933047 - configure should fail if CXX can't link C++ executables

Status: RESOLVED FIXED

(Firefox Build System :: General, defect)

Description

[Michael Shal [:mshal]]

While trying to setup a cross compile, I inadvertently set CXX to be 'clang' instead of 'clang++' in my mozconfig. The configure step still passed, but the build failed later when trying to link a C++ executable because it wasn't using the right libraries. It would be nice if configure would check to make sure that CXX is actually capable of linking properly.

Comment 1

[Michael Shal [:mshal]]

Attachment: 0001-Bug-933047-WIP.patch

Does this look somewhat appropriate? It seems to correctly flag CXX=clang in the mozconfig as invalid, though I have to rm -rf objdir when I change CXX.

Comment 2

[Mike Hommey [:glandium]]

Attachment: Add a configure check whether the C++ compiler actually is a C++ compiler

Comment 3

[Mike Hommey [:glandium]]

Comment on attachment 824986 [details] [diff] [review]
0001-Bug-933047-WIP.patch

This is roughly what i did, at a different level with a different test code.

Comment 4

[Mike Hommey [:glandium]]

Attachment: Add a configure check whether the C++ compiler actually is a C++ compiler

Missing AC_MSG_RESULTs

Comment 5

[Mike Hommey [:glandium]]

sigh. the test doesn't work with MSVC. OTOH, we do have a specific similar test for MSVC already in configure.in.

Comment 6

[Mike Hommey [:glandium]]

Attachment: Add a configure check whether the C++ compiler actually is a C++ compiler.

This fixes it. The fixup is trivial enough to not rerequest review.

Comment 7

[Mike Hommey [:glandium]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/cb728c8c416e

Comment 8

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/cb728c8c416e