</c> + operator, where the compiler assumed that it always + produced a list (<c>[] ++ RHS</c> returns <c>RHS</c> + verbatim, even if it's not a list).</p> + <p> + Own Id: OTP-15841</p> + </item> + <item> + <p>An <c>is_binary/1</c> test followed by + <c>is_bitstring/1</c> (or vice versa) could fail because + of an usafe optimization.</p> + <p> + Own Id: OTP-15845</p> + </item> + <item> + <p>A Core Erlang module where the last clause in a + <c>case</c> matched a map would fail to load.</p> + <p> + Own Id: OTP-15846 Aux Id: ERL-955 </p> + </item> + <item> + <p>Fixed a bug that could cause the compiler to crash + when compiling complex nested case expressions.</p> + <p> + Own Id: OTP-15848 Aux Id: ERL-956 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p><c>record_info/2</c> is a pseudo-function that + requires literal arguments known at compile time. + Therefore, the following usage is illegal: <c>fun + record/info/2</c>. The compiler would crash when during + compilation of that kind of code. Corrected to issue a + compilation error.</p> + <p> + Own Id: OTP-15760 Aux Id: ERL-907 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The compiler has been rewritten to internally use an + intermediate representation based on Static Single + Assignment (SSA). The new intermediate representation + makes more optimizations possible.</p> + <p> + Most noticeable is that the binary matching optimizations + are now applicable in many more circumstances than + before.</p> + <p> + Another noticeable change is that type optimizations are + now applied across local function calls, and will remove + a lot more redundant type tests than before.</p> + <p> + Own Id: OTP-14894 Aux Id: ERL-714 </p> + </item> + <item> + <p>Funs are no longer created when they are only used + locally, greatly improving the performance of named funs + and "fun-wrapped" macros.</p> + <p> + Own Id: OTP-15273 Aux Id: ERL-639 </p> + </item> + <item> + <p>All compiler options that can be given in the source + file can now also be given in the option list or from the + command line for <c>erlc</c>.</p> + <p>Specifically, the option + <c>{nowarn_deprecated_function,MFAs}</c> was only + recognized when given in the file with the attribute + <c>-compile()</c>. The option + <c>{nowarn_unused_function,FAs}</c> was incorrectly + documented to only work in a file, but it also worked + when given in the option list.</p> + <p> + Own Id: OTP-15456</p> + </item> + <item> + <p> Do not allow function specifications for functions + residing in other modules. </p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-15563 Aux Id: ERL-845, OTP-15562 </p> + </item> + <item> + <p>Internal documentation has now been added to the + <em>Erts</em> and <em>Compiler</em> applications.</p> + <p>The internal documents for <em>Erts</em> describe + miscellaneous interesting implementation details. Those + details can change at any time.</p> + <p>The internal documentation for <em>Compiler</em> + documents the API for the Core Erlang modules. While we + will not change those APIs without good reason, we don't + give the same guarantees about backward compatibility as + for the rest of the APIs in OTP.</p> + <p> + Own Id: OTP-15715</p> + </item> + <item> + <p> There are new compiler options <c>nowarn_removed</c> + and <c>{nowarn_removed,Items}</c> to suppress warnings + for functions and modules that have been removed from + OTP.</p> + <p> + Own Id: OTP-15749 Aux Id: ERL-904 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.3.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>An expression such as <c>(A / B) band 16#ff</c> would + crash the compiler.</p> + <p> + Own Id: OTP-15518 Aux Id: ERL-829 </p> + </item> + <item> + <p>There could be an incorrect warning when the + <c>tuple_calls</c> option was given. The generated code + would be correct. Here is an example of code that would + trigger the warning:</p> + <p><c>(list_to_atom("prefix_" ++ + atom_to_list(suffix))):doit(X)</c>.</p> + <p> + Own Id: OTP-15552 Aux Id: ERL-838 </p> + </item> + <item> + <p>Optimize (again) Dialyzer's handling of + left-associative use of <c>andalso</c> and <c>orelse</c> + in guards.