February 2014 - ghc-tickets

[GHC] #8830: internal error: Misaligned section: 18206e5b on Windows
by GHC 21 Jan '16

21 Jan '16

#8830: internal error: Misaligned section: 18206e5b on Windows ----------------------------+------------------------------- Reporter: joeyhess | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Windows Architecture: x86 | Type of failure: GHCi crash Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------+------------------------------- Loading package gnutls-0.1.5 ... ghc.exe: internal error: Misaligned section: 18206e5b (GHC version 7.6.3 for i386_unknown_mingw32) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. Only occurs when loading the module in as part of a build involving TH. A non-TH-using program using this library links successfully. I have installed a gnutls built for Windows, from http://josefsson.org/gnutls4win/. Different versions have different section offsets, but all the versions I've tried fail like this. I've also gotten the same error linking gnuidn, instead of gnutls, with gnuidn from ftp://ftp.gnu.org/gnu/libidn/libidn-1.28-win32.zip This makes me think this may be a general ghci on windows bug, rather than a misbuilt library. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8830> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8114: GHC panic when building `thyme`
by GHC 16 Jan '16

16 Jan '16

#8114: GHC panic when building `thyme` -----------------------------------+--------------------------------------- Reporter: Ptharien's | Owner: Flame | Status: new Type: bug | Milestone: Priority: normal | Version: 7.6.3 Component: Compiler | Operating System: MacOS X Keywords: | Type of failure: Compile-time crash Architecture: x86_64 (amd64) | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- While attempting to build `thyme` from Hackage with core, stg, and cmm linting and -O2 enabled, GHC crashed with an internal panic. See attached terminal log. {{{ rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ ghc --version The Glorious Glasgow Haskell Compilation System, version 7.6.3 rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ cabal --version cabal-install version 1.16.0.2 using version 1.16.0 of the Cabal library rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which ghc /usr/local/bin/ghc rrdhcp-10-32-234-247:thyme-0.2.4.1 Alexander$ which cabal /Users/Alexander/Library/Haskell/bin/cabal }}} -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8114> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8613: simplifier ticks exhausted
by GHC 13 Jan '16

