[GHC] #12517: Simplify runghc command line options
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Keywords: runghc | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- Currently there are three ways runghc can pass options to GHC: 1. unrecognized options are automatically passed to GHC 2. options after a `--` are passed to GHC 3. `--ghc-args=<arg>` passes arg to GHC The command line is difficult to comprehend and non-intuitive with all these different ways to pass options to GHC. Other than having multiple ways to do the same thing there are other problems too. For example: 1. The meaning of `--` is overloaded, the usual meaning is that everything after it is non option or opaque args. This is difficult to explain and creates confusion. 2. To pass a filename starting with a dash we need something like `runghc -- -- -prog.hs`. Which is not a usual use case but it needs to be explained in the manual anyway. 3. It first appears that options after `--` will be passed to GHC including those not starting with a `-` but that is not the case. For args not starting with a `-` we need to use `--ghc-arg=` so there is not much use of the `--` anyway other than increased confusion. I propose to do away with all other mechanisms other than the explicit `--ghc-arg=<arg>` method. This will make the documentation and understanding of the command straightforward and intuitive. Though the change will not be backward compatible. If backward compatibility is really needed we will have to use deprecation warnings for the unsupported methods and remove them from the official documentation and wait for some time before we actually remove them. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by harendra): A problem with transparently passing unrecognized flags to ghc is a very confusing and hard to understand behavior like this: {{{ runghc -package text-1.2.2.1 hello.hs text-1.2.2.0:1:74: Not in scope: ‘main’ Perhaps you meant ‘min’ (imported from Prelude) }}} What happened here is that runghc passed `-package` option to ghc but it did not pass text-1.2.2.0 which is being treated as the program name. This happens because of different ways to pass `-package` and its argument. So we will have to use `--ghc-arg=` for the arg like this: {{{ runghc -package --ghc-arg=text-1.2.2.1 hello.hs hello }}} If we had the same way to pass both the flag and the argument we won't have this very confusing behavior. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by thomie): How about this: {{{ runghc [runghc flags] module|filename [GHC flags] [-- [program args]] }}} Clarification: * `runghc -package ..` would be an error, because `-package` is not a runghc flag, nor is it a valid module or filename. Note that GHC doesn't even support filenames starting with a dash (try `ghc -hello.hs`), so I don't understand why the following hack even exists: {{{ pastArgs :: String -> Bool -- You can use -- to mark the end of the flags, in case you need to use -- a file called -foo.hs for some reason. You almost certainly shouldn't, -- though. pastArgs "--" = True pastArgs ('-':_) = False pastArgs _ = True }}} * `"--"` is no longer overloaded. It just separates the GHC flags from the program arguments, and to pass program arguments you //have to// use `"--"`. This is an improvement, because currently you might think that `-v` in `runghc hello.hs -v` is a GHC flag, while it is actually a program arguments (and might silently get ignored). * `--ghc-arg` can be deprecated * Your example would become: `runghc hello.hs -package text-1.2.2.1` Are there any drawbacks to this approach (other than also breaking backward compatibility)? Fwiw: currenly, your example can also be solved without `--ghc-arg` using: `runghc -package=text-1.2.2.1 hello.hs`. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by harendra): This approach looks clever at the first glance. But then: * As you noted in the end - the program name is absent in the stdin case * Usually Haskell programs (e.g. `ghc hello.hs -package text`) can specify options anywhere i.e. before or after the arguments. So designating before and after for different purposes could still be confusing because of the usual conventions being different.
your example can also be solved without --ghc-arg using: runghc -package=text-1.2.2.1 hello.hs.
