Gcc Configure System

Gcc Configure System

[Tom Browder]

I'm trying to help with a new front end for gcc and have a question
about the configure system:

I notice that each Makefile generated by configure defines srcdir at
the top as the directory it is formed in (and then sometimes redefines
it later).

How, then, should one refer to the absolute root of the source tree
regardless of the depth of the Makefile?

Thanks.

-Tom

Re: Gcc Configure System

[Tom Browder]

On 1/16/08, Tom Browder <tom.browder@gmail.com> wrote:
> I'm trying to help with a new front end for gcc and have a question
> about the configure system:
>
> I notice that each Makefile generated by configure defines srcdir at
> the top as the directory it is formed in (and then sometimes redefines
> it later).
>
> How, then, should one refer to the absolute root of the source tree
> regardless of the depth of the Makefile?

I should have been a little more specific:

The recommended way to build gcc is to use a clean directory outside
the source tree somthing like this:

  mkdir build_dir
  cd build_dir
/path/to/gcc_src/configure <options>

I want to know if there is a preferred or defined way to refer to
"/path/to/gcc_src" in build scripts or configure inputs since
"$(srcdir)" seems to be locally defined per Makefile.

Thanks.

-Tom

Re: Gcc Configure System

[Tim Prince]

Tom Browder wrote:
> On 1/16/08, Tom Browder <tom.browder@gmail.com> wrote:
>> I'm trying to help with a new front end for gcc and have a question
>> about the configure system:
>>
>> I notice that each Makefile generated by configure defines srcdir at
>> the top as the directory it is formed in (and then sometimes redefines
>> it later).
>>
>> How, then, should one refer to the absolute root of the source tree
>> regardless of the depth of the Makefile?
> 
> I should have been a little more specific:
> 
> The recommended way to build gcc is to use a clean directory outside
> the source tree somthing like this:
> 
>   mkdir build_dir
>   cd build_dir
> /path/to/gcc_src/configure <options>
> 
> I want to know if there is a preferred or defined way to refer to
> "/path/to/gcc_src" in build scripts or configure inputs since
> "$(srcdir)" seems to be locally defined per Makefile.
> 

During bootstrap, by default, I observe that $HOME is included in a
search for your /path/to/gcc_src
When $HOME refers to a path which misleads the bootstrap machinery, it
is necessary to export HOME=
in order to make the bootstrap succeed.  Is there documentation on how
this is intended to work?

Re: Gcc Configure System

[Ian Lance Taylor]

"Tom Browder" <tom.browder@gmail.com> writes:

> The recommended way to build gcc is to use a clean directory outside
> the source tree somthing like this:
> 
>   mkdir build_dir
>   cd build_dir
> /path/to/gcc_src/configure <options>
> 
> I want to know if there is a preferred or defined way to refer to
> "/path/to/gcc_src" in build scripts or configure inputs since
> "$(srcdir)" seems to be locally defined per Makefile.

Most Makefiles know where they are in the heirarchy, and thus do not
require any special handling--they use $(srcdir)/.. or whatever.

Where that is not the case, for libraries which are built using
multilib, we use the make variable top_srcdir.  E.g.,
libstdc++-v3/Makefile.am uses it.

Ian

Re: Gcc Configure System

[Tom Browder]

On 16 Jan 2008 16:55:05 -0800, Ian Lance Taylor <iant@google.com> wrote:
> "Tom Browder" <tom.browder@gmail.com> writes:
...
> > I want to know if there is a preferred or defined way to refer to
> > "/path/to/gcc_src" in build scripts or configure inputs since
> > "$(srcdir)" seems to be locally defined per Makefile.
>
> Most Makefiles know where they are in the heirarchy, and thus do not
> require any special handling--they use $(srcdir)/.. or whatever.
>
> Where that is not the case, for libraries which are built using
> multilib, we use the make variable top_srcdir.  E.g.,
> libstdc++-v3/Makefile.am uses it.

Thanks, Ian, I'll try that.

-Tom