September 2015 - ghc-tickets

[GHC] #10639: Optimization changes concurrent program's behaviour
by GHC 16 Dec '15

16 Dec '15

#10639: Optimization changes concurrent program's behaviour -------------------------------------+------------------------------------- Reporter: gizmo.mk0 | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.1 Keywords: | Operating System: Windows Architecture: x86_64 | Type of failure: Incorrect result (amd64) | at runtime Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- Here is a program that spawns a thread from the main thread, which tries to constantly write out a message to the console. {{{#!hs module Main where import Control.Concurrent (forkIO) main :: IO () main = do _ <- forkIO $ runForever $ putStrLn "Hey" runForever $ return () runForever :: IO () -> IO () runForever action = action >> runForever action }}} If you compile it with 'ghc main', it works correctly - it prints out the message continuously, and you can terminate it by pressing Ctrl-C. However, if you compile it with 'ghc -O main' (or -O2, or -O3...), it doesn't print out anything, and the only way to exit is to kill the process from Task Manager. This was reproducable with GHC 7.10.1, on a Windows 7 x64 machine, with an AMD A4-5300 APU. ''(Disclaimer: this is my first bugreport, and I'm not sure what else can I do to investigate this issue.)'' -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10639> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #8424: quasi-quotes have carriage returns on Windows
by GHC 16 Dec '15

16 Dec '15

#8424: quasi-quotes have carriage returns on Windows ------------------------------------+------------------------------------- Reporter: GregWeber | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Template Haskell | 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 Windows user rerported using Data.Text.IO.writeFile to write out quasi- quoted text. writeFile automatically translates '\r' to "\r\n", so the user ended up writing out "\r\r\n" to a file. Haskell seems to be adopting the policy or removing '\r' from Haskell land. Is there any reason why quasi-quotes should not automatically strip carriage returns? I asked this question on ghc-users and there was no response. I am willing to make this fix if it is deemed appropriate. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8424> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10820: Provide a way to detect what extensions are enabled via TH
by GHC 15 Dec '15

15 Dec '15

#10820: Provide a way to detect what extensions are enabled via TH -------------------------------------+------------------------------------- Reporter: spinda | Owner: Type: feature | Status: new request | Priority: normal | Milestone: Component: Template | Version: 7.10.2 Haskell | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- This would be helpful for providing users with intuitive error messages if generated code relies on an extension that the user may not have enabled. Sample specification, to get things started: {{{ enabledExts :: Q [Extension] isExtEnabled :: Extension -> Q Bool data Extension = LiberalTypeSynonyms | RankNTypes | ... -- mirroring ExtensionFlag in DynFlags }}} See #10819 for an example case where this could be of use. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10820> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9348: "Symbol not found" when using a shared library
by GHC 15 Dec '15

15 Dec '15

#9348: "Symbol not found" when using a shared library -----------------------------------+----------------------------------- Reporter: alex.davis | Owner: simonmar Type: bug | Status: new Priority: normal | Milestone: Component: Runtime System | Version: 7.8.3 Keywords: | Differential Revisions: Operating System: MacOS X | Architecture: x86 Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: -----------------------------------+----------------------------------- I'm trying to make a shared library from a simple program. It works fine on my Windows box, but gives an error on Mac OS X. Furthermore, the error seems to be generated from one of GHC's shared libraries. What happens is this. I compile my shared library with GHC, which works fine. But when I try to use it from another program (specifically, R), I get an error message containing the following: Symbol not found: _stg_IND_STATIC_info Referenced from: /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc- prim-0.3.1.0-ghc7.8.3.dylib Expected in: flat namespace in /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc- prim-0.3.1.0-ghc7.8.3.dylib More details: The program I'm trying to use is R. In R, you load a shared library with the command "dyn.load". When I try this, the command I use is "dyn.load('final.dylib')", and the full error message is what follows: --- Error in dyn.load("final.dylib") : unable to load shared object '/Users/alexanderdavis/Desktop/illustrate bug copy/final.dylib': dlopen(/Users/alexanderdavis/Desktop/illustrate bug copy/final.dylib, 6): Symbol not found: _stg_IND_STATIC_info Referenced from: /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc- prim-0.3.1.0-ghc7.8.3.dylib Expected in: flat namespace in /usr/local/lib/ghc-7.8.3/ghc-prim-0.3.1.0/libHSghc- prim-0.3.1.0-ghc7.8.3.dylib --- As I said, I have done all of this with no trouble on Windows. I compiled into a DLL, loaded the program into R, and was able to use the functions in it. My Mac OS version is 10.9.4. My R version is 3.0.2. When loaded, it displays "Platform: x86_64-apple- darwin10.8.0 (64-bit)", but Sys.getev("R_ARCH") returns the empty string. Command used for compiler: ghc --make -dynamic -fPIC -shared SumRoots.hs StartEnd.c -o final.dylib The code is attached. It is from a blog post by Neil Mitchelll (author of HLint) about calling Haskell from R: http://neilmitchell.blogspot.com/2011/10/calling-haskell-from-r.html -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9348> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9378: Make unknown LANGUAGE pragmas a warning, not an error
by GHC 15 Dec '15

