cmake: build with exceptions disabled by default

Only re-enable exceptions for the modules that do
CONFIG+=exceptions
in qmake

Change-Id: I9f19078adbdc1b8fa3d4102fb51a099e7e35522e
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

cmake/QtBuild.cmake

@@ -982,6 +982,21 @@ function(qt_internal_add_target_aliases target)
     endif()
 endfunction()
 
+# Sets the exceptions flags for the given target
+function(qt_internal_set_no_exceptions_flags target)
+    target_compile_definitions("${target}" PRIVATE "QT_NO_EXCEPTIONS")
+    if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
+        target_compile_options("${target}" PRIVATE "/wd4530 /wd4577")
+    elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
+        target_compile_options("${target}" PRIVATE "-fno-exceptions")
+    elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
+        target_compile_options("${target}" PRIVATE "-fno-exceptions")
+    elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
+        target_compile_options("${target}" PRIVATE "-fno-exceptions")
+    elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Intel")
+        target_compile_options("${target}" PRIVATE "-fno-exceptions")
+    endif()
+endfunction()
 
 # This is the main entry function for creating a Qt module, that typically
 # consists of a library, public header files, private header files and configurable
@@ -998,7 +1013,7 @@ function(add_qt_module target)
 
     # Process arguments:
     qt_parse_all_arguments(arg "add_qt_module"
-        "NO_MODULE_HEADERS;STATIC;DISABLE_TOOLS_EXPORT"
+        "NO_MODULE_HEADERS;STATIC;DISABLE_TOOLS_EXPORT;EXCEPTIONS"
         "CONFIG_MODULE_NAME"
         "${__default_private_args};${__default_public_args};QMAKE_MODULE_CONFIG" ${ARGN})
 
@@ -1118,6 +1133,9 @@ function(add_qt_module target)
     if(FEATURE_largefile)
         target_compile_definitions("${target}" PRIVATE "_LARGEFILE64_SOURCE;_LARGEFILE_SOURCE")
     endif()
+    if(NOT ${arg_EXCEPTIONS})
+        qt_internal_set_no_exceptions_flags("${target}")
+    endif()
 
     set(configureFile "${CMAKE_CURRENT_SOURCE_DIR}/configure.cmake")
     if(EXISTS "${configureFile}")
@@ -1355,7 +1373,7 @@ function(add_qt_plugin target)
 
     qt_internal_set_qt_known_plugins("${QT_KNOWN_PLUGINS}" "${target}")
 
-    qt_parse_all_arguments(arg "add_qt_plugin" "STATIC"
+    qt_parse_all_arguments(arg "add_qt_plugin" "STATIC;EXCEPTIONS"
         "TYPE;CLASS_NAME;OUTPUT_DIRECTORY;INSTALL_DIRECTORY;ARCHIVE_INSTALL_DIRECTORY"
         "${__default_private_args};${__default_public_args}" ${ARGN})
 
@@ -1447,6 +1465,9 @@ function(add_qt_plugin target)
     if(FEATURE_largefile)
         target_compile_definitions("${target}" PRIVATE "_LARGEFILE64_SOURCE;_LARGEFILE_SOURCE")
     endif()
+    if(NOT ${arg_EXCEPTIONS})
+        qt_internal_set_no_exceptions_flags("${target}")
+    endif()
 
 
     set(qt_libs_private "")
@@ -1512,7 +1533,7 @@ endfunction()
 # Please consider to use a more specific version target like the one created
 # by add_qt_test or add_qt_tool below.
 function(add_qt_executable name)
-    qt_parse_all_arguments(arg "add_qt_executable" "GUI;BOOTSTRAP;NO_QT;NO_INSTALL" "OUTPUT_DIRECTORY;INSTALL_DIRECTORY" "EXE_FLAGS;${__default_private_args}" ${ARGN})
+    qt_parse_all_arguments(arg "add_qt_executable" "GUI;BOOTSTRAP;NO_QT;NO_INSTALL;EXCEPTIONS" "OUTPUT_DIRECTORY;INSTALL_DIRECTORY" "EXE_FLAGS;${__default_private_args}" ${ARGN})
 
