unify windows mkspecs: update definitions

mingw-w64 toolchain:
- add missing compiler definitions, similar to
  'msvc-desktop.conf' toolchain,
- describe the reasons of missing compiler definitions, available in
  'msvc-desktop.conf' toolchain,
- add missing 'QMAKE_CXXFLAGS' and 'QMAKE_CXXFLAGS_WARN_ON' variables,
  similar to 'msvc-desktop.conf' toolchain.

ICC on Windows toolchain:
- add 'QMAKE_CFLAGS_OPTIMIZE_FULL' variable, similar to 'gcc-base.conf'
  toolchain, though left it unused for now,
- add missing flags to 'QMAKE_CFLAGS' variable, similar to
  'msvc-desktop.conf' toolchain,
- update deprecated 'Qwd' flag with 'Qdiag-disable',
- use 'QMAKE_CFLAGS_OPTIMIZE_DEBUG' variable instead of '-Od' flag,
  similar to 'gcc-base.conf' toolchain (ICC implies '-O2' optimization
  level by default, while MSVC implies '-Od'),
- add 'QMAKE_CFLAGS_UTF8_SOURCE' variable, similar to
  'msvc-version.conf' toolchain; use a workaround to initialize it,
  until '-utf-8' flag would be supported by ICC on Windows,
- update deprecated '-Qstd=c++1z' flag with '-Qstd=c++17',

MSVC toolchain:
- remove 'incremental' from MSVC 'CONFIG' variable, since it has
  relevance only for the Unix generator,
- add 'QMAKE_CFLAGS_OPTIMIZE_DEBUG' variable, used in ICC for Windows
  toolchain,
- add empty 'QMAKE_LIBS' variable, similar to 'win32-g++' toolchain,
- add 'uuid.lib' library to 'QMAKE_LIBS_GUI' variable, similar to
  'win32-g++' toolchain,
- add C++14 and C++17 language support flags, though left them disabled
  for now, similar to 'win32-icc' toolchain.

Change-Id: Ideef62d0422674184836faa655bfc5d09a5f612f
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@qt.io>

mkspecs/common/msvc-desktop.conf

@@ -15,14 +15,15 @@
 MAKEFILE_GENERATOR      = MSVC.NET
 QMAKE_PLATFORM          = win32
 QMAKE_COMPILER          = msvc
-CONFIG                 += incremental flat debug_and_release debug_and_release_target precompile_header autogen_precompile_source embed_manifest_dll embed_manifest_exe
+CONFIG                 += flat debug_and_release debug_and_release_target precompile_header autogen_precompile_source embed_manifest_dll embed_manifest_exe
 DEFINES                += UNICODE _UNICODE WIN32
 QMAKE_COMPILER_DEFINES += _WIN32
 contains(QMAKE_TARGET.arch, x86_64) {
     DEFINES += WIN64
     QMAKE_COMPILER_DEFINES += _WIN64
 }
 
+QMAKE_CFLAGS_OPTIMIZE_DEBUG = -Od
 QMAKE_CFLAGS_OPTIMIZE      = -O2
 QMAKE_CFLAGS_OPTIMIZE_SIZE = -O1
 
@@ -92,7 +93,8 @@ QMAKE_EXTENSION_SHLIB   = dll
 QMAKE_PREFIX_STATICLIB  =
 QMAKE_EXTENSION_STATICLIB = lib
 
-QMAKE_LIBS_GUI          = gdi32.lib comdlg32.lib oleaut32.lib imm32.lib winmm.lib ws2_32.lib ole32.lib user32.lib advapi32.lib
+QMAKE_LIBS              =
+QMAKE_LIBS_GUI          = gdi32.lib comdlg32.lib oleaut32.lib imm32.lib winmm.lib ws2_32.lib ole32.lib uuid.lib user32.lib advapi32.lib
 QMAKE_LIBS_NETWORK      = ws2_32.lib
 QMAKE_LIBS_OPENGL       = glu32.lib opengl32.lib gdi32.lib user32.lib
 QMAKE_LIBS_OPENGL_ES2   = gdi32.lib user32.lib

mkspecs/common/msvc-version.conf

@@ -85,6 +85,11 @@ greaterThan(QMAKE_MSC_VER, 1909) {
     # API is used in direct2d, but also in multimedia, positioning and sensors.
     # We can try again with a later version of Visual Studio.
     # QMAKE_CXXFLAGS_STRICTCXX = -permissive-
+    # MSVC partially supports the following, but '__cplusplus' definition is set
+    # as for C++98 until MSVC fully conforms with C++14, see
+    # https://developercommunity.visualstudio.com/content/problem/139261/msvc-incorrectly-defines-cplusplus.html
+    # QMAKE_CXXFLAGS_CXX14 = -std:c++14
+    # QMAKE_CXXFLAGS_CXX1Z = -std:c++latest
 }
 
