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diff --git a/lib/compiler/doc/src/notes.xml b/lib/compiler/doc/src/notes.xml new file mode 100644 index 0000000000..7d1913d740 --- /dev/null +++ b/lib/compiler/doc/src/notes.xml @@ -0,0 +1,1331 @@ +<?xml version="1.0" encoding="latin1" ?> +<!DOCTYPE chapter SYSTEM "chapter.dtd"> + +<chapter> + <header> + <copyright> + <year>2004</year><year>2009</year> + <holder>Ericsson AB. All Rights Reserved.</holder> + </copyright> + <legalnotice> + The contents of this file are subject to the Erlang Public License, + Version 1.1, (the "License"); you may not use this file except in + compliance with the License. You should have received a copy of the + Erlang Public License along with this software. If not, it can be + retrieved online at http://www.erlang.org/. + + Software distributed under the License is distributed on an "AS IS" + basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + the License for the specific language governing rights and limitations + under the License. + + </legalnotice> + + <title>Compiler Release Notes</title> + <prepared>otp_appnotes</prepared> + <docno>nil</docno> + <date>nil</date> + <rev>nil</rev> + <file>notes.xml</file> + </header> + <p>This document describes the changes made to the Compiler + application.</p> + +<section><title>Compiler 4.6.4</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The compiler's 'E' option now works with modules with + types and specifications.</p> + <p> + Own Id: OTP-8238 Aux Id: OTP-8150 </p> + </item> + <item> + <p> + Certain uses of binary matching in a + <c>begin</c>-<c>end</c> in a list comprehension could + cause the compiler to crash or generate incorrect code.</p> + <p> + Own Id: OTP-8271</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The documentation is now built with open source tools + (xsltproc and fop) that exists on most platforms. One + visible change is that the frames are removed.</p> + <p> + Own Id: OTP-8201</p> + </item> + <item> + <p> + The compiler could crash if invalid calls to is_record/2 + was used in (for example) a list comprehension. (Thanks + to Tobias Lindahl.)</p> + <p> + Own Id: OTP-8269</p> + </item> + <item> + <p>The -on_load() directive can be used to run a function + when a module is loaded. It is documented in the section + about code loading in the Reference Manual.</p> + <p> + Own Id: OTP-8295</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.6.3</title> + + <section><title>Improvements and New Features</title> + <list> + <item> + <p>Corrected liveness optimization to eliminate a + compiler crash that could occur when compiling bit syntax + construction code. (Thanks to Mikage Sawatari.)</p> + <p>Calling BIFs such as <c>length/1</c> in guard context + in a try/catch block could cause a compiler crash. + (Thanks to Paul Fisher.)</p> + <p>Using filter expressions containing <c>andalso</c> or + <c>orelse</c> in a list comprehension could cause a + compiler crash. (Thanks to Martin Engstr�m.)</p> + <p> + Own Id: OTP-8054</p> + </item> + <item> + <p> + A guard with nested 'not' operators could cause the + compiler to crash. (Thanks to Tuncer Ayaz.)</p> + <p> + Own Id: OTP-8131</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.6.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + The compiler would crash while compiling certain complex + function bodies containing <c>receive after</c> due to a + bug in the jump optimizer (a label that had only had + backward references could still be removed). (Thanks to + Vincent de Phily.)</p> + <p> + Own Id: OTP-7980</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.6.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Miscellaneous minor bugs fixed.</p> + <p> + Own Id: OTP-7937</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + There will be more efficient code if there is a clause + that matches the empty binary and no other clauses that + matches non-empty binaries.</p> + <p> + Own Id: OTP-7924</p> + </item> + <item> + <p>There is new option to allow a module to have a module + name other than the filename. Do not use it unless you + know what you are doing.</p> + <p> + Own Id: OTP-7927</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.6.0.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Using <c>andalso</c>/<c>orelse</c> or record access in + a <c>try</c>...<c>catch</c> could cause a compiler + crash.</p> + <p>Som large and complex functions could require + extremely long compilation times (hours or days).</p> + <p> + Own Id: OTP-7905</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.6</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + For some complex guards which used + <c>andalso</c>/<c>orelse</c>, the compiler would crash. + (Thanks to Hunter Morris.)