CMake: Rewrite double-conversion find module

Rename FindWrapDoubleConversion.cmake into
FindWrapSystemDoubleConversion.cmake.
Merge contents of Finddouble-conversion.cmake into the one above.
This allows users to provide their own Finddouble-conversion.cmake
file (Conan can do it).
Don't mark the system package as required, because we have a bundled
one too.
Add link to upstream.
Make sure to show either Config file or library path when one is
found.

Pick-to: 6.2 6.3 6.4
Fixes: QTBUG-104541
Change-Id: I9ea2330697c6fc280328849ca11522291c4073d8
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

6 files changed, 84 insertions, 58 deletions

diff --git a/cmake/FindWrapDoubleConversion.cmake b/cmake/FindWrapDoubleConversion.cmake
deleted file mode 100644
index 1908467086..0000000000
--- a/cmake/FindWrapDoubleConversion.cmake
+++ /dev/null
@@ -1,22 +0,0 @@
-# We can't create the same interface imported target multiple times, CMake will complain if we do
-# that. This can happen if the find_package call is done in multiple different subdirectories.
-if(TARGET WrapDoubleConversion::WrapDoubleConversion)
-    set(WrapDoubleConversion_FOUND ON)
-    return()
-endif()
-
-set(WrapDoubleConversion_FOUND OFF)
-
-find_package(double-conversion QUIET)
-if (double-conversion_FOUND)
-    include(FeatureSummary)
-    set_package_properties(double-conversion PROPERTIES TYPE REQUIRED)
-    add_library(WrapDoubleConversion::WrapDoubleConversion INTERFACE IMPORTED)
-    target_link_libraries(WrapDoubleConversion::WrapDoubleConversion
-                          INTERFACE double-conversion::double-conversion)
-    set(WrapDoubleConversion_FOUND ON)
-    return()
-endif()
-
-include(FindPackageHandleStandardArgs)
-find_package_handle_standard_args(WrapDoubleConversion DEFAULT_MSG WrapDoubleConversion_FOUND)
diff --git a/cmake/FindWrapSystemDoubleConversion.cmake b/cmake/FindWrapSystemDoubleConversion.cmake
new file mode 100644
index 0000000000..164e79ed54
--- /dev/null
+++ b/cmake/FindWrapSystemDoubleConversion.cmake
@@ -0,0 +1,77 @@
+# We can't create the same interface imported target multiple times, CMake will complain if we do
+# that. This can happen if the find_package call is done in multiple different subdirectories.
+if(TARGET WrapSystemDoubleConversion::WrapSystemDoubleConversion)
+    set(WrapSystemDoubleConversion_FOUND ON)
+    return()
+endif()
+
+set(WrapSystemDoubleConversion_REQUIRED_VARS "__double_conversion_found")
+
+# Find either Config package or Find module.
+# Upstream can be built either with CMake and then provides a Config file, or with Scons in which
+# case there's no Config file.
+# A Find module might be provided by a 3rd party, for example Conan might generate a Find module.
+find_package(double-conversion ${${CMAKE_FIND_PACKAGE_NAME}_FIND_VERSION} QUIET)
+set(__double_conversion_target_name "double-conversion::double-conversion")
+if(double-conversion_FOUND AND TARGET "${__double_conversion_target_name}")
+    set(__double_conversion_found TRUE)
+    # This ensures the Config file is shown in the fphsa message.
+    if(double-conversion_CONFIG)
+        list(PREPEND WrapSystemDoubleConversion_REQUIRED_VARS
+            double-conversion_CONFIG)
+    endif()
+endif()
+
+if(NOT __double_conversion_found)
+    list(PREPEND WrapSystemDoubleConversion_REQUIRED_VARS
+        DOUBLE_CONVERSION_LIBRARY DOUBLE_CONVERSION_INCLUDE_DIR)
+
+    find_path(DOUBLE_CONVERSION_INCLUDE_DIR
+        NAMES
+            double-conversion.h
+        PATH_SUFFIXES
