Select CFLAGS_SL at configure time, not in platform-specific Makefiles.

Move the platform-dependent logic that sets CFLAGS_SL from
src/makefiles/Makefile.foo to src/template/foo, so that the value
is determined at configure time and thus is available while running
configure's tests.

On a couple of platforms this might save a few microseconds of build
time by eliminating a test that make otherwise has to do over and over.
Otherwise it's pretty much a wash for build purposes; in particular,
this makes no difference to anyone who might be overriding CFLAGS_SL
via a make option.

This patch in itself does nothing with the value and thus should not
change any behavior, though you'll probably have to re-run configure
to get a correctly updated Makefile.global.  We'll use the new
configure variable in a follow-on patch.

Per gripe from Kyotaro Horiguchi.  Back-patch to all supported branches,
because the follow-on patch is a portability bug fix.

Discussion: https://postgr.es/m/20191010.144533.263180400.horikyota.ntt@gmail.com

10 files changed, 43 insertions, 0 deletions

diff --git a/src/template/aix b/src/template/aix
index 999cd35945..cec240d27b 100644
--- a/src/template/aix
+++ b/src/template/aix
@@ -1,3 +1,5 @@
+# src/template/aix
+
 # Set default options if using xlc.  This formerly included -qsrcmsg, but that
 # option elicits internal compiler errors from xlc v16.1.0.  Note: configure
 # will add -qnoansialias if the compiler accepts it, even if user specifies a
@@ -17,6 +19,9 @@ if test "$GCC" != yes ; then
   FORCE_DISABLE_RESTRICT=yes
 fi
 
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL=""
+
 # Native memset() is faster, tested on:
 # 	AIX 5.1 and 5.2, XLC 6.0 (IBM's cc)
 # 	AIX 5.3 ML3, gcc 4.0.1
diff --git a/src/template/cygwin b/src/template/cygwin
index b6ea0ded52..79a108145f 100644
--- a/src/template/cygwin
+++ b/src/template/cygwin
@@ -2,6 +2,9 @@
 
 SRCH_LIB="/usr/local/lib"
 
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL=""
+
 # --allow-multiple-definition is required to link pg_dump because it finds
 # pg_toupper() etc. in both libpq and pgport
 # we'd prefer to use --disable-auto-import to match MSVC linking behavior,
diff --git a/src/template/darwin b/src/template/darwin
index c05adca0bf..f4d4e9d7cf 100644
--- a/src/template/darwin
+++ b/src/template/darwin
@@ -16,6 +16,9 @@ if test x"$PG_SYSROOT" != x"" ; then
   fi
 fi
 
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL=""
+
 # Select appropriate semaphore support.  Darwin 6.0 (macOS 10.2) and up
 # support System V semaphores; before that we have to use named POSIX
 # semaphores, which are less good for our purposes because they eat a
diff --git a/src/template/freebsd b/src/template/freebsd
index a82d5a494c..41fa4a1aba 100644
--- a/src/template/freebsd
+++ b/src/template/freebsd
@@ -4,3 +4,6 @@
 if test x"$PREFERRED_SEMAPHORES" = x"" ; then
   PREFERRED_SEMAPHORES=UNNAMED_POSIX
 fi
+
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL="-fPIC -DPIC"
diff --git a/src/template/hpux b/src/template/hpux
index 79d3475664..50fff80c53 100644
--- a/src/template/hpux
+++ b/src/template/hpux
@@ -8,6 +8,13 @@ if test "$GCC" != yes ; then
   CFLAGS="+O2"
 fi
 
+# Extra CFLAGS for code that will go into a shared library
+if test "$GCC" = yes ; then
+  CFLAGS_SL="-fPIC"
+else
+  CFLAGS_SL="+Z"
+fi
+
 # Pick right test-and-set (TAS) code.  We need out-of-line assembler
 # when not using gcc.
 case $host in
diff --git a/src/template/linux b/src/template/linux
index e39290845a..ec3302c4a2 100644
--- a/src/template/linux
+++ b/src/template/linux
@@ -9,6 +9,9 @@ fi
 # This is also required for ppoll(2), and perhaps other things
 CPPFLAGS="$CPPFLAGS -D_GNU_SOURCE"
 
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL="-fPIC"
+
 # If --enable-profiling is specified, we need -DLINUX_PROFILE
 PLATFORM_PROFILE_FLAGS="-DLINUX_PROFILE"
 
diff --git a/src/template/netbsd b/src/template/netbsd
index 198697723d..d97f995c74 100644
--- a/src/template/netbsd
+++ b/src/template/netbsd
@@ -1,2 +1,5 @@
 # src/template/netbsd
 # tools/thread/thread_test must be run
+
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL="-fPIC -DPIC"
diff --git a/src/template/openbsd b/src/template/openbsd
index e69de29bb2..365268c489 100644
--- a/src/template/openbsd
+++ b/src/template/openbsd
@@ -0,0 +1,4 @@
+# src/template/openbsd
+
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL="-fPIC -DPIC"
diff --git a/src/template/solaris b/src/template/solaris
index e07b9a0a8d..f88b1cdad3 100644
--- a/src/template/solaris
+++ b/src/template/solaris
@@ -1,3 +1,12 @@
+# src/template/solaris
+
+# Extra CFLAGS for code that will go into a shared library
+if test "$GCC" = yes ; then
+  CFLAGS_SL="-fPIC"
+else
+  CFLAGS_SL="-KPIC"
+fi
+
 if test "$SUN_STUDIO_CC" = yes ; then
   CC="$CC -Xa"			# relaxed ISO C mode
   CFLAGS="-v"			# -v is like gcc -Wall
diff --git a/src/template/win32 b/src/template/win32
index 7da9719acb..1380d16548 100644
--- a/src/template/win32
+++ b/src/template/win32
@@ -1,5 +1,8 @@
 # src/template/win32
 
+# Extra CFLAGS for code that will go into a shared library
+CFLAGS_SL=""
+
 # --allow-multiple-definition is required to link pg_dump because it finds
 # pg_toupper() etc. in both libpq and pgport
 # --disable-auto-import is to ensure we get MSVC-like linking behavior