Trivial patch to allow bootstrap on MacOS

Dear all,
the following is required to allow bootstrap in libcc1 during stage3 on MacOS Catalina (10.15). libcc1 invokes g++ with —nostdinc++

MacOS Catalina doesn’t provide /usr/include anymore, instead one builds with:
OSX_SDK_VERSION=`xcodebuild -showsdks | grep 'macOS\ 10' | cut -f2- -d'-' | cut -f2 -d' '`
OSX_SDK_PATH=`xcodebuild -sdk $OSX_SDK_VERSION -version | grep -E '^Path: ' | cut -f2 -d' '`

configure … --with-build-sysroot=$OSX_SDK_PATH

GMP however is installed elsewhere (by Homebrew, MacPorts etc), so ignore any -nostdinc

Please note, I am not subscribed to the list.

Best regards,
Rainer Keller

gcc/Changelog:
	* Have gmp.h be found outside of sysroot

--

Hello Rainer,

thanks for the patch, but I think it’s only a work-around to part of the  
problem and there are alternate strategies for the “usual case” on  
MacOS/Darwin.

Keller, Rainer <Rainer.Keller@hs-esslingen.de> wrote:

> the following is required to allow bootstrap in libcc1 during stage3 on  
> MacOS Catalina (10.15). libcc1 invokes g++ with —nostdinc++
>
> MacOS Catalina doesn’t provide /usr/include anymore, instead one builds  
> with:
> OSX_SDK_VERSION=`xcodebuild -showsdks | grep 'macOS\ 10' | cut -f2- -d'-'  
> | cut -f2 -d' '`
> OSX_SDK_PATH=`xcodebuild -sdk $OSX_SDK_VERSION -version | grep -E '^Path:  
> ' | cut -f2 -d' '`
>
> configure … --with-build-sysroot=$OSX_SDK_PATH

—with-build-sysroot=  is known to have some problems;

see, for example, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79885

There is also a current series of patches on the topic from Maciej Rozicki.

I’m not sure what the intent is in using it in the MacOS builds - since I  
expect you will be using the same sysroot (SDK) at run time as you are at  
build time?

====

—with-sysroot= does, however, work (we also now honour SDKROOT in trunk,  
open branches and gcc-7, but not on gcc-6 or gcc-5 [I will probably do some  
Darwin-specific extra patches for the closed branches at some point])

I have sucessfully bootstrapped and tested on Catalina see (for example):

https://gcc.gnu.org/ml/gcc-testresults/2019-11/msg01492.html

Usually, I am using the command line tools, so the installation is not  
going to move….

… however, if you configure with “—with-sysroot=$OSX_SDK_PATH” and then the  
path moves (e.g. you relocate XCode) then you would have to supply the SDK  
position at runtime anyway (either by setting SDKROOT or by passing  
—sysroot=$NEW_SDK_POSITION for each compilation line)

> GMP however is installed elsewhere (by Homebrew, MacPorts etc), so ignore  
> any -nostdinc

it also works to symlink the sources for gmp, mpfr, mpc (and isl, if you  
use it) into the source tree - those then get boostrapped along with the  
compiler and there are no resulting external dependencies (which I find  
preferable).

However, —with-gmp= etc should also work with it (I’ll take a look at that  
case).

> Please note, I am not subscribed to the list.

HTH,
Iain

>
> Best regards,
> Rainer Keller
>
> gcc/Changelog:
> 	* Have gmp.h be found outside of sysroot
>
> --
> Index: gcc/system.h
> ===================================================================
> --- gcc/system.h        (revision 278783)
> +++ gcc/system.h        (working copy)
> @@ -684,7 +684,7 @@
>
> /* Do not introduce a gmp.h dependency on the build system.  */
> #ifndef GENERATOR_FILE
> -#include <gmp.h>
> +#include "gmp.h"
> #endif
>
> /* Get libiberty declarations.  */

Hello again Rainer,

Iain Sandoe <idsandoe@googlemail.com> wrote:

>> GMP however is installed elsewhere (by Homebrew, MacPorts etc), so  
>> ignore any -nostdinc
>
> it also works to symlink the sources for gmp, mpfr, mpc (and isl, if you  
> use it) into the source tree - those then get boostrapped along with the  
> compiler and there are no resulting external dependencies (which I find  
> preferable).
>
> However, —with-gmp= etc should also work with it (I’ll take a look at  
> that case).

It works fine when using —with-sysroot=   and  
—with-gmp=/somewhere/outside/the/SDK  (/opt/….)

So, I think one can get the desired behaviour with this configuration scheme.

thanks
Iain

Dear Iain,
thanks for the quick reply. I wasn’t aware of the ticket 79885.

Yes, the intent is to use the same sysroot for build & run.

Hmm, the —with-sysroot is from gcc/configure option — not from the main configure.
Not wanting to turn this into a bug-report, but… using —with-sysroot instead of —with-build-sysroot failed, too.

Let’s keep track of this in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92719
I am happy to provide more info.

Thanks again for Your help,
Rainer


> On 28. Nov 2019, at 16:34, Iain Sandoe <idsandoe@googlemail.com> wrote:
> 
> Hello again Rainer,
> 
> Iain Sandoe <idsandoe@googlemail.com> wrote:
> 
>>> GMP however is installed elsewhere (by Homebrew, MacPorts etc), so ignore any -nostdinc
>> 
>> it also works to symlink the sources for gmp, mpfr, mpc (and isl, if you use it) into the source tree - those then get boostrapped along with the compiler and there are no resulting external dependencies (which I find preferable).
>> 
>> However, —with-gmp= etc should also work with it (I’ll take a look at that case).
> 
> It works fine when using —with-sysroot=   and —with-gmp=/somewhere/outside/the/SDK  (/opt/….)
> 
> So, I think one can get the desired behaviour with this configuration scheme.
> 
> thanks
> Iain
> 

---------------------------------------------------------------------
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Professor für Betriebssysteme, verteilte und parallele Systeme
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