[PATCH] libstdc++: Add wrapper for internal uses of std::terminate

[Jonathan Wakely via Gcc-patches]

This adds an inline wrapper for std::terminate that doesn't add the
declaration of std::terminate to namespace std. This allows the
library to terminate without including all of <exception>.

libstdc++-v3/ChangeLog:

        * include/bits/atomic_timed_wait.h: Remove unused header.
        * include/bits/c++config (std:__terminate): Define.
        * include/bits/semaphore_base.h: Remove <exception> and use
        __terminate instead of terminate.
        * include/bits/std_thread.h: Likewise.
        * libsupc++/eh_terminate.cc (std::terminate): Use qualified-id
        to call __cxxabiv1::__terminate.


This avoids including a few thousand lines of <exception> just for one
function declaration. Any objections or better ideas?



commit 79cd06f3072fd8a68b8636f7d11bb42e62eaa6fa
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Fri Oct 8 11:35:53 2021

    libstdc++: Add wrapper for internal uses of std::terminate
    
    This adds an inline wrapper for std::terminate that doesn't add the
    declaration of std::terminate to namespace std. This allows the
    library to terminate without including all of <exception>.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/atomic_timed_wait.h: Remove unused header.
            * include/bits/c++config (std:__terminate): Define.
            * include/bits/semaphore_base.h: Remove <exception> and use
            __terminate instead of terminate.
            * include/bits/std_thread.h: Likewise.
            * libsupc++/eh_terminate.cc (std::terminate): Use qualified-id
            to call __cxxabiv1::__terminate.

diff --git a/libstdc++-v3/include/bits/atomic_timed_wait.h 
b/libstdc++-v3/include/bits/atomic_timed_wait.h
index 64c1ba62a3e..efbe3da8b6c 100644
--- a/libstdc++-v3/include/bits/atomic_timed_wait.h
+++ b/libstdc++-v3/include/bits/atomic_timed_wait.h
@@ -40,7 +40,6 @@
 #include <bits/chrono.h>
 
 #ifdef _GLIBCXX_HAVE_LINUX_FUTEX
-#include <exception> // std::terminate
 #include <sys/time.h>
 #endif
 
diff --git a/libstdc++-v3/include/bits/c++config 
b/libstdc++-v3/include/bits/c++config
index 69343a25533..b76ffeb2562 100644
--- a/libstdc++-v3/include/bits/c++config
+++ b/libstdc++-v3/include/bits/c++config
@@ -293,6 +293,15 @@ namespace std
 #if __cplusplus >= 201103L
   typedef decltype(nullptr)    nullptr_t;
 #endif
+
+  // This allows the library to terminate without including all of <exception>
+  // and without making the declaration of std::terminate visible to users.
+  __attribute__ ((__noreturn__, __always_inline__))
+  inline void __terminate() _GLIBCXX_USE_NOEXCEPT
+  {
+    void terminate() _GLIBCXX_USE_NOEXCEPT __attribute__ ((__noreturn__));
+    terminate();
+  }
 }
 
 #define _GLIBCXX_USE_DUAL_ABI
diff --git a/libstdc++-v3/include/bits/semaphore_base.h 
b/libstdc++-v3/include/bits/semaphore_base.h
index 2c8d7576894..afd636704e8 100644
--- a/libstdc++-v3/include/bits/semaphore_base.h
+++ b/libstdc++-v3/include/bits/semaphore_base.h
@@ -40,7 +40,6 @@
 #endif // __cpp_lib_atomic_wait
 
 #ifdef _GLIBCXX_HAVE_POSIX_SEMAPHORE
-# include <exception>  // std::terminate
 # include <cerrno>     // errno, EINTR, EAGAIN etc.
 # include <limits.h>   // SEM_VALUE_MAX
 # include <semaphore.h>        // sem_t, sem_init, sem_wait, sem_post etc.
@@ -80,7 +79,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          if (__err && (errno == EINTR))
            continue;
          else if (__err)
-           std::terminate();
+           std::__terminate();
          else
            break;
        }
@@ -97,7 +96,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          else if (__err && (errno == EAGAIN))
            return false;
          else if (__err)
-           std::terminate();
+           std::__terminate();
          else
            break;
        }
@@ -111,7 +110,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        {
           auto __err = sem_post(&_M_semaphore);
           if (__err)
-            std::terminate();
+            std::__terminate();
        }
     }
 
@@ -138,7 +137,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
              else if (errno == ETIMEDOUT || errno == EINVAL)
                return false;
              else
-               std::terminate();
+               std::__terminate();
            }
          else
            break;
diff --git a/libstdc++-v3/include/bits/std_thread.h 
b/libstdc++-v3/include/bits/std_thread.h
index 2a500bf1777..801033b00ad 100644
--- a/libstdc++-v3/include/bits/std_thread.h
+++ b/libstdc++-v3/include/bits/std_thread.h
@@ -35,7 +35,6 @@
 #if __cplusplus >= 201103L
 #include <bits/c++config.h>
 
-#include <exception>           // std::terminate
 #include <iosfwd>              // std::basic_ostream
 #include <tuple>               // std::tuple
 #include <bits/functional_hash.h> // std::hash
@@ -149,7 +148,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     ~thread()
     {
       if (joinable())
-       std::terminate();
+       std::__terminate();
     }
 
     thread(const thread&) = delete;
@@ -162,7 +161,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     thread& operator=(thread&& __t) noexcept
     {
       if (joinable())
-       std::terminate();
+       std::__terminate();
       swap(__t);
       return *this;
     }
diff --git a/libstdc++-v3/libsupc++/eh_terminate.cc 
b/libstdc++-v3/libsupc++/eh_terminate.cc
index db6735f308e..a94f173bb2e 100644
--- a/libstdc++-v3/libsupc++/eh_terminate.cc
+++ b/libstdc++-v3/libsupc++/eh_terminate.cc
@@ -55,7 +55,7 @@ __cxxabiv1::__terminate (std::terminate_handler handler) 
throw ()
 void
 std::terminate () throw()
 {
-  __terminate (get_terminate ());
+  __cxxabiv1::__terminate (get_terminate ());
 }
 
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"