15 Dec '15

#9378: Make unknown LANGUAGE pragmas a warning, not an error -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.2 Keywords: | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Unknown | Type of failure: Blocked By: | None/Unknown Related Tickets: | Test Case: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Currently, if I say `{-# LANGUAGE Foo #-}` at the top of my file, it fails to compile. This failure seems unnecessary, especially because any new language feature `Foo` enables will fail to compile later on down the file. Is it possible to have a "stern warning" that is produced even when other parts of the file produce errors? The reason I'm bringing this up is that, when 7.8 came out with its role annotations, users needed CPP in two different places: both to protect the `RoleAnnotations` pragma and to protect the role annotations themselves. This may be unavoidable on the role annotations directly, but I think we can improve the situation around `LANGUAGE` pragmas. Is there a downside to this? -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9378> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10368: Armhf/Linux : test T7815 failing
by GHC 15 Dec '15

15 Dec '15

#10368: Armhf/Linux : test T7815 failing -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.11 Keywords: | Operating System: Unknown/Multiple Architecture: arm | Type of failure: Incorrect result Test Case: | at runtime Blocking: | Blocked By: Differential Revisions: | Related Tickets: -------------------------------------+------------------------------------- During validation on armhf/linux, I found this test had failed. Unfortunately, it only fails intermittently on one quad core Arm board and not at all on another quad core Arm board. If I do 10 runs of the test like: {{{ for x in $(seq 1 10) ; do testsuite/tests/rts/T7815 50000 +RTS -N2 ; echo $? ; done }}} one will fail at least 4 or 5 times and ocassionally as many as 9 or 10 times. The two boards are: * Inforce Computing ifc6540 with a Qualcomm Snapdragon 805 CPU. * Radxa Rock with a Rockchip RK3199 CPU. The ifc6540 is the one that fails. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10368> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #10029: unit-tests: internal error: evacuate(static): strange closure type 62744
by GHC 15 Dec '15

15 Dec '15

#10029: unit-tests: internal error: evacuate(static): strange closure type 62744 -------------------------------------+------------------------------------- Reporter: | Owner: juhpetersen | Status: new Type: bug | Milestone: Priority: normal | Version: 7.8.4 Component: Compiler | Operating System: Linux Keywords: | Type of failure: Compile-time Architecture: arm | crash Test Case: | Blocked By: Blocking: | Related Tickets: Differential Revisions: | -------------------------------------+------------------------------------- The syb-0.4.1 testsuite fails on ARMv7 Linux (Fedora 22 devel) with ghc-7.8.4: {{{ + ./Setup test Running 1 test suites... Test suite unit-tests: RUNNING... Cases: 29 Tried: 0 Errors: 0 Failures: 0 Cases: 29 Tried: 1 Errors: 0 Failures: 0 Cases: 29 Tried: 2 Errors: 0 Failures: 0 Cases: 29 Tried: 3 Errors: 0 Failures: 0 Cases: 29 Tried: 4 Errors: 0 Failures: 0 Cases: 29 Tried: 5 Errors: 0 Failures: 0 Cases: 29 Tried: 6 Errors: 0 Failures: 0 Cases: 29 Tried: 7 Errors: 0 Failures: 0 Cases: 29 Tried: 8 Errors: 0 Failures: 0 Cases: 29 Tried: 9 Errors: 0 Failures: 0 Cases: 29 Tried: 10 Errors: 0 Failures: 0 Cases: 29 Tried: 11 Errors: 0 Failures: 0 Cases: 29 Tried: 12 Errors: 0 Failures: 0 Cases: 29 Tried: 13 Errors: 0 Failures: 0 Cases: 29 Tried: 14 Errors: 0 Failures: 0 Cases: 29 Tried: 15 Errors: 0 Failures: 0 Cases: 29 Tried: 16 Errors: 0 Failures: 0 Cases: 29 Tried: 17 Errors: 0 Failures: 0 Cases: 29 Tried: 18 Errors: 0 Failures: 0unit-tests: internal error: evacuate(static): strange closure type 62744 (GHC version 7.8.4 for arm_unknown_linux) Please report this as a GHC bug: http://www.haskell.org/ghc/reportabug Test suite unit-tests: FAIL Test suite logged to: dist/test/syb-0.4.1-unit-tests.log 0 of 1 test suites (0 of 1 test cases) passed. }}} Let me know if I can provide any more details. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10029> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9952: Add -g<level>
by GHC 15 Dec '15