13 Jan '16

#8613: simplifier ticks exhausted ----------------------------------+---------------------------- Reporter: guest | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: MacOS X Architecture: x86_64 (amd64) | Type of failure: Other Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------------+---------------------------- (Sent by chrisreade(a)mac.com ) Compiler giving up with simplifier ticks exhausted. Large amount of simplification may be going on to cause this. The problem goes away when using -fsimpl-tick-factor=1000 and the code runs. This is the session output without the flag (asking to have bug reported): chris$ ghc -O2 -rtsopts RedBlackStencilOpt.hs -v Glasgow Haskell Compiler, Version 7.6.3, stage 2 booted by GHC version 7.4.2 Using binary package database: /Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/package.conf.d/package.cache Using binary package database: /Users/chris/.ghc/x86_64-darwin-7.6.3/package.conf.d/package.cache hiding package binary-0.5.1.1 to avoid conflict with later version binary-0.6.4.0 hiding package Cabal-1.16.0 to avoid conflict with later version Cabal-1.18.1.1 wired-in package ghc-prim mapped to ghc- prim-0.3.0.0-d5221a8c8a269b66ab9a07bdc23317dd wired-in package integer-gmp mapped to integer- gmp-0.5.0.0-2f15426f5b53fe4c6490832f9b20d8d7 wired-in package base mapped to base-4.6.0.1-6c351d70a24d3e96f315cba68f3acf57 wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.8.0.0-c2c1b21dbbb37ace4b7dc26c966ec664 wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: -static *** Chasing dependencies: Chasing modules from: *RedBlackStencilOpt.hs Stable obj: [] Stable BCO: [] Ready for upsweep [NONREC ModSummary { ms_hs_date = 2013-12-13 13:12:37 UTC ms_mod = main:RedBlackStencilOpt, ms_textual_imps = [import (implicit) Prelude, import Data.Array.Repa.Stencil.Dim2 as A, import Data.Array.Repa.Stencil as A, import Data.Array.Repa as A] ms_srcimps = [] }] *** Deleting temp files: Deleting: compile: input file RedBlackStencilOpt.hs Created temporary directory: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0 *** Checking old interface for main:RedBlackStencilOpt: [1 of 1] Compiling RedBlackStencilOpt ( RedBlackStencilOpt.hs, RedBlackStencilOpt.o ) *** Parser: *** Renamer/typechecker: *** Simplify: *** CorePrep: *** ByteCodeGen: Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. *** gcc: '/usr/bin/gcc' '-m64' '-fno-stack-protector' '-m64' '-L/Library/Frameworks/GHC.framework/Versions/7.6.3-x86_64/usr/lib/ghc-7.6.3/base-4.6.0.1' '--print-file-name' 'libiconv.dylib' Loading package base ... linking ... done. Loading package pretty-1.1.1.0 ... linking ... done. Loading package array-0.4.0.1 ... linking ... done. Loading package deepseq-1.3.0.1 ... linking ... done. Loading package containers-0.5.0.0 ... linking ... done. Loading package old-locale-1.0.0.5 ... linking ... done. Loading package time-1.4.0.1 ... linking ... done. Loading package random-1.0.1.1 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package QuickCheck-2.6 ... linking ... done. Loading package bytestring-0.10.0.2 ... linking ... done. Loading package primitive-0.5.0.1 ... linking ... done. Loading package vector-0.10.0.1 ... linking ... done. Loading package repa-3.2.3.3 ... linking ... done. *** Simplify: *** CorePrep: *** ByteCodeGen: *** Desugar: Result size of Desugar (after optimization) = {terms: 900, types: 1,810, coercions: 340} *** Simplifier: Result size of Simplifier iteration=1 = {terms: 834, types: 1,757, coercions: 567} Result size of Simplifier iteration=2 = {terms: 830, types: 1,721, coercions: 567} Result size of Simplifier = {terms: 830, types: 1,721, coercions: 567} *** Specialise: Result size of Specialise = {terms: 830, types: 1,721, coercions: 567} *** Float out(FOS {Lam = Just 0, Consts = True, PAPs = False}): Result size of Float out(FOS {Lam = Just 0, Consts = True, PAPs = False}) = {terms: 993, types: 2,131, coercions: 567} *** Float inwards: Result size of Float inwards = {terms: 993, types: 2,131, coercions: 567} *** Simplifier: *** Deleting temp files: Deleting: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0/ghc93155_0.s Warning: deleting non-existent /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0/ghc93155_0.s *** Deleting temp dirs: Deleting: /var/folders/dz/m1mks1yn1bsft72zgh105sw40000gn/T/ghc93155_0 ghc: panic! (the 'impossible' happened) (GHC version 7.6.3 for x86_64-apple-darwin): Simplifier ticks exhausted When trying RuleFired Class op szipWith To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 60402 Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8613> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8736: GHCi doesn't load .dyn_o files appropriately
by GHC 09 Jan '16

09 Jan '16

#8736: GHCi doesn't load .dyn_o files appropriately ------------------------------------+------------------------------------- Reporter: thoughtpolice | Owner: thoughtpolice Type: bug | Status: new Priority: high | Milestone: 7.8.1 Component: Compiler | Version: 7.8.1-rc1 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- Now that GHCi generally defaults to dynamic linking, it handles dynamic object files. But it doesn't implicitly handle the `-dynamic-too` case appropriately: {{{ $ cat Test.hs main = return () $ ./inplace/bin/ghc-stage2 -dynamic Test.hs [1 of 1] Compiling Main ( Test.hs, Test.o ) Linking Test ... $ ./inplace/bin/ghc-stage2 --interactive Test GHCi, version 7.8.20140130: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Ok, modules loaded: Main. Prelude Main> ^D $ ./inplace/bin/ghc-stage2 -dynamic-too Test.hs [1 of 1] Compiling Main ( Test.hs, Test.o ) Linking Test ... $ ./inplace/bin/ghc-stage2 --interactive Test GHCi, version 7.8.20140130: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. [1 of 1] Compiling Main ( Test.hs, interpreted ) Ok, modules loaded: Main. *Main> }}} Also: {{{ $ ./inplace/bin/ghc-stage2 --interactive Test.dyn_o GHCi, version 7.8.20140130: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Warning: ignoring unrecognised input `Test.dyn_o' Prelude> }}} but it does handle the `.o` case. This should all be fixed and merged to 7.8 since it'll likely be very annoying. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8736> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8793: Improve GHC.Event.IntTable performance
by GHC 09 Jan '16

