NDK APP_CFLAGS can't handle <> characters? - android-ndk

I am including a procedurally generated file into code used by several libraries, using something like
#include MY_CONFIG_FILE_H
Then I am attempting to set this value in my Application.mk using the following directive
APP_CFLAGS += -DMY_CONFIG_FILE_H=<Config/MyFile.h>
however, this results in ndk-build not finding the path. It fails right away on the first file it tries to compile
"Compile++ thumb : MyLibraryName <= MyFirstFile.cpp
The system cannot find the path specified.
make: *** [obj/local/armeabi-v7a/objs/MyLibraryName/MyFirstFile.o] Error 1
Indeed, the file is not there, but it did manage to create the file path. There must be some strange/inconsistent string manipulation going on.
Any ideas? Work arounds? Is this a known issue in ndk-build.cmd? For the record I'm on Windows x64 and NDK R9.
Also notice that if I only include > and no <, I get a different error
The filename, directory name, or volume label syntax is incorrect.

Changing the line to
APP_CFLAGS += -DMY_CONFIG_FILE_H="<Config/MyFile.h>"
worked. Hope this helps anyone else!

Related

how to print the value inside a variable in cmakelist.txt

I'm using CMake for my recent project and I want to confirm that the right path is set
set(_protobuf_include_path -I . -I ${_gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR})
I used message to check the value of _gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR but not printing anything in terminal
message( STATUS ${_gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR} ) # no output for this
My intention is to build Grpc1.14.1, bit it is having dependency with protobuf, so I downloaded protobuf 3.6.01 and both grpc and protobuf kept under same directory (home/user/src).
While building I got this error
google/protobuf/stubs/common.h: No such file or directory
#include <google/protobuf/stubs/common.h>
So I opened protobuff.cmake in directory gRPC/cmake and changed the protobuf root path
if(NOT PROTOBUF_ROOT_DIR)
#set(PROTOBUF_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/protobuf)
set(PROTOBUF_ROOT_DIR ../../ThirdParty/protobuf)
[...]
After doing this, I'm still getting the same issue.
First, something a bit irrelevant to the question, but related to modern CMake techniques and usage.
In order to set the include path, it is preferred to use the target_include_directories command, e.g.
target_include_directories(mytarget
PUBLIC ${CMAKE_CURRENT_SOURCE_DIR}
PUBLIC ${_gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR}
)
Now, for the actual question, it would help if you could show the actual setting of ${_gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR}, (is it through the command line via `-D) options?)but you could print it like this:
message(STATUS "include dir: ${_gRPC_PROTOBUF_WELLKNOWN_INCLUDE_DIR}")
I'm suspecting spurious whitespace or something along those lines in the actual variable contents.

NDK - Android Java with native (JNI) C++ code build issue

I am using a mix of Java and native JNI C++ code for an android project, using NDK r8b, in Eclipse in OSX. I want to be able to use the regular C++ classes (map, string) in std namespace.
In the Android.mk file the following were added:
APP_STL := stlport_shared
Here I also tried static library. Refer to http://docs.huihoo.com/android/ndk/r5/CPLUSPLUS-SUPPORT.html
STLPORT_FORCE_REBUILD := true
Also tried removing the forced build.
In the C/C++ path and variables:
${NDKROOT}/sources/cxx-stl/stlport/stlport
"map" and "string" headers were included in the .cpp file. I am able to use std::string and std::map. The assistant picks up on them. When searching for the definition (F3 in eclipse) the header file is shown, i.e. resolved. Also, the outline shows the "string" and "map" header files and when double clicking them it also brings the headers to the forefront.
However, the build doesn't pick them up. I get the following:
> ndk-build
> Gdbserver : [arm-linux-androideabi-4.6] libs/armeabi/gdbserver
> Gdbsetup : libs/armeabi/gdb.setup
> Gdbserver : [arm-linux-androideabi-4.6] libs/armeabi-v7a/gdbserver
> Gdbsetup : libs/armeabi-v7a/gdb.setup
> Compile++ arm : ImageTargets <= ImageTargets.cpp
> xxx/Project/Code/MyImageTarget/jni/ImageTargets.cpp:20:18: fatal error: string: No such file > or directory
> compilation terminated.
> make: *** [xxx/Project/Code/MyImageTarget/obj/local/armeabi/objs-> debug/ImageTargets/ImageTargets.o] Error 1
Has anyone any idea what else is there to try.
Use V=1 parameter on ndk-build command line. This will echo all executed commands, including compilation and link, with all their parameters that NDK build assigns.
In your case, the answer can be found without detailed build log:
In the Android.mk file the following were added:
APP_STL := stlport_shared
This is your mistake. The document you cited explains that this setting should go into Application.mk. This file is usually considered optional. Yes it is. Instead of creating this file, you can specify APP_STL on the command line:
ndk-build V=1 APP_STL=stlport_static
I don't know why and how Eclipse resolves #include <string> or map.

