[HN Gopher] CIL: C Intermediate Language
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CIL: C Intermediate Language
Author : tosh
Score : 74 points
Date : 2024-10-28 09:57 UTC (4 days ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| saagarjha wrote:
| Is anyone using this? Perhaps for transpiring to a more limited
| compiler?
| nikki93 wrote:
| Frama-C uses CIL.
| KsassPeuk wrote:
| Well, Frama-C uses a quite modified version of CIL.
| mingodad wrote:
| See also https://melt.cs.umn.edu/ableC/ that has a similar
| goal.
| Tiberium wrote:
| One thing that CIL allows is creating amalgamations -
| converting the whole program into a single C file that can be
| then compiled by GCC or other compilers.
| HexDecOctBin wrote:
| This reminds me, is there any C compilers that allows injecting
| custom parsing rules? Say, if it is parsing or type checking and
| hits upon an error, it calls a callback instead of bailing. This
| would be very useful for adding simple extensions to the
| language. I tried to make LLVM do this but couldn't figure it
| out.
| tester756 wrote:
| It seems like you're interested in frontend - Clang, not
| backend - LLVM.
| Gibbon1 wrote:
| I saw someones tool that allows you to embed python code to
| generate C code.
|
| https://nedbatchelder.com/code/cog/
|
| Never used it.
| fuhsnn wrote:
| If you are ok with unoptimized codegen, chibicc[0] is very easy
| to modify. For an example checkout the patch set for adding
| defer in my fork[1].
|
| [0] https://github.com/rui314/chibicc [1]
| https://github.com/fuhsnn/slimcc-defer/commits
| neonsunset wrote:
| A bit unfortunate choice of the name since there is another CIL
| too: https://ecma-international.org/publications-and-
| standards/st...
| someothherguyy wrote:
| That is CLI (Common Language Infrastructure)?
|
| https://en.wikipedia.org/wiki/Common_Language_Infrastructure
| tubs wrote:
| Partition III: CIL Instruction Set - Describes the Common
| Intermediate Language (CIL) instruction set.
| almost wrote:
| There are a finite number of names, and an even smaller number
| of good names. But apparently an infinite number of hacker news
| posters who comment on every new project to complain that the
| name has been used before for something else.
|
| And even the fact that this is a fork of an earlier project and
| the name comes from that doesn't stop it!
|
| (I'm aware I have chosen a very weird thing to be getting
| annoyed at over my breakfast crumpets this morning)
| Philpax wrote:
| I would normally agree with you on this, but these projects
| are in the same realm (language compiler infrastructure), so
| it's a bit more unfortunate than in the usual case
| fuhsnn wrote:
| People are more triggered by "this is improper in my culture"
| type of comments, those tend to actually derail the thread.
| PeterWhittaker wrote:
| Not to mention SELinux CIL, Common Intermediate Language,
| https://selinuxproject.org/page/PolicyLanguage
| pkhuong wrote:
| https://github.com/goblint/cil/blob/develop/LICENSE Copyright
| (c) 2001-2020
|
| (I first learned about CIL in
| https://people.eecs.berkeley.edu/~necula/Papers/cil_cc02.pdf)
|
| I guess ECMA should have done better research.
| fluoridation wrote:
| https://en.wikipedia.org/wiki/Common_Language_Infrastructure
|
| 2012 is just the latest version. It was first published in
| 2001, and started in 2000. They're so close together that
| it's difficult to say if one would have been able to find the
| other.
| riperoni wrote:
| Can someone explain to a C-noob how this differs from and
| compares to LLVM?
| Philpax wrote:
| LLVM is a backend: it takes LLVM IR (intermediate
| representation) and generates machine code.
|
| This is a frontend: it takes C and generates its own IR (a
| simplified version of C).
|
| You could glue these together with an adapter from CIL to LLVM
| IR to get a complete C compiler.
|
| Clang is both a frontend and a complete compiler in this
| respect: the Clang frontend compiles C to LLVM IR, and these
| are bundled together to produce the Clang compiler.
|
| (Note: I'm simplifying things here. Clang and LLVM are more
| intertwined than these, and there are several nuances I'm not
| covering; I'm going for a high-level perspective here)
| riperoni wrote:
| High-level is good enough for me for the beginning, thanks!
| pizlonator wrote:
| Great question.
|
| First of all, llvm has clang, which means that llvm as a whole
| is equipped to understand C (and C++ and Objective-C) both at a
| high level (abstract syntax tree, all types as declared by the
| programmer) and low level (SSA form, only the types that are
| meaningful for sound analysis and optimization).
|
| I think that CIL was a really big deal before llvm and clang.
| Back then, it was a more approachable alternative to trying to
| fiddle with C than using GCC, since GCC has a steep learning
| curve. But in the last 15 years or so, most of the research
| that would have been done in CIL before is now done in llvm.
| That's because llvm is much more complete _and_ it's designed
| for ergonomics, specifically in the case where you just want to
| mess around and even if you're a newcomer to the compiler. The
| docs are great and the APIs are top notch.
|
| I think that LLVM's SSA form is especially good for doing
| sophisticated analysis and instrumentation of C. I've used that
| a lot for my C experiments. Clang's AST is really great, too -
| and it's amazing for doing higher level stuff where you want to
| see the original C types and declarations before lowering.
|
| I suspect that there is very little that CIL can do for you
| that can't be done in llvm more straightforwardly. And
| llvm+clang support all of C, plus the adjacent languages (C++
| and others).
|
| So, it's cool that CIL is still around (having alternatives is
| good, generally) but in my opinion as someone who does
| experimental work in C compilers, C language extensions, and
| static/dynamic analysis of C, llvm completely subsumes CIL.
| WalterBright wrote:
| I considered developing such a language, but could not justify
| it. The intermediate code I developed works just fine for this,
| and would be trivial to convert to/from a text based form, but I
| couldn't see the point.
| ranger_danger wrote:
| I just want a way to add simple inheritable classes to C without
| bringing in the entirety of C++ and all its differences and
| baggage. But I guess things like constructors/destructors are not
| possible to implement in a language standard-compliant way (not
| relying on compiler extensions).
| mingodad wrote:
| Have a look at http://ecere.org/ they already have it working.
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