09 Jan '16

#8793: Improve GHC.Event.IntTable performance ------------------------------------+------------------------------------- Reporter: cdk | Owner: Type: task | Status: new Priority: normal | Milestone: 7.8.1 Component: libraries/base | 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: | ------------------------------------+------------------------------------- The performance of `GHC.Event.IntTable` can be improved. I've managed to get some nice increases across the board. Benchmarking using `criterion` shows: function, % faster than current impl. `insert`: 4% `lookup`: 26% `update`: 11% `delete`: 5% There is one strange thing I noted. In `updateWith`, there is an inner loop that looks like this: {{{ data Bucket a = Empty | Bucket Int a (Bucket a) go _ Empty = (False, Nothing, Empty) go cont (Bucket key val next) | key == k = case f val of Nothing -> (True, Just val, cont next) Just v -> (False, Just val, cont (Bucket key v next)) | otherwise = go (\x -> cont (Bucket key val x)) next }}} which returns a tuple that is immediately consumed like so: {{{ (delete_occurred, old_val, new_bkt) <- go id ... when (isJust old_val) $ do <updateIntTable> when delete_occurred <decIntTableSize> return old_val }}} I expected that inlining the `<updateIntTable>` and `<decIntTableSize>` code blocks directly into `go` would result in better code than creating a tuple and then pattern matching on it afterwards. ie. {{{ go _ Empty = return Nothing go cont (Bucket key val next) | key == k = do case f val of Nothing -> <updateIntTable> (cont next) >> <decIntTableSize> Just v -> <updateIntTable> (cont (Bucket key v next) return (Just val) | otherwise = go (\x -> cont (Bucket key val x)) next }}} which has the exact same semantics. To my suprise, this code is almost 2x slower! The core generated in both cases is exactly what I'd expect; if anything, the second version seems tighter. I'm not sure why the first version is faster, but perhaps the original author, Bryan O'Sullivan, can shed some light as he used the tupled method in the first version. I'll attach my patch, `criterion`'s html output for the benchmarks as well as the benchmarking code, and the core for the oddity I discussed above. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8793> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8060: Undefined symbols when using Template Haskell linked from another object with unexposed modules
by GHC 08 Jan '16

