1411613 - with -std=c++17, memory is failing to build with 'xxx' is missing exception specification 'throw()'

Status: RESOLVED FIXED

(Core :: Memory Allocator, defect, P4)

Description

[Sylvestre Ledru [:Sylvestre]]

In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/obj-x86_64-pc-linux-gnu/memory/build/Unified_cpp_memory_build0.cpp:11:
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:14:
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:51:1: error: 'free' is missing exception specification 'throw()'
 MALLOC_DECL(free, void, void *)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:12:30: note: expanded from macro 'MALLOC_DECL'
   MOZ_MEMORY_API return_type name ## _impl(__VA_ARGS__);
                              ^
 <scratch space>:160:1: note: expanded from here
 free_impl
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.h:148:53: note: expanded from macro 'free_impl'
 #define free_impl                mozmem_malloc_impl(free)
                                                     ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:51:1: note: previous declaration is here
 MALLOC_DECL(free, void, void *)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozjemalloc.cpp:5205:52: note: expanded from macro 'MALLOC_DECL'
 #define MALLOC_DECL(...) MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (__VA_ARGS__))
                                                    ^
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/obj-x86_64-pc-linux-gnu/memory/build/Unified_cpp_memory_build0.cpp:11:
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:14:
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:55:1: error: 'posix_memalign' is missing exception specification 'throw()'
 MALLOC_DECL(posix_memalign, int, void **, size_t, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:12:30: note: expanded from macro 'MALLOC_DECL'
   MOZ_MEMORY_API return_type name ## _impl(__VA_ARGS__);
                              ^
 <scratch space>:162:1: note: expanded from here
 posix_memalign_impl
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.h:144:53: note: expanded from macro 'posix_memalign_impl'
 #define posix_memalign_impl      mozmem_malloc_impl(posix_memalign)
                                                     ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:55:1: note: previous declaration is here
 MALLOC_DECL(posix_memalign, int, void **, size_t, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozjemalloc.cpp:5205:52: note: expanded from macro 'MALLOC_DECL'
 #define MALLOC_DECL(...) MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (__VA_ARGS__))
                                                    ^
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/obj-x86_64-pc-linux-gnu/memory/build/Unified_cpp_memory_build0.cpp:11:
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:14:
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:56:1: error: 'aligned_alloc' is missing exception specification 'throw()'
 MALLOC_DECL(aligned_alloc, void *, size_t, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:12:30: note: expanded from macro 'MALLOC_DECL'
   MOZ_MEMORY_API return_type name ## _impl(__VA_ARGS__);
                              ^
 <scratch space>:163:1: note: expanded from here
 aligned_alloc_impl
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.h:145:53: note: expanded from macro 'aligned_alloc_impl'
 #define aligned_alloc_impl       mozmem_malloc_impl(aligned_alloc)
                                                     ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:56:1: note: previous declaration is here
 MALLOC_DECL(aligned_alloc, void *, size_t, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozjemalloc.cpp:5205:52: note: expanded from macro 'MALLOC_DECL'
 #define MALLOC_DECL(...) MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (__VA_ARGS__))
                                                    ^
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/obj-x86_64-pc-linux-gnu/memory/build/Unified_cpp_memory_build0.cpp:11:
 In file included from /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:14:
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:57:1: error: 'valloc' is missing exception specification 'throw()'
 MALLOC_DECL(valloc, void *, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.cpp:12:30: note: expanded from macro 'MALLOC_DECL'
   MOZ_MEMORY_API return_type name ## _impl(__VA_ARGS__);
                              ^
 <scratch space>:164:1: note: expanded from here
 valloc_impl
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozmemory_wrap.h:150:53: note: expanded from macro 'valloc_impl'
 #define valloc_impl              mozmem_malloc_impl(valloc)
                                                     ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/malloc_decls.h:57:1: note: previous declaration is here
 MALLOC_DECL(valloc, void *, size_t)
 ^
 /home/sylvestre/dev/mozilla/mozilla-central.hg/memory/build/mozjemalloc.cpp:5205:52: note: expanded from macro 'MALLOC_DECL'
 #define MALLOC_DECL(...) MOZ_MEMORY_API MACRO_CALL(GENERIC_MALLOC_DECL, (__VA_ARGS__))

Comment 1

[Mike Hommey [:glandium]]

Not that I expect it would fix anything, but if you're going to try new C++ standards, you should use -std=gnu++xx instead of -std=c++xx. Also, we're on C++11 currently, and we can hardly bump to C++14, so C++17 is still a loooong way.

Comment 2

[Nathan Froyd [:froydnj]]

Attachment: Bug 1411613 - mark certain allocation functions as non-throwing; r=glandium

glibc marks various allocation functions as throw(). This addition
hasn't been a problem until we tried to enable C++17, where clang
started complaining that we were redeclaring functions with mismatched
exception specifications. Peculiarly, glibc declares virtually
everything we redeclare as throw(), but clang only complains about the
mismatches for a particular subset of functions.

The approach taken in this patch is to add another potentially defined
macro to malloc_decls.h, NOTHROW_MALLOC_DECL. This macro works
exactly like MALLOC_DECL, except that clients can define
NOTHROW_MALLOC_DECL to add appropriate throw() specifiers when
declaring functions at global scope, and thereby avoid mismatched
exception specifications.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/55974feb88c1
mark certain allocation functions as non-throwing; r=glandium

Comment 4

[Cristina Coroiu [:ccoroiu]]

https://hg.mozilla.org/mozilla-central/rev/55974feb88c1