</p> + <p> + Own Id: OTP-7679</p> + </item> + <item> + <p> + Code that (incorrectly) used the the value of nested + applications of <c>setelement/3</c> in bit syntax + construction could crash the compiler.</p> + <p> + Own Id: OTP-7690</p> + </item> + <item> + <p>Modules containing huge integers (consisting of + several hundreds of thousands of digits or more) could be + slow to compile. This problem has been corrected.</p> + <p> + Own Id: OTP-7707 Aux Id: seq11129 </p> + </item> + <item> + <p>If the generator in a list comprehension is given a + non-list term, there will now be <c>function_clause</c> + exception instead of a <c>case_clause</c> exception (as + it was in all releases before R12B).</p> + <p> + Own Id: OTP-7844</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The compiler could crash if the size for a binary segment + in matching was a complex literal such as binary or + tuple.</p> + <p> + Own Id: OTP-7650</p> + </item> + <item> + <p> + The compiler generates more compact and faster code for + matching of complex constants (such as constant lists and + tuples).</p> + <p> + Own Id: OTP-7655</p> + </item> + <item> + <p> + The undocumented, unsupported, and deprecated guard BIF + <c>is_constant/1</c> has been removed.</p> + <p> + *** INCOMPATIBILITY with R12B ***</p> + <p> + Own Id: OTP-7673</p> + </item> + <item> + <p>The compiler generates better code for many guard + expressions, and especially for guards that use + <c>andalso</c>/<c>orelse</c> or record fields.</p> + <p>(In technical terms, <c>andalso</c>/<c>orelse</c> in a + guard would case the creation of a stack frame and saving + of all x registers that could potentially be alive after + the guard and restoring all x registers before leaving + the guard. For certain guards, far too many x registers + were saved and subsequently restored. In this version of + the compiler, no stack frame is created and no x + registers are saved and restored.)</p> + <p> + Own Id: OTP-7718</p> + </item> + <item> + <p>The default size for the resulting binary created by a + binary comprehension was 64Kb in R12B (it would grow if + needed). This was often far too much. In this release, + the default is changed to 256 bytes. Furthermore, for + most binary comprehensions without filters, the exact + size of the resulting binary can be calculated beforehand + and the compiler now generates code that does that + calculation.</p> + <p> + Own Id: OTP-7737</p> + </item> + <item> + <p>The short-circuit operators <c>andalso</c> and + <c>orelse</c> no longer guarantees that their second + argument is either <c>true</c> or <c>false</c>. As a + consequence, <c>andalso</c>/<c>orelse</c> are now + tail-recursive.</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-7748</p> + </item> + <item> + <p>The compiler will refuse to a compile file where the + module name in the file differs from the output file + name.</p> + <p>When compiling using <c>erlc</c>, the current working + directory will no be included in the code path (unless + explicitly added using "-pa .").</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-7793</p> + </item> + <item> + <p>There will no longer be any warnings for list + comprehensions without generators, as such list + comprehension have turned out to be useful.</p> + <p> + Own Id: OTP-7846</p> + </item> + <item> + <p>Warnings for obsolete guard tests are now turned on. + (That is, writing <c>list(L)</c> in a guard instead of + <c>is_list(L)</c> will generate a warning.)</p> + <p>The warnings can be turned off using the + <c>nowarn_obsolete_guard</c> option.</p> + <p> + Own Id: OTP-7850</p> + </item> + <item> + <p>The copyright notices have been updated.</p> + <p> + Own Id: OTP-7851</p> + </item> + <item> + <p>If a module contains an exported function with the + same name as an auto-imported BIF (such as + <c>length/1</c>), any calls to the BIF must have an + explicit <c>erlang:</c> prefix, or there will be a + compilation error (such calls would only generate a + warning in previous releases).</p> + <p>(The reason for the change is to avoid breaking code + in a future major release, R14 or R15, in which we plan + to make calls without a module prefix always call the + local function in the same module even if there is an + auto-imported BIF with the same name.)</p> + <p> + *** POTENTIAL INCOMPATIBILITY ***</p> + <p> + Own Id: OTP-7873</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>Matching on a zero-width segment in the bit syntax + would crash the compiler. (Thanks to Will.)</p> + <p> + Own Id: OTP-7591</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + In bit syntax expressions which started with a binary + segment, and was followed by at least two segments of + variable size, too little space could be allocated for + the binary, leading to memory corruption.