configure: Implement --enable-host-pie

[ This is my third attempt to add this configure option.  The first
version was approved but it came too late in the development cycle.
The second version was also approved, but I had to revert it:
<https://gcc.gnu.org/pipermail/gcc-patches/2022-November/607082.html>.
I've fixed the problem (by moving $(PICFLAG) from INTERNAL_CFLAGS to
ALL_COMPILERFLAGS).  Another change is that since r13-4536 I no longer
need to touch Makefile.def, so this patch is simplified. ]

This patch implements the --enable-host-pie configure option which
makes the compiler executables PIE.  This can be used to enhance
protection against ROP attacks, and can be viewed as part of a wider
trend to harden binaries.

It is similar to the option --enable-host-shared, except that --e-h-s
won't add -shared to the linker flags whereas --e-h-p will add -pie.
It is different from --enable-default-pie because that option just
adds an implicit -fPIE/-pie when the compiler is invoked, but the
compiler itself isn't PIE.

Since r12-5768-gfe7c3ecf, PCH works well with PIE, so there are no PCH
regressions.

When building the compiler, the build process may use various in-tree
libraries; these need to be built with -fPIE so that it's possible to
use them when building a PIE.  For instance, when --with-included-gettext
is in effect, intl object files must be compiled with -fPIE.  Similarly,
when building in-tree gmp, isl, mpfr and mpc, they must be compiled with
-fPIE.

With this patch and --enable-host-pie used to configure gcc:

$ file gcc/cc1{,plus,obj,gm2} gcc/f951 gcc/lto1 gcc/cpp gcc/go1 gcc/rust1 gcc/gnat1
gcc/cc1:     ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=98e22cde129d304aa6f33e61b1c39e144aeb135e, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/cc1plus: ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=859d1ea37e43dfe50c18fd4e3dd9a34bb1db8f77, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/cc1obj:  ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=1964f8ecee6163182bc26134e2ac1f324816e434, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/cc1gm2:  ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=a396672c7ff913d21855829202e7b02ecf42ff4c, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/f951:    ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=59c523db893186547ac75c7a71f48be0a461c06b, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/lto1:    ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=084a7b77df7be2d63c2d4c655b5bbc3fcdb6038d, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/cpp:     ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=3503bf8390d219a10d6653b8560aa21158132168, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/go1:     ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=988cc673af4fba5dcb482f4b34957b99050a68c5, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/rust1:   ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=b6a5d3d514446c4dcdee0707f086ab9b274a8a3c, for GNU/Linux 3.2.0, with debug_info, not stripped
gcc/gnat1:   ELF 64-bit LSB pie executable, x86-64, version 1 (GNU/Linux), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, BuildID[sha1]=bb11ccdc2c366fe3fe0980476bcd8ca19b67f9dc, for GNU/Linux 3.2.0, with debug_info, not stripped

I plan to add an option to link with -Wl,-z,now.

Bootstrapped on x86_64-pc-linux-gnu with --with-included-gettext
--enable-host-pie as well as without --enable-host-pie.  Also tested
on a Debian system where the system gcc was configured with
--enable-default-pie.

Co-Authored by: Iain Sandoe  <iain@sandoe.co.uk>

ChangeLog:

	* configure.ac (--enable-host-pie): New check.  Set PICFLAG after this
	check.
	* configure: Regenerate.

c++tools/ChangeLog:

	* Makefile.in: Rename PIEFLAG to PICFLAG.  Set LD_PICFLAG.  Use it.
	Use pic/libiberty.a if PICFLAG is set.
	* configure.ac (--enable-default-pie): Set PICFLAG instead of PIEFLAG.
	(--enable-host-pie): New check.
	* configure: Regenerate.

fixincludes/ChangeLog:

	* Makefile.in: Set and use PICFLAG and LD_PICFLAG.  Use the "pic"
	build of libiberty if PICFLAG is set.
	* configure.ac:
	* configure: Regenerate.

gcc/ChangeLog:

	* Makefile.in: Set LD_PICFLAG.  Use it.  Set enable_host_pie.
	Remove NO_PIE_CFLAGS and NO_PIE_FLAG.  Pass LD_PICFLAG to
	ALL_LINKERFLAGS.  Use the "pic" build of libiberty if --enable-host-pie.
	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG and LD_PICFLAG after this
	check.
	* configure: Regenerate.
	* doc/install.texi: Document --enable-host-pie.

gcc/ada/ChangeLog:

	* gcc-interface/Make-lang.in (ALL_ADAFLAGS): Remove NO_PIE_CFLAGS.  Add
	PICFLAG.  Use PICFLAG when building ada/b_gnat1.o and ada/b_gnatb.o.
	* gcc-interface/Makefile.in: Use pic/libiberty.a if PICFLAG is set.
	Remove NO_PIE_FLAG.

gcc/m2/ChangeLog:

	* Make-lang.in: New var, GM2_PICFLAGS.  Use it.

gcc/d/ChangeLog:

	* Make-lang.in: Remove NO_PIE_CFLAGS.

intl/ChangeLog:

	* Makefile.in: Use @PICFLAG@ in COMPILE as well.
	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG after this check.
	* configure: Regenerate.

libcody/ChangeLog:

	* Makefile.in: Pass LD_PICFLAG to LDFLAGS.
	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG and LD_PICFLAG after this
	check.
	* configure: Regenerate.

libcpp/ChangeLog:

	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG after this check.
	* configure: Regenerate.

libdecnumber/ChangeLog:

	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG after this check.
	* configure: Regenerate.

libiberty/ChangeLog:

	* configure.ac: Also set shared when enable_host_pie.
	* configure: Regenerate.

zlib/ChangeLog:

	* configure.ac (--enable-host-shared): Don't set PICFLAG here.
	(--enable-host-pie): New check.  Set PICFLAG after this check.
	* configure: Regenerate.

