Hi,
(Short because I'm by phone)
Const should be ignored so you can keep it (if not is a bug)
Unsigned does not exist :)
You can always put an alias, but the type you are looking for is "uint"
Cheers,
Esteban
> On 31 Aug 2016, at 18:59, Ben Coman <b...@openinworld.com> wrote:
>
> For this definition pulled from a library header file...
> typedef struct {
> const void *data;
> unsigned private_flags;
> } CXString;
>
> which is used with a helper function to get a usable string like...
> void show_clang_version(void)
> { CXString version = clang_getClangVersion();
> printf("%s\n", clang_getCString(version));
> clang_disposeString(version);
> }
>
> ==> 'Debian clang version 3.5.0-10 (tags/RELEASE_350/final) (based on
> LLVM 3.5.0)'
>
>
> So I defined...
> FFIExternalStructure subclass: #CXString
> instanceVariableNames: ''
> classVariableNames: ''
> package: 'LibCLang'
>
> and ignoring the const as advised in the manual [1], I try...
> CXString class >> fieldsDesc
> ^ #(
> void *data;
> unsigned private_flags;
> )
>
> but...
> CXString rebuildFieldAccessors.
> ==>Error: Unable to resolve external type: unsigned
>
> I also tried "unsigned int private_flags;"
> but get the same error. Any ideas what is wrong?
>
>
> Actually I can kind of ignore creating accessors since this is like an
> opaque type where I'm not expected to access its internals, but I do
> need CXString as a return value like this...
>
> LibCLang class >> getClangVersion
> ^ self ffiCall: #( CXString clang_getClangVersion () ) module: LibCLang
>
> which needs to be passed to this function to get a workable string....
>
> LibCLang class >> getString: aCXString
> ^ self ffiCall: #( String clang_getCString ( CXString aCXString )
> ) module: LibCLang
>
> However this doesn't work if I use FFIOpaqueObject instead of
> FFIExternalStructure.
> I guess the difference is opaque objects are normally pointers to a
> type, whereas here that pointer is contained in a struct.
>
> What I've done at the moment to push ahead with experimenting is avoid
> needing to generate accessors by adding...
>
> CXString >> printOn: asStream
> self getString printOn: aStream
>
> CXString >> getString
> ^ self ffiCall: #( String clang_getCString ( CXString self ) )
> module: LibCLang
>
> such that...
> LibCLang getClangVersion "<Print It>"
> ==> 'Debian clang version 3.5.0-10 (tags/RELEASE_350/final) (based
> on LLVM 3.5.0)'
>
>
> Is there a better way to approach this?
>
> cheers -ben
>
> btw, this is in Pharo 5 (Moose 6).
>
> [1]
> https://ci.inria.fr/pharo-contribution/view/Books/job/PharoBookWorkInProgress/lastSuccessfulBuild/artifact/book-result/UnifiedFFI/UnifiedFFI.pdf
>
