[Windows] Pass "/MD" and variants outside the "runtime_library" target

Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org

Committed: https://crrev.com/964b1666ed2178c3f9242ef140ed16c94df24edd
Cr-Commit-Position: refs/heads/master@{#421596}

[Raphael Kubo da Costa (rakuco), 2016-09-28 16:42:30]

PTAL

[brettw, 2016-09-28 17:22:02]

https://codereview.chromium.org/2379573003/diff/1/build/config/win/BUILD.gn
File build/config/win/BUILD.gn (right):

https://codereview.chromium.org/2379573003/diff/1/build/config/win/BUILD.gn#n...
build/config/win/BUILD.gn:201: config("crt") {
If we're going to be changing this, I think a better structure would be to call
this "default_crt" and have that conditionally reference a "static_crt" or a
"dynamic_crt" config based on that. This way your target code removes the
default and adds the dynamic one without hard-coding CRT flags.

(The dynamic and static CRT configs would have the debug/release logic inside
them, it seems like overkill to separate out this into separate configs.)

[Raphael Kubo da Costa (rakuco), 2016-09-28 17:52:33]

Patch v2 is up adapting to your suggestion (I've also updated the CL message).
I had originally thought of something similar, but didn't think of the
"default_crt" bit which simplifies the whole thing quite a lot.

[Raphael Kubo da Costa (rakuco), 2016-09-28 17:53:00]

Description was changed from

==========
[Windows] Pass "/MD" and variants outside the "runtime_library" target

Create a separate configuration called "crt" that takes care of passing
"/MD", "/MT" and others to the compiler and depend on it by default in
the BUILDCONFIG so that the end result remains the same.

The main reason behind this is to allow users to config -= the "crt"
config: in gyp, it was possible to configure what was going to be passed
to the compiler via the "win_{release,debug}_RuntimeLibrary" variable,
which was useful when building code that needs to pass "/CLR", as it
requires "/MD" and does not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org
==========

to

==========
Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org
==========

[Dirk Pranke, 2016-09-28 17:53:21]

lgtm

[brettw, 2016-09-28 18:03:54]

https://codereview.chromium.org/2379573003/diff/40001/build/config/win/BUILD.gn
File build/config/win/BUILD.gn (right):

https://codereview.chromium.org/2379573003/diff/40001/build/config/win/BUILD....
build/config/win/BUILD.gn:277: config = [ ":dynamic_crt" ]
Does this work? These should read "configs".

[Raphael Kubo da Costa (rakuco), 2016-09-28 18:11:10]

On 2016/09/28 18:03:54, brettw (ping on IM after 24h) wrote:
>
https://codereview.chromium.org/2379573003/diff/40001/build/config/win/BUILD.gn
> File build/config/win/BUILD.gn (right):
> 
>
https://codereview.chromium.org/2379573003/diff/40001/build/config/win/BUILD....
> build/config/win/BUILD.gn:277: config = [ ":dynamic_crt" ]
> Does this work? These should read "configs".

I think the Patch v4 is finally The One: sorry about the mistakes in the others,
I was trying to adapt the patch without having to turn on my Windows VM, with
obvious consequences :-)

[brettw, 2016-09-28 18:16:59]

lgtm

[Raphael Kubo da Costa (rakuco), 2016-09-28 18:23:02]

The CQ bit was checked by raphael.kubo.da.costa@intel.com

[Raphael Kubo da Costa (rakuco), 2016-09-28 18:23:02]

The patchset sent to the CQ was uploaded after l-g-t-m from dpranke@chromium.org
Link to the patchset: https://codereview.chromium.org/2379573003/#ps60001
(title: "Fix another brainfart")

[commit-bot: I haz the power, 2016-09-28 18:23:35]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-28 19:14:33]

Description was changed from

==========
Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org
==========

to

==========
Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org
==========

[commit-bot: I haz the power, 2016-09-28 19:14:42]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-09-28 19:16:17]

Description was changed from

==========
Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org
==========

to

==========
Create separate configurations for passing "/MD", "/MT" and their debug
variants: "dynamic_crt" passes "/MD" and "/MDd", whereas "static_crt"
passes "/MT" and "/MTd". BUILDCONFIG then depends on "default_crt",
which has some logic to choose whether to use either dynamic_crt or
static_crt.

The main reason behind this is to allow users to config -= the
"default_crt" config: in gyp, it was possible to configure what was
going to be passed to the compiler via the
"win_{release,debug}_RuntimeLibrary" variable, which was useful when
building code that needs to pass "/CLR", as it requires "/MD" and does
not work with "/MT".

R=brettw@chromium.org,dpranke@chromium.org,scottmg@chromium.org

Committed: https://crrev.com/964b1666ed2178c3f9242ef140ed16c94df24edd
Cr-Commit-Position: refs/heads/master@{#421596}
==========

[commit-bot: I haz the power, 2016-09-28 19:16:17]

Patchset 4 (id:??) landed as
https://crrev.com/964b1666ed2178c3f9242ef140ed16c94df24edd
Cr-Commit-Position: refs/heads/master@{#421596}