</p> + <p> + Own Id: OTP-7556</p> + </item> + <item> + <p>In user-defined attributes, <c>Name/Arity</c> is now + allowed and will be translated to <c>{Name,Arity}</c>. + (An implementation of EEP-24 by Richard O'Keefe.)</p> + <p>The <c>module_info/{0,1}</c> functions automatically + inserted into each compiled modules are now documented in + the Modules section in the Reference Manual.</p> + <p> + Own Id: OTP-7586</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5.4</title> + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Certain complex bit syntax matching operations matching + out binaries and having several clauses could give + incorrect results (the matched out binaries were too + short). (Thanks to Christian von Roques for bug report + and correction.)</p> + <p> + Own Id: OTP-7498</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5.3</title> + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + New option <c>warn_export_all</c> to warn for a module + using <c>export_all</c>. (Thanks to Richard Carlsson.)</p> + <p> + Own Id: OTP-7392</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5.2.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + In rare circumstances, the length/1 BIF (and a few other + guard BIFs) would seem to return an incorrect value (of + any type).</p> + <p> + Own Id: OTP-7345 Aux Id: seq10962 </p> + </item> + </list> + </section> + +</section> +<section><title>Compiler 4.5.2</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>A bug in the old inliner has been fixed. Some + undocumented functionality has been removed.</p> + <p> + Own Id: OTP-7223</p> + </item> + <item> + <p>Matching several binary patterns in parallel using the + '=' operator is not allowed (an implementation + limitation), but the compiler did not reject all such + attempts (depending on the patterns, the generated code + might or might not work correctly). Now the compiler + rejects all binary patterns joined by '='.</p> + <p> + Own Id: OTP-7227</p> + </item> + <item> + <p>Complex combinations of record operations and binary + matching could cause the compiler to crash. (Thanks to + Vladimir Klebansky.)</p> + <p> + Own Id: OTP-7233</p> + </item> + <item> + <p> + In rare circumstances, mixing binary matching clauses + with clauses matching other data types, the compiler + could crash.</p> + <p> + Own Id: OTP-7240 Aux Id: seq10916 </p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5.1.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + Corrected a compiler bug that could cause a complex + binary matching operation to fail when it shouldn't. + (Thanks to Tomas Stejskal.)</p> + <p> + Own Id: OTP-7188</p> + </item> + <item> + <p> + In unusual circumstances, the environment for a fun could + bind wrong values.</p> + <p> + Own Id: OTP-7202 Aux Id: seq10887 </p> + </item> + <item> + <p>Long sequences of list comprehensions without + generators joined by the '++' operator would cause a code + expansion explosion, which could cause the compiler to + run out of memory. To resolve this problem, in + '<c>[...||...]++Expr</c>', <c>Expr</c> is now evaluated + before the list comprehension. This change <em>is</em> + backwards compatible (see the following note about + evaluation order if you have doubts).</p> + <p>Note about evaluation order: The Reference manual says + that subexpressions are evaluated <em>in any order</em> + before the expression itself. Therefore, in an expression + such as '<c>LeftExpr++RightExpr</c>', you should not + depend on <c>LeftExpr</c> being evaluated before + <c>RightExpr</c> or vice versa. The evaluation order is + only important if the expressions contains and/or depends + on operations with side-effects, such as message passing + or <c>ets</c> operations.</p> + <p> + Own Id: OTP-7206</p> + </item> + </list> + </section> + +</section> + + +<section><title>Compiler 4.5.1</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p> + A match expression inside a function call could cause a + false "a term is constructed but never used" warning.</p> + <p> + Own Id: OTP-7018 Aux Id: seq10824 </p> + </item> + <item> + <p>The compiler could crash if a binary tail was matched + out, and then used in a binary append operation. (Thanks + to Oleg Avdeev.)</p> + <p>Similarly, the compiler could crash if a binary tail + was matched out, and then used (incorrectly) in binary + construction in an integer field. (Thanks to Fredrik + Svahn.) Or was incorrectly used in a float field. Or was + used in a binary field with a given length. (Thanks to + Chih - Wei Yu.) </p> + <p> + Own Id: OTP-7022</p> + </item> + <item> + <p> + Matching an empty binary in a record and then using the + same record again could cause a compiler crash. (Thanks + to Fredrik Thulin.)