- C2hs - Haskell.org

[c2hs] #38: Need to think how to bind C enums with aliases
by c2hs 26 Aug '11

26 Aug '11

#38: Need to think how to bind C enums with aliases -------------------------+-------------------------------------------------- Reporter: duncan | Owner: Type: enhancement | Status: new Priority: normal | Milestone: Component: general | Version: 0.16.0 Keywords: | -------------------------+-------------------------------------------------- Consider this C enum: {{{ typedef enum { GTK_ANCHOR_CENTER, GTK_ANCHOR_NORTH, GTK_ANCHOR_NORTH_WEST, GTK_ANCHOR_NORTH_EAST, GTK_ANCHOR_SOUTH, GTK_ANCHOR_SOUTH_WEST, GTK_ANCHOR_SOUTH_EAST, GTK_ANCHOR_WEST, GTK_ANCHOR_EAST, GTK_ANCHOR_N = GTK_ANCHOR_NORTH, GTK_ANCHOR_NW = GTK_ANCHOR_NORTH_WEST, GTK_ANCHOR_NE = GTK_ANCHOR_NORTH_EAST, GTK_ANCHOR_S = GTK_ANCHOR_SOUTH, GTK_ANCHOR_SW = GTK_ANCHOR_SOUTH_WEST, GTK_ANCHOR_SE = GTK_ANCHOR_SOUTH_EAST, GTK_ANCHOR_W = GTK_ANCHOR_WEST, GTK_ANCHOR_E = GTK_ANCHOR_EAST } GtkAnchorType; }}} Of course in C, enums are really ints, so it's ok to have aliases. It is the case that `GTK_ANCHOR_E = GTK_ANCHOR_EAST` since both enum names have the int value 9. Currently c2hs binds this as: {{{ data GtkAnchorType = GtkAnchorCenter | GtkAnchorNorth | GtkAnchorNorthWest | GtkAnchorNorthEast | GtkAnchorSouth | GtkAnchorSouthWest | GtkAnchorSouthEast | GtkAnchorWest | GtkAnchorEast | GtkAnchorN | GtkAnchorNw | GtkAnchorNe | GtkAnchorS | GtkAnchorSw | GtkAnchorSe | GtkAnchorW | GtkAnchorE deriving (Eq,Show) instance Enum GtkAnchorType where fromEnum GtkAnchorCenter = 0 fromEnum GtkAnchorNorth = 1 fromEnum GtkAnchorNorthWest = 2 fromEnum GtkAnchorNorthEast = 3 fromEnum GtkAnchorSouth = 4 fromEnum GtkAnchorSouthWest = 5 fromEnum GtkAnchorSouthEast = 6 fromEnum GtkAnchorWest = 7 fromEnum GtkAnchorEast = 8 fromEnum GtkAnchorN = 1 fromEnum GtkAnchorNw = 2 fromEnum GtkAnchorNe = 3 fromEnum GtkAnchorS = 4 fromEnum GtkAnchorSw = 5 fromEnum GtkAnchorSe = 6 fromEnum GtkAnchorW = 7 fromEnum GtkAnchorE = 8 toEnum 0 = GtkAnchorCenter toEnum 1 = GtkAnchorNorth toEnum 2 = GtkAnchorNorthWest toEnum 3 = GtkAnchorNorthEast toEnum 4 = GtkAnchorSouth toEnum 5 = GtkAnchorSouthWest toEnum 6 = GtkAnchorSouthEast toEnum 7 = GtkAnchorWest toEnum 8 = GtkAnchorEast toEnum 1 = GtkAnchorN toEnum 2 = GtkAnchorNw toEnum 3 = GtkAnchorNe toEnum 4 = GtkAnchorS toEnum 5 = GtkAnchorSw toEnum 6 = GtkAnchorSe toEnum 7 = GtkAnchorW toEnum 8 = GtkAnchorE toEnum unmatched = error ("GtkAnchorType.toEnum: Cannot match " ++ show unmatched) }}} Note in particular that the `toEnum` has overlaps. It's also obviously not the case in Haskell that `GtkAnchorE = GtkAnchorEast`. Perhaps we should ignore aliases, that is pretend that the enum values `GTK_ANCHOR_E` etc are simply not present. -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/38> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 0

timespec and c2hs
by Erik Hesselink 21 Apr '11

21 Apr '11

Hi, I'm trying to write a Storable instance for timespec using c2hs. Since timespec is defined something like: struct timespec { time_t tv_sec; long tv_nsec; }; I've defined the following in Haskell: #include <sys/time.h> #c typedef struct timespec timespec_t; #endc data TimeSpec = TimeSpec { seconds :: CTime , nanoseconds :: CLong } instance Storable TimeSpec where peek t = TimeSpec <$> {#get timespec_t->tv_sec #} t <*> {#get timespec_t->tv_nsec#} t ... However, this fails to compile. For tv_sec, c2hs generates "peekByteOff ptr 0 :: IO CLong" instead of "IO CTime". Why is this? Am I doing something wrong, or is there a bug/missing feature in c2hs? Erik

