#10333: hs-boot modification doesn't induce recompilation -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Description changed by ezyang: Old description:

Consider these modules:

X.hs-boot {{{ module X where }}}

Y.hs {{{ module Y where import {-# SOURCE #-} X data T = T data S = S T }}}

X.hs {{{ module X where import Y }}}

`ghc --make Y.hs` will compile fine. Now, modify `X.hs-boot` to add a `data T` (which will cause an ambiguous identifier error in Y.hx`. Run `ghc --make Y.hs` and nothing happens!

(You might also notice something else a bit funny, which is that `X.hs` gets compiled, even though it's not directly in the import chain of Y. I think this might be intentional but I'm not sure.)

Discovered this while poking around #10182.

New description: Consider these modules: X.hs-boot {{{ module X where }}} Y.hs {{{ module Y where import {-# SOURCE #-} X data T = T data S = S T }}} X.hs {{{ module X where import Y }}} `ghc --make Y.hs` will compile fine. Now, modify `X.hs-boot` to add a `data T` (which will cause an ambiguous identifier error in `Y.hx`. Run `ghc --make Y.hs` and nothing happens! (You might also notice something else a bit funny, which is that `X.hs` gets compiled, even though it's not directly in the import chain of Y. I think this might be intentional but I'm not sure.) Discovered this while poking around #10182. -- -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10333#comment:1> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

#10333: hs-boot modification doesn't induce recompilation -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by Edward Z. Yang <ezyang@…>): In [changeset:"06d46b1e4507e09eb2a7a04998a92610c8dc6277/ghc" 06d46b1e/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="06d46b1e4507e09eb2a7a04998a92610c8dc6277" Unify hsig and hs-boot; add preliminary "hs-boot" merging. This patch drops the file level distinction between hs-boot and hsig; we figure out which one we are compiling based on whether or not there is a corresponding hs file lying around. To make the "import A" syntax continue to work for bare hs-boot files, we also introduce hs-boot merging, which takes an A.hi-boot and converts it to an A.hi when there is no A.hs file in scope. This will be generalized in Backpack to merge multiple A.hi files together; which means we can jettison the "load multiple interface files" functionality. This works automatically for --make, but for one-shot compilation we need a new mode: ghc --merge-requirements A will generate an A.hi/A.o from a local A.hi-boot file; Backpack will extend this mechanism further. Has Haddock submodule update to deal with change in msHsFilePath behavior. - This commit drops support for the hsig extension. Can we support it? It's annoying because the finder code is written with the assumption that where there's an hs-boot file, there's always an hs file too. To support hsig, you'd have to probe two locations. Easier to just not support it. - #10333 affects us, modifying an hs-boot still doesn't trigger recomp. - See compiler/main/Finder.hs: this diff is very skeevy, but it seems to work. - This code cunningly doesn't drop hs-boot files from the "drop hs-boot files" module graph, if they don't have a corresponding hs file. I have no idea if this actually is useful. Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu> Test Plan: validate Reviewers: simonpj, austin, bgamari, spinda Subscribers: thomie Differential Revision: https://phabricator.haskell.org/D1098 }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10333#comment:3> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

#10333: hs-boot modification doesn't induce recompilation -------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.11 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: GHC accepts | Unknown/Multiple invalid program | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by ezyang): * owner: => ezyang -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10333#comment:5> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler