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2012-01-04Add the beam_except pass to optimize exceptionsBjörn Gustavsson
In order to save space, rewrite suitable calls to erlang:error/{1,2} to special BEAM instructions. This code is probably longer than the code taken out of v3_life and v3_codegen in the previous commit, but it is much easier to understand and maintain since the BEAM assembler format is better understood than the v3_life format.
2012-01-04Eliminate the match_fail primop in v3_kernel and later passesBjörn Gustavsson
In the v3_life pass, it is assumed that a 'match_fail' primop only occur at the top-level and at the end of a function. But this code: do_split_cases(A) -> case A of x -> Z = dummy1; _ -> Z = dummy2, a=b end, Z. will be optimized by sys_core_fold to the following code: 'split_cases'/1 = fun (_cor0) -> let <_cor7,Z> = case _cor0 of <'x'> when 'true' -> < 'dummy1','dummy1' > <_cor6> when 'true' -> %% Here follows a 'match_fail' primop inside %% multiple return values: < primop 'match_fail'({'badmatch','b'}),'dummy2' > end in Z moving the 'match_fail' primop into a "values" construction. In the future, we would like to get rid of the v3_life pass (it is there for historical reasons), so in the mean-time we prefer to not add more code to it by generalizing the handling of 'match_fail'. Since the 'match_fail' primop can be simulated by erlang:error/{1,2}, the simplest solution is to translate 'match_fail' to a call to erlang:error/{1,2} in v3_kernel and remove the handling of 'match_fail' in v3_life and v3_codegen. It is tempting to get rid of 'match_fail' also in the Core Erlang format, but there are two issues: - Removing the support for 'match_fail' completely may break tools that generate Core Erlang code. We should not do that in a minor release. - There is no easy way to generate a 'function_clause' exception that will remain correct if it will be inlined into another function. (Calling "erlang:error(function_clause, Args)" is fine only if it is not inlined into another function.) A good solution probably involves introducing new instructions, which is better done in a major release. Noticed-by: Håkan Matsson Minimized-test-case-by: Erik Søe Sørensen
2011-12-12Prepare releaseErlang/OTP
2011-12-09Update copyright yearsBjörn-Egil Dahlberg
2011-12-06beam_validator: Fix type for failure label for bs_start_match2/5Björn Gustavsson
A bs_start_match2/5 instruction will never fail (take the branch) if given a match state or a binary. Therefore, the type at the failure label should be 'term', not match state or binary. Without this correction, the beam_validator will reject safe programs.
2011-12-06inline_SUITE: Add the comma_splitter/1 test caseBjörn Gustavsson
Compilation would fail with an error message similar to: comma_splitter: function split_at_comma/2+32: Internal consistency check failed - please report this bug. Instruction: {put,{x,0}} Error: {match_context,{x,0}}: Noticed-by: René Kijewski
2011-12-06Teach the compiler the 'no_dead' optionBjörn Gustavsson
To facilitate debugging of compiler bugs, teach the compiler the 'no_dead' option. Since the beam_dead pass used to do the necessary splitting of basic blocks to expose all labels, we must move that splitting into a separate pass that is always run.
2011-11-30compiler: Turn calls to math:pi/0 into constant valuesBjörn Gustavsson
Mark math:pi/0 as pure, informing the compiler that the value can be calculated at compile time.
2011-11-28Merge branch 'bjorn/compiler/options/OTP-9752'Björn Gustavsson
* bjorn/compiler/options/OTP-9752: filename documentation: Recommend against using filename:find_src/1,2 Teach filename:find_src/1,2 to handle slim or stripped BEAM files filename: Eliminate failing call to Mod:module_info(source_file) filename.erl:filter_options/1: Remove handling of dead options compiler: Don't include {cwd,_} in module_info(compile) compiler: Don't include source code options in module_info(compile) hipe: Teach hipe to handle slim or stripped BEAM files
2011-11-28Merge branch 'bjorn/major-release-cleanups'Björn Gustavsson
* bjorn/major-release-cleanups: observer tests: Test compatibility with R13, not R12 emulator tests: Test compatibility with R13, not R12 Teach the compiler the 'r14' option erl_lint: The types introduced in R12B-5 are no longer "newly introduced" otp_internal: Stop warning for functions removed in R12 or earlier Conflicts: lib/stdlib/src/otp_internal.erl
2011-11-24compiler: Don't include {cwd,_} in module_info(compile)Björn Gustavsson
The {cwd,Dir} option is always included if the module has been compiled by erlc. Since its presence cannot be relied upon and it wastes memory, get rid of it.
