[MacPorts] #58726: libvirt @5.5.0: error: expected '; ' before 'virTemporaryReturnPointer'

[MacPorts]

#58726: libvirt @5.5.0: error: expected ';' before 'virTemporaryReturnPointer'
----------------------+------------------------
  Reporter:  kencu    |      Owner:  ryandesign
      Type:  defect   |     Status:  assigned
  Priority:  Normal   |  Milestone:
 Component:  ports    |    Version:
Resolution:           |   Keywords:
      Port:  libvirt  |
----------------------+------------------------

Comment (by kencu):

 The port will not build on Mojave with `-std=c99` set in the Portfile:
 {{{
 /bin/sh ../libtool  --tag=CC   --mode=compile /usr/bin/clang
 -DHAVE_CONFIG_H -I. -I..  -I../gnulib/lib -I../gnulib/lib -I..
 -I../include -I../include -I./util -I./util -DIN_LIBVIRT
 -Dabs_top_builddir="\"/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_sysutils_libvirt/libvirt/work/libvirt-5.5.0\""
 -Dabs_top_srcdir="\"/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_sysutils_libvirt/libvirt/work/libvirt-5.5.0\""
 -I/opt/local/include
 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk
 -I/opt/local/include/yajl  -I/opt/local/include/libxml2 -fno-common -W
 -Waddress -Wall -Wattributes -Wbad-function-cast -Wbuiltin-macro-redefined
 -Wcast-align -Wchar-subscripts -Wcomment -Wcomments -Wcpp -Wdangling-else
 -Wdate-time -Wdeprecated-declarations -Wdiv-by-zero -Wdouble-promotion
 -Wduplicate-decl-specifier -Wempty-body -Wendif-labels -Wexpansion-to-
 defined -Wextra -Wformat-extra-args -Wformat-security -Wformat-y2k
 -Wformat-zero-length -Wignored-attributes -Wignored-qualifiers -Wimplicit
 -Wimplicit-function-declaration -Wimplicit-int -Wincompatible-pointer-
 types -Winit-self -Winline -Wint-conversion -Wint-to-pointer-cast
 -Winvalid-pch -Wlogical-not-parentheses -Wmain -Wmemset-transposed-args
 -Wmissing-braces -Wmissing-declarations -Wmissing-field-initializers
 -Wmissing-include-dirs -Wmissing-prototypes -Wmultichar -Wnarrowing
 -Wnested-externs -Wnonnull -Wnull-dereference -Wodr -Wold-style-definition
 -Woverflow -Wparentheses -Wpointer-arith -Wpointer-sign -Wpointer-to-int-
 cast -Wpragmas -Wreturn-type -Wsequence-point -Wshadow -Wshift-count-
 negative -Wshift-count-overflow -Wshift-negative-value -Wsizeof-array-
 argument -Wsizeof-pointer-memaccess -Wstrict-aliasing -Wstrict-prototypes
 -Wswitch -Wswitch-bool -Wtautological-compare -Wtrigraphs -Wtype-limits
 -Wuninitialized -Wunknown-pragmas -Wunused -Wunused-function -Wunused-
 label -Wunused-local-typedefs -Wunused-parameter -Wunused-result -Wunused-
 value -Wunused-variable -Wvarargs -Wvariadic-macros -Wvolatile-register-
 var -Wwrite-strings -Wno-sign-compare -Wswitch-enum -Wno-format-nonliteral
 -fexceptions -fasynchronous-unwind-tables -Wframe-larger-than=4096
 -I/opt/local/include/p11-kit-1   -pipe -Os -std=c99
 -isysroot/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.14.sdk
 -arch x86_64 -MT util/libvirt_util_la-virmodule.lo -MD -MP -MF util/.deps
 /libvirt_util_la-virmodule.Tpo -c -o util/libvirt_util_la-virmodule.lo
 `test -f 'util/virmodule.c' || echo './'`util/virmodule.c
 util/virhostdev.c:202:5: warning: implicit declaration of function
 'typeof' is invalid in C99 [-Wimplicit-function-declaration]
     VIR_RETURN_PTR(hostdevMgr);
 }}}

 If `-std=c99` is removed, and no standard is set, then the port builds
 again on Mojave. So Apple's clang does accept the `typeof` keyword by
 default, as opposed to llvm's clang, which does not.

 Using `-std=gnu99` the port does build with Mojave using the default
 clang, and also builds with llvm's clang (5 and 8 tested).

 So that appears to be a safe fix.

 Upstream could consider using `__typeof__` instead of `typeof` and then we
 would not need to worry about C standards at all.

-- 
Ticket URL: <https://trac.macports.org/ticket/58726#comment:5>
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