</p> + <p> + Own Id: OTP-15577 Aux Id: ERL-851, PR-2141, PR-1944 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.3.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>An optimization that avoided allocation of a stack + frame for some <c>case</c> expressions was introduced in + OTP 21. (ERL-504/OTP-14808) It turns out that in rare + circumstances, this optimization is not safe. Therefore, + this optimization has been disabled.</p> + <p>A similar optimization will be included in OTP 22 in a + safe way.</p> + <p> + Own Id: OTP-15501 Aux Id: ERL-807, ERL-514, OTP-14808 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a rare internal consistency failure caused by a + bug in the <c>beam_jump</c> pass. (Thanks to Simon + Cornish for reporting this bug.)</p> + <p> + Own Id: OTP-15400 Aux Id: ERL-759 </p> + </item> + <item> + <p>The compiler could fail with an internal consistency + check failure when compiling code that used the + <c>is_function/2</c> BIF.</p> + <p> + Own Id: OTP-15435 Aux Id: ERL-778 </p> + </item> + <item> + <p>When an external fun was used, warnings for unused + variables could be suppressed.</p> + <p> + Own Id: OTP-15437 Aux Id: ERL-762 </p> + </item> + <item> + <p>The compiler would crash when compiling an + <c>after</c> block that called <c>erlang:raise/3</c> like + this: <c>erlang:raise(Class, Stacktrace, + Stacktrace)</c></p> + <p> + Own Id: OTP-15481</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>When specified, the <c>+{source,Name}</c> option will + now override the actual file name in stack traces, + instead of only affecting the return value of + <c>Mod:module_info()</c>.</p> + <p>The <c>+deterministic</c> flag will also affect stack + traces now, omitting all path information except the file + name, fixing a long-standing issue where deterministic + builds required deterministic paths.</p> + <p> + Own Id: OTP-15245 Aux Id: ERL-706 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.7</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a bug where incorrect code was generated + following a binary match guard.</p> + <p> + Own Id: OTP-15353 Aux Id: ERL-753 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.6</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>In rare circumstances, the matched out tail of a + binary could be the entire original binary. (There was + partial correction to this problem in version 7.2.5 of + the compiler application.)</p> + <p> + Own Id: OTP-15335 Aux Id: ERL-689, OTP-15219 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed a bug that prevented certain variable-sized + binary comprehensions from compiling.</p> + <p> + Own Id: OTP-15186 Aux Id: ERL-665 </p> + </item> + <item> + <p>When compiling from Core Erlang, funs created in + certain expressions that were only used for their + side-effects were subtly broken.</p> + <p> + Own Id: OTP-15188 Aux Id: ERL-658 </p> + </item> + <item> + <p>There could be an internal consistency failure when a + <c>receive</c> was nested in a + <c>try</c>/<c>catch</c>.</p> + <p> + Own Id: OTP-15218 Aux Id: ERL-684 </p> + </item> + <item> + <p>In rare circumstances, the matched out tail of a + binary could be the entire original binary.</p> + <p> + Own Id: OTP-15219 Aux Id: ERL-689 </p> + </item> + <item> + <p>When <c>is_map_key/2</c> was used in a guard together + with the <c>not/1</c> or <c>or/2</c> operators, the error + behavior could be wrong when <c>is_map_key/2</c> was + passed a non-map as the second argument. </p> + <p>In rare circumstances, compiling code that uses + <c>is_map_key/2</c> could cause an internal consistency + check failure.</p> + <p> + Own Id: OTP-15227 Aux Id: ERL-699 </p> + </item> + <item> + <p>The compiler could crash when compiling a function + with multiple receives in multiple clauses.</p> + <p> + Own Id: OTP-15235 Aux Id: ERL-703 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fix a regression in OTP-15204 that removed + <c>.beam</c> file metadata that some external build tools + relied on.</p> + <p> + Own Id: OTP-15292</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed an issue where files compiled with the + <c>+deterministic</c> option differed if they were + compiled in a different directory but were otherwise + identical.