CMake finds the correct library, but VC++ attempts to link with something else

I have a CMake module to locate FreeGLUT:
FIND_PATH(FREEGLUT_INCLUDE_DIR NAMES GL/freeglut.h)
FIND_LIBRARY(FREEGLUT_LIBRARY NAMES freeglut freeglut_static)
SET(FREEGLUT_LIBRARIES ${FREEGLUT_LIBRARY})
SET(FREEGLUT_INCLUDE_DIRS ${FREEGLUT_INCLUDE_DIR})
INCLUDE(FindPackageHandleStandardArgs)
FIND_PACKAGE_HANDLE_STANDARD_ARGS(FreeGLUT DEFAULT_MSG FREEGLUT_LIBRARY FREEGLUT_INCLUDE_DIR)
MARK_AS_ADVANCED(FREEGLUT_INCLUDE_DIR FREEGLUT_LIBRARY)
It works fine and locates freeglut_static.lib when I generate NMake Makefiles on Windows. I'm attempting to statically link FreeGLUT into my DLL:
FIND_PACKAGE(FreeGLUT REQUIRED)
ADD_LIBRARY(vti SHARED ${VTI_SOURCES})
ADD_DEFINITIONS("-DBUILD_VTI=1 -DFREEGLUT_STATIC=1")
INCLUDE_DIRECTORIES(${CMAKE_SOURCE_DIR}/include ${FREEGLUT_INCLUDE_DIRS})
TARGET_LINK_LIBRARIES(vti ${FREEGLUT_LIBRARIES})
My source code builds correctly, but when it gets to the linking stage, VC++ fails with:
LINK : fatal error LNK1104: cannot open file 'freeglut.lib'
Which is strange since freeglut.lib isn't mentioned anywhere that I can see in the generated NMake makefiles. It should be trying to link with freeglut_static.lib, which CMake locates and sets in FREEGLUT_LIBRARIES.
What might be causing this?
This is caused with pragma directives in FreeGLUT code (see freeglut_std.h). Using FREEGLUT_STATIC should really fix that for you, but I think you should pass it to CMake without quotes: ADD_DEFINITIONS(-DBUILD_VTI -DFREEGLUT_STATIC)