+            double-conversion
+    )
+    find_library(DOUBLE_CONVERSION_LIBRARY NAMES double-conversion)
+    include(SelectLibraryConfigurations)
+    select_library_configurations(DOUBLE_CONVERSION)
+    mark_as_advanced(DOUBLE_CONVERSION_INCLUDE_DIR DOUBLE_CONVERSION_LIBRARY)
+
+    if(DOUBLE_CONVERSION_LIBRARIES AND DOUBLE_CONVERSION_INCLUDE_DIRS)
+        set(__double_conversion_found TRUE)
+    endif()
+endif()
+
+include(FindPackageHandleStandardArgs)
+
+set(__double_conversion_fphsa_args "")
+if(double-conversion_VERSION)
+    set(WrapSystemDoubleConversion_VERSION "${double-conversion_VERSION}")
+    list(APPEND __double_conversion_fphsa_args VERSION_VAR WrapSystemDoubleConversion_VERSION)
+endif()
+
+find_package_handle_standard_args(WrapSystemDoubleConversion
+    REQUIRED_VARS ${WrapSystemDoubleConversion_REQUIRED_VARS}
+    ${__double_conversion_fphsa_args})
+
+if(WrapSystemDoubleConversion_FOUND)
+    add_library(WrapSystemDoubleConversion::WrapSystemDoubleConversion INTERFACE IMPORTED)
+    if(TARGET "${__double_conversion_target_name}")
+        target_link_libraries(WrapSystemDoubleConversion::WrapSystemDoubleConversion
+                              INTERFACE "${__double_conversion_target_name}")
+    else()
+        target_link_libraries(WrapSystemDoubleConversion::WrapSystemDoubleConversion
+            INTERFACE ${DOUBLE_CONVERSION_LIBRARIES})
+        target_include_directories(WrapSystemDoubleConversion::WrapSystemDoubleConversion
+            INTERFACE ${DOUBLE_CONVERSION_INCLUDE_DIRS})
+    endif()
+endif()
+unset(__double_conversion_target_name)
+unset(__double_conversion_found)
+unset(__double_conversion_fphsa_args)
+
+include(FeatureSummary)
+set_package_properties(WrapSystemDoubleConversion PROPERTIES
+  URL "https://github.com/google/double-conversion"
+  DESCRIPTION "double-conversion library")
+
diff --git a/cmake/Finddouble-conversion.cmake b/cmake/Finddouble-conversion.cmake
deleted file mode 100644
index 43d2076289..0000000000
--- a/cmake/Finddouble-conversion.cmake
+++ /dev/null
@@ -1,32 +0,0 @@
-# Fallback find module for double-conversion
-# if double-conversion is built with CMake it'll install a config module, which we prefer
-# if it's built with Scons (their default), we search ourselves
-
-find_package(double-conversion CONFIG)
-if (double-conversion_FOUND)
-    if(TARGET double-conversion::double-conversion)
-        return()
-    endif()
-endif()
-
-find_path(DOUBLE_CONVERSION_INCLUDE_DIR
-    NAMES
-        double-conversion.h
-    PATH_SUFFIXES
-        double-conversion
-)
-find_library(DOUBLE_CONVERSION_LIBRARY NAMES double-conversion)
-
-include(FindPackageHandleStandardArgs)
-FIND_PACKAGE_HANDLE_STANDARD_ARGS(
-    double-conversion DEFAULT_MSG
-    DOUBLE_CONVERSION_LIBRARY DOUBLE_CONVERSION_INCLUDE_DIR)
-
-if(double-conversion_FOUND AND NOT TARGET double-conversion::double-conversion)
-    add_library(double-conversion::double-conversion UNKNOWN IMPORTED)
-    set_target_properties(double-conversion::double-conversion PROPERTIES
-        IMPORTED_LOCATION "${DOUBLE_CONVERSION_LIBRARY}"
-        INTERFACE_INCLUDE_DIRECTORIES "${DOUBLE_CONVERSION_INCLUDE_DIR}")
-endif()
-
-mark_as_advanced(DOUBLE_CONVERSION_INCLUDE_DIR DOUBLE_CONVERSION_LIBRARY)
diff --git a/src/corelib/CMakeLists.txt b/src/corelib/CMakeLists.txt
index 5394ee642d..b0fb1f52ac 100644
--- a/src/corelib/CMakeLists.txt
+++ b/src/corelib/CMakeLists.txt
@@ -711,7 +711,7 @@ qt_internal_extend_target(Core CONDITION QT_FEATURE_backtrace
 
