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, 193 insertions, 0 deletions

diff --git a/Source/cmExportBuildAndroidMKGenerator.cxx b/Source/cmExportBuildAndroidMKGenerator.cxx
new file mode 100644
index 0000000..3247cc8
--- /dev/null
+++ b/Source/cmExportBuildAndroidMKGenerator.cxx
@@ -0,0 +1,193 @@
+/*============================================================================
+  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 "cmExportBuildAndroidMKGenerator.h"
+
+#include "cmExportSet.h"
+#include "cmGeneratorTarget.h"
+#include "cmGlobalGenerator.h"
+#include "cmLocalGenerator.h"
+#include "cmMakefile.h"
+#include "cmTargetExport.h"
+
+cmExportBuildAndroidMKGenerator::cmExportBuildAndroidMKGenerator()
+{
+  this->LG = CM_NULLPTR;
+  this->ExportSet = CM_NULLPTR;
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateImportHeaderCode(
+  std::ostream& os, const std::string&)
+{
+  os << "LOCAL_PATH := $(call my-dir)\n\n";
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateImportFooterCode(std::ostream&)
+{
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateExpectedTargetsCode(
+  std::ostream&, const std::string&)
+{
+}
+
+void cmExportBuildAndroidMKGenerator::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 := ";
+  std::string path = target->GetLocalGenerator()->ConvertToOutputFormat(
+    target->GetFullPath(), cmOutputConverter::MAKERULE);
+  os << path << "\n";
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateImportPropertyCode(
+  std::ostream&, const std::string&, cmGeneratorTarget const*,
+  ImportPropertyMap const&)
+{
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateMissingTargetsCheckCode(
+  std::ostream&, const std::vector<std::string>&)
+{
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
+  const cmGeneratorTarget* target, std::ostream& os,
+  const ImportPropertyMap& properties)
+{
+  std::string config = "";
+  if (this->Configurations.size()) {
+    config = this->Configurations[0];
+  }
+  cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
+    target, os, properties, cmExportBuildAndroidMKGenerator::BUILD, config);
+}
+
+void cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
+  const cmGeneratorTarget* target, std::ostream& os,
+  const ImportPropertyMap& properties, GenerateType type,
+  std::string const& config)
+{
+  const bool newCMP0022Behavior =
+    target->GetPolicyStatusCMP0022() != cmPolicies::WARN &&
+    target->GetPolicyStatusCMP0022() != cmPolicies::OLD;
+  if (!newCMP0022Behavior) {
+    std::ostringstream w;
+    if (type == cmExportBuildAndroidMKGenerator::BUILD) {
+      w << "export(TARGETS ... ANDROID_MK) called with policy CMP0022";
+    } else {
+      w << "install( EXPORT_ANDROID_MK ...) called with policy CMP0022";
+    }
+    w << " set to OLD for target " << target->Target->GetName() << ". "
+      << "The export will only work with CMP0022 set to NEW.";
+    target->Makefile->IssueMessage(cmake::AUTHOR_WARNING, w.str());
+  }
+  if (!properties.empty()) {
+    os << "LOCAL_CPP_FEATURES := rtti exceptions\n";
+    for (ImportPropertyMap::const_iterator pi = properties.begin();
+         pi != properties.end(); ++pi) {
+      if (pi->first == "INTERFACE_COMPILE_OPTIONS") {
+        os << "LOCAL_CPP_FEATURES += ";
+        os << (pi->second) << "\n";
+      } else if (pi->first == "INTERFACE_LINK_LIBRARIES") {
+        // need to look at list in pi->second and see if static or shared
+        // FindTargetToLink
+        // target->GetLocalGenerator()->FindGeneratorTargetToUse()
+        // then add to LOCAL_CPPFLAGS
+        std::vector<std::string> libraries;
+        cmSystemTools::ExpandListArgument(pi->second, libraries);
+        std::string staticLibs;
+        std::string sharedLibs;
+        std::string ldlibs;
+        for (std::vector<std::string>::iterator i = libraries.begin();
+             i != libraries.end(); ++i) {
+          cmGeneratorTarget* gt =
+            target->GetLocalGenerator()->FindGeneratorTargetToUse(*i);
+          if (gt) {
+
+            if (gt->GetType() == cmState::SHARED_LIBRARY ||
+                gt->GetType() == cmState::MODULE_LIBRARY) {
+              sharedLibs += " " + *i;
+            } else {
+              staticLibs += " " + *i;
+            }
+          } else {
+            // evaluate any generator expressions with the current
+            // build type of the makefile
+            cmGeneratorExpression ge;
+            CM_AUTO_PTR<cmCompiledGeneratorExpression> cge = ge.Parse(*i);
+            std::string evaluated =
+              cge->Evaluate(target->GetLocalGenerator(), config);
+            bool relpath = false;
+            if (type == cmExportBuildAndroidMKGenerator::INSTALL) {
+              relpath = i->substr(0, 3) == "../";
+            }
+            // check for full path or if it already has a -l, or
+            // in the case of an install check for relative paths
+            // if it is full or a link library then use string directly
+            if (cmSystemTools::FileIsFullPath(evaluated) ||
+                evaluated.substr(0, 2) == "-l" || relpath) {
+              ldlibs += " " + evaluated;
+              // if it is not a path and does not have a -l then add -l
+            } else if (!evaluated.empty()) {
+              ldlibs += " -l" + evaluated;
+            }
+          }
+        }
+        if (!sharedLibs.empty()) {
+          os << "LOCAL_SHARED_LIBRARIES :=" << sharedLibs << "\n";
+        }
+        if (!staticLibs.empty()) {
+          os << "LOCAL_STATIC_LIBRARIES :=" << staticLibs << "\n";
+        }
+        if (!ldlibs.empty()) {
+          os << "LOCAL_EXPORT_LDLIBS :=" << ldlibs << "\n";
+        }
+      } else if (pi->first == "INTERFACE_INCLUDE_DIRECTORIES") {
+        std::string includes = pi->second;
+        std::vector<std::string> includeList;
+        cmSystemTools::ExpandListArgument(includes, includeList);
+        os << "LOCAL_EXPORT_C_INCLUDES := ";
+        std::string end;
+        for (std::vector<std::string>::iterator i = includeList.begin();
+             i != includeList.end(); ++i) {
+          os << end << *i;
+          end = "\\\n";
+        }
+        os << "\n";
+      } else {
+        os << "# " << pi->first << " " << (pi->second) << "\n";
+      }
+    }
+  }
+  switch (target->GetType()) {
+    case cmState::SHARED_LIBRARY:
+    case cmState::MODULE_LIBRARY:
+      os << "include $(PREBUILT_SHARED_LIBRARY)\n";
+      break;
+    case cmState::STATIC_LIBRARY:
+      os << "include $(PREBUILT_STATIC_LIBRARY)\n";
+      break;
+    case cmState::EXECUTABLE:
+    case cmState::UTILITY:
+    case cmState::OBJECT_LIBRARY:
+    case cmState::GLOBAL_TARGET:
+    case cmState::INTERFACE_LIBRARY:
+    case cmState::UNKNOWN_LIBRARY:
+      break;
+  }
+  os << "\n";
+}