 greaterThan(QMAKE_MSC_VER, 1910) {

mkspecs/win32-g++/qmake.conf

@@ -16,8 +16,11 @@ include(../common/g++-base.conf)
 MAKEFILE_GENERATOR      = MINGW
 QMAKE_PLATFORM          = win32 mingw
 CONFIG                 += debug_and_release debug_and_release_target precompile_header
-DEFINES                += UNICODE _UNICODE
-QMAKE_COMPILER_DEFINES += __GNUC__ WIN32
+DEFINES                += UNICODE _UNICODE WIN32
+QMAKE_COMPILER_DEFINES += __GNUC__ _WIN32
+# can't add 'DEFINES += WIN64' and 'QMAKE_COMPILER_DEFINES += _WIN64' defines for
+# x86_64 platform similar to 'msvc-desktop.conf' toolchain, because, unlike for MSVC,
+# 'QMAKE_TARGET.arch' is inherently unavailable.
 
 QMAKE_CC                = $${CROSS_COMPILE}gcc
 QMAKE_LEX               = flex
@@ -30,6 +33,8 @@ QMAKE_CFLAGS_WARN_ON   += -Wextra
 QMAKE_CFLAGS_SSE2      += -mstackrealign
 
 QMAKE_CXX               = $${CROSS_COMPILE}g++
+QMAKE_CXXFLAGS          = $$QMAKE_CFLAGS
+QMAKE_CXXFLAGS_WARN_ON  = $$QMAKE_CFLAGS_WARN_ON
 QMAKE_CXXFLAGS_RTTI_ON  = -frtti
 QMAKE_CXXFLAGS_RTTI_OFF = -fno-rtti
 QMAKE_CXXFLAGS_EXCEPTIONS_ON = -fexceptions -mthreads

mkspecs/win32-icc/qmake.conf

@@ -4,7 +4,7 @@
 # Written for Intel C++ Compiler on Windows / icl 16.0 or higher
 #
 
-# Use the Microsoft (R) C/C++ Optimizing Compiler configuration,
+# Use the Microsoft C/C++ Optimizing Compiler configuration,
 # since ICC on Windows pretends to be MSVC
 
 include(../common/msvc-desktop.conf)
@@ -13,11 +13,14 @@ include(../common/msvc-desktop.conf)
 
 QMAKE_COMPILER         += intel_icl
 
+QMAKE_CFLAGS_OPTIMIZE_FULL = -O3
+
 QMAKE_CC                = icl
-QMAKE_CFLAGS            = -nologo -Zm200 /Qprec /Qwd1744,1738,809,3373
-QMAKE_CFLAGS_WARN_ON    = -W3 /Qwd673
-QMAKE_CFLAGS_WARN_OFF   = -W0 /Qwd673
-QMAKE_CFLAGS_DEBUG      = -Od -Zi -MDd
+QMAKE_CFLAGS            = -nologo -Zc:wchar_t -Qprec -Zm200 -Qdiag-disable:1744,1738,809,3373
+QMAKE_CFLAGS_WARN_ON    = -W3 -Qdiag-disable:673
+QMAKE_CFLAGS_WARN_OFF   = -W0 -Qdiag-disable:673
+QMAKE_CFLAGS_DEBUG      = $$QMAKE_CFLAGS_OPTIMIZE_DEBUG -Zi -MDd
+QMAKE_CFLAGS_UTF8_SOURCE = -Qoption,cpp,--unicode_source_kind,UTF-8
 QMAKE_CFLAGS_LTCG       = -Qipo
 QMAKE_CFLAGS_DISABLE_LTCG = -Qno-ipo
 
@@ -44,7 +47,7 @@ QMAKE_CXXFLAGS_WARN_OFF = $$QMAKE_CFLAGS_WARN_OFF
 QMAKE_CXXFLAGS_CXX11    = -Qstd=c++11
 # ICC supports the following but Qt won't compile
 #QMAKE_CXXFLAGS_CXX14    = -Qstd=c++14
-#QMAKE_CXXFLAGS_CXX1Z    = -Qstd=c++1z
+#QMAKE_CXXFLAGS_CXX1Z    = -Qstd=c++17
 QMAKE_CXXFLAGS_LTCG     = $$QMAKE_CFLAGS_LTCG
 QMAKE_CXXFLAGS_DISABLE_LTCG = $$QMAKE_CFLAGS_DISABLE_LTCG