Re: [committed] libstdc++: Break header cycle between and

[Jonathan Wakely via Gcc-patches]

On 02/09/20 14:15 +0100, Jonathan Wakely wrote:

The <new> and <exception> headers each include each other, which makes
building them as header-units "exciting". The <new> header only needs
the definition of std::exception (in order to derive from it) which is
already in its own header, so just include that.

libstdc++-v3/ChangeLog:

        * include/bits/stl_iterator.h: Include <bits/exception_defines.h>
        for definitions of __try, __catch and __throw_exception_again.
        (counted_iterator::operator++(int)): Use __throw_exception_again
        instead of throw.
        * libsupc++/new: Include <bits/exception.h> not <exception>.
        * libsupc++/new_opvnt.cc: Include <bits/exception_defines.h>.
        * testsuite/18_support/destroying_delete.cc: Include
        <type_traits> for std::is_same_v definition.
        * testsuite/20_util/variant/index_type.cc: Qualify size_t.

Tested powerpc64le-linux. Committed to trunk.

commit 6bdbf0f37bda2587a4e82cbb956de7a159a397ae
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Sep 2 13:27:57 2020

   libstdc++: Break header cycle between <new> and <exception>

   The <new> and <exception> headers each include each other, which makes
   building them as header-units "exciting". The <new> header only needs
   the definition of std::exception (in order to derive from it) which is
   already in its own header, so just include that.

   libstdc++-v3/ChangeLog:

           * include/bits/stl_iterator.h: Include <bits/exception_defines.h>
           for definitions of __try, __catch and __throw_exception_again.
           (counted_iterator::operator++(int)): Use __throw_exception_again
           instead of throw.
           * libsupc++/new: Include <bits/exception.h> not <exception>.
           * libsupc++/new_opvnt.cc: Include <bits/exception_defines.h>.
           * testsuite/18_support/destroying_delete.cc: Include
           <type_traits> for std::is_same_v definition.
           * testsuite/20_util/variant/index_type.cc: Qualify size_t.

diff --git a/libstdc++-v3/include/bits/stl_iterator.h 
b/libstdc++-v3/include/bits/stl_iterator.h
index f0cf4c55c09..da740e3732e 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -79,6 +79,7 @@
#if __cplusplus > 201703L
# include <compare>
# include <new>
+# include <bits/exception_defines.h>
# include <bits/iterator_concepts.h>
#endif

@@ -2062,7 +2063,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
            return _M_current++;
          } __catch(...) {
            ++_M_length;
-           throw;
+           __throw_exception_again;
          }

      }

I've also changed the line above on the gcc-10 branch. Even though
both GCC and Clang accept it with -fno-exceptions (rather
mysteriously) it should be using the __throw_exception_again macro
instead.


commit 7eb76b3b1721247bc2c9ab6a41c1655158ed3411
Author: Jonathan Wakely <jwak...@redhat.com>
Date:   Wed Sep 2 14:50:34 2020

    libstdc++: Use __throw_exception_again macro for -fno-exceptions
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/stl_iterator.h (counted_iterator::operator++(int)):
            Use __throw_exception_again macro.

diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index 19b1d53f781..d6bb085b3c6 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -2013,7 +2013,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 	    return _M_current++;
 	  } __catch(...) {
 	    ++_M_length;
-	    throw;
+	    __throw_exception_again;
 	  }
 
       }