[tor-commits] [tor-browser-build/master] Bug 34359: Adapt abicheck.cc to deal with newer GCC version

[sysrqb at torproject.org]

commit 756b3f0a6f3dd6b0a6ce262528f027f79b1e3c07
Author: Georg Koppen <gk at torproject.org>
Date:   Wed Aug 12 08:32:50 2020 +0000

    Bug 34359: Adapt abicheck.cc to deal with newer GCC version
    
    ESR 78 compiled with GCC 9.3.0 requires GLIBCXX_3.4.28.
---
 projects/firefox/abicheck.cc | 29 +++++++++++++++--------------
 projects/firefox/build       |  2 +-
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/projects/firefox/abicheck.cc b/projects/firefox/abicheck.cc
index ba5f858..53d1dcc 100644
--- a/projects/firefox/abicheck.cc
+++ b/projects/firefox/abicheck.cc
@@ -1,23 +1,24 @@
 /*
- * Bug 25485: Browser/TorBrowser/Tor/libstdc++.so.6: version `CXXABI_1.3.11' not found
- * Bug 31646: Update abicheck to require newer libstdc++.so.6
+ * Bug 34359: Update abicheck to require newer libstdc++.so.6
  * This program is useful in determining if the libstdc++.so.6 installed
- * on the system is recent enough. Specifically this program requires
- * `GLIBCXX_3.4.25` which should be provided by libstdc++.so.6 from
- * gcc >= 8.0.0. If the program executes successfully, that means we
+ * on the system is recent enough. Specifically, this program requires
+ * `GLIBCXX_3.4.28` which should be provided by libstdc++.so.6 from
+ * gcc >= 9.3.0. If the program executes successfully, that means we
  * should use the system version of libstdc++.so.6 and if not, that means
  * we should use the bundled version.
  *
- * We use std::random_device::entropy() in order to require GLIBCXX_3.4.25:
- * https://github.com/gcc-mirror/gcc/blob/gcc-8_3_0-release/libstdc%2B%2B-v3/config/abi/pre/gnu.ver#L1978
+ * We use std::pmr::monotonic_buffer_resource in order to require
+ * GLIBCXX_3.4.28:
+ * https://github.com/gcc-mirror/gcc/blob/9e4ebad20a064d10df451cfb2cea9853d339a898/libstdc%2B%2B-v3/config/abi/pre/gnu.ver#L2303
+ * The example below got inspired by
+ * https://www.mail-archive.com/gcc-patches@gcc.gnu.org/msg227964.html.
  */
 
-#include <iostream>
-#include <random>
+#include <memory_resource>
 
-int main()
-{
-    std::random_device rd;
-    std::cout << "entropy: " << rd.entropy() << std::endl;
-    return 0;
+int main () {
+  std::pmr::monotonic_buffer_resource res;
+  void* a = res.allocate(1);
+  res.release();
+  return 0;
 }
diff --git a/projects/firefox/build b/projects/firefox/build
index 5ddd4de..ea03088 100644
--- a/projects/firefox/build
+++ b/projects/firefox/build
@@ -277,7 +277,7 @@ END;
 %]
 
 [% IF c("var/linux") %]
-  /var/tmp/dist/gcc/bin/g++ $rootdir/abicheck.cc -o Browser/abicheck
+  /var/tmp/dist/gcc/bin/g++ $rootdir/abicheck.cc -o Browser/abicheck -std=c++17
 [% END %]
 
 [% c('tar', {