November 2014 - ghc-tickets

[GHC] #8144: Interface hashes include time stamp of included .h file when CPP is used
by GHC 25 Jun '15

25 Jun '15

#8144: Interface hashes include time stamp of included .h file when CPP is used -------------------------+------------------------------------------------- Reporter: nh2 | Owner: Type: bug | Status: new Priority: | Milestone: normal | Version: 7.6.3 Component: | Operating System: Unknown/Multiple Compiler | Type of failure: Compile-time performance bug Keywords: | Test Case: Architecture: | Blocking: Unknown/Multiple | Difficulty: | Unknown | Blocked By: | Related Tickets: | -------------------------+------------------------------------------------- See https://github.com/nh2/ghc-bug-time-dependent-interface-hashes for a fast test case. Having '''Test.hs''': {{{ {-# LANGUAGE CPP #-} module Test () where }}} and an empty '''cabal_macros.h''', {{{ touch cabal_macros.h ghc -c Test.hs -optP-include -optPcabal_macros.h }}} will generate you a different interface hash ''most of the time'' in '''ghc --show-iface Test.hi'''. It looks like the modification time of the .h file makes it into the interface hash, but only at second resolution, and you get ''compilation IS NOT required'' if you manage to run it twice per second. I think the interface hash should be independent from the time stamp of the header file. This bug can trigger unnecessary recompilation and makes compilations with identical inputs non-deterministic. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8144> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 34

[GHC] #8785: Replace hooks API in the RTS with something better
by GHC 16 Jun '15

16 Jun '15

#8785: Replace hooks API in the RTS with something better ------------------------------------+------------------------------------- Reporter: simonmar | Owner: simonmar Type: task | Status: new Priority: high | Milestone: 7.10.1 Component: Runtime System | Version: 7.6.3 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Hooks rely on static linking behaviour which doesn't always work: we have to disable -Bsymbolic for the RTS on Linux (see `compiler/main/SysTools.lhs`) and it apparently doesn't work at all on Mac (#8754). So instead of hooks we should be passing in information when we initialize the RTS, like we already do for some other things (`-rtsopts` etc.). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8785> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9769: ghc-7.8.3-x86_64-unknown-mingw32.tar.xz missing User's Guide
by GHC 14 Jun '15

14 Jun '15

#9769: ghc-7.8.3-x86_64-unknown-mingw32.tar.xz missing User's Guide -------------------------------------+------------------------------------- Reporter: Dangthrimble | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Documentation | Version: 7.8.3 Keywords: | Operating System: Windows Architecture: x86_64 (amd64) | Type of failure: Difficulty: Unknown | Documentation bug Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Context: I am relatively new to Haskell and am trying to build a Haskell IDE around `Sublime Text`. I have been using `Haskell Platform` but have encountered a number of problems using `cabal`. Consequently I have been advised to uninstall `Haskell Platform` and download `ghc`. I have just downloaded and extracted `ghc-7.8.3-x86_64-unknown- mingw32.tar.xz`. Hoping for advice on setting up `ghc`, I have opened `ghc-7.8.3\doc\html\index.html` in Firefox and clicked on "The User's Guide". Unfortunately the `ghc-7.8.3/doc/html/users_guide` folder is missing. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9769> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 4

[GHC] #8591: Concurrent executions of ghc-pkg can cause inconstant package.cache files
by GHC 14 Jun '15

