Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread David Morsberger
I went down a rabbit hole and pulled myself back out. I narrowed it down to the following. We are using cmake to check if the linker supports ‘-Wl,—as-needed'. The test compile (and link?) command cmake builds using ‘cmake -G Xcode’ does not fail. The command from ‘cmake -G’ has been narrowed

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Guy Harris
On Jan 21, 2016, at 6:08 AM, David Morsberger wrote: > It appears the linker isn’t called when the -c and the -o options are present. Correct. It's not *supposed* to be called. In UNIX C compilers, the "-c" flag means "compile to an object file, but don't link the resulting object file into

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread David Morsberger
On Thu, Jan 21, 2016 at 2:29 PM, Guy Harris wrote: > On Jan 21, 2016, at 6:08 AM, David Morsberger wrote: > > > It appears the linker isn’t called when the -c and the -o options are > present. > > Correct. It's not *supposed* to be called. In UNIX C compilers, the "-c" > flag means "compile to

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Guy Harris
On Jan 21, 2016, at 12:10 PM, David Morsberger wrote: > I think this is a bug in cmake because: > > 1. the 'and run' in "CheckCSourceRuns: Check if the given C source code > compiles and runs" should imply linking and executing the software. Yes, and it *does* imply that. The problem is that

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread David Morsberger
Sent from my iPhone > On Jan 21, 2016, at 3:28 PM, Guy Harris wrote: > >> On Jan 21, 2016, at 12:10 PM, David Morsberger wrote: >> >> I think this is a bug in cmake because: >> >> 1. the 'and run' in "CheckCSourceRuns: Check if the given C source code >> compiles and runs" should imply lin

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Guy Harris
On Jan 21, 2016, at 2:53 PM, David Morsberger wrote: >> On Jan 21, 2016, at 3:28 PM, Guy Harris wrote: >> >>> On Jan 21, 2016, at 12:10 PM, David Morsberger wrote: >>> >>> I think this is a bug in cmake because: >>> >>> 1. the 'and run' in "CheckCSourceRuns: Check if the given C source code

[Wireshark-dev] Why are we linking with --as-needed?

2016-01-21 Thread Guy Harris
The GNU linker documentation says of the --as-needed flag --as-needed --no-as-needed This option affects ELF DT_NEEDED tags for dynamic libraries mentioned on the command line after the --as-needed option. Normally the linker will add a DT_NEEDED tag for each dynamic library mentioned on

Re: [Wireshark-dev] Why are we linking with --as-needed?

2016-01-21 Thread Jeff Morriss
On 01/21/2016 10:17 PM, Guy Harris wrote: The GNU linker documentation says of the --as-needed flag --as-needed --no-as-needed This option affects ELF DT_NEEDED tags for dynamic libraries mentioned on the command line after the --as-needed option. Normally the linker will add a DT_NEED

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Roland Knall
On Fri, Jan 22, 2016 at 1:40 AM, Guy Harris wrote: > > > This means we can't use CMAKE_REQUIRED_FLAGS, and have to find some > *other* way to specify the flag to be tested. FYI, the only sure-fire way in CMAKE to set specific only linker flags is using the target properties. The following code m

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Guy Harris
On Jan 21, 2016, at 9:36 PM, Roland Knall wrote: > FYI, the only sure-fire way in CMAKE to set specific only linker flags is > using the target properties. So what's the best way to, within a .cmake file, create a temporary target, with those properties, and with a particular small piece of so

Re: [Wireshark-dev] Mac Build Error

2016-01-21 Thread Roland Knall
On Fri, Jan 22, 2016 at 8:26 AM, Guy Harris wrote: > On Jan 21, 2016, at 9:36 PM, Roland Knall wrote: > > > FYI, the only sure-fire way in CMAKE to set specific only linker flags > is using the target properties. > > So what's the best way to, within a .cmake file, create a temporary > target, w