From dda6775c940129d2a38fecd6cf6273f7d97ccca0 Mon Sep 17 00:00:00 2001
From: Brad King <brad.king@kitware.com>
Date: Fri, 7 Oct 2016 14:57:26 -0400
Subject: [PATCH] Android: Record use of C++ by static libs in exported
 Android.mk files

When a `PREBUILT_STATIC_LIBRARY` uses C++ in its sources then the `.a`
file will have a link-time dependency on the C++ runtime libraries.
Android NDK r14 will add a way to give this information to the NDK build
system by adding a `LOCAL_HAS_CPP` setting to the `Android.mk` file.
Add this for exported static libraries that use C++.
---
 Source/cmExportBuildAndroidMKGenerator.cxx           | 12 ++++++++++++
 Tests/RunCMake/AndroidMK/AndroidMK.cmake             |  2 +-
 Tests/RunCMake/AndroidMK/bar.c                       |  3 +++
 Tests/RunCMake/AndroidMK/expectedBuildAndroidMK.txt  |  3 +++
 .../RunCMake/AndroidMK/expectedInstallAndroidMK.txt  |  3 +++
 5 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 Tests/RunCMake/AndroidMK/bar.c

diff --git a/Source/cmExportBuildAndroidMKGenerator.cxx b/Source/cmExportBuildAndroidMKGenerator.cxx
index bb0231152..f5e662820 100644
--- a/Source/cmExportBuildAndroidMKGenerator.cxx
+++ b/Source/cmExportBuildAndroidMKGenerator.cxx
@@ -9,6 +9,8 @@
 #include "cmMakefile.h"
 #include "cmTargetExport.h"
 
+#include <algorithm>
+
 cmExportBuildAndroidMKGenerator::cmExportBuildAndroidMKGenerator()
 {
   this->LG = CM_NULLPTR;
@@ -164,6 +166,16 @@ void cmExportBuildAndroidMKGenerator::GenerateInterfaceProperties(
       }
     }
   }
+
+  // Tell the NDK build system if prebuilt static libraries use C++.
+  if (target->GetType() == cmState::STATIC_LIBRARY) {
+    cmLinkImplementation const* li = target->GetLinkImplementation(config);
+    if (std::find(li->Languages.begin(), li->Languages.end(), "CXX") !=
+        li->Languages.end()) {
+      os << "LOCAL_HAS_CPP := true\n";
+    }
+  }
+
   switch (target->GetType()) {
     case cmState::SHARED_LIBRARY:
     case cmState::MODULE_LIBRARY:
diff --git a/Tests/RunCMake/AndroidMK/AndroidMK.cmake b/Tests/RunCMake/AndroidMK/AndroidMK.cmake
index ed21e5869..2596e8c30 100644
--- a/Tests/RunCMake/AndroidMK/AndroidMK.cmake
+++ b/Tests/RunCMake/AndroidMK/AndroidMK.cmake
@@ -2,7 +2,7 @@ project(build)
 set(CMAKE_BUILD_TYPE Debug)
 add_library(foo foo.cxx)
 add_library(car foo.cxx)
-add_library(bar  foo.cxx)
+add_library(bar bar.c)
 add_library(dog  foo.cxx)
 target_link_libraries(foo car bar dog debug -lm)
 export(TARGETS bar dog car foo  ANDROID_MK
diff --git a/Tests/RunCMake/AndroidMK/bar.c b/Tests/RunCMake/AndroidMK/bar.c
new file mode 100644
index 000000000..e1f4df614
--- /dev/null
+++ b/Tests/RunCMake/AndroidMK/bar.c
@@ -0,0 +1,3 @@
+void bar(void)
+{
+}
diff --git a/Tests/RunCMake/AndroidMK/expectedBuildAndroidMK.txt b/Tests/RunCMake/AndroidMK/expectedBuildAndroidMK.txt
index def8fcb48..bbf67a51c 100644
--- a/Tests/RunCMake/AndroidMK/expectedBuildAndroidMK.txt
+++ b/Tests/RunCMake/AndroidMK/expectedBuildAndroidMK.txt
@@ -7,11 +7,13 @@ include.*PREBUILT_STATIC_LIBRARY.*
 include.*CLEAR_VARS.*
 LOCAL_MODULE.*dog
 LOCAL_SRC_FILES.*.*dog.*
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*
 .*
 include.*CLEAR_VARS.*
 LOCAL_MODULE.*car
 LOCAL_SRC_FILES.*.*car.*
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*
 .*
 include.*CLEAR_VARS.*
@@ -20,4 +22,5 @@ LOCAL_SRC_FILES.*.*foo.*
 LOCAL_CPP_FEATURES.*rtti exceptions
 LOCAL_STATIC_LIBRARIES.*car bar dog
 LOCAL_EXPORT_LDLIBS := -lm
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*
diff --git a/Tests/RunCMake/AndroidMK/expectedInstallAndroidMK.txt b/Tests/RunCMake/AndroidMK/expectedInstallAndroidMK.txt
index 1bdb30822..3515fb9e9 100644
--- a/Tests/RunCMake/AndroidMK/expectedInstallAndroidMK.txt
+++ b/Tests/RunCMake/AndroidMK/expectedInstallAndroidMK.txt
@@ -9,11 +9,13 @@ include.*PREBUILT_STATIC_LIBRARY.*
 include.*CLEAR_VARS.
 LOCAL_MODULE.*dog
 LOCAL_SRC_FILES.*_IMPORT_PREFIX./lib.*dog.*
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*
 
 include.*CLEAR_VARS.*
 LOCAL_MODULE.*car
 LOCAL_SRC_FILES.*_IMPORT_PREFIX./lib.*car.*
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*
 
 include.*CLEAR_VARS.*
@@ -22,4 +24,5 @@ LOCAL_SRC_FILES.*_IMPORT_PREFIX\)/lib.*foo.*
 LOCAL_CPP_FEATURES.*rtti exceptions
 LOCAL_STATIC_LIBRARIES.*car bar dog
 LOCAL_EXPORT_LDLIBS := -lm
+LOCAL_HAS_CPP := true
 include.*PREBUILT_STATIC_LIBRARY.*