15 Dec '15

#9952: Add -g<level> -------------------------------------+------------------------------------- Reporter: tibbe | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.8.4 Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: None/Unknown Unknown/Multiple | Blocked By: Test Case: | Related Tickets: Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- We should add debug info levels, just like GCC and LLVM has. In particular, I'd like to have -g1 which has (from https://gcc.gnu.org/onlinedocs/gcc/Debugging-Options.html) > minimal information, enough for making backtraces in parts of the program that you don't plan to debug. This includes descriptions of functions and external variables, and line number tables, but no information about local variables. This should let us have -g1 turned on even in production code, as it should grow binary sizes by much. This in turn should be a boon for debugability of programs. It should also allow us to offer some for of stack traces without any runtime cost (except when an exception with a stack trace is actually raised.) -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9952> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9499: Add -prelude-is flag
by GHC 15 Dec '15

15 Dec '15

#9499: Add -prelude-is flag -------------------------------------+------------------------------------- Reporter: agibiansky | Owner: agibiansky Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.9 Keywords: flag | Operating System: Architecture: Unknown/Multiple | Unknown/Multiple Difficulty: Easy (less than 1 | Type of failure: hour) | None/Unknown Blocked By: | Test Case: Related Tickets: | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- I would like GHC to have a `-prelude-is` flag, which would specify an alternate Prelude to use instead of the default Haskell prelude. The benefit this would have is that this would give alternate preludes a more first-class status. Instead of having to import an alternative prelude everywhere, you could just have a ghc-options: -prelude-is=... flag in your *.cabal file, and have a different prelude be used. This is important for my own work, as I highly prefer other preludes for my non- library development; I think this is a feature which will be very useful as Haskell develops and we try to figure out how to get rid of the warts in the current Prelude. Additional discussion here: https://groups.google.com/forum/#!topic /haskell-cafe/NCVzXZcxNmQ -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9499> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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[GHC] #9573: Add warning for invalid digits in integer literals
by GHC 15 Dec '15

15 Dec '15

#9573: Add warning for invalid digits in integer literals -------------------------------------+------------------------------------- Reporter: vlopez | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.10.1 Component: Compiler (Parser) | Version: 7.9 Keywords: parsing, integer, | Operating System: octal, binary, hexadecimal, | Unknown/Multiple Architecture: Unknown/Multiple | Type of failure: Difficulty: Difficult (2-5 | None/Unknown days) | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- In its latest version, GHC can parse binary (with `-XBinaryLiterals`), octal and hexadecimal literals: {{{#!hs > 0b101010 > 0o52 > 0x2A }}} Currently, the parser/lexer reads digits from the input as long as they are valid for the specified radix. All subsequent digits are interpreted as a new, separate token. If the user uses a digit which isn't valid for the radix, it may be reported with a non-obvious error message, or interpreted in surprising ways: {{{#!hs > :t 0o567 0o576 :: Num a => a > :t 0o5678 0o5678 :: (Num (a -> t), Num a) => t Prelude> :t 0x1bfah <interactive>:1:7: Not in scope: ‘h’ > replicate 0o5678 [8,8,8,8,8,8,8... }}} We suggest warning the user when a literal of this sort is written, while respecting any other error messages and the original behaviour. More specifically, the parser or lexer would give a warning if a token starting with an alphanumeric character is found immediately after a numeric literal, without a blank between them. -- Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9573> GHC <http://www.haskell.org/ghc/> The Glasgow Haskell Compiler

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