2011-11-24compiler: Don't include source code options in module_info(compile)Björn Gustavsson
As far as I know, the purpose of the compiler options included in Mod:module_info(compile) has never been documented. An educated guess is that they are there in case you want to re-compile the module with the same options, and also to aid in debugging when you need to know how a module was compiled. In neither case is there any need to include options given in the source itself in options included in Mod:module_info(compile). Including those options will only waste memory. Therefore, only include in the BEAM file the options that were given to compile:file/2.
2011-11-24hipe: Teach hipe to handle slim or stripped BEAM filesBjörn Gustavsson
2011-11-24Teach the compiler the 'r14' optionBjörn Gustavsson
2011-11-24sys_expand_pmod: Handle external funs in parameterized modulesBjörn Gustavsson
Starting in ff432e262e65243cbc983fcb002527f8fae8c78b, sys_pre_expand passes external funs through to the downstream passes. It used to translate external funs to a call to erlang:make_fun/3. Therefore, we will now need to handle external funs in sys_expand_pmod. Noticed-by: Stavros Aronis
2011-11-22Revert "Update version numbers for pre-release of R15"Björn-Egil Dahlberg
This reverts commit e21ff9b0b69219ab3853be7e80813156113152b7.
2011-11-22Update version numbers for pre-release of R15OTP_R15ABjörn Gustavsson
2011-11-08Merge branch 'bjorn/line-numbers/OTP-9468'Björn Gustavsson
* bjorn/line-numbers/OTP-9468: beam_type: Improve FP optimizations in the presence of line numbers
2011-11-07Merge branch 'bjorn/fun-improvements/OTP-9667'Björn Gustavsson
* bjorn/fun-improvements/OTP-9667: sys_pre_expand: Remove incorrect comment compiler: Eliminate use of deprecated erlang:hash/2 beam_asm: Fix broken NewIndex in fun entries beam_asm: Strenghten the calculation of Uniq for funs
2011-11-07sys_pre_expand: Remove incorrect commentBjörn Gustavsson
sys_pre_expand does not keep track of used or new variables (and have not done since about the time Core Erlang was introduced).
2011-11-07compiler: Eliminate use of deprecated erlang:hash/2Björn Gustavsson
Now that beam_asm computes the Index and Uniq values for funs, there is no need to compute those values in the sys_pre_expand and v3_kernel modules, thus eliminating the calls to the deprecated erlang:hash/2 function. It would be tempting to stop generating the name for the fun in sys_pre_expand so that we did not have to add the Info field to a tuple. But: * The debugger depends on the name being there. (Simple solution: Let the debugger generate the name itself.) * When a fun has been inlined into another function, the fun name in 'id' annotation will be used to notice the inlining and change the final clause of the top-level case from generating a 'function_clause' exception to a case_clause exception. (Possible workaround: Have the inliner set an inlined attribute on functions that have been inlined, or have the inliner rewrite 'function_clause' exceptions itself.)
2011-11-07beam_asm: Fix broken NewIndex in fun entriesBjörn Gustavsson
The calculation of the NewIndex field in fun entries is broken: the sys_pre_expand and v3_kernel modules keep separate index counters starting at zero; thus there is no guarantee that each fun within a module will have its own unique NewIndex. We don't really need the NewIndex any more (see below), but since we do need the NewUniq field, we should fix NewIndex for cleanliness sake. The simplest way is to assign NewIndex as late as possible, namely in beam_asm, and to set it to the same value as Index. Historical Note: Why NewIndex Was Introduced There was once an idea that the debugger should be able to interpret only a single function in a module (for speed). To make sure that interpreted funs could be called from BEAM code and vice versa, the fun identification must be visible in the abstract code. Therefore a NewIndex field was introduced in each fun in the abstract code. However, it turned out that interpreting single functions does not play well with aggressive code optimization. For example, in this code: f() -> X = 1, fun() -> X+2 end. the variable X will seem to be free in the fun, but an aggressive optimizer will replace X with 1 in the fun; thus the fun will no longer have any free variables. Therefore, the debugger will always interpret entire modules.