08 Jan '16

#8060: Undefined symbols when using Template Haskell linked from another object with unexposed modules -----------------------------------+--------------------------------------- Reporter: tvynr | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.6.3 Keywords: | Operating System: Linux Architecture: | Type of failure: Compile-time crash Unknown/Multiple | Test Case: Difficulty: Unknown | Blocking: Blocked By: | Related Tickets: | -----------------------------------+--------------------------------------- I have constructed two Cabal projects named "first" and "second". The "first" project defines three files: Logging.hs (which provides some basic logging functionality) and FirstExample.hs and FirstDependent.hs (the latter of which imports the former). In the cabal file, only Logging and FirstDependent are exposed modules. FirstDependent uses a Template Haskell function "loggingFunctions" which defines logging functions for that module. Using cabal or cabal-dev to build this package works quite nicely. The second project depends on the first project and contains a single file, Second.hs. This file imports Logging but neither of the other two files. It also uses the loggingFunctions routine to generate local logging functions. The presence of the "$(loggingFunctions)" splice in Second.hs makes the problem visible, but the real problem is in the first project. Upon compilation of the "second" project with cabal or cabal- dev, the following error is generated: {{{ cabal-dev -s ../cabal-dev-sandbox --with-cabal-install=cabal configure Resolving dependencies... Configuring second-0.1... cabal-dev -s ../cabal-dev-sandbox --with-cabal-install=cabal build Building second-0.1... Preprocessing library second-0.1... [1 of 1] Compiling Second ( lib-src/Second.hs, dist/build/Second.o ) Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package array-0.4.0.1 ... linking ... done. Loading package deepseq-1.3.0.1 ... linking ... done. Loading package containers-0.5.0.0 ... linking ... done. Loading package filepath-1.3.0.1 ... linking ... done. Loading package old-locale-1.0.0.5 ... linking ... done. Loading package time-1.4.0.1 ... linking ... done. Loading package bytestring-0.10.0.2 ... linking ... done. Loading package unix-2.6.0.1 ... linking ... done. Loading package directory-1.2.0.1 ... linking ... done. Loading package transformers-0.3.0.0 ... linking ... done. Loading package mtl-2.1.2 ... linking ... done. Loading package text-0.11.3.1 ... linking ... done. Loading package parsec-3.1.3 ... linking ... done. Loading package network-2.4.1.2 ... linking ... done. Loading package process-1.1.0.2 ... linking ... done. Loading package hslogger-1.2.1 ... linking ... done. Loading package pretty-1.1.1.0 ... linking ... done. Loading package template-haskell ... linking ... done. Loading package first-0.2 ... linking ... ghc: /home/some- directories/example/first/../cabal-dev- sandbox//lib/first-0.2/ghc-7.6.1.20121207/HSfirst-0.2.o: unknown symbol `firstzm0zi2_FirstExample_zdfShowErrorSpec3_closure' ghc: unable to load package `first-0.2' make[1]: *** [build] Error 1 }}} Upon further investigation, it would seem that the .o file constructed to represent the "first" project has not been completely constructed: {{{ $ objdump -t cabal-dev- sandbox/lib/first-0.2/ghc-7.6.1.20121207/HSfirst-0.2.o | grep '\*UND\*' | grep first 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfOrdErrorSpeczuzdczg_info 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfShowErrorSpec3_closure 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfOrdErrorSpeczuzdczl_info 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfEqErrorSpeczuzdczeze_info 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfOrdErrorSpeczuzdczlze_info 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfOrdErrorSpeczuzdccompare_info 00000000 *UND* 00000000 firstzm0zi2_FirstExample_zdfOrdErrorSpeczuzdczgze_info }}} (While the above dump is for ghc 7.6.1, this has also been tested on ghc 7.6.3 as well as on both i386- and amd64-based OS installs.) If the "$(loggingFunctions)" splice is removed from Second.hs, then the project builds (presumably because the logic used by non-Template Haskell projects for linking differs from that of Template Haskell projects). Fortunately, it seems that exposing every module of the "first" project resolves this issue. But please note that the FirstExample.hs and FirstDependent.hs files are completely unrelated to the Second.hs file; the latter does not depend on the former in any way. It seems strange that I can't use Template Haskell across projects without exposing all of my project modules. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8060> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8652: Cross-compiling broken for ARM/Linux target
by GHC 07 Jan '16

07 Jan '16

#8652: Cross-compiling broken for ARM/Linux target ----------------------------+---------------------------------------- Reporter: kgardas | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Linux Architecture: arm | Type of failure: Building GHC failed Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ----------------------------+---------------------------------------- I've attempted to cross compile GHC HEAD on Ubuntu 13.10 with ubuntu's hard-float tool-chain and LLVM. I've configured GHC with: {{{ $ ./configure --target=arm-linux-gnueabihf }}} and compiling by make works till it fails with: {{{ inplace/bin/deriveConstants --gen-header -o includes/dist- derivedconstants/header/DerivedConstants.h --tmpdir includes/dist- derivedconstants/header/ --gcc-program "/usr/bin/gcc" --gcc-flag -fno- stack-protector --gcc-flag -Iincludes --gcc-flag -Iincludes/dist --gcc- flag -Iincludes/dist-derivedconstants/header --gcc-flag -Iincludes/dist- ghcconstants/header --gcc-flag -Irts --gcc-flag -fcommon --nm-program "/usr/bin/arm-linux-gnueabihf-nm" /usr/bin/arm-linux-gnueabihf-nm: includes/dist- derivedconstants/header/tmp.o: File format not recognized deriveConstants: readProcess: /usr/bin/arm-linux-gnueabihf-nm "includes /dist-derivedconstants/header/tmp.o" (exit 1): failed make[1]: *** [includes/dist-derivedconstants/header/DerivedConstants.h] Error 1 }}} As a workaround for this issue, it's possible to use --with-gcc= and this way deriveConstants gets the right cross GCC. Looks like a bug somewhere in make machinery or configure itself. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8652> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8560: undeducable Typeable error with data kinds when deriving Data for GADT in GHC version 7.7.20131122
by GHC 05 Jan '16