</p> + <p> + Own Id: OTP-15204 Aux Id: ERL-679 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>In rare cases involving matching of binary literal + strings, the compiler could optimize away code that + should be executed.</p> + <p> + Own Id: OTP-15156 Aux Id: ERL-655 </p> + </item> + <item> + <p>There could be an internal consistency check failure + when compiling code that called <c>map_get(Key, Map)</c> + and then updated the same map.</p> + <p> + Own Id: OTP-15157</p> + </item> + <item> + <p>In rare circumstances, the compiler could crash in + <c>beam_jump</c> when compiling a floating point + operation.</p> + <p> + Own Id: OTP-15166 Aux Id: ERL-660 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The could could crash when compiling a complicated + function that used the binary syntax.</p> + <p> + Own Id: OTP-15150 Aux Id: ERL-650 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed an error in an optimization pass that caused + impossible tuple matching.</p> + <p> + Own Id: OTP-14855 Aux Id: ERL-549 </p> + </item> + <item> + <p>The exception thrown when a list comprehension was + given a non-list term was not always correct.</p> + <p> + Own Id: OTP-14992 Aux Id: ERL-572 </p> + </item> + <item> + <p>The compiler could produce incorrect code in rare + circumstances when the <c>[{inline,F/A}]</c> option was + used.</p> + <p> + Own Id: OTP-15115 Aux Id: PR-1831 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>Changed the default behaviour of <c>.erlang</c> + loading: <c>.erlang</c> is no longer loaded from the + current directory. <c>c:erlangrc(PathList)</c> can be + used to search and load an <c>.erlang</c> file from user + specified directories.</p> <p><c>escript</c>, + <c>erlc</c>, <c>dialyzer</c> and <c>typer</c> no longer + load an <c>.erlang</c> at all.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14439</p> + </item> + <item> + <p>Support for "tuple calls" have been removed from the + run-time system. Tuple calls was an undocumented and + unsupported feature which allowed the module argument for + an apply operation to be a tuple: <c>Var = dict:new(), + Var:size()</c>. This "feature" frequently caused + confusion, especially when such call failed. The + stacktrace would point out functions that don't exist in + the source code.</p> + <p>For legacy code that need to use parameterized modules + or tuple calls for some other reason, there is a new + compiler option called <c>tuple_calls</c>. When this + option is given, the compiler will generate extra code + that emulates the old behavior for calls where the module + is a variable.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-14497</p> + </item> + <item> + <p>In code such as <c>example({ok, Val}) -> {ok, + Val}.</c> a tuple would be built. The compiler will now + automatically rewrite the code to + <c>example({ok,Val}=Tuple) -> Tuple.</c> which will + reduce code size, execution time, and remove GC + pressure.</p> + <p> + Own Id: OTP-14505</p> + </item> + <item> + <p>The optimization of <c>case</c> expression where only + one of the case arms can execute successfully has been + improved.</p> + <p> + Own Id: OTP-14525</p> + </item> + <item> + <p>Some uses of binary matching has been slightly + improved, eliminating unnecessary register shuffling.</p> + <p> + Own Id: OTP-14594 Aux Id: ERL-444 </p> + </item> + <item> + <p>There is a new <c>{compile_info,Info}</c> option for + the compiler that allows BEAM-based languages such as + Elixir and LFE to add their own compiler versions.</p> + <p> + Own Id: OTP-14615 Aux Id: PR-1558 </p> + </item> + <item> + <p>Loaded BEAM code in a 64-bit system requires less + memory because of better packing of operands for + instructions.</p> + <p>These memory savings were achieved by major + improvements to the <c>beam_makeops</c> scripts used when + building the run time system and BEAM compiler. There is + also new for documentation for <c>beam_makeops</c> that + describes how new BEAM instructions and loader + transformations can be implemented. The documentation is + found in here in a source directory or git repository: + erts/emulator/internal_doc/beam_makeops.md. An online + version can be found here: + https://github.com/erlang/otp/blob/master/erts/emulator/internal_doc/beam_makeops.md</p> + <p> + Own Id: OTP-14626</p> + </item> + <item> + <p>Size calculations for binary constructions has been + somewhat optimized, producing smaller code.