[libcxx-commits] [PATCH] D100277: [libc++] [test] Detect an improperly noexcept'ed __decay_copy.

[Arthur O'Dwyer via Phabricator via libcxx-commits]

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  `__decay_copy` is used by `std::thread`'s constructor to copy its arguments
  into the new thread. If `__decay_copy` claims to be noexcept, but then
  copying the argument does actually throw, we'd call std::terminate instead
  of passing this test. (And I've verified that adding an unconditional `noexcept`
  to `__decay_copy` does indeed fail this test.)

(This came out of review comments on D100255 <https://reviews.llvm.org/D100255>.)


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D100277

Files:
  libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp


Index: libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
===================================================================
--- libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
+++ libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
@@ -23,6 +23,7 @@
 #include <atomic>
 #include <cstdlib>
 #include <cassert>
+#include <vector>
 
 #include "test_macros.h"
 
@@ -51,7 +52,7 @@
 
 bool f_run = false;
 
-void f()
+void f(const std::vector<int>&)
 {
     f_run = true;
 }
@@ -125,9 +126,10 @@
 
 void test_throwing_new_during_thread_creation() {
 #ifndef TEST_HAS_NO_EXCEPTIONS
+    std::vector<int> v(10);
     throw_one = 0xFFF;
     {
-        std::thread t(f);
+        std::thread t(f, v);
         t.join();
     }
     numAllocs = 0xFFF - throw_one;
@@ -137,7 +139,7 @@
         f_run = false;
         unsigned old_outstanding = outstanding_new;
         try {
-            std::thread t(f);
+            std::thread t(f, v);
             assert(i == numAllocs); // Only final iteration will not throw.
             t.join();
             assert(f_run);
@@ -156,7 +158,8 @@
 {
     test_throwing_new_during_thread_creation();
     {
-        std::thread t(f);
+        std::vector<int> v(10);
+        std::thread t(f, v);
         t.join();
         assert(f_run == true);
     }


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