2011-11-07beam_asm: Strenghten the calculation of Uniq for funsBjörn Gustavsson
Funs are identified by a triple, <Module,Uniq,Index>, where Module is the module name, Uniq is a 27 bit hash value of some intermediate representation of the code for the fun, and index is a small integer. When a fun is loaded, the triple for the fun will be compared to previously loaded funs. If all elements in the triple in the newly loaded fun are the same, the newly loaded fun will replace the previous fun. The idea is that if Uniq are the same, the code for the fun is also the same. The problem is that Uniq is only based on the intermediate representation of the fun itself. If the fun calls local functions in the same module, Uniq may remain the same even if the behavior of the fun has been changed. See http://erlang.org/pipermail/erlang-bugs/2007-June/000368.htlm for an example. As a long-term plan to fix this problem, the NewIndex and NewUniq fields was added to each fun in the R8 release (where NewUniq is the MD5 of the BEAM code for the module). Unfortunately, it turns out that the compiler does not assign unique value to NewIndex (if it isn't tested, it doesn't work), so we cannot use the <Module,NewUniq,NewIndex> triple as identification. It would be possible to use <Module,NewUniq,Index>, but that seems ugly. Therefore, fix the problem by making Uniq more unique by taking 27 bits from the MD5 for the BEAM code. That only requires a change to the compiler. Also update a test case for cover, which now fails because of the stronger Uniq calculation. (The comment in test case about why the Pid2 process survived is not correct.)
2011-11-07EEP-23: Allow variables in fun M:F/ABjörn Gustavsson
Currently, the external fun syntax "fun M:F/A" only supports literals. That is, "fun lists:reverse/1" is allowed but not "fun M:F/A". In many real-life situations, some or all of M, F, A are not known until run-time, and one is forced to either use the undocumented erlang:make_fun/3 BIF or to use a "tuple fun" (which is deprecated). EEP-23 suggests that the parser (erl_parse) should immediately transform "fun M:F/A" to "erlang:make_fun(M, F, A)". We have not followed that approach in this implementation, because we want the abstract code to mirror the source code as closely as possible, and we also consider erlang:make_fun/3 to be an implementation detail that we might want to remove in the future. Instead, we will change the abstract format for "fun M:F/A" (in a way that is not backwards compatible), and while we are at it, we will move the translation from "fun M:F/A" to "erlang:make_fun(M, F, A)" from sys_pre_expand down to the v3_core pass. We will also update the debugger and xref to use the new format. We did consider making the abstract format backward compatible if no variables were used in the fun, but decided against it. Keeping it backward compatible would mean that there would be different abstract formats for the no-variable and variable case, and tools would have to handle both formats, probably forever. Reference: http://www.erlang.org/eeps/eep-0023.html
2011-11-04beam_type: Improve FP optimizations in the presence of line numbersBjörn Gustavsson
Allow line/1 instructions to be part of a sequence of floating point instructions to avoid outputting fclearerror / fcheckerror around every floating point instruction.
2011-11-02Test calling a parameterized module within a funBjörn Gustavsson
It is tempting to transform code such as: fun(X) -> M:foo(X) end to: fun M:foo/1 Unfortunately, that transformation is not safe if M happens to be a parameterized module. Add a test case so that we don't attempt to do such an optimization in the future.
2011-10-27Remove unused */doc/src/make.dep filesBjörn Gustavsson
These dependency files was once used when building the documentation, but are no longer needed.
2011-10-13Allow noncharacter code points in unicode encoding and decodingBjörn Gustavsson
The two noncharacter code points 16#FFFE and 16#FFFF were not allowed to be encoded or decoded using the unicode module or bit syntax. That causes an inconsistency, since the noncharacters 16#FDD0 to 16#FDEF could be encoded/decoded. There is two ways to fix that inconsistency. We have chosen to allow 16#FFFE and 16#FFFF to be encoded and decoded, because the noncharacters could be useful internally within an application and it will make encoding and decoding slightly faster. Reported-by: Alisdair Sullivan
2011-10-07Automatically generate 'behaviour_info' function from '-callback' attributesStavros Aronis
'behaviour_info(callbacks)' is a special function that is defined in a module which describes a behaviour and returns a list of its callbacks. This function is now automatically generated using the '-callback' specs. An error is returned by lint if user defines both '-callback' attributes and the behaviour_info/1 function. If no type info is needed for a callback use a generic spec for it.