Reusing custom makefile for static library with cmake

I guess this would be a generic question on including libraries with existing makefiles within cmake; but here's my context -
I'm trying to include scintilla in another CMake project, and I have the following problem:
On Linux, scintilla has a makefile in (say) the ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk directory; if you run make in that directory (as usual), you get a ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/bin/scintilla.a file - which (I guess) is the static library.
Now, if I'd try to use cmake's ADD_LIBRARY, I'd have to manually specify the sources of scintilla within cmake - and I'd rather not mess with that, given I already have a makefile. So, I'd rather call the usual scintilla make - and then instruct CMAKE to somehow refer to the resulting scintilla.a. (I guess that this then would not ensure cross-platform compatibility - but note that currently cross-platform is not an issue for me; I'd just like to build scintilla as part of this project that already uses cmake, only within Linux)
So, I've tried a bit with this:
ADD_CUSTOM_COMMAND(
OUTPUT scintilla.a
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target" )
... but then, add_custom_command adds a "target with no output"; so I'm trying several approach to build upon that, all of which fail (errors given as comment):
ADD_CUSTOM_TARGET(scintilla STATIC DEPENDS scintilla.a) # Target "scintilla" of type UTILITY may not be linked into another target.
ADD_LIBRARY(scintilla STATIC DEPENDS scintilla.a) # Cannot find source file "DEPENDS".
ADD_LIBRARY(scintilla STATIC) # You have called ADD_LIBRARY for library scintilla without any source files.
ADD_DEPENDENCIES(scintilla scintilla.a)
I'm obviously quote a noob with cmake - so, is it possible at all to have cmake run a pre-existing makefile, and "capture" its output library file, such that other components of the cmake project can link against it?
Many thanks for any answers,
Cheers!
EDIT: possible duplicate: CMake: how do i depend on output from a custom target? - Stack Overflow - however, here the breakage seems to be due to the need to specifically have a library that the rest of the cmake project would recognize...
Another related: cmake - adding a custom command with the file name as a target - Stack Overflow; however, it specifically builds an executable from source files (which I wanted to avoid)..
You could also use imported targets and a custom target like this:
# set the output destination
set(SCINTILLA_LIBRARY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk/scintilla.a)
# create a custom target called build_scintilla that is part of ALL
# and will run each time you type make
add_custom_target(build_scintilla ALL
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target")
# now create an imported static target
add_library(scintilla STATIC IMPORTED)
# Import target "scintilla" for configuration ""
set_property(TARGET scintilla APPEND PROPERTY IMPORTED_CONFIGURATIONS NOCONFIG)
set_target_properties(scintilla PROPERTIES
IMPORTED_LOCATION_NOCONFIG "${SCINTILLA_LIBRARY}")
# now you can use scintilla as if it were a regular cmake built target in your project
add_dependencies(scintilla build_scintilla)
add_executable(foo foo.c)
target_link_libraries(foo scintilla)
# note, this will only work on linux/unix platforms, also it does building
# in the source tree which is also sort of bad style and keeps out of source
# builds from working.
OK, I think I have it somewhat; basically, in the CMakeLists.txt that build scintilla, I used this only:
ADD_CUSTOM_TARGET(
scintilla.a ALL
COMMAND ${CMAKE_MAKE_PROGRAM}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/scintilla/gtk
COMMENT "Original scintilla makefile target" )
... and then, the slightly more complicated part, was to find the correct cmake file elsewhere in the project, where the ${PROJECT_NAME} was defined - so as to add a dependency:
ADD_DEPENDENCIES(${PROJECT_NAME} scintilla.a)
... and finally, the library needs to be linked.
Note that in the commands heretofore, the scintilla.a is merely a name/label/identifier/string (so it could be anything else, like scintilla--a or something); but for linking - the full path to the actual `scintilla.a file is needed (which in this project ends up in a variable ${SCINTILLA_LIBRARY}). In this project, the linking basically occurs through a form of a
list(APPEND PROJ_LIBRARIES ${SCINTILLA_LIBRARY} )
... and I don't really know how cmake handles the actual linking afterwards (but it seems to work)
For consistency, I tried to use ${SCINTILLA_LIBRARY} instead of scintilla.a as identifier in the ADD_CUSTOM_TARGET, but got error: "Target names may not contain a slash. Use ADD_CUSTOM_COMMAND to generate files". So probably this could be solved smarter/more correct with ADD_CUSTOM_COMMAND - however, I read that it "defines a new command that can be executed during the build process. The outputs named should be listed as source files in the target for which they are to be generated."... And by now I'm totally confused so as to what is a file, what is a label, and what is a target - so I think I'll leave at this (and not fix it if it ain't broken :) )
Well, it'd still be nice to know a more correct way to do this eventually,
Cheers!

Installing and Linking PhysX Libraries in Debian Linux

I am trying to get PhysX working using Ubuntu.
First, I downloaded the SDK here:
http://developer.download.nvidia.com/PhysX/2.8.1/PhysX_2.8.1_SDK_CoreLinux_deb.tar.gz
Next, I extracted the files and installed each package with:
dpkg -i filename.deb
This gives me the following files located in /usr/lib/PhysX/v2.8.1:
libNxCharacter.so
libNxCooking.so
libPhysXCore.so
libNxCharacter.so.1
libNxCooking.so.1
libPhysXCore.so.1
Next, I created symbolic links to /usr/lib:
sudo ln -s /usr/lib/PhysX/v2.8.1/libNxCharacter.so.1 /usr/lib/libNxCharacter.so.1
sudo ln -s /usr/lib/PhysX/v2.8.1/libNxCooking.so.1 /usr/lib/libNxCooking.so.1
sudo ln -s /usr/lib