2 1

[c2hs] #37: Export C2HS.hs module from library part of the c2hs package
by c2hs 17 Apr '11

17 Apr '11

#37: Export C2HS.hs module from library part of the c2hs package --------------------+------------------------------------------------------- Reporter: guest | Type: enhancement Status: new | Priority: normal Milestone: | Component: general Version: 0.16.0 | Keywords: --------------------+------------------------------------------------------- I see some packages (portaudio, alsa) at Hackage, that contain a plain copy of the C2HS module. Wouldn't it be better to add a library part to the c2hs package and export the C2HS module? -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/37> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 1

ANNOUNCE: c2hs 0.16.3
by Duncan Coutts 24 Mar '11

24 Mar '11

All, c2hs version 0.16.3 is out and is available from hackage http://hackage.haskell.org/package/c2hs What is c2hs ============ c2hs is an FFI preprocessor tool, a bit like hsc2hs, that helps with the development of Haskell bindings to C libraries. The major advantages of using c2hs compared to writing foreign imports by hand (or using hsc2hs) are: * Cross-language type safety: C functions are imported with the correct Haskell types. * Saves time: boilerplate marshaling code is generated. It works by extracting interface information from C header files and it generates Haskell code with foreign imports and marshalling. Changes in this release ======================= * In and out marshallers may now have arguments, rather than just being single function names. * Foreign function imports will now use stdcall if the C headers specify this calling convention. This will help with bindings to some C libraries on Windows. * New {# alignof #} hook, like the existing {# sizeof #} hook. This is useful for the alignment in Storable instances. * Fewer marshalling functions are needed from the bundled C2HS module. The trend is towards eliminating the need for any axillary marshalling module. Credits ======= Thanks to Jonathan Rockway, ron(a)gamr7.com and Dmitry Astapov for contributions to this release. Links ===== Home page: http://www.cse.unsw.edu.au/~chak/haskell/c2hs/ Bug tracker: http://hackage.haskell.org/trac/c2hs/ Duncan

1 0

[c2hs] #36: Allow parametrized yet monomorphic data types in {#pointer ... #}
by c2hs 26 Jan '11

26 Jan '11

#36: Allow parametrized yet monomorphic data types in {#pointer ... #} --------------------+------------------------------------------------------- Reporter: guest | Type: enhancement Status: new | Priority: normal Milestone: | Component: general Version: 0.16.2 | Keywords: --------------------+------------------------------------------------------- Hello. Currently pointer declaration could only use non-parametrized types. But sometimes it's too restrictive. I think examples below are self- explanatory: This is OK but pointer is untyped {{{ {#pointer *OKA__Hit as OKA_Hit #} }}} This doesn't work although it's perfectly sound. On syntactic level it may require addition of parenthesis. {{{ {#pointer *OKA__Hit as OKA_Hit -> Hit Chan () #} ./Event.chs:23: (column 42) [ERROR] >>> Syntax error! The phrase `Chan' is not allowed here. }}} There is workaround with type synonyms but it's not very elegant. {{{ type Typedef = Hit Chan () {#pointer *OKA__Hit as OKA_Hit -> Typedef #} }}} -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/36> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 0

Re: [C2hs] [c2hs] #9: sizeof computation fails for nested derived types (pointer to array or array of pointers)
by c2hs 19 Jan '11

19 Jan '11

#9: sizeof computation fails for nested derived types (pointer to array or array of pointers) --------------------+------------------------------------------------------- Reporter: guest | Type: defect Status: new | Priority: normal Milestone: | Component: general Version: 0.15.1 | Keywords: --------------------+------------------------------------------------------- Comment(by guest): I think this may be related: bug.h {{{ typedef char inner_t[32]; typedef struct { inner_t first; inner_t second; } outer_t; }}} bug.chs {{{ module Bug where #include "bug.h" main :: IO () main = print ({# sizeof inner_t #}, {# sizeof outer_t #}) }}} Running c2hs bug.chs (on a 64-bit machine) gives me… {{{ module Bug where main :: IO () main = print (32, 16) }}} Shurely schome mischtake? On the other hand, okay.h {{{ typedef struct { char first[32]; char second[32]; } outer_t; }}} okay.chs {{{ module Okay where #include "okay.h" main :: IO () main = print {# sizeof outer_t #} }}} gives… {{{ module Okay where main :: IO () main = print 64 }}} -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/9#comment:1> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 0

patch applied (c2hs): "Version bump" and 1 others
by Manuel M T Chakravarty 21 Dec '10

