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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.
2011-11-24Teach 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
2011-11-08Merge 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.
2011-10-07Automatically 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.
2011-09-29Merge 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.
2011-08-16Include 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.
2011-08-16v3_kernel: Make sure that line number annotations are passed throughBjörn Gustavsson
2011-08-16v3_core: Annotate exception-generating clauses with line numbersBjörn Gustavsson
2011-08-16Fix binary matching in the debuggerBjörn Gustavsson
'eval_bits' is a common utility module used for evaluting binary construction and matching. The functions that do matching (match_bits/{6,7} and bin_gen/6) are supposed to treat the bindings as an abstract data type, but they assume that the bindings have the same representation as in the erl_eval module. That may cause binary matching to fail in the debugger, because the debugger represents the bindings as an unordered list of two-tuples, while the erl_eval modules uses an ordered list of two-tuple (an ordset). One way to fix the problem would be to let the debugger to use ordered lists to represent the bindings. Unfortunately, that would also change how the bindings are presented in the user interface. Currently, the variable have most been recently assigned is shown first, which is convenient. Fix the matching problem by mending the leaky abstraction in eval_bits. The matching functions needs to be passed two additional operations: one for looking up a variable in the bindings and one for adding a binding. Those operations could be passed as two more funs (in addition to the evaluation and match fun already passed), but the functions already have too many arguments. Therefore, change the meaning of the match fun, so that the first argument is the operation to perform ('match', 'binding', or 'add_binding') and second argument is a tuple with arguments for the operation.
2011-07-06Remove deprecated concat_binary/1Björn Gustavsson
concat_binary/1 was deprecated in R13B04, but already in the R10B-2 release, the documentation recommends using list_to_binary/1 instead.
2011-05-20Update copyright yearsBjörn-Egil Dahlberg
2011-04-12beam_bsm: Eliminate uncovered line in warning generationBjörn Gustavsson
In warning_translate_label/2, gb_trees:lookup/2 is called to translate from the entry label for a function to its name. Since the gb_tree has an entry for all functions in the module, there is no way that the lookup can fail unless there is a serious bug. Therefore, use gb_trees:get/2 so that an exception and an internal compiler error will be generated if the lookup would ever fail.
2011-04-12beam_dead: Remove uncovered special case handling of empty blocksBjörn Gustavsson
There is never any empty blocks when beam_dead is invoked. Even if there were, they will be removed a little bit later in forward/4.
2011-04-12beam_dead: Remove uncovered clauses in binary matching optimizationBjörn Gustavsson
In the optimization of binary matching, it seems that two clauses cannot never be reached. Removing the clauses is safe, since that would only mean that an opportunity for an optimization is lost
2011-04-12beam_dead: Remove uncoverable case clause in update_value_dict/3Björn Gustavsson
Because the code generator (v3_codegen) would not include the same value more than once in a select_val/3 instruction and because a label can only be referenced by one select_val/3 instruction, there is no way that the correct value could already be in the gb_tree. (Even if it could happen, this change is safe because only opportunity for an optimization would be missed; incorrect code would not be generated.)
2011-04-12beam_dead: Remove code that cannot be covered in forward/4Björn Gustavsson
Since the optimizations in forward/4 already depends on some assumptions on how code is generated anyway, document the assumptions in a comment and remove the uncoverable code.
2011-03-29beam_dict: Eliminate the redundant next_atom record elementBjörn Gustavsson
It is not needed because it can be trivially calculated using gb_trees:size/1.
2011-03-29beam_dict: Fix typo in commentBjörn Gustavsson
2011-03-25sys_core_fold: Eliminate incorrect warningBjörn Gustavsson
The compiler (sys_core_fold) tries to avoid constructing tuples in case expressions. The following code: c(A, B) -> case {A,B} of {ok,X} -> X; {_,_} -> error end. will be rewritten so that no tuple is built. If a clause requires a tuple to be built as in this code: c(A, B) -> case {A,B} of {ok,X} -> X; V -> V %The tuple will be built here end. the tuple will be built in the clause(s) in which it is needed. If the value returned from the case is not used as in this code: c(A, B) -> case {A,B} of V -> V %Warning: a term is constructed, but never used end, ok. there will be an incorrect warning. Basically, what happens is that the code is reduced to: c(A, B) -> {A,B}, %Warning: a term is constructed, but never used ok. and the optimizer sees that the {A,B} tuple can't possibly be used. Eliminate the warning by adding a 'compiler_generated' annotation to the tuple. Reported-by: Kostis Sagonas
2011-03-25sys_core_fold: Be careful to preserve annotations while optimizingBjörn Gustavsson
2011-03-23v3_core: Fix variable incorrectly unbound after binary matchBjörn Gustavsson
In the following code: m(<<Sz:8,_:Sz/binary>>) -> Sz = wrong. the Sz variable is supposed to be bound in the function header and the matching "Sz = wrong" should cause a badarg exception. But what happens is that the Sz variables seems to be unbound and the matching succeds and the m/1 function returns 'wrong'. If the Sz variable is used directly (not matched), it will have the expected value. Thus the following code: m(<<Sz:8,_:Sz/binary>>) -> Sz. will correctly return the value of Sz that was matched out from the binary. Reported-by: Bernard Duggan