On Fri, Nov 3, 2017 at 5:44 PM, <tonywalker...@gmail.com> wrote: > > Thanks Ian. I had included that because it seems required in order for me to > refer to the return type (C.FILE) and so I can access the underlying C.fopen > function. This is the approach I have with open but perhaps this is > different. > If I'm not supposed to use the include, can you advise how I should refer to > the type/function from the header?
I'm sorry, nothing comes to mind. In C you would just write the declaration the way the header file expects, but cgo doesn't provide a way to do that. Ian > On Friday, November 3, 2017 at 8:28:38 PM UTC-4, Ian Lance Taylor wrote: >> >> On Fri, Nov 3, 2017 at 2:24 PM, <tonywa...@gmail.com> wrote: >> > >> > I've been writing a shared-object which I'll use via LD_PRELOAD to >> > override >> > the open syscall. This is currently working OK but now I want to move on >> > to >> > fopen. I've defined it (as far as I can tell) in-line with the stdio >> > header >> > see here. However, when I try and build: >> > >> > $ go build -buildmode=c-shared >> > # github.com/walkert/loader >> > In file included from >> > $WORK/github.com/walkert/loader/_obj/_cgo_export.c:3:0: >> > ./main.go:56:14: error: conflicting types for ‘fopen’ >> > In file included from ./main.go:5:0, >> > from >> > $WORK/github.com/walkert/loader/_obj/_cgo_export.c:3: >> > /usr/include/stdio.h:275:14: note: previous declaration of ‘fopen’ was >> > here >> > extern FILE *fopen (const char *__restrict __filename, >> > ^~~~~ >> > >> > /tmp/go-build775342366/github.com/walkert/loader/_obj/_cgo_export.c:17:7: >> > error: conflicting types for ‘fopen’ >> > FILE* fopen(char* p0, char* p1) >> > ^~~~~ >> > In file included from ./main.go:5:0, >> > from >> > $WORK/github.com/walkert/loader/_obj/_cgo_export.c:3: >> > /usr/include/stdio.h:275:14: note: previous declaration of ‘fopen’ was >> > here >> > extern FILE *fopen (const char *__restrict __filename, >> > ^~~~~ >> > >> > I've seen this before when I was trying to return an int instead of >> > C.int so >> > I have a feeling I'm missing something simple here. Any pointers would >> > be >> > much appreciated. >> >> It looks like the same file is doing #include <stdio.h> and `//export >> fopen`. That won't work, because, as you can see, the definition of >> the Go function fopen will conflict with the declaration in stdio.h. >> >> Ian > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
