find_package: Respect CPS default_license

Modify CPS import to set the `SPDX_LICENSE` on imported targets using
the specified `default_license`, if present (and if no per-component
`license` is specified).

Source/cmPackageInfoReader.cxx

@@ -479,6 +479,14 @@ std::unique_ptr<cmPackageInfoReader> cmPackageInfoReader::Read(
     }
   }
 
+  // Check for a default license.
+  Json::Value const& defaultLicense = reader->Data["default_license"];
+  if (!defaultLicense.isNull()) {
+    reader->DefaultLicense = defaultLicense.asString();
+  } else if (parent) {
+    reader->DefaultLicense = parent->DefaultLicense;
+  }
+
   return reader;
 }
 
@@ -582,12 +590,14 @@ void cmPackageInfoReader::SetImportProperty(cmTarget* target,
   }
 }
 
-void cmPackageInfoReader::SetMetaProperty(cmTarget* target,
-                                          cm::string_view property,
-                                          Json::Value const& value) const
+void cmPackageInfoReader::SetMetaProperty(
+  cmTarget* target, cm::string_view property, Json::Value const& value,
+  std::string const& defaultValue) const
 {
   if (!value.isNull()) {
     target->SetProperty(property.data(), value.asString());
+  } else if (!defaultValue.empty()) {
+    target->SetProperty(property.data(), defaultValue);
   }
 }
 
@@ -671,7 +681,8 @@ void cmPackageInfoReader::SetTargetProperties(
 
   // Add other information.
   if (configuration.empty()) {
-    this->SetMetaProperty(target, "SPDX_LICENSE"_s, data["license"]);
+    this->SetMetaProperty(target, "SPDX_LICENSE"_s, data["license"],
+                          this->DefaultLicense);
   }
 }
 

Source/cmPackageInfoReader.h

@@ -98,7 +98,8 @@ private:
                          cm::string_view configuration,
                          Json::Value const& value) const;
   void SetMetaProperty(cmTarget* target, cm::string_view property,
-                       Json::Value const& value) const;
+                       Json::Value const& value,
+                       std::string const& defaultValue = {}) const;
 
   std::string ResolvePath(std::string path) const;
 
@@ -108,4 +109,5 @@ private:
 
   std::map<std::string, cmTarget*> ComponentTargets;
   std::vector<std::string> DefaultConfigurations;
+  std::string DefaultLicense;
 };

Tests/RunCMake/find_package-CPS/License.cmake

@@ -0,0 +1,27 @@
+cmake_minimum_required(VERSION 4.0)
+
+include(Setup.cmake)
+
+set(CMAKE_FIND_PACKAGE_SORT_ORDER NAME)
+set(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
+
+find_package(LicenseTest REQUIRED)
+
+function(expect_license COMPONENT EXPECTED)
+  set(target LicenseTest::${COMPONENT})
+  if(TARGET ${target})
+    get_target_property(license ${target} "SPDX_LICENSE")
+    if (NOT "${license}" STREQUAL "${EXPECTED}")
+      message(SEND_ERROR
+        "Target ${target} has wrong license '${license}'"
+        " (expected '${EXPECTED}') !")
+    endif()
+  else()
+    message(SEND_ERROR "Expected target ${target} was not found !")
+  endif()
+endfunction()
+
+expect_license(SpecifiedOnTarget "Apache-2.0")
+expect_license(InheritFromRoot "BSD-3-Clause")
+expect_license(InheritFromAppendix "Apache-2.0")
+expect_license(DisableInheritance "license-NOTFOUND")

Tests/RunCMake/find_package-CPS/RunCMakeTest.cmake

@@ -18,7 +18,7 @@ run_cmake(TransitiveVersion)
 run_cmake(CustomVersion)
 
 # Metadata Tests
-run_cmake(SupplementalAttributes)
+run_cmake(License)
 
 # Version-matching failure tests
 run_cmake(MissingVersion1)

Tests/RunCMake/find_package-CPS/SupplementalAttributes.cmake

@@ -1,13 +0,0 @@
-cmake_minimum_required(VERSION 4.0)
-
-include(Setup.cmake)
-
-set(CMAKE_FIND_PACKAGE_SORT_ORDER NAME)
-set(CMAKE_FIND_PACKAGE_SORT_DIRECTION DEC)
-
-find_package(SupplementalAttributesTest REQUIRED COMPONENTS Sample)
-
-get_target_property(license SupplementalAttributesTest::Sample "SPDX_LICENSE")
-if (NOT "${license}" STREQUAL "BSD-3-Clause")
-  message(SEND_ERROR "SupplementalAttributesTest wrong license ${license} !")
-endif()

Tests/RunCMake/find_package-CPS/cps/licensetest-notinherited.cps

@@ -0,0 +1,11 @@
+{
+  "cps_version": "0.13",
+  "name": "LicenseTest",
+  "default_license": "",
+  "cps_path": "@prefix@/cps",
+  "components": {
+    "DisableInheritance": {
+      "type": "interface"
+    }
+  }
+}

Tests/RunCMake/find_package-CPS/cps/licensetest-override.cps

@@ -0,0 +1,11 @@
+{
+  "cps_version": "0.13",
+  "name": "LicenseTest",
+  "default_license": "Apache-2.0",
+  "cps_path": "@prefix@/cps",
+  "components": {
+    "InheritFromAppendix": {
+      "type": "interface"
+    }
+  }
+}

Tests/RunCMake/find_package-CPS/cps/licensetest.cps

@@ -0,0 +1,16 @@
+{
+  "cps_version": "0.13",
+  "name": "LicenseTest",
+  "version": "1.0",
+  "default_license": "BSD-3-Clause",
+  "cps_path": "@prefix@/cps",
+  "components": {
+    "SpecifiedOnTarget": {
+      "type": "interface",
+      "license": "Apache-2.0"
+    },
+    "InheritFromRoot": {
+      "type": "interface"
+    }
+  }
+}

Tests/RunCMake/find_package-CPS/cps/supplementalattributestest.cps

@@ -1,12 +0,0 @@
-{
-  "cps_version": "0.13",
-  "name": "SupplementalAttributesTest",
-  "version": "1.0",
-  "cps_path": "@prefix@/cps",
-  "components": {
-    "Sample": {
-      "type": "interface",
-      "license": "BSD-3-Clause"
-    }
-  }
-}