Revert "Remove -fPIC with more than just MSVC."

This reverts commit 222de975c487977eafce9c6706da2221b6aa2f68.

I realized how to do it with a compile test.

Change-Id: I9468c50777e387c572f60411ca39ea86ba6ce520
Reviewed-on: https://code.wireshark.org/review/11078
Reviewed-by: Guy Harris <guy@alum.mit.edu>

1 files changed, 2 insertions, 37 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2f0a61fb3d..85d77b73cf 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -872,46 +872,11 @@ if(HAVE_LIBZLIB)
 	include_directories(BEFORE ${ZLIB_INCLUDE_DIRS})
 endif()
 if (Qt5Widgets_FOUND)
-	#
 	# Qt5CoreConfigExtras.cmake in Qt 5.5.0 sets -fPIC unconditionally.
 	# https://bugreports.qt.io/browse/QTBUG-47942
-	#
-	# This *should* be done the same way we do it for autotools, by
-	# checking whether we can compile a simple file that with just
-	# "#include <QtCore>", and whatever else is necessary to let it
-	# make it through check_cxx_source_compiles(), but doing that
-	# is a bit of a pain - we'd need to somehow arrange that
-	# the right include flags get passed to a compile done by
-	# CMake rather than done in a Makefile or whatever generated
-	# *by* CMake.
-	#
-	# So, for now, based on our knowledge that the "you have to build
-	# everything with -fPIC" test only happens on systems using ELF
-	# (which rules out Windows, OS X, AIX, 32-bit HP-UX, Tru64 UNIX,
-	# and IRIX) with systems that claim to be GCC 5.0 or later, we
-	# remove -fPIC for other systems.  Checking for 32-bit HP-UX is
-	# tricky, so we don't do it, and we hope that checking for
-	# "Tru64" and "OSF1" handles that OS under all three of its
-	# names (DEC OSF/1, Digital UNIX, Tru64 UNIX).  It's also
-	# some work to check the GCC version, so we don't do it for
-	# now.
-	#
-	# Ultimately, we want *Qt* to fix the bug above.  Our goal is
-	# to suppress as many complaints that come from unnecessary
-	# use of -fPIC, whether it's compiles failing because that
-	# option is there or just Clang annoyingly whining that
-	# -fPIC is being ignored.
-	#
-	if(CMAKE_CXX_PLATFORM_ID MATCHES "Cygwin" OR
-	   CMAKE_CXX_PLATFORM_ID MATCHES "MinGW" OR
-	   CMAKE_CXX_PLATFORM_ID MATCHES "Darwin"
-	   CMAKE_CXX_PLATFORM_ID MATCHES "Windows"
-	   CMAKE_CXX_PLATFORM_ID MATCHES "AIX"
-	   CMAKE_CXX_PLATFORM_ID MATCHES "IRIX"
-	   CMAKE_CXX_PLATFORM_ID MATCHES "Tru64"
-	   CMAKE_CXX_PLATFORM_ID MATCHES "OSF1")
+	if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
 		list(REMOVE_ITEM Qt5Widgets_EXECUTABLE_COMPILE_FLAGS "-fPIC")
-	endif()
+	endif() # MSVC
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${Qt5Widgets_EXECUTABLE_COMPILE_FLAGS}")
 	set (QT_FOUND ON)
 	set (QT_LIBRARIES ${Qt5Widgets_LIBRARIES} ${Qt5PrintSupport_LIBRARIES})