</p> + <p> + Own Id: OTP-7029</p> + </item> + <item> + <p>In rare circumstances, constants containing floating + points and integers could be confused. Example:</p> + <p><c>f(a) -> [1]; f(b) -> [1.0].</c></p> + <p>Both <c>f(a)</c> and <c>f(b)</c> would return + <c>[1]</c>.</p> + <p> + Own Id: OTP-7073</p> + </item> + <item> + <p>Some bit syntax code such as</p> + <p><c>matching d(_,<$lt;$gt;$gt;) -> one; d(0,<$lt;D$gt;$gt;) + ->two.</c></p> + <p>could crash the compiler. (Thanks to Simon + Cornish.)</p> + <p> + Own Id: OTP-7094</p> + </item> + <item> + <p> + In unusual circumstances, a call to a fun could fail due + to an unsafe optimization. (Thanks to Simon Cornish.)</p> + <p> + Own Id: OTP-7102</p> + </item> + <item> + <p> + Bit syntax matching with a guard containing two or more + uses of andalso/orelse could cause the compiler to crash. + (Thanks to Mateusz Berezecki.)</p> + <p> + Own Id: OTP-7113</p> + </item> + <item> + <p> + This was only a problem if you generated or wrote your + own Core Erlang code: The Core Erlang optimizer code + could move nested calls such as + <c>erlang:'$lt;'(erlang:length(L), 2)</c> as case expression + into a guard, which would change the semantics. (Thanks + to Robert Virding.)</p> + <p> + Own Id: OTP-7117</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + The compiler could generate suboptimal code for record + updates if the record update code consisted of multiple + source code lines.</p> + <p> + Own Id: OTP-7101</p> + </item> + </list> + </section> + +</section> + +<section><title>Compiler 4.5</title> + + <section><title>Fixed Bugs and Malfunctions</title> + <list> + <item> + <p>The compiler used to allow that a binary field without + size could be used in other positions than at the end in + bit syntax pattern. For instance, + <c><![CDATA[<<B/binary,EmptyBinary/binary>> = Bin]]></c> + used to compile, but now the compilation will fail with + an an error message.</p> + <p>Also, it is now longer permitted to give a literal + string in a binary pattern a type or a size; for + instance, <c><![CDATA[<<"abc"/binary>> = Bin]]></c> will + no longer compile. (In previous releases, there would + always be a <c>badmatch</c> exception at run-time.)</p> + <p> + Own Id: OTP-6885</p> + </item> + </list> + </section> + + + <section><title>Improvements and New Features</title> + <list> + <item> + <p> + Bitstrings (bit-level) binaries and binary comprehensions + are now part of the language. See the Reference Manual.</p> + <p> + Own Id: OTP-6558</p> + </item> + <item> + <p> + The '<c>compressed</c>' option for the compiler has been + documented.</p> + <p> + Own Id: OTP-6801</p> + </item> + <item> + <p>If the value of a list comprehension is not used, such + as in '<c>[do_something(X) || X <- List], ok</c>', a + result list will no longer be built. For more details, + see the Efficiency Guide.</p> + <p>If the value of an expression is not used, and the + expression has no side effects except for possibly + throwing an exception, a warning will be generated. + Examples: '<c>self(),ok</c>' and + '<c>{error,Reason},ok</c>'.</p> + <p> + Own Id: OTP-6824</p> + </item> + <item> + <p> + Three new functions have been added to the <c>compile</c> + module: <c>noenv_file/2</c>, <c>noenv_forms/2</c>, and + <c>noenv_output_generated/1</c>.</p> + <p> + Own Id: OTP-6829</p> + </item> + <item> + <p>Many bit syntax operations, both construction and + matching, are faster. For further information, see the + Efficiency Guide.</p> + <p> + Own Id: OTP-6838</p> + </item> + <item> + <p>Literal lists, tuples, and binaries are no longer + constructed at run-time as they used to be, but are + stored in a per-module constant pool. Literals that are + used more than once are stored only once.</p> + <p>This is not a change to the language, only in the + details of its implementation. Therefore, the + implications of this change is described in the + Efficiency Guide.</p> + <p>Example 1: In the expression <c>element(BitNum-1, + {1,2,4,8,16,32,64,128})</c>, the tuple used to be + constructed every time the expression was executed, which + could be detrimental to performance in two ways if the + expression was executed in a loop: the time to build the + tuple itself and the time spent in garbage collections + because the heap filled up with garbage faster.</p> + <p>Example 2: Literal strings, such as <c>"abc"</c>, used + to be stored in the compiled code compactly as a byte + string and expanded to a list at run-time. Now all + strings will be stored expanded to lists (such as + <c>[$a,$b,$c]</c>) in the constant pool. That means that + the string will be faster to use at run-time, but that it + will require more space even when not used. If space is + an issue, you might want to use binary literals (that is, + <c><<"abc"<<</c>) instead of string literals for + infrequently used long strings (such as error + messages).