21 Dec '10

Fri Dec 17 03:21:49 EST 2010 Dmitry Astapov <dastapov(a)gmail.com> * Version bump Ignore-this: 3348983ad02750d8346d76d381466c7 M ./c2hs.cabal -1 +1 Fri Dec 17 04:53:11 EST 2010 Dmitry Astapov <dastapov(a)gmail.com> * Allow in- and out-marshallers to have arguments, like this: 'alloca foo'- `ComparisonResult' 'peekEnum "bar"'* Ignore-this: 2d01fb02a09a8e84fa54fbf0f2816c17 Rule "quote identifier to distinguish it from C->Haskell keyword" was extended. Now, anything quoted in the hook body would be transferred to the output file verbatim. Special token is intoduced to contain such code and make changes in the parser minimally intrusive. This change should be perfectly backwards-compatible. Tested on a bunch of packages from Hackage as tests seem to be semi-broken. M ./src/C2HS/CHS.hs -26 +40 M ./src/C2HS/CHS/Lexer.hs -13 +22 M ./src/C2HS/Gen/Bind.hs -32 +38

1 0

darcs patch: Convert an accented surname in a comment... (and 5 more)
by will＠willthompson.co.uk 12 Nov '10

12 Nov '10

6 patches for repository http://code.haskell.org/c2hs: Mon Nov 8 23:46:25 GMT 2010 will(a)willthompson.co.uk * Convert an accented surname in a comment to UTF-8 hasktags makes the (reasonable) assumption that source files are UTF-8, and gets very upset if they're not. Tue Nov 9 06:02:13 GMT 2010 will(a)willthompson.co.uk * Fix generation of superclass instances Previously, specifying a superclass in a {# class #} rule would generate incorrect code. For instance, the 'pointer' test case includes the following: > {#pointer *Point as APoint newtype#} > {#class APointClass APoint#} > > {#pointer *ColourPoint as AColourPoint newtype#} > {#class APointClass => AColourPointClass AColourPoint#} This generates an incorrect instance of APointClass for AColourPoint, as follows: > instance APointClass AColourPoint where > aColourPoint (AColourPoint p) = AColourPoint (castPtr p) > fromAColourPoint (AColourPoint p) = AColourPoint (castPtr p) This was due to the code generator using the name of the type being defined rather than the name of the superclass type, which was due to a missing apostrophe. This is my favourite kind of bug fix. Tue Nov 9 06:13:26 GMT 2010 will(a)willthompson.co.uk * Split collecting superclasses out of a where clause This would have prevented the bug I just fixed, since the mistaken type identifier would not have been in scope. Tue Nov 9 06:16:37 GMT 2010 will(a)willthompson.co.uk * Simplify generating class cast instances Tue Nov 9 16:37:47 GMT 2010 will(a)willthompson.co.uk * Squash an unused result warning Tue Nov 9 17:49:46 GMT 2010 will(a)willthompson.co.uk * Fix deprecation warnings and build trivia in test suite The test suite was passing -fffi to GHC; this patch adds LANGUAGE ForeignFunctionInterface to the relevant files instead. The test suite also used the deprecated C2HS module for converting between Int and CInt; this patch fixes all tests that were using these functions. Also, the Sizeof test didn't compile. It now compiles, but still fails due to bug #10. Finally, compilation errors would previously not cause `make` to fail in some cases.

3 3

#35: c2hs: Errors during expansion of binding hooks
by c2hs 27 Sep '10

27 Sep '10

#35: c2hs: Errors during expansion of binding hooks --------------------+------------------------------------------------------- Reporter: guest | Type: defect Status: new | Priority: normal Milestone: | Component: general Version: 0.16.2 | Keywords: --------------------+------------------------------------------------------- Running c2hs on -- module CDIO.Device where #include <cdio/cdio.h> getHWInfo = {#call unsafe cdio_get_hwinfo#} -- produces: c2hs: Errors during expansion of binding hooks: /usr/include/cdio/device.h:428: (column 3) [ERROR] >>> Illegal type! The type specifiers of this declaration do not form a legal ANSI C(89) type. The C function cdio_get_hwinfo returns bool, which is defined in cdio/types.h as #define bool uint8_t -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/35> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 0

#34: C header contains errors
by c2hs 18 Sep '10

18 Sep '10

#34: C header contains errors --------------------+------------------------------------------------------- Reporter: guest | Type: defect Status: new | Priority: blocker Milestone: | Component: general Version: 0.16.2 | Keywords: --------------------+------------------------------------------------------- c2hs: C header contains errors: /usr/include/cdio/device.h:33: (column 20) [ERROR] >>> Syntax error ! The symbol `cdio_drive_read_cap_t' does not fit here. -- Ticket URL: <http://hackage.haskell.org/trac/c2hs/ticket/34> c2hs <http://www.cse.unsw.edu.au/~chak/haskell/c2hs/> C->Haskell, An Interface Generator for Haskell

1 1