lang/(erlang(-runtime2[13])?): work around dtrace failures with clang 13

During an exp-run for llvm 13 (see bug 258209), it turned out that
lang/erlang and lang/erlang-runtime2[13] fail to build with clang 13.

What appears to happen is that for these versions of erlang, PGO is
enabled, and it first builds a PGO-enabled beam.smp:

gmake[5]: Entering directory '/wrkdirs/usr/ports/lang/erlang/work/otp-OTP-21.3.8.24/erts/emulator'
if utils/gen_git_version amd64-portbld-freebsd14.0/gen_git_version.mk; then touch beam/erl_bif_info.c; fi
echo " PROFILE beam.prof.smp"
 PROFILE beam.prof.smp
rm -f obj/amd64-portbld-freebsd14.0/opt/smp/erl*.profraw
set -e; LLVM_PROFILE_FILE="obj/amd64-portbld-freebsd14.0/opt/smp/erlc-%m.profraw" \
          ERL_FLAGS="-emu_type prof +S 1" erlc -W  -DPGO \
  -o obj/amd64-portbld-freebsd14.0/opt/smp test/estone_SUITE.erl > obj/amd64-portbld-freebsd14.0/opt/smp/PROFILE_LOG

after which it does a test run, and uses llvm-profdata to merge the
profiling data into beam_emu_pu.o:

  llvm-profdata merge -output obj/amd64-portbld-freebsd14.0/opt/smp/default.profdata obj/amd64-portbld-freebsd14.0/opt/smp/*.profraw
  cc -fprofile-instr-use=obj/amd64-portbld-freebsd14.0/opt/smp/default.profdata  -Werror=undef -Werror=implicit -Werror=return-type   -O3 -fomit-frame-pointer -pipe  -fno-omit-frame-pointer -DMAP_NORESERVE=0 -fstack-protector-strong -fno-strict-aliasing  -I/wrkdirs/usr/ports/lang/erlang/work/otp-OTP-21.3.8.24/erts/amd64-portbld-freebsd14.0    -DHAVE_CONFIG_H -Wall -Wstrict-prototypes -Wmissing-prototypes -Wdeclaration-after-statement -DUSE_THREADS -D_THREAD_SAFE -D_REENTRANT -DPOSIX_THREADS   -Iamd64-portbld-freebsd14.0/opt/smp -Ibeam -Isys/unix -Isys/common -Iamd64-portbld-freebsd14.0 -Ipcre -Ihipe -I../include -I../include/amd64-portbld-freebsd14.0 -I../include/internal -I../include/internal/amd64-portbld-freebsd14.0 -c beam/beam_emu.c -o obj/amd64-portbld-freebsd14.0/opt/smp/beam_emu_pu.o

Later, it runs dtrace over all the collected objects, and this dies:

  dtrace -G -C -Ibeam \
    -s beam/erlang_dtrace.d \
    -o obj/amd64-portbld-freebsd14.0/opt/smp/erlang_pu_dtrace.o
    ... long list of objects ...
  dtrace: failed to link script beam/erlang_dtrace.d: an error was encountered while processing obj/amd64-portbld-freebsd14.0/opt/smp/beam_emu_pu.o
  gmake[5]: *** [amd64-portbld-freebsd14.0/Makefile:1005: obj/amd64-portbld-freebsd14.0/opt/smp/erlang_pu_dtrace.o] Error 1
  gmake[5]: Leaving directory '/wrkdirs/usr/ports/lang/erlang/work/otp-OTP-21.3.8.24/erts/emulator'

Something in beam_emu_pu.o (emitted by clang or llvm 13) is tripping up
dtrace, but I have very little knowledge about dtrace so I need help
here. :)

Now some other erlang runtimes such as lang/erlang-runtime24 *do* build
successfully with clang 13, but this is only because upstream disabled
the PGO feature, as a side effect of
https://github.com/erlang/otp/commit/b165524c732 ("erts: Implement the
BeamAsm JIT"):

--- a/erts/configure.in
+++ b/erts/configure.in
...
@@ -704,6 +719,9 @@ else
   fi
 fi

+dnl Disable pgo for now
+USE_PGO=false
+
 AC_SUBST(USE_PGO)
 AC_SUBST(PROFILE_COMPILER)

I am unsure why upstream disabled this "for now", as it has been
disabled for more than a year. So, for now, work around the dtrace
failures by disabling PGO using the configure flag --disable-pgo, when
building with clang >= 13.

PR:		258494
Approved by:	maintainer timeout (2 weeks)
MFH:		2021Q4

1 files changed, 6 insertions, 1 deletions

diff --git a/lang/erlang-runtime23/Makefile b/lang/erlang-runtime23/Makefile
index 4a585d177c6e..5bff1294db73 100644
--- a/lang/erlang-runtime23/Makefile
+++ b/lang/erlang-runtime23/Makefile
@@ -15,7 +15,7 @@ LICENSE=	APACHE20
 
 BROKEN_sparc64=	Fails to build: error: fp_except undeclared
 
-USES=		autoreconf:build cpe gmake ncurses perl5
+USES=		autoreconf:build compiler cpe gmake ncurses perl5
 USE_GITHUB=	nodefault
 GH_ACCOUNT=	erlang:otp,corba
 GH_PROJECT=	otp:otp corba:corba
@@ -94,6 +94,11 @@ WX_VARS=			USE_GL="gl glu" \
 
 .include <bsd.port.pre.mk>
 
+.if ${COMPILER_TYPE} == clang && ${COMPILER_VERSION} >= 130
+# PR 258494
+CONFIGURE_ARGS+=	--disable-pgo
+.endif
+
 .if ${OPSYS} == FreeBSD
 CFLAGS+=	-DMAP_NORESERVE=0
 .endif