</p> + <p> + Own Id: OTP-6850</p> + </item> + <item> + <p> + Recursive calls now usually consume less stack than in + R11B. See the Efficiency Guide.</p> + <p> + Own Id: OTP-6862 Aux Id: seq10746 </p> + </item> + <item> + <p>Two new guard BIFs have been introduced as a + recommended replacement for <c>size/1</c>. (The + <c>size/1</c> BIF will be removed no earlier than in + R14B.) The BIFs are <c>tuple_size/1</c> to calculate the + size of a tuple and <c>byte_size/1</c> to calculate the + number of bytes needed for the contents of the binary or + bitstring (rounded up to the nearest number of bytes if + necessary).</p> + <p>There is also a new <c>bit_size/1</c> BIF that returns + the exact number of bits that a binary or bitstring + contains.</p> + <p> + Own Id: OTP-6902</p> + </item> + <item> + <p> + The two internal functions <c>erl_bifs:is_bif/3</c> and + <c>erl_bifs:is_guard/3</c> have been removed. They were + unsupported, undocumented, and unmaintained.</p> + <p> + Own Id: OTP-6966</p> + </item> + </list> + </section> + +</section> + + <section> + <title>Compiler 4.4.5</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>The compiler would crash if you tried to combine to + non-list literals with '<c><![CDATA[++]]></c>' (for instance, + <c><![CDATA[an_atom++"string"]]></c>).</p> + <p>Own Id: OTP-6630 Aux Id: seq10635 </p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>Minor Makefile changes.</p> + <p>Own Id: OTP-6689</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4.4</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Incorrect code could be generated for bit syntax matching + if the old inliner was used with aggressive settings.</p> + <p>Own Id: OTP-6461</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4.3</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>The R10B compiler could generate unsafe + <c><![CDATA[bs_save/bs_restore]]></c> instructions that could cause + memory corruption. (The R11B compiler does not have that + problem.) The erlang emulator will now refuse to load + R10B-compiled modules that contain such unsafe + <c><![CDATA[bs_save/bs_restore]]></c> instructions. In addition, the + beam_validator module in the compiler will also reject + such instructions (in case it is used to validate R10B + code). (Thanks to Matthew Reilly.)</p> + <p>Own Id: OTP-6386</p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>Directives for parse transforms that have been run are + now removed from the abstract code stored when the + debug_info option is given, to prevent the parse + transforms to be run again.</p> + <p>Own Id: OTP-5344</p> + </item> + <item> + <p>Minor improvements in code generation for some guards + expression involving boolean expressions.</p> + <p>Own Id: OTP-6347</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4.2.1</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>The compiler could generate incorrect code for bit syntax + matching consisting of several clauses.</p> + <p>Own Id: OTP-6392 Aux Id: seq10539 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4.2</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Defining a fun itself containing a fun in an + <c><![CDATA[after]]></c> block of a <c><![CDATA[try]]></c> would cause the + compiler to crash or generate incorrect code. (Thanks to + Tim Rath.)</p> + <p>Shorter compilation times for modules containing with + an extreme number of functions (10000 functions or more).</p> + <p>(The compiled could generate deprecated instructions + for certain bit syntax matching operations.)</p> + <p>Own Id: OTP-6212 Aux Id: seq10446 </p> + </item> + <item> + <p>Fixed several bugs that would cause warnings to be shown + without file name and line number.</p> + <p>Own Id: OTP-6260 Aux Id: seq10461 </p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>The <c><![CDATA[strict_record_tests]]></c> option is now default; + that is, reading a field from a record using the + <c><![CDATA[Record#record_tag.field]]></c> syntax will fail if + <c><![CDATA[Record]]></c> is not a record of the correct type.</p> + <p>If necessary, the record tests can be turned off by + giving the <c><![CDATA[no_strict_record_tests]]></c> option. To avoid + editing Makefiles, the environment variable + <c><![CDATA[ERL_COMPILER_OPTIONS]]></c> can be set to + "<c><![CDATA[no_strict_record_tests]]></c>".</p> + <p>The <c><![CDATA[no_strict_record_tests]]></c> option will probably + be removed in the R12B release.