2011-10-07Add '-callback' attribute to language syntaxStavros Aronis
Behaviours may define specs for their callbacks using the familiar spec syntax, replacing the '-spec' keyword with '-callback'. Simple lint checks are performed to ensure that no callbacks are defined twice and all types referred are declared. These attributes can be then used by tools to provide documentation to the behaviour or find discrepancies in the callback definitions in the callback module.
2011-10-04Merge branch 'dev' into majorBjörn-Egil Dahlberg
2011-10-04Prepare releaseOTP_R14B04Erlang/OTP
2011-09-29Merge branch 'dev' into majorBjörn-Egil Dahlberg
* dev: Update copyright years
2011-09-29Update copyright yearsBjörn-Egil Dahlberg
2011-09-22Merge branch 'dev' into majorHenrik Nord
2011-09-22Merge branch 'hl/beam_disasm-no_attri_chunk' into devHenrik Nord
* hl/beam_disasm-no_attri_chunk: beam_disasm: Handle stripped BEAM files OTP-9571
2011-09-21beam_disasm: Handle stripped BEAM filesHaitao Li
beam_disasm:file/1 would crash if asked to disassemble a stripped BEAM file without an "Attr" chunk.
2011-09-14Merge branch 'dev' into majorBjörn Gustavsson
* dev: sys_pre_expand: Don't duplicate options given in the source code
2011-09-14Merge branch 'bjorn/compiler-options/OTP-9534' into devBjörn Gustavsson
* bjorn/compiler-options/OTP-9534: sys_pre_expand: Don't duplicate options given in the source code
2011-09-14sys_pre_expand: Don't duplicate options given in the source codeBjörn Gustavsson
Any compiler options given with a -compile() attribute in source file would be included both at the beginning and the end of the option list for the compiler. Including the options twice is harmless during compilation, but since the options will also be available in Mod:module_info(compile), including them twice will waste memory. Include the options from the source first in the list so that they override options given on the command line.
2011-09-13Merge branch 'dev' into majorHenrik Nord
Conflicts: lib/asn1/doc/src/asn1ct.xml
2011-09-08compile: optimize werror/1Tuncer Ayaz
2011-09-08compile: log warnings as errors if -Werror is enabledTuncer Ayaz
2011-09-08Do not write beam file if Werr and warnings /= []Tuncer Ayaz
2011-08-18compiler: Add no_line_info for suppressing line/1 instructionsBjörn Gustavsson
Also update the r12 and r13 options so that they imply no_line_info.
2011-08-16compiler: Don't create filenames starting with "./"Björn Gustavsson
In the location information tables in the run-time system, source filenames that are the same as the module name plus ".erl" extension are not stored explicitly, thus saving memory. To take advantage of that optimization, avoid complicating the names of files in the current working directory; specifically, make sure that "./" is not prepended to the name.
2011-08-16emulator: Add a fourth element in exception stacktracesBjörn Gustavsson
This commit is a preparation for introducing location information (filename/line number) in stacktraces in exceptions. Currently a stack trace looks like: [{Mod1,Function1,Arity1}, . . . {ModN,FunctionN,ArityN}] Add a forth element to each tuple that can be used indication the filename and line number of the source file: [{Mod1,Function1,Arity1,Location1}, . . . {ModN,FunctionN,ArityN,LocationN}] In this commit, the fourth element will just be an empty list, and we will change all code that look at or manipulate stacktraces.
2011-08-16Include location information for line instructions in BEAM filesBjörn Gustavsson
2011-08-16compiler: Generate line instructionsBjörn Gustavsson
2011-08-16compiler, emulator: Introduce the line/1 instructionBjörn Gustavsson
Introduce the line/1 instruction in the compiler and the BEAM virtual machine. It will not yet be generated by the compiler and will not actually carry any information.