05 Jan '16

#8560: undeducable Typeable error with data kinds when deriving Data for GADT in GHC version 7.7.20131122 ------------------------------------+------------------------------------- Reporter: carter | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This may be an artifact of issue #8128 (see https://ghc.haskell.org/trac/ghc/ticket/8128#comment:5) but I'm seeing examples involving data kinds where Typeable isn't deducible. This could be an artifact of other problems, BUT since with 7.7 onwards, we have baked in polykinded Typeable, things should always "just work™" right? the error with current head is as follows (and i'm attaching the code + current finger print too) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8560> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8182: Parser.y.pp needs special treatment with -fcmm-sink
by GHC 31 Dec '15

31 Dec '15

#8182: Parser.y.pp needs special treatment with -fcmm-sink ------------------------------------+------------------------------------- Reporter: thoughtpolice | Owner: thoughtpolice Type: bug | Status: new Priority: highest | Milestone: 7.8.1 Component: Build System | Version: 7.7 Keywords: | Operating System: Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: None/Unknown Difficulty: Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | ------------------------------------+------------------------------------- This bug is really more of a reminder, but it's critical for the 7.8.1 release. Right now, `Parser.y.pp` uses a very weird hack to pass `-fcmm-sink` to the compiler. Here's the relevant comment: {{{ -- CPP tricks because we want the directives in the output of the -- first CPP pass. -- -- Clang note, 6/17/2013 by aseipp: It is *extremely* important (for -- some reason) that there be a line of whitespace between the two -- definitions here, and the subsequent use of __IF_GHC_77__ - this -- seems to be a bug in clang or something, where having the line of -- whitespace will make the preprocessor correctly format the rendered -- lines in the 'two step' CPP pass. No, this is not a joke. #define __IF_GHC_77__ #if __GLASGOW_HASKELL__ >= 707 #define __ENDIF__ #endif __IF_GHC_77__ -- Required on x86 to avoid the register allocator running out of -- stack slots when compiling this module with -fPIC -dynamic. {-# OPTIONS_GHC -fcmm-sink #-} __ENDIF__ }}} This is because the parser is first preprocessed before being run with GHC (which again preprocesses,) so we want the resulting `#ifdef` in the final `.hs` file. Things to note: * We really shouldn't be doing this, it's amazingly fragile. I think the correct thing to do is to ensure the build system correctly passes `-fcmm- sink` during the stage[2,3] build. * `./configure.ac` needs to check to see if the bootstrapping compiler is `ghc >= 7.7` (or `7.8`) and if it is, ''also'' pass `-fcmm-sink` during the stage1 build. * This hack needs to be removed once we can rely on >= 7.8 for bootstrap. Probably something like the hypothetical 7.12-7.14 timeframe. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8182> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8347: Add a Strict LANGUAGE pragma
by GHC 16 Dec '15

16 Dec '15

#8347: Add a Strict LANGUAGE pragma ------------------------------------+------------------------------------- Reporter: tibbe | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | 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: | ------------------------------------+------------------------------------- A `Strict` `LANGUAGE` pragma would allow us to experiment with writing in a strict sub-language. Since this pragma works on a per module basis, it needs to be modular. I propose the following semantics: * Patterns are strict at the top-level, as if they had a top-level bang, unless an explicit ~ is used to make the pattern lazy. * Functions evaluate their parameters to WHNF. * Data type fields are strict (as if they had a bang-pattern). -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8347> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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