</p> + <p> + Own Id: OTP-14654</p> + </item> + <item> + <p>When the value returned from a '<c>catch</c>' + expression is ignored, no stacktrace will be built if an + exception is caught. That will save time and produce less + garbage. There are also some minor optimizations of + '<c>try</c>/<c>catch</c>' both in the compiler and + run-time system.</p> + <p> + Own Id: OTP-14683</p> + </item> + <item> + <p>There is a new syntax in '<c>try/catch</c>' for + retrieving the stacktrace without calling + '<c>erlang:get_stacktrace/0</c>'. See the reference + manual for a description of the new syntax. The + '<c>erlang:get_stacktrace/0</c>' BIF is now + deprecated.</p> + <p> + Own Id: OTP-14692</p> + </item> + <item> + <p>The following is an internal change in the compiler, + that is not noticeable for normal use of the compiler: + The module <c>v3_life</c> has been removed. Its + functionality has been simplified and integrated into + <c>v3_codegen</c>.</p> + <p> + Own Id: OTP-14712</p> + </item> + <item> + <p>The optimization of binary matching that delays + creation of sub binaries (see the Efficiency Guide) could + be thwarted by the argument order and could be necessary + to change the argument order. The compiler has now become + smarter and can handle any argument order.</p> + <p> + Own Id: OTP-14774</p> + </item> + <item> + <p>When the compiler was faced with complex case + expressions it would unnecessarily allocate stack + elements and shuffle data between x and y registers. + Improved code generation to only allocate a stack frame + when strictly necessary.</p> + <p> + Own Id: OTP-14808 Aux Id: ERL-514 </p> + </item> + <item> + <p>There is a new option '<c>makedep_side_effect</c>' for + the compiler and <c>-MMD</c> for '<c>erlc</c>' that + generates dependencies and continues to compile as + normal.</p> + <p> + Own Id: OTP-14830</p> + </item> + <item> + <p>When compiling modules with huge functions, the + compiler would generate a lot of atoms for its internal, + sometimes so many that the atom table would overflow. The + compiler has been rewritten to generate far less internal + atoms to avoid filling the atom table.</p> + <p> + Own Id: OTP-14968 Aux Id: ERL-563 </p> + </item> + <item> + <p>External funs with literal values for module, name, + and arity (e.g. <c>erlang:abs/1</c>) are now treated as + literals. That means more efficient code that produces + less garbage on the heap.</p> + <p> + Own Id: OTP-15003</p> + </item> + <item> + <p>Two new guards BIFs operating on maps have been added: + <c>map_get/2</c> and <c>is_map_key/2</c>. They do the + same as <c>maps:get/2</c> and <c>maps:is_key/2</c>, + respectively, except that they are allowed to be used in + guards.</p> + <p> + Own Id: OTP-15037 Aux Id: PR-1784, PR-1802 </p> + </item> + <item> + <p>A call or apply of a literal external fun will be + replaced with a direct call.</p> + <p> + Own Id: OTP-15044 Aux Id: ERL-614 </p> + </item> + <item> + <p>Part of EEP-44 has been implemented.</p> + <p>There is a new predefined macro called + <c>OTP_RELEASE</c> which is an integer indicating the OTP + release number (its value is <c>21</c> in this + release).</p> + <p>There are new preprocessor directives + <c>-if(Condition).</c> and <c>-elif(Condition).</c>. The + <c>if/elif</c> supports the builtin function + <c>defined(Symbol)</c>.</p> + <p> + Own Id: OTP-15087 Aux Id: PR-1810 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.5.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fix a regression in OTP-15204 that removed + <c>.beam</c> file metadata that some external build tools + relied on.</p> + <p> + Own Id: OTP-15292</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.5.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fixed an issue where files compiled with the + <c>+deterministic</c> option differed if they were + compiled in a different directory but were otherwise + identical.