</p> + <p>*** POTENTIAL INCOMPATIBILITY ***</p> + <p>Own Id: OTP-6294</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4.1</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>The compiler used to crash if a module contained code + similar to '<c><![CDATA[fun(1=0) -> ok end]]></c>'. (Thanks to + Richard Carlsson.)</p> + <p>The compiler would spend really long time compiling + bit syntax expressions such as + '<c><![CDATA[<<1:(50*1024*1024)>>]]></c>' and produce a huge .beam + file. Corrected.</p> + <p>The compiler would compile list comprehensions with + many generators really, really slow. (Thanks to Thomas + Raes.)</p> + <p>Module attributes would be stored in reverse order + compared to the order in the source code. (Thus, + <c><![CDATA[M:module_info(attributes)]]></c> would also return the + attributes in reversed order.)</p> + <p>Defining a fun in an <c><![CDATA[after]]></c> block of a + <c><![CDATA[try]]></c> would cause the compiler to crash or generate + incorrect code. (Thanks to Martin Bjorklund.)</p> + <p>The combination of binary pattern and a guard with + andalso/orelse could cause the compiler to crash.</p> + <p>Own Id: OTP-6121 Aux Id: seq10400 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.4</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>When a <c><![CDATA[.hrl]]></c> file is included using + <c><![CDATA[-include_lib]]></c>, the include path is temporarily + updated to include the directory the <c><![CDATA[.hrl]]></c> file was + found in, which will allow that <c><![CDATA[.hrl]]></c> file to itself + include files from the same directory using + <c><![CDATA[-include]]></c>. (Thanks to Richard Carlsson.)</p> + <p>Own Id: OTP-5944</p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>The <c><![CDATA[andalso]]></c> and <c><![CDATA[orelse]]></c> operators are + now allowed to be used in guards. That also applies to + match specifications.</p> + <p>Own Id: OTP-5894 Aux Id: OTP-5149 </p> + </item> + <item> + <p>When given the new option + <c><![CDATA[strict_record_tests]]></c>, the compiler will generate + code that verifies the record type for + <c><![CDATA[R#record.field]]></c> operations in guards. Code that + verifies record types in bodies has already been + generated since R10B, but in this release there will be a + <c><![CDATA[{badrecord,RecordTag}]]></c> instead of a + <c><![CDATA[badmatch]]></c> if the record verification test fails. + See <c><![CDATA[compile(3)]]></c> for more information.</p> + <p>The Erlang shell always applies strict record tests.</p> + <p>Own Id: OTP-5915 Aux Id: OTP-5714 </p> + </item> + <item> + <p>The BIF <c><![CDATA[is_record/3]]></c> can now be used in guards. + Also, <c><![CDATA[is_record/3]]></c> can now be called without an + <c><![CDATA[erlang:]]></c> module prefix for consistency with the other + <c><![CDATA[is_*]]></c> functions.</p> + <p>Own Id: OTP-5916</p> + </item> + <item> + <p>The compiler options <c><![CDATA[ignore_try]]></c> and + <c><![CDATA[ignore_cond]]></c>, which allowed code that used + unquoted <c><![CDATA[try]]></c> or <c><![CDATA[cond]]></c> as atoms or record + tags, has been removed. Old code that depended on the + options need to be revised to have occurrences of + <c><![CDATA[try]]></c> or <c><![CDATA[cond]]></c> as atom or record tags + single-quoted. (Note: Although <c><![CDATA[cond]]></c> is a reserved + keyword, there is no <c><![CDATA[cond]]></c> statement. It might be + introduced in a future release.)</p> + <p>*** POTENTIAL INCOMPATIBILITY ***</p> + <p>Own Id: OTP-6058</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.12</title> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>The following code would crash the compiler: <c><![CDATA[case T of #r{s = ""} -> T #r{s = "x"} end]]></c>. (Thanks to + Richard Carlsson.)</p> + <p>The compiler could crash if binaries were constructed + in certain guards involving boolean operators (including + semicolon). (Thanks to Torbjorn Tornkvist.)</p> + <p>Own Id: OTP-5872</p> + </item> + <item> + <p>The compiler will now warn that the + <c><![CDATA[megaco:format_versions/1]]></c> function is deprecated.</p> + <p>Own Id: OTP-5976</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.11</title> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>The compiler would assume that some patterns with + aliases ('=') would not match if they were split into + several lines. (Thanks to Peter Nagy/Mats Cronqvist.)</p> + <p>Minor cleanups to eliminate Dialyzer warnings.</p> + <p>Own Id: OTP-5791 Aux Id: seq10141 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.10</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>When given the new option + <c><![CDATA[strict_record_tests]]></c>, the compiler will generate + code that verifies the record type for + <c><![CDATA[R#record.field]]></c> operations (in body context only, + not in guards). See the documentation for the + <c><![CDATA[compile]]></c> module for more information.