     if ("x${arg_OUTPUT_DIRECTORY}" STREQUAL "x")
         set(arg_OUTPUT_DIRECTORY "${CMAKE_BINARY_DIR}/${INSTALL_BINDIR}")
@@ -1561,6 +1582,9 @@ function(add_qt_executable name)
     if(FEATURE_largefile)
         target_compile_definitions("${name}" PRIVATE "_LARGEFILE64_SOURCE;_LARGEFILE_SOURCE")
     endif()
+    if(NOT ${arg_EXCEPTIONS})
+        qt_internal_set_no_exceptions_flags("${name}")
+    endif()
 
 
     if(WIN32)
@@ -1579,10 +1603,15 @@ endfunction()
 
 # This function creates a CMake test target with the specified name for use with CTest.
 function(add_qt_test name)
-    qt_parse_all_arguments(arg "add_qt_test" "RUN_SERIAL" "" "${__default_private_args}" ${ARGN})
+    qt_parse_all_arguments(arg "add_qt_test" "RUN_SERIAL;EXCEPTIONS" "" "${__default_private_args}" ${ARGN})
     set(path "${CMAKE_CURRENT_BINARY_DIR}")
 
+    if (${arg_EXCEPTIONS})
+        set(EXCEPTIONS_TEXT "EXCEPTIONS")
+    endif()
+
     add_qt_executable("${name}"
+        ${EXCEPTIONS_TEXT}
         NO_INSTALL
         OUTPUT_DIRECTORY "${path}"
         SOURCES "${arg_SOURCES}"

src/concurrent/CMakeLists.txt

@@ -5,6 +5,7 @@
 #####################################################################
 
 add_qt_module(Concurrent
+    EXCEPTIONS
     SOURCES
         qtconcurrent_global.h
         qtconcurrentcompilertest.h

src/corelib/CMakeLists.txt

@@ -17,6 +17,7 @@ endif()
 #####################################################################
 
 add_qt_module(Core
+    EXCEPTIONS
     QMAKE_MODULE_CONFIG moc resources
     SOURCES
         # special case: remove ../3rdparty/harfbuzz

src/testlib/CMakeLists.txt

@@ -6,6 +6,7 @@
 
 add_qt_module(Test
     CONFIG_MODULE_NAME testlib # special case
+    EXCEPTIONS
     SOURCES
         qabstracttestlogger.cpp qabstracttestlogger_p.h
         qasciikey.cpp

tests/auto/corelib/global/qglobalstatic/CMakeLists.txt

@@ -1,4 +1,5 @@
 add_qt_test(tst_qglobalstatic
+    EXCEPTIONS
     SOURCES
         tst_qglobalstatic.cpp
     DEFINES

tests/auto/testlib/selftests/exceptionthrow/CMakeLists.txt

@@ -5,6 +5,7 @@
 #####################################################################
 
 add_qt_executable(exceptionthrow
+    EXCEPTIONS
     NO_INSTALL # special case
     OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR} # special case
     GUI

tests/auto/testlib/selftests/verifyexceptionthrown/CMakeLists.txt

@@ -5,6 +5,7 @@
 #####################################################################
 
 add_qt_executable(verifyexceptionthrown
+    EXCEPTIONS
     NO_INSTALL # special case
     OUTPUT_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR} # special case
     GUI

util/cmake/pro2cmake.py

@@ -1545,6 +1545,9 @@ def write_main_part(cm_fh: typing.IO[str], name: str, typename: str,
     # Evaluate total condition of all scopes:
     recursive_evaluate_scope(scope)
 
+    if 'exceptions' in scope.get('CONFIG'):
+        extra_lines.append('EXCEPTIONS')
+
     # Get a flat list of all scopes but the main one:
     scopes = flatten_scopes(scope)
     total_scopes = len(scopes)