3 files changed, 29 insertions, 4 deletions

diff --git a/fixincludes/Makefile.in b/fixincludes/Makefile.in
index 1937dcaa32d..e6ce41dba39 100644
--- a/fixincludes/Makefile.in
+++ b/fixincludes/Makefile.in
@@ -73,7 +73,7 @@ default : all
 # Now figure out from those variables how to compile and link.
 
 .c.o:
-	$(CC) -c $(CFLAGS) $(WARN_CFLAGS) $(CPPFLAGS) $(FIXINC_CFLAGS) $<
+	$(CC) -c $(CFLAGS) $(PICFLAG) $(WARN_CFLAGS) $(CPPFLAGS) $(FIXINC_CFLAGS) $<
 
 # The only suffixes we want for implicit rules are .c and .o.
 .SUFFIXES:
@@ -87,7 +87,11 @@ default : all
 ##
 ## # # # # # # # # # # # # # # # # # # # # # # # # # # # # # #
 
+ifeq ($(PICFLAG),)
 LIBIBERTY=../libiberty/libiberty.a
+else
+LIBIBERTY=../libiberty/pic/libiberty.a
+endif
 
 ALLOBJ = fixincl.o fixtests.o fixfixes.o server.o procopen.o \
       fixlib.o fixopts.o
@@ -107,15 +111,15 @@ oneprocess : full-stamp
 twoprocess : test-stamp $(AF)
 
 full-stamp : $(ALLOBJ) $(LIBIBERTY)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $(FI) $(ALLOBJ) $(LIBIBERTY)
+	$(CC) $(CFLAGS) $(PICFLAG) $(LDFLAGS) $(LD_PICFLAG) -o $(FI) $(ALLOBJ) $(LIBIBERTY)
 	$(STAMP) $@
 
 test-stamp : $(TESTOBJ) $(LIBIBERTY)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $(FI) $(TESTOBJ) $(LIBIBERTY)
+	$(CC) $(CFLAGS) $(PICFLAG) $(LDFLAGS) $(LD_PICFLAG) -o $(FI) $(TESTOBJ) $(LIBIBERTY)
 	$(STAMP) $@
 
 $(AF): $(FIXOBJ) $(LIBIBERTY)
-	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(FIXOBJ) $(LIBIBERTY)
+	$(CC) $(CFLAGS) $(PICFLAG) $(LDFLAGS) $(LD_PICFLAG) -o $@ $(FIXOBJ) $(LIBIBERTY)
 
 $(ALLOBJ)   : $(HDR)
 fixincl.o   : fixincl.c  $(srcdir)/fixincl.x
diff --git a/fixincludes/configure b/fixincludes/configure
index bdcc41f6ddc..f1748ebef74 100755
--- a/fixincludes/configure
+++ b/fixincludes/configure
@@ -623,6 +623,8 @@ ac_subst_vars='LTLIBOBJS
 LIBOBJS
 get_gcc_base_ver
 MAINT
+LD_PICFLAG
+PICFLAG
 TARGET
 target_noncanonical
 WERROR
@@ -695,6 +697,7 @@ enable_option_checking
 enable_werror_always
 with_local_prefix
 enable_twoprocess
+enable_host_pie
 enable_maintainer_mode
 with_gcc_major_version_only
 '
@@ -1323,6 +1326,7 @@ Optional Features:
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-werror-always  enable -Werror despite compiler version
   --enable-twoprocess       Use a separate process to apply the fixes
+  --enable-host-pie       build host code as PIE
   --enable-maintainer-mode enable make rules and dependencies not useful
                           (and sometimes confusing) to the casual installer
 
@@ -4835,6 +4839,15 @@ $as_echo "#define SEPARATE_FIX_PROC 1" >>confdefs.h
 
 fi
 
+# Enable --enable-host-pie.
+# Check whether --enable-host-pie was given.
+if test "${enable_host_pie+set}" = set; then :
+  enableval=$enable_host_pie; PICFLAG=-fPIE; LD_PICFLAG=-pie
+fi
+
+
+
+
 case $host in
 	vax-dec-bsd* )
 
diff --git a/fixincludes/configure.ac b/fixincludes/configure.ac
index ef2227e3c93..4e78511d20f 100644
--- a/fixincludes/configure.ac
+++ b/fixincludes/configure.ac
@@ -68,6 +68,14 @@ if test $TARGET = twoprocess; then
 		  [Define if testing and fixing are done by separate process])
 fi
 
+# Enable --enable-host-pie.
+AC_ARG_ENABLE(host-pie,
+[AS_HELP_STRING([--enable-host-pie],
+       [build host code as PIE])],
+[PICFLAG=-fPIE; LD_PICFLAG=-pie], [])
+AC_SUBST(PICFLAG)
+AC_SUBST(LD_PICFLAG)
+
 case $host in
 	vax-dec-bsd* )
 		AC_DEFINE(exit, xexit, [Define to xexit if the host system does not support atexit])