</p> + <p> + Own Id: OTP-15204 Aux Id: ERL-679 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The internal compiler pass (<c>beam_validator</c>) + that validates the generated code has been + strengthened.</p> + <p>When compiling from BEAM assembly code, the + <c>beam_type</c> optimizer pass could make the code + unsafe. Corrected.</p> + <p> + Own Id: OTP-14863</p> + </item> + <item> + <p>Corrected optimizations of integers matched out from + binaries and used in bit operations.</p> + <p> + Own Id: OTP-14898</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The '<c>deterministic</c>' option was not recognized + when given in a <c>-compile()</c> attribute in the source + code.</p> + <p> + Own Id: OTP-14773 Aux Id: ERL-498 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.3</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The compiler could issue an incorrect internal + consistency failure diagnostic for some complicated bit + syntax maches.</p> + <p> + Own Id: OTP-14640 Aux Id: ERL-490 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fail labels on guard BIFs weren't taken into account + during an optimization pass, and a bug in the validation + pass sometimes prevented this from being noticed when a + fault occurred.</p> + <p> + Own Id: OTP-14522 Aux Id: ERIERL-48 </p> + </item> + <item> + <p> + When compiling from Core Erlang, an 'apply' with a nested + apply in the function position would be treated as an + invalid call. Corrected. (Thanks to Mikael Pettersson for + reporting this bug.)</p> + <p> + Own Id: OTP-14526</p> + </item> + <item> + <p>Fixed checking of binary matching in the + <c>beam_validator</c> module to ensure that potential + compiler bugs are found at compile-time instead as + emulator crash at run-time.</p> + <p> + Own Id: OTP-14591</p> + </item> + <item> + <p>There could be false warnings for + <c>erlang:get_stacktrace/0</c> being used outside of a + <c>try</c> block when using multiple <c>catch</c> + clauses.</p> + <p> + Own Id: OTP-14600 Aux Id: ERL-478 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> The Erlang code linter no longer checks that the + functions mentioned in <c>nowarn_deprecated_function</c> + options are declared in the module. </p> + <p> + Own Id: OTP-14378</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fail labels on guard BIFs weren't taken into account + during an optimization pass, and a bug in the validation + pass sometimes prevented this from being noticed when a + fault occurred.</p> + <p> + Own Id: OTP-14522 Aux Id: ERIERL-48 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>For many releases, it has been legal to override a BIF + with a local function having the same name. However, + calling a local function with the same name as guard BIF + as filter in a list comprehension was not allowed.</p> + <p> + Own Id: OTP-13690</p> + </item> + <item> + <p>compile:forms/2 would not return the module name as + documented when one of the options '<c>from_core</c>', + '<c>from_asm</c>', or '<c>from_beam</c>' was given. Also, + the compiler would crash if one of those options was + combined with '<c>native</c>'.</p> + <p> + Own Id: OTP-14408 Aux Id: ERL-417 </p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Optimized test for tuples with an atom as first element.</p> + <p> + Own Id: OTP-12148</p> + </item> + <item> + <p> + Compilation of modules with huge literal binary strings + is now much faster.</p> + <p> + Own Id: OTP-13794</p> + </item> + <item> + <p>Replaced usage of deprecated symbolic <seealso + marker="erts:erlang#type-time_unit"><c>time + unit</c></seealso> representations.</p> + <p> + Own Id: OTP-13831 Aux Id: OTP-13735 </p> + </item> + <item> + <p>The undocumented and unsupported module + <c>sys_pre_expand</c> has been removed. As a partial + replacement for the functionality, there is a new + function <c>erl_internal:add_predefined_functions/1</c> + and <c>erl_expand_records</c> will now add a module + prefix to calls to BIFs and imported functions.</p> + <p> + Own Id: OTP-13856</p> + </item> + <item> + <p>The internal compiler passes now start all generated + variables with "@" to avoid any conflicts with variables + in languages such as Elixir or LFE.