</p> + <p>The beam validator pass of the compiler could crash + given in rare circumstances when given certain + combinations of catches and record operations. (Thanks to + Mats Cronqvist.)</p> + <p>Attributes containing binaries (such as -a(<<1,2,3>>)) + would crash the compiler. (Thanks to Roger Price.)</p> + <p>Multiple behaviours in the same module will no longer + generate a warning, unless one or more callbacks for the + behaviours overlap. For instance, using both the + <c><![CDATA[application]]></c> and <c><![CDATA[supervisor]]></c> behaviours + in the same module will NOT generate any warning, but + using <c><![CDATA[gen_server]]></c> and <c><![CDATA[gen_fsm]]></c> will.</p> + <p>Own Id: OTP-5714 Aux Id: seq10073 </p> + </item> + <item> + <p>The pre-processor used to complain that the macro + definition <c><![CDATA[-define(S(S), ??S).]]></c> was circular, + which it isn't. (Thanks to Richard Carlsson.)</p> + <p>Own Id: OTP-5777</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.9</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Updating at least two fields of a record with a literal + string could cause the compiler to generate dangerous + code that could cause a crash at run-time (e.g. + <c><![CDATA[R#r{a="abc",b=1}]]></c>). (Thanks to Mikael Karlsson.)</p> + <p>Unecessary tests (such as a 'case' with two case + branches that were identical) could cause the compiler to + crash. (Thanks to Fredrik Thulin.)</p> + <p>The validation pass of the compiler could generate an + error for correct code when floating point operations + were used in try/catch statements.</p> + <p>In bit syntax construction, any field following a + binary field would always be marked as "aligned" (which + may or may not be correct). That would cause the hipe + native compiler to generate incorrect code if the field + was in fact unaligned. (Thanks to Per Gustafsson.)</p> + <p>Some complex guard expressions (such as <c><![CDATA[A#a.b==""; A#a.b==undefined]]></c>) would crash the compiler. (Thanks + to Sean Hinde.)</p> + <p>Compilation speed has been increased for modules with + many functions and/or atoms (such as modules generated by + the Asn1 application or other code generators).</p> + <p>Own Id: OTP-5632 Aux Id: seq10057 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.8</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>In some circumstances, having two try/catch constructs + following each in a function body, would cause an + internal error to be generated (when in fact the + generated code was correct). (Thanks to Fredrik Thulin.)</p> + <p>Incorrect calls such as <c><![CDATA[M:42()]]></c> would crash the + compiler. The compiler now generates a warning. (Thanks + to Ulf Wiger.)</p> + <p>Own Id: OTP-5553</p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>The new <c><![CDATA[fun M:F/A]]></c> construct creates a fun that + refers to the latest version of <c><![CDATA[M:F/A]]></c>. This syntax is + meant to replace tuple funs <c><![CDATA[{M,F}]]></c> which have many + problems.</p> + <p>The new type test <c><![CDATA[is_function(Fun, A)]]></c> (which may be + used in guards) test whether <c><![CDATA[Fun]]></c> is a fun that can be + applied with <c><![CDATA[A]]></c> arguments. (Currently, <c><![CDATA[Fun]]></c> can + also be a tuple fun.)</p> + <p>Own Id: OTP-5584</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.7</title> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>Further improvements of encrypted debug info: New option + <c><![CDATA[encrypt_debug_info]]></c> for compiler.</p> + <p>Own Id: OTP-5541 Aux Id: seq9837 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.6</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Fixed a bug in the validator of the generated code + (beam_validator) which caused an internal compiler error + even though the generated code was indeed correct.</p> + <p>Own Id: OTP-5481 Aux Id: seq9798 </p> + </item> + </list> + </section> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>It is now possible to encrypt the debug information in + Beam files, to help keep the source code secret. See the + documentation for <c><![CDATA[compile]]></c> on how to provide the key + for encrypting, and the documentation for <c><![CDATA[beam_lib]]></c> + on how to provide the key for decryption so that tools such + as the Debugger, Xref, or Cover can be used.</p> + <p>The <c><![CDATA[beam_lib:chunks/2]]></c> functions now accepts an + additional chunk type <c><![CDATA[compile_info]]></c> to retrieve + the compilation information directly as a term. (Thanks + to Tobias Lindahl.)</p> + <p>Own Id: OTP-5460 Aux Id: seq9787 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.5</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Complex functions could cause the internal validator in + the compiler to generate an internal error even though + the generated code was correct.