 qt_internal_extend_target(Core CONDITION QT_FEATURE_system_doubleconversion
     LIBRARIES
-        WrapDoubleConversion::WrapDoubleConversion
+        WrapSystemDoubleConversion::WrapSystemDoubleConversion
 )
 
 qt_internal_extend_target(Core CONDITION QT_FEATURE_doubleconversion AND NOT QT_FEATURE_system_doubleconversion
diff --git a/src/corelib/configure.cmake b/src/corelib/configure.cmake
index b29f24172a..183decb530 100644
--- a/src/corelib/configure.cmake
+++ b/src/corelib/configure.cmake
@@ -19,7 +19,9 @@ if((UNIX AND NOT QNX) OR QT_FIND_ALL_PACKAGES_ALWAYS)
     # offerings
     qt_find_package(WrapBacktrace PROVIDED_TARGETS WrapBacktrace::WrapBacktrace MODULE_NAME core QMAKE_LIB backtrace)
 endif()
-qt_find_package(WrapDoubleConversion PROVIDED_TARGETS WrapDoubleConversion::WrapDoubleConversion MODULE_NAME core QMAKE_LIB doubleconversion)
+qt_find_package(WrapSystemDoubleConversion
+                PROVIDED_TARGETS WrapSystemDoubleConversion::WrapSystemDoubleConversion
+                MODULE_NAME core QMAKE_LIB doubleconversion)
 qt_find_package(GLIB2 PROVIDED_TARGETS GLIB2::GLIB2 MODULE_NAME core QMAKE_LIB glib)
 qt_find_package(ICU COMPONENTS i18n uc data PROVIDED_TARGETS ICU::i18n ICU::uc ICU::data MODULE_NAME core QMAKE_LIB icu)
 if(QT_FEATURE_dlopen)
@@ -548,7 +550,7 @@ qt_feature("doubleconversion" PUBLIC PRIVATE
 qt_feature_definition("doubleconversion" "QT_NO_DOUBLECONVERSION" NEGATE VALUE "1")
 qt_feature("system-doubleconversion" PRIVATE
     LABEL "  Using system DoubleConversion"
-    CONDITION QT_FEATURE_doubleconversion AND WrapDoubleConversion_FOUND
+    CONDITION QT_FEATURE_doubleconversion AND WrapSystemDoubleConversion_FOUND
     ENABLE INPUT_doubleconversion STREQUAL 'system'
     DISABLE INPUT_doubleconversion STREQUAL 'qt'
 )
diff --git a/util/cmake/helper.py b/util/cmake/helper.py
index 86033a734d..f40ea4d61f 100644
--- a/util/cmake/helper.py
+++ b/util/cmake/helper.py
@@ -365,7 +365,8 @@ _library_map = [
     LibraryMapping("db2", "DB2", "DB2::DB2"),
     LibraryMapping("dbus", "WrapDBus1", "dbus-1", resultVariable="DBus1", extra=["1.2"]),
     LibraryMapping(
-        "doubleconversion", "WrapDoubleConversion", "WrapDoubleConversion::WrapDoubleConversion"
+        "doubleconversion", "WrapSystemDoubleConversion",
+        "WrapSystemDoubleConversion::WrapSystemDoubleConversion"
     ),
     LibraryMapping("dlt", "DLT", "DLT::DLT"),
     LibraryMapping("drm", "Libdrm", "Libdrm::Libdrm"),