From 94ea1327d8643c1a66aa615fbcdbd69f26080fca Mon Sep 17 00:00:00 2001
From: Kyle Brenneman <kbrenneman@nvidia.com>
Date: Mon, 13 Sep 2021 16:45:47 -0600
Subject: [PATCH 1/3] meson: Change the 'tls' option to be boolean.

Change the 'tls' option to be a boolean value instead of a feature.

This still allows manually disabling TLS in builds that would otherwise
support it, but it shouldn't be affected by meson's --auto-features
option.
---
 .gitlab-ci.yml    | 6 +++---
 meson.build       | 7 +++++--
 meson_options.txt | 5 +++--
 3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index bde630d..6fba5a6 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -84,7 +84,7 @@ build-x86_64-tsd-meson:
   extends:
     - .build-check-meson
   variables:
-    CONFIGURE_OPTIONS: -Dtls=disabled
+    CONFIGURE_OPTIONS: -Dtls=false
 
 build-i386-tsd:
   extends:
@@ -96,7 +96,7 @@ build-i386-tsd-meson:
   extends:
     - .build-check-meson
   variables:
-    CONFIGURE_OPTIONS: -Dtls=disabled --cross-file .gitlab-ci/i686-linux-gnu
+    CONFIGURE_OPTIONS: -Dtls=false --cross-file .gitlab-ci/i686-linux-gnu
 
 build-pure-c-tls:
   extends:
@@ -120,4 +120,4 @@ build-pure-c-tld-meson:
   extends:
     - .build-check-meson
   variables:
-    CONFIGURE_OPTIONS: -Dasm=disabled -Dtls=disabled
+    CONFIGURE_OPTIONS: -Dasm=disabled -Dtls=false
diff --git a/meson.build b/meson.build
index 7d8ac0a..f38744f 100644
--- a/meson.build
+++ b/meson.build
@@ -114,14 +114,17 @@ if cc.compiles('typeof(int *);', name : 'typeof')
 endif
 
 with_tls = get_option('tls')
-if with_tls.auto()
+if with_tls
+  # Use a __thread variable if possible, even if we can't use the TLS assembly
+  # stubs, because it's still faster than calling pthread_getspecific.
   have_tls = cc.compiles(
     '__thread int foo;',
     name : '__thread',
   )
 else
-  have_tls = with_tls.enabled()
+  have_tls = false
 endif
+message('Using TLS variable for dispatch table: @0@'.format(have_tls))
 
 if have_tls
   add_project_arguments('-DGLDISPATCH_USE_TLS', language : ['c'])
diff --git a/meson_options.txt b/meson_options.txt
index 7a1d419..bc5ec07 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -60,8 +60,9 @@ option(
 )
 option(
   'tls',
-  type : 'feature',
-  description : 'Use Thread Local Storage.'
+  type : 'boolean',
+  value : true,
+  description : 'Use Thread Local Storage (if supported).'
 )
 option(
   'dispatch-page-size',

From 79b012c645ec392b7d7b0b32c6595cc7a9166706 Mon Sep 17 00:00:00 2001
From: Kyle Brenneman <kbrenneman@nvidia.com>
Date: Mon, 13 Sep 2021 17:05:21 -0600
Subject: [PATCH 2/3] meson: Add an option to use the TSD dispatch stubs.

Add a 'dispatch-tls' option. Setting the option to false will force it
to use the TSD dispatch stubs for builds that would otherwise support
the TLS stubs.

This is mostly for test coverage, to make it easier to test builds that
use the __thread variable (u_current_tls.c), but still use the TSD
dispatch stubs.
---
 meson.build       | 10 +++++++++-
 meson_options.txt |  6 ++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/meson.build b/meson.build
index f38744f..a25c771 100644
--- a/meson.build
+++ b/meson.build
@@ -136,7 +136,15 @@ if use_asm
   # FreeBSD and glibc). on other platforms we use TSD stubs to allow calling
   # extension functions unknown at compile time.
   # https://gitlab.freedesktop.org/glvnd/libglvnd/-/merge_requests/249
-  thread_type = have_tls and (host_machine.system() == 'freebsd' or cc.has_header_symbol('features.h', '__GLIBC__')) ? 'tls' : 'tsd'
+  thread_type = 'tsd'
+  if get_option('dispatch-tls')
+    if have_tls
+      if host_machine.system() == 'freebsd' or cc.has_header_symbol('features.h', '__GLIBC__')
+        thread_type = 'tls'
+      endif
+    endif
+  endif
+
   if host_machine.cpu_family().startswith('x86')
     gl_dispatch_type = '@0@_@1@'.format(
       host_machine.cpu_family(),
diff --git a/meson_options.txt b/meson_options.txt
index bc5ec07..c4b7bc1 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -64,6 +64,12 @@ option(
   value : true,
   description : 'Use Thread Local Storage (if supported).'
 )
+option(
+  'dispatch-tls',
+  type : 'boolean',
+  value : true,
+  description : 'Use TLS-based stubs in libGLdispatch (if supported).'
+)
 option(
   'dispatch-page-size',
   type : 'integer',

From 4de6e6734b7d6ac7239ef187426c9e3c22bb2bce Mon Sep 17 00:00:00 2001
From: Kyle Brenneman <kbrenneman@nvidia.com>
Date: Mon, 13 Sep 2021 17:14:57 -0600
Subject: [PATCH 3/3] CI: Test builds with TSD stubs and TLS variables

Add builds to the CI script that use the TSD dispatch stubs, but use the
TLS variable in u_current_tls.c for the dispatch table.

That's the combination you'd get with musl or other non-glibc systems.
---
 .gitlab-ci.yml | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6fba5a6..7080f5a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -86,6 +86,12 @@ build-x86_64-tsd-meson:
   variables:
     CONFIGURE_OPTIONS: -Dtls=false
 
+build-x86_64-tsd-tls-meson:
+  extends:
+    - .build-check-meson
+  variables:
+    CONFIGURE_OPTIONS: -Ddispatch-tls=false
+
 build-i386-tsd:
   extends:
     - .build-check-at
@@ -98,6 +104,12 @@ build-i386-tsd-meson:
   variables:
     CONFIGURE_OPTIONS: -Dtls=false --cross-file .gitlab-ci/i686-linux-gnu
 
+build-i386-tsd-tls-meson:
+  extends:
+    - .build-check-meson
+  variables:
+    CONFIGURE_OPTIONS: -Ddispatch-tls=false --cross-file .gitlab-ci/i686-linux-gnu
+
 build-pure-c-tls:
   extends:
     - .build-check-at