</p> + <p>Own Id: OTP-5436 Aux Id: seq9781 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.4</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>In rare circumstances, incorrect code for record or + tuple access could be generated. The incorrect code would + either trigger an internal error in the compiler or cause + an exception at run time. (Thanks to Martin Bjorklund.)</p> + <p>Corrected a bug in in bit syntax matching where + clauses could match in the wrong order. (Thanks to Ulf + Wiger.)</p> + <p>Own Id: OTP-5404 Aux Id: seq9767 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.3</title> + + <section> + <title>Improvements and New Features</title> + <list type="bulleted"> + <item> + <p>Given bit syntax construction in certain complex + contexts involving a catch, the compiler would either + crash or terminate due to failure in an internal + consistency check. (Thanks to Fredrik Thulin.)</p> + <p>Matches such as + <c><![CDATA[<<103133:64/float>> = <<103133:64/float>>]]></c> + used to fail. Now they succeed.</p> + <p>Shadowing of variables in bit syntax matches in fun heads + such as in + <c><![CDATA[L = 8, F = fun(<<L:L,B:L>>) -> B end]]></c> was + handled incorrectly by the compiler. The fun used to be + compiled as if it was written + '<c><![CDATA[>fun(<<8:8,B:8>>)]]></c>, while it should be + compiled in the same way as <c><![CDATA[fun(<<L:8,B:L>>)]]></c>.</p> + <p>A bug in the validation pass has been corrected. It + sometimes occurred when the compiler optimized by reusing + code for causing an exception when the reused code was + called from within catch or try-catch statements. Then the + validator refused to approve the code and complained about + <c><![CDATA[fun(<<L:L,B:L>>) -> B end]]></c> was handled + incorrectly by the in the same way as + <c><![CDATA[fun(<<L:8,B:L>>)]]></c>.</p> + <p>A bug in the unknown_catch_try_state.</p> + <p>Corrected a bug in the optimizer that would cause + the compiler to crash. (Thanks to Peter-Henry Mander.)</p> + <p>There are now warnings generated if a bit syntax + construction will fail at run-time because of a type + mismatch (e.g. <c><![CDATA[<<an_atom:8>>]]></c>).</p> + <p>Own Id: OTP-5342 Aux Id: OTP-5118, OTP-5270, OTP-5323 </p> + </item> + <item> + <p>Binary pattern matching such as + <c><![CDATA[t(<<A:8>> = <<A:8>)]]></c> used to silently + fail at runtime (i.e. never match). The compiler now + generates an error for any such patterns.</p> + <p>Own Id: OTP-5371</p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.2</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>In rare cases, the code compiler code generate code + for a tuple match that could crash the emulator if passed + a term that was not a tuple.</p> + <p>If a bit syntax construction failed within a catch, + previously assigned variables could get the wrong value.</p> + <p>The compiler now runs a validation pass on the + generated code and aborts before writing a Beam file if + any suspect code is found. In particular, the validation + pass checks for incorrect code that may cause emulator + crashes or other strange symptoms in the emulator.</p> + <p>Some corrections to the unsupported feature + parameterized modules by Richard Carlsson (HiPE).</p> + <p>Own Id: OTP-5247 Aux Id: OTP-5235 </p> + </item> + </list> + </section> + </section> + + <section> + <title>Compiler 4.3.1</title> + + <section> + <title>Fixed Bugs and Malfunctions</title> + <list type="bulleted"> + <item> + <p>Corrected the release note regarding <c><![CDATA[try/catch]]></c> below. + <c><![CDATA[try/catch]]></c> DOES work in the initial R10B release.</p> + <p>A few minor issues code generation issues were corrected. + Although the generated code was correct, it was slightly + slower and larger than it needed to be.</p> + <p>A debug printout (that could be seen in rare + circumstances) has been removed.</p> + <p><c><![CDATA[not record_test(not_a_tuple, RecordTag)]]></c> and + similar expressions in a guard would fail.</p> + <p>New options <c><![CDATA[basic_validation]]></c> and + <c><![CDATA[strong_validation]]></c> to do a quick check of the code + of a module.</p> + <p>The <c><![CDATA[inline]]></c> option was not recognized if it + appeared in a <c><![CDATA[-compile()]]></c> directive inside the + module.</p> + <p>Corrected some bugs in the undocumented feature + "parameterized modules".</p> + <p>Own Id: OTP-5198</p> + </item> + <item> + <p>When the undocumented feature "parameterized modules" was + used, the <c><![CDATA[?MODULE]]></c> macro did not work correctly.</p> + <p>Own Id: OTP-5224</p> + </item> + </list> + </section> + </section> +</chapter> + |