</p> + <p> + Own Id: OTP-13924</p> + </item> + <item> + <p>The function <c>fmod/2</c> has been added to the + <c>math</c> module.</p> + <p> + Own Id: OTP-14000</p> + </item> + <item> + <p>Code generation for complicated guards have been + improved.</p> + <p> + Own Id: OTP-14042</p> + </item> + <item> + <p> + The compiler has new warnings for repeated identical map + keys.</p> + <p> + A map expression such as,</p> + <p> + <c> #{'a' => 1, 'b' => 2, 'a' => 3}.</c></p> + <p> + will produce a warning for the repeated key 'a'.</p> + <p> + Own Id: OTP-14058</p> + </item> + <item> + <p>By default, there will now be a warning when + <c>export_all</c> is used. The warning can be disabled + using <c>nowarn_export_all</c>.</p> + <p> + Own Id: OTP-14071</p> + </item> + <item> + <p> + Optimize maps pattern matching by only examining the + common keys in each clause first instead of all keys. + This will reduce the number of lookups of each key in + maps pattern matching.</p> + <p> + Own Id: OTP-14072</p> + </item> + <item> + <p>There is a new '<c>deterministic</c>' option to omit + '<c>source</c>' and '<c>options</c>' tuples in the BEAM + file.</p> + <p> + Own Id: OTP-14087</p> + </item> + <item> + <p> + Analyzing modules with binary construction with huge + strings is now much faster. The compiler also compiles + such modules slightly faster.</p> + <p> + Own Id: OTP-14125 Aux Id: ERL-308 </p> + </item> + <item> + <p>Atoms may now contain arbitrary Unicode + characters.</p> + <p> + Own Id: OTP-14178</p> + </item> + <item> + <p><c>compile:file/2</c> now accepts the option + <c>extra_chunks</c> to include extra chunks in the BEAM + file.</p> + <p> + Own Id: OTP-14221</p> + </item> + <item> + <p>The format of debug information that is stored in BEAM + files (when <c>debug_info</c> is used) has been changed. + The purpose of the change is to better support other + BEAM-based languages such as Elixir or LFE.</p> + <p>All tools included in OTP (dialyzer, debugger, cover, + and so on) will handle both the new format and the + previous format. Tools that retrieve the debug + information using <c>beam_lib:chunk(Beam, + [abstract_code])</c> will continue to work with both the + new and old format. Tools that call + <c>beam_lib:chunk(Beam, ["Abst"])</c> will not work with + the new format.</p> + <p>For more information, see the description of + <c>debug_info</c> in the documentation for + <c>beam_lib</c> and the description of the + <c>{debug_info,{Backend,Data}}</c> option in the + documentation for <c>compile</c>.</p> + <p> + Own Id: OTP-14369 Aux Id: PR-1367 </p> + </item> + <item> + <p>In a future release, <c>erlang:get_stacktrace/0</c> + will probably only work when called from within a + '<c>try</c>' expression (otherwise it will return + <c>[]</c>.</p> + <p>To help prepare for that change, the compiler will now + by default warn if '<c>get_stacktrace/0</c>' is used in a + way that will not work in the future. Note that the + warning will not be issued if '<c>get_stacktrace/0</c>' + is used in a function that uses neither '<c>catch</c>' + nor '<c>try</c>' (because that could be a legal use if + the function is called from within a '<c>try</c>'.</p> + <p> + Own Id: OTP-14401</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 7.0.4.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fail labels on guard BIFs weren't taken into account + during an optimization pass, and a bug in the validation + pass sometimes prevented this from being noticed when a + fault occurred.</p> + <p> + Own Id: OTP-14522 Aux Id: ERIERL-48 </p> + </item> + </list> + </section> + +</section> + <section><title>Compiler 7.0.4</title> <section><title>Fixed Bugs and Malfunctions</title> @@ -231,6 +1287,22 @@ </section> + +<section><title>Compiler 6.0.3.1</title> + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Fail labels on guard BIFs weren't taken into account + during an optimization pass, and a bug in the validation + pass sometimes prevented this from being noticed when a + fault occurred.</p> + <p> + Own Id: OTP-14522 Aux Id: ERIERL-48 </p> + </item> + </list> + </section> +</section> + <section><title>Compiler 6.0.3</title> <section><title>Fixed Bugs and Malfunctions</title> |