Disable -fPIE for HiPE on x86_64

[sverker]

This is an attempt to fix https://bugs.erlang.org/browse/ERL-294
by letting configure disable position independent executable (PIE) if

• PIE is enabled by default
• and hipe is enabled
• and architecture is x86_64 (amd64)

I encourage stake holders to test this before we merge into maint for OTP-19.2.

[weisslj]

This does not work, #ifdef should be changed to #if.

[sverker]

Thanks.
Believe it or not but I actually tested both branches of AC_TRY_COMPILE.
#ifdef define(..) succeeded with just a warning "extra tokens at end of #ifdef directive" (that I never saw).
Then I changed it to !defined(..) and that did not compile as expected.

[weisslj]

This does not work for me with the Debian gcc-6 compiler:

 MAKE   depend
make[1]: Entering directory '/home/weisslj/src/otp/erts/emulator'
 MAKE   generate
make[2]: Entering directory '/home/weisslj/src/otp/erts/emulator'
 GEN    x86_64-unknown-linux-gnu/gen_git_version.mk
 LD /home/weisslj/src/otp/bin/x86_64-unknown-linux-gnu/hipe_mkliterals
/usr/bin/ld: obj/x86_64-unknown-linux-gnu/opt/plain/hipe_mkliterals.o: relocation R_X86_64_32 against `.rodata.str1.8' can not be used when making a shared object; recompile with -fPIC
/usr/bin/ld: final link failed: Nonrepresentable section on output
collect2: error: ld returned 1 exit status
x86_64-unknown-linux-gnu/Makefile:934: recipe for target '/home/weisslj/src/otp/bin/x86_64-unknown-linux-gnu/hipe_mkliterals' failed
make[2]: *** [/home/weisslj/src/otp/bin/x86_64-unknown-linux-gnu/hipe_mkliterals] Error 1
make[2]: Leaving directory '/home/weisslj/src/otp/erts/emulator'
/home/weisslj/src/otp/make/run_make.mk:42: recipe for target 'generate' failed
make[1]: *** [generate] Error 2
make[1]: Leaving directory '/home/weisslj/src/otp/erts/emulator'
Makefile:493: recipe for target 'depend' failed
make: *** [depend] Error 2

The minimal set of flags which seems to work for me is LDFLAGS=-no-pie, no added STATIC_CFLAGS, see this table:

STATIC_CFLAGS	LDFLAGS	Result
		HiPE broken
	-no-pie	OK
	-fno-pie	HiPE broken
	-no-pie -fno-pie	OK
-no-pie		HiPE broken
-no-pie	-no-pie	OK
-no-pie	-fno-pie	HiPE broken
-no-pie	-no-pie -fno-pie	OK
-fno-pie		build error
-fno-pie	-no-pie	build error
-fno-pie	-fno-pie	build error
-fno-pie	-no-pie -fno-pie	build error
-no-pie -fno-pie		build error
-no-pie -fno-pie	-no-pie	OK
-no-pie -fno-pie	-fno-pie	build error
-no-pie -fno-pie	-no-pie -fno-pie	OK
-no-pie	-Wl,-no-pie	HiPE broken
	-Wl,-no-pie	HiPE broken
-fno-pie	-Wl,-no-pie	build error

[sverker]

Seems this is the correct and best combination:

STATIC_CFLAGS	LDFLAGS
-fno-pie	-no-pie

The reason that it failed for you is that CFLAGS was used instead of LDFLAGS at one place (hipe_mkliterals).
I've pushed two more commits. Hopefully it will work better now. I don't have access to
gcc configured with --enable-default-pie so I only tested it with a gcc wrapper script that tries to simulate
--enable-default-pie.

[sverker]

If you do get build errors again, please rerun with export V=1 so we can see all arguments passed to gcc.

[weisslj]

Thanks, now it works perfectly, with gcc and clang. I agree that CFLAGS=-fno-pie and LDFLAGS=-no-pie is the best combination!

[sverker]

Rebased to two commits and merged to maint and master.

[weisslj]

Thanks!