hi Nate, just to confirm, I think you're right as for the code that should be generated. I tried it out with the perl implementation of the M0 interp. It works! I'll keep using the perl interp for now.
cheers kjs On Wed, Jun 6, 2012 at 5:58 PM, kjstol <[email protected]> wrote: > hi Nate, > > On Wed, Jun 6, 2012 at 5:51 PM, Nathan Brown <[email protected]> wrote: >> Hey kjs, >> >> No problem, since I helped to get the poke_caller test to pass I figured I >> could help out. >> >> On Jun 6, 2012, at 12:35 PM, kjstol <[email protected]> wrote: >> >>> hi Nate, >>> >>> thanks very much for your analysis. Much appreciated. >>> >>> On Wed, Jun 6, 2012 at 12:24 PM, Nathan Brown <[email protected]> wrote: >>>> Hey kjs, >>>> >>>> So after a quick look last night, I've concluded that we should try to >>>> implement the chunk_map portion of the m0 spec because the poke_caller >>>> test looks like it's using it but in reality it isn't. Lines 271-274 >>>> (https://github.com/parrot/parrot/blob/m0/t/m0/integration/m0_poke_caller.m0#L271) >>>> in the test are misleading, the original code is: >>>> >>>> # S3 is the parent call frame's CHUNK >>>> set_imm I3, 0, CHUNK >>>> deref I3, CONSTS, I3 >>>> goto_chunk I3, I4, x >>>> >>>> But this only works because CHUNK = 5 and the 5th item in the callee >>>> const table is "&caller". >>> >>> Does this mean it is a coincidence/accident that the example >>> (poke_caller) is actually working? Just because CHUNK has the value 5, >>> and the caller happens to be at the 5th position in the callee's CONST >>> table? >> >> Yes, I didn't notice this coincidence before. I was initially just working >> to get the test passing and removing the workarounds that were blocking me. >> Somehow I didn't notice this issue. > > Good to know :-) (and amazing in a sense!) > >> >> >> >>> >>> I think the code should be: >>>> >>>> # I3 is the parent call frame's CHUNK >>>> set_imm I3, 0, CHUNK >>>> deref I3, PCF, I3 >>>> goto_chunk I3, I4, x >>>> >>>> But for this to work, we need to make the CHUNK register (see >>>> https://github.com/parrot/parrot/blob/m0/docs/pdds/draft/pdd32_m0.pod#register-types-and-call-frame-structure) >>>> and CHUNKS, CHUNK_INFO and CHUNK_MAP interpereter data (see >>>> https://github.com/parrot/parrot/blob/m0/docs/pdds/draft/pdd32_m0.pod#interpreter-data) >>>> get populated correctly and used throughout m0. >>> >>> Do you know whether this has been implemented in M0? >> >> It had not in c. I think it has in perl. > > Ah yes, I'm just scrolling back the IRC logs from yesterday. I saw the > link with the todo for the C impl. > > I had implemented a hashtable for PIRC, the code is available at: > https://github.com/parrot/pirc/blob/master/src/pirsymbol.c > > > Probably the only thing that can be copied from that is the hash > algorithm. (I believe I took that from the dragon book IIRC). The rest > of handling buckets and linking symbols is probably easier to write > from scratch. > > I will also need a hashtable for M1. Perhaps we can write a single > hashtable that is reusable. However, getting it to work first is more > important. Refactoring can be done later. > > kjs > > >> >>>> >>>> The spec states that CHUNK register should be "the index of the >>>> currently-executing chunk." The spec also says we should be using >>>> chunk indices and not names when we use the goto_chunk op. I believe >>>> that implementing this will mean m1 won't have to store the current >>>> chunk's name in its const table. >>>> >>>> If no one beats me to it, I'll take a swing at this stuff this weekend. >>> >>> Great! >>> cheers, >>> kjs >>> >>>> >>>> -Nate >>>> >>>> On Jun 5, 2012, at 8:12 PM, Nathan Brown <[email protected]> wrote: >>>> >>>>> Hi kjs, >>>>> >>>>> Nothing stands out to me immediately, but I'll try to get m1 working >>>>> and look at it. From the code excerpts, it looks like it works, but >>>>> I'd like to see all the m0 code and try to figure it out. >>>>> >>>>> I've been away for a bit, but I'm almost back and would love to help >>>>> getting m0 and m1 to work better together. >>>>> >>>>> Nate >>>>> >>>>> On Tue, Jun 5, 2012 at 5:18 PM, kjstol <[email protected]> wrote: >>>>>> hi Nate, >>>>>> >>>>>> thanks for your reply. >>>>>> I've actually stolen most of the code that is generated by M1 from >>>>>> that particular example. If you look at that example, you'll see that >>>>>> the callee chunk has the caller's name in its constants segment, which >>>>>> is loaded at the end. >>>>>> >>>>>> When M1 generates the following code (as it does now): >>>>>> >>>>>> set_imm I2, 0, PCF >>>>>> deref P0, CF, I2 >>>>>> set_imm I3, 0, RETPC >>>>>> deref I3, P0, I3 >>>>>> set_imm I2, 0, 2 >>>>>> deref I2, CONSTS, I2 >>>>>> goto_chunk I2, I3, x >>>>>> >>>>>> and you add "&main" at index 2 of the const segment, then it works. >>>>>> However, when M1 is changed to access the parent's CF instead: >>>>>> >>>>>> set_imm I2, 0, PCF >>>>>> deref P0, CF, I2 >>>>>> set_imm I3, 0, RETPC >>>>>> deref I3, P0, I3 >>>>>> set_imm I5, 0, CONSTS ## get index of CONSTS >>>>>> deref P1, P0, I5 ## get CONSTS thingy from parent CF (in P0) >>>>>> set_imm I6, 0, 0 ## load "0" >>>>>> deref I4, P1, I6 ## get the name of the calling function, in >>>>>> P1, >>>>>> which is the parent's CF's CONST segment. The name is ALWAYS stored at >>>>>> index 0. >>>>>> goto_chunk I4, I3, x >>>>>> >>>>>> With this code, the function doesn't return. >>>>>> Perhaps I'm overlooking something...? >>>>>> >>>>>> kjs >>>>>> >>>>>> >>>>>> On Tue, Jun 5, 2012 at 4:16 PM, Nathan Brown <[email protected]> wrote: >>>>>>> Hello kjs, >>>>>>> >>>>>>> m0 actually already has a mechanism for tracking the caller, it's the >>>>>>> parent (or previous) call frame PCF register. Since functions and call >>>>>>> frames are equivalent in M0, setting the parent/previous call frame >>>>>>> register in the child call frame to the address of the current call >>>>>>> frame prior to invoking the child call frame will give you knowledge of >>>>>>> the caller. This is the way that the poke_caller test in the m0 test >>>>>>> suite does it. >>>>>>> >>>>>>> Hope that helps, >>>>>>> Nate >>>>>>> >>>>>>> On Jun 5, 2012, at 8:35 AM, kjstol <[email protected]> wrote: >>>>>>> >>>>>>>> hi there, >>>>>>>> >>>>>>>> M1's getting more complete by the day. Function invocations and >>>>>>>> returns are working, _almost_ (making a few minor manual fixes in the >>>>>>>> generated M0 code makes it work). The problem is that the called >>>>>>>> function needs to know about which function it called, so its caller. >>>>>>>> This is a problem, because obviously, any function can call any other >>>>>>>> function. In particular, for a function to return, it needs to know >>>>>>>> the name of the caller, which it takes from the CONSTS segment. >>>>>>>> >>>>>>>> One way to do this is of course to pass the name of the caller. I >>>>>>>> suspect this has something to do with continuation-passing style, >>>>>>>> where you pass a continuation chunk, which is then invoked in order to >>>>>>>> return. This will have to be figured out. So, please consider this >>>>>>>> email as a request for further spec. of M0 :-) >>>>>>>> >>>>>>>> Meanwhile, I'll continue with more basic stuff; enumerations, variable >>>>>>>> scoping, and perhaps namespaces are next. Suggestions and feedback and >>>>>>>> requests for features are welcome. >>>>>>>> >>>>>>>> Comments welcome, >>>>>>>> kjs >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Sun, May 20, 2012 at 2:59 PM, kjstol <[email protected]> wrote: >>>>>>>>> hi there, >>>>>>>>> >>>>>>>>> Attached a new version; this does some basic code generation. I'm not >>>>>>>>> really familiar with M0 instructions yet, but I made a few guesses. >>>>>>>>> Expression handling seems to work well. >>>>>>>>> >>>>>>>>> There's many todos', but it's quite close to generating valid M0 >>>>>>>>> (acceptable by the perl assembler script). Conditional and iteration >>>>>>>>> statements are not done yet (needs handling of labels etc.) but could >>>>>>>>> easily be added. >>>>>>>>> >>>>>>>>> I'm not entirely sure what kind of syntax and functionality is needed >>>>>>>>> at the M1 level. Is the idea to write PMCs at this level? In that case >>>>>>>>> you'd want to have a "PMC" keyword I think, and allow writing member >>>>>>>>> functions in such a PMC. Also, allocating memory could be built-in, >>>>>>>>> rather than copying C's malloc and free function implementations. >>>>>>>>> Also, do exceptions live at this level? In that case you'd probably >>>>>>>>> want some kind of "try/catch" or alternative notation. >>>>>>>>> >>>>>>>>> to run: >>>>>>>>> ==== >>>>>>>>> unzip the zip file >>>>>>>>> cd m1 >>>>>>>>> make >>>>>>>>> ./m1 t2.m1 >>>>>>>>> >>>>>>>>> Feedback would be appreciated. >>>>>>>>> thanks >>>>>>>>> kjs >>>>>>>>> >>>>>>>>> On Sun, May 20, 2012 at 3:06 AM, kjstol <[email protected]> wrote: >>>>>>>>>> hi! >>>>>>>>>> >>>>>>>>>> On Sun, May 20, 2012 at 2:55 AM, Vasily Chekalkin <[email protected]> >>>>>>>>>> wrote: >>>>>>>>>>> Hello. >>>>>>>>>>> >>>>>>>>>>> Welcome back :) >>>>>>>>>> >>>>>>>>>> thanks :-) >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> For the record, current nqp-rx based ops compiler does parse subset >>>>>>>>>>> of >>>>>>>>>>> C already. In opsc_llvm branch it does parse even more. I would >>>>>>>>>>> suggest to join efforts in defining "C subset" which we are going to >>>>>>>>>>> use as m1 ops language. >>>>>>>>>>> >>>>>>>>>>> Most problematic parts iirc was: >>>>>>>>>>> 1. Macros. C macros are pure evil. If we are going to support >>>>>>>>>>> free-defined C macros it will require a lot of work. Limiting them >>>>>>>>>>> to >>>>>>>>>>> VTABLE macros will reduce this issue to trivial. >>>>>>>>>>> 2. Ambiguous casting. >>>>>>>>>>> 3. Implicit string concatenation. >>>>>>>>>> >>>>>>>>>> Thanks for sharing. I can see how scattered efforts are not helpful. >>>>>>>>>> >>>>>>>>>> It wasn't so much an effort to implement parts of C per se, more that >>>>>>>>>> it's inspired by C: it's easy to read, easy to learn, and easy to >>>>>>>>>> implement so far. Also, my efforts so far were an expression of my >>>>>>>>>> self indulgence in some good hacking sessions, which I hadn't done >>>>>>>>>> for >>>>>>>>>> a long time. It's been fun :-) >>>>>>>>>> >>>>>>>>>> In my opinion, for M1, we shouldn't strive for a subset of C per se. >>>>>>>>>> There's many things wrong with C, and those things cause a lot of >>>>>>>>>> pain >>>>>>>>>> and bugs. If there's going to be a language M1 or Lorito to implement >>>>>>>>>> most of parrot (incl PMCs) it would be a good idea to define a >>>>>>>>>> language that prevents many of those bugs, to create a language >>>>>>>>>> that's >>>>>>>>>> really stable, clearly defined, and so on, and that forbids bad >>>>>>>>>> constructs. For instance, no goto statement! (I'm even no fan of >>>>>>>>>> break >>>>>>>>>> and continue statements). C's preprocessor is a cheap way of doing >>>>>>>>>> modules properly, but it's kindof awful. There's better ways I'm sure >>>>>>>>>> to support multi-file programs. I think it would be a good idea to >>>>>>>>>> think well about how to encourage sound programming practices (C >>>>>>>>>> doesn't really), and implement a language that does that well, while >>>>>>>>>> still being easy to learn by C programmers. >>>>>>>>>> >>>>>>>>>> Meanwhile, my goal was to (1) indulge in my need for some hacking >>>>>>>>>> creativity, and (2) create a clean and simple language implementation >>>>>>>>>> that targets M0. Consider it a prototyping effort to identify gaps in >>>>>>>>>> M0 and see how far we can get with little effort. >>>>>>>>>> >>>>>>>>>> cheers >>>>>>>>>> kjs >>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>>> Bacek >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>> -- >>>>>>>>>>> Vasily >>>>>>>>>>> >>>>>>>>>>> On Sat, May 19, 2012 at 6:15 AM, kjstol <[email protected]> >>>>>>>>>>> wrote: >>>>>>>>>>>> hi there, >>>>>>>>>>>> >>>>>>>>>>>> I've indulged in some hacking time, and implemented a simple >>>>>>>>>>>> subset of C. >>>>>>>>>>>> Attached is a zip file, just type "make" and it should work >>>>>>>>>>>> (assuming >>>>>>>>>>>> you have bison and flex). >>>>>>>>>>>> >>>>>>>>>>>> What it currently does, it generates the parsed code from the AST >>>>>>>>>>>> (mostly). >>>>>>>>>>>> Not everything of the language is supported yet (e.g., parameters >>>>>>>>>>>> etc.) The parser would have to be fixed a bit, it has some known >>>>>>>>>>>> limitations. >>>>>>>>>>>> >>>>>>>>>>>> The idea next is to implement a simple code generator to generate >>>>>>>>>>>> the >>>>>>>>>>>> M0 ops that have been spec'ed so far. >>>>>>>>>>>> There are many todos (e.g, thread-safety of the compiler), >>>>>>>>>>>> register-allocator, etc.) most of which would be easy to implement. >>>>>>>>>>>> For now, the focus would be on a simple and clean language >>>>>>>>>>>> implementation that generate M0. >>>>>>>>>>>> >>>>>>>>>>>> Comments welcome, >>>>>>>>>>>> kjs >>>>>>>>>>>> >>>>>>>>>>>> _______________________________________________ >>>>>>>>>>>> http://lists.parrot.org/mailman/listinfo/parrot-dev >>>>>>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> http://lists.parrot.org/mailman/listinfo/parrot-dev _______________________________________________ http://lists.parrot.org/mailman/listinfo/parrot-dev
