Add support for creating prebuilt Android.mk files

Add options to the `install()` and `export()` commands to export the
targets we build into Android.mk files that reference them as prebuilt
libraries with associated usage requirements (compile definitions,
include directories, link libraries).  This will allow CMake-built
projects to be imported into projects using the Android NDK build
system.

Closes: #15562

1 files changed, 146 insertions, 0 deletions

diff --git a/Source/cmExportInstallAndroidMKGenerator.cxx b/Source/cmExportInstallAndroidMKGenerator.cxx
new file mode 100644
index 0000000..8f815b7
--- /dev/null
+++ b/Source/cmExportInstallAndroidMKGenerator.cxx
@@ -0,0 +1,146 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+#include "cmExportInstallAndroidMKGenerator.h"
+
+#include "cmAlgorithms.h"
+#include "cmExportBuildAndroidMKGenerator.h"
+#include "cmExportSet.h"
+#include "cmExportSetMap.h"
+#include "cmGeneratedFileStream.h"
+#include "cmGeneratorTarget.h"
+#include "cmGlobalGenerator.h"
+#include "cmInstallExportGenerator.h"
+#include "cmInstallTargetGenerator.h"
+#include "cmLocalGenerator.h"
+#include "cmTargetExport.h"
+
+cmExportInstallAndroidMKGenerator::cmExportInstallAndroidMKGenerator(
+  cmInstallExportGenerator* iegen)
+  : cmExportInstallFileGenerator(iegen)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportHeaderCode(
+  std::ostream& os, const std::string&)
+{
+  std::string installDir = this->IEGen->GetDestination();
+  os << "LOCAL_PATH := $(call my-dir)\n";
+  size_t numDotDot = cmSystemTools::CountChar(installDir.c_str(), '/');
+  numDotDot += (installDir.size() > 0) ? 1 : 0;
+  std::string path;
+  for (size_t n = 0; n < numDotDot; n++) {
+    path += "/..";
+  }
+  os << "_IMPORT_PREFIX := "
+     << "$(LOCAL_PATH)" << path << "\n\n";
+  for (std::vector<cmTargetExport*>::const_iterator tei =
+         this->IEGen->GetExportSet()->GetTargetExports()->begin();
+       tei != this->IEGen->GetExportSet()->GetTargetExports()->end(); ++tei) {
+    // Collect import properties for this target.
+    cmTargetExport const* te = *tei;
+    if (te->Target->GetType() == cmState::INTERFACE_LIBRARY) {
+      continue;
+    }
+    std::string dest;
+    if (te->LibraryGenerator) {
+      dest = te->LibraryGenerator->GetDestination("");
+    }
+    if (te->ArchiveGenerator) {
+      dest = te->ArchiveGenerator->GetDestination("");
+    }
+    te->Target->Target->SetProperty("__dest", dest.c_str());
+  }
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportFooterCode(std::ostream&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportTargetCode(
+  std::ostream& os, const cmGeneratorTarget* target)
+{
+  std::string targetName = this->Namespace;
+  targetName += target->GetExportName();
+  os << "include $(CLEAR_VARS)\n";
+  os << "LOCAL_MODULE := ";
+  os << targetName << "\n";
+  os << "LOCAL_SRC_FILES := $(_IMPORT_PREFIX)/";
+  os << target->Target->GetProperty("__dest") << "/";
+  std::string config = "";
+  if (this->Configurations.size()) {
+    config = this->Configurations[0];
+  }
+  os << target->GetFullName(config) << "\n";
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateExpectedTargetsCode(
+  std::ostream&, const std::string&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportPropertyCode(
+  std::ostream&, const std::string&, cmGeneratorTarget const*,
+  ImportPropertyMap const&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateMissingTargetsCheckCode(
+  std::ostream&, const std::vector<std::string>&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateInterfaceProperties(
+  cmGeneratorTarget const* target, std::ostream& os,
+  const ImportPropertyMap& properties)
+{
+  std::string config = "";
+  if (this->Configurations.size()) {
+    config = this->Configurations[0];
+  }
+  cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
+    target, os, properties, cmExportBuildAndroidMKGenerator::INSTALL, config);
+}
+
+void cmExportInstallAndroidMKGenerator::LoadConfigFiles(std::ostream&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportPrefix(std::ostream&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateRequiredCMakeVersion(
+  std::ostream&, const char*)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::CleanupTemporaryVariables(
+  std::ostream&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportedFileCheckLoop(
+  std::ostream&)
+{
+}
+
+void cmExportInstallAndroidMKGenerator::GenerateImportedFileChecksCode(
+  std::ostream&, cmGeneratorTarget*, ImportPropertyMap const&,
+  const std::set<std::string>&)
+{
+}
+
+bool cmExportInstallAndroidMKGenerator::GenerateImportFileConfig(
+  const std::string&, std::vector<std::string>&)
+{
+  return true;
+}