I never thought about that. That's pretty nifty for current state of affairs. Yet another way. Big problem with having too many ways to do that same thing is discoverability and retention. I did not even know that ghc accepts arguments that way as well. I just looked into the man page, it is not mentioned. Could not find it in the users guide as well on a quick look in the `Using GHC` section. All of the users guide lists flags in the `-package text` convention, so that's what sticks. If I cannot easily find this and it is optional then it does not exist for me, it does not matter, its tribal knowledge. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by harendra):
Note that GHC doesn't even support filenames starting with a dash
Yeah, I had tried this earlier and wondered why do we have this if ghc does not support it, but I ignored it (maybe in future ghc might support that). Now I think we should just get rid of it to keep the code and documentation simple. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options
-------------------------------------+-------------------------------------
Reporter: harendra | Owner: harendra
Type: bug | Status: new
Priority: normal | Milestone:
Component: None | Version: 8.0.1
Resolution: | Keywords: runghc
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by Ben Gamari
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: closed Priority: normal | Milestone: 8.0.2 Component: None | Version: 8.0.1 Resolution: fixed | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: new => closed * resolution: => fixed * milestone: => 8.0.2 Comment: Merged to `ghc-8.0` with d7cb24d1c482bffd8ba509b7e364dc8e40bc14d7. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by harendra): * status: closed => new * owner: harendra => * resolution: fixed => Comment: I wrongly attached that commit with this bug. I am reopening it. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by harendra): * owner: => harendra -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 8.0.2 => 8.2.1 Comment: Bumping off to 8.2.1 since the proposed simplification won't happen for 8.0.2. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): harendra, do you think you will be able to do this? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by harendra): Let me try. I will need a reviewer. I guess all we need to do for now is - add deprecation warnings for what is to be removed in future and remove it from the documentation. The deprecation warnings will show on stderr. Later, at some point in time we will remove the unsupported ways/flags of invoking runghc. Does that sound good? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options
-------------------------------------+-------------------------------------
Reporter: harendra | Owner: harendra
Type: bug | Status: new
Priority: normal | Milestone: 8.2.1
Component: None | Version: 8.0.1
Resolution: | Keywords: runghc
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
-------------------------------------+-------------------------------------
Comment (by bgamari):
> Let me try. I will need a reviewer. I guess all we need to do for now is
- add deprecation warnings for what is to be removed in future and remove
it from the documentation. The deprecation warnings will show on stderr.
Later, at some point in time we will remove the unsupported ways/flags of
invoking runghc.
Sounds reasonable to me. I'll gladly review.
--
Ticket URL:
GHC
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): D2940 Wiki Page: | -------------------------------------+------------------------------------- Changes (by harendra): * differential: => D2940 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2940 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * differential: D2940 => Phab:D2940 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2940 Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): I think thomie's version could be made a bit more intuitive using something like {{{ runghc [runghc flags] module|filename [--ghc-flags [GHC flags]] [-- [program args]] }}} For example {{{ runghc Foo --ghc-flags -Wall -ddump-simpl -- -hi --bi }}} Like thomie's version, this requires the GHC flags to come after all runghc options and the module name, but it marks them out explicitly. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2940 Wiki Page: | -------------------------------------+------------------------------------- Comment (by dfeuer): I think this issue should probably be addressed using the new GHC proposal process. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: 8.2.1 Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2940 Wiki Page: | -------------------------------------+------------------------------------- Comment (by harendra): I find it rather unintuitive to embed the ghc flags between the program name and the program flags. It is simpler to say and understand: {{{ runghc [flags] [filename [program args]] }}} ghc options becomes just one of the flags which is easier to understand (IMO). I agree that using one "--ghc-options" for all ghc flags is more convenient. If that is acceptable, I can try to find existing code to be able to do that (i.e. handle the escaping). I am fine with the proposal process but I won't be able to drive that myself, though I can contribute to it. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:17 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
#12517: Simplify runghc command line options -------------------------------------+------------------------------------- Reporter: harendra | Owner: harendra Type: bug | Status: new Priority: normal | Milestone: Component: None | Version: 8.0.1 Resolution: | Keywords: runghc Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2940 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * milestone: 8.6.1 => Comment: Removing milestone as no one is currently actively working on this. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12517#comment:20 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler
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