14 Jun '15

#8591: Concurrent executions of ghc-pkg can cause inconstant package.cache files ------------------------------------+---------------------------- Reporter: janm | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Package system | Version: 7.6.3 Keywords: ghc-pkg race | Operating System: FreeBSD Architecture: Unknown/Multiple | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+---------------------------- I am doing 24 way parallel builds of system images, including all packages on a system. This includes ghc and multiple ghc packages. I am seeing intermittent dependency failure from the ghc packaging system. From examining Main.hs in ghc-pkg, I see the function withFileAtomic write to a temporary file in package.conf.d and then atomically rename on top of a target file, package.cache in the case. With parallel execution the last rename would win, leading to lost entries in package.cache. In my case, the following things happened: ("Building" indicates a start, "Built" indicates completion, "Installing" is setup in a separate chroot'd environment and is isolated) The FreeBSD ports system is used to drive the Haskell build system. The process works single threaded and fails intermittently when done in parallel. Building: devel/hs-data-default-instances-base Building: devel/hs-data-default-instances-containers Building: devel/hs-data-default-instances-old-locale Built: devel/hs-dlist Building: devel/hs-data-default-instances-dlist Built: devel/hs-temporary Built: jail-image-full Installing: system-image__jail-image-full Built: devel/hs-base64-bytestring Built: archivers/hs-zlib Building: security/hs-digest Built: devel/hs-syb Building: textproc/hs-hs-bibutils Building: textproc/hs-pandoc-types Built: devel/hs-utf8-string Built: devel/hs-data-default-instances-old-locale Built: devel/hs-data-default-instances-containers Built: devel/hs-data-default-instances-base Built: devel/hs-data-default-instances-dlist Building: devel/hs-data-default Built: devel/hs-random Installed: system-image__lang/ghc Installing: system-image__archivers/hs-zlib Installing: system-image__devel/hs-utf8-string Installing: system-image__devel/hs-syb Installing: system-image__devel/hs-base64-bytestring Installing: system-image__devel/hs-data-default-class Installing: system-image__devel/hs-dlist Installing: system-image__devel/hs-random Installing: system-image__devel/hs-temporary Installing: system-image__devel/hs-extensible-exceptions Built: devel/hs-data-default FAILED The error from the Haskell data-default build was: setup: At least the following dependencies are missing: data-default-instances-base -any Looking in the in the package.conf.d directory shows that the data- default-instances-base-0.0.1-7bdf8678f0d8637e096e397e7910f82a.conf file was present, but running "ghc-pkg list" did not show data-default- instances-base Running /usr/local/lib/cabal/ghc-7.6.3/data-default-instances- base-0.0.1/register.sh (which was also present) caused ghc-pkg to now show data-default-instances-base. To me this looks like a race condition between multiple instances of ghc- pkg causing the cache to become inconsistent. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8591> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 11

[GHC] #9511: Remove deprecated -fglasgow-exts from NoFib suite
by GHC 14 Jun '15

14 Jun '15

#9511: Remove deprecated -fglasgow-exts from NoFib suite -------------------------------------+------------------------------------- Reporter: dfeuer | Owner: Type: task | Status: new Priority: low | Milestone: Component: NoFib benchmark | Version: 7.8.3 suite | Operating System: Keywords: | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Someone on #ghc noted that replacing -fglasgow-exts with only the necessary options in each case may change compile times, which may be undesirable. I think a reasonable workaround would be to just put all the options on the command line, whether necessary or not. This will increase the time needed to parse the command lines, but presumably by a trivial amount. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9511> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 1

[GHC] #8435: Do not copy stack after stack overflow
by GHC 12 Jun '15

12 Jun '15

#8435: Do not copy stack after stack overflow ------------------------------+-------------------------------------------- Reporter: ezyang | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime | Version: 7.7 System | Operating System: Unknown/Multiple Keywords: | Type of failure: Runtime performance bug Architecture: | Test Case: Unknown/Multiple | Blocking: Difficulty: Unknown | Blocked By: | Related Tickets: | ------------------------------+-------------------------------------------- I am not sure, but I was doing a close reading of `threadStackOverflow` and noticed that after we throw a stack overflow exception, we fall through to the code responsible for allocating a new stack and copying the code over. An old iteration of the stack overflow code (removed in the commit cited below) did return after throwing the exception, and I did not see anything in the commit message suggesting the change was intentional. It seems sound to copy the stack; it will just become dead immediately. The relevant commit: {{{ commit f30d527344db528618f64a25250a3be557d9f287 Author: Simon Marlow <marlowsd(a)gmail.com> Date: Wed Dec 15 12:08:43 2010 +0000 Implement stack chunks and separate TSO/STACK objects }}} Suggested (untested) patch: {{{ diff --git a/rts/Threads.c b/rts/Threads.c index 742119d..ccd6b17 100644 --- a/rts/Threads.c +++ b/rts/Threads.c @@ -533,6 +533,7 @@ threadStackOverflow (Capability *cap, StgTSO *tso) // Send this thread the StackOverflow exception throwToSingleThreaded(cap, tso, (StgClosure *)stackOverflow_closure); + return; } }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8435> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

[GHC] #9746: tests/ghci/scripts/T8172 is sensitive to drive name on Windows
by GHC 11 Jun '15

11 Jun '15

#9746: tests/ghci/scripts/T8172 is sensitive to drive name on Windows -------------------------------------+------------------------------------- Reporter: gintas | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Test Suite | Version: 7.8.3 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: Difficulty: Unknown | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- The test fails when the checkout is not on drive C:, like this: --- ./ghci/scripts/T8172.stdout-mingw32 2014-10-28 23:28:12.264410700 +0100 +++ ./ghci/scripts/T8172.run.stdout 2014-10-30 15:20:13.964595800 +0100 @@ -1,11 +1,11 @@ current working directory: - C:\ + K:\ module import search paths: . current working directory: - C:\ + K:\ module import search paths: none current working directory: - C:\ + K:\ module import search paths: / -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9746> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 3

[GHC] #9252: Generalize hs-boot files to be more like module signatures
by GHC 11 Jun '15

11 Jun '15

#9252: Generalize hs-boot files to be more like module signatures ------------------------------------+------------------------------------- Reporter: ezyang | Owner: ezyang Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: backpack | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Right now, `hs-boot` is used solely to support mutually recursive modules. However, as [wiki:Backpack Backpack] has shown, signatures are an essential part of separate modular development, and since hs-boot files are essentially module signatures, it would be good to move away from "hs- boot as a technical mechanism to make mutual recursion to work" to "hsig as a module signature useful for separate modular development and mutual recursion." Here are some of the things that this would entail: 1. Introduce hsig as a valid alternate file suffix to hs-boot (similarly have hisig for hi-boot; the plan being to eventually deprecate the hs-boot prefix) 2. Given an hsig file corresponding to a module in the current package database (but not from the currently being compiled package), check if the corresponding module implements the signature (this is the reverse of the current check we do for hs-boot files, which occurs when we typecheck the module, as opposed to the hs-boot file.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9252> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 9

[GHC] #8172: Expose CWD and import search paths in GHCi via new `:show paths` command
by GHC 11 Jun '15

11 Jun '15

#8172: Expose CWD and import search paths in GHCi via new `:show paths` command -------------------------------------------+------------------------------- Reporter: hvr | Owner: hvr Type: feature request | Status: new Priority: normal | Milestone: Component: GHCi | Version: 7.7 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 hour) | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: -------------------------------------------+------------------------------- - Currently, GHCi provides a `:cd` command but no respective builtin command to query the currently set path. - Moreover, there's no obvious way to query the currently active `importPaths` dynamic flags field, to find out which `-i` options are currently in effect. The attached patch extends `:show` with a `:show paths` subcommand, printing the CWD and the current value of `importPaths`: {{{ Ok, modules loaded: Main, InteractiveUI, Paths_ghci_ng, GhciMonad, GhciTags. λ> :show paths current working directory: /home/hvr/Haskell/My/ghci-ng module import search paths: dist/build/ghci-ng/ghci-ng-tmp ghc dist/build/autogen λ> :set -i λ> :show paths current working directory: /home/hvr/Haskell/My/ghci-ng module import search paths: none > :cd /tmp Warning: changing directory causes all loaded modules to be unloaded, because the search path has changed. > :show paths current working directory: /tmp module import search paths: none }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8172> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 7

[GHC] #9663: Windows build process should give better message if you forgot to clone tarballs
by GHC 09 Jun '15

09 Jun '15

#9663: Windows build process should give better message if you forgot to clone tarballs -------------------------------------+------------------------------------- Reporter: ezyang | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Build System | Version: 7.9 Keywords: | Operating System: Windows Architecture: Unknown/Multiple | Type of failure: Difficulty: Unknown | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- If you forget to clone ghc-tarballs into the directory when building on Windows, configure will report that it can't find a working C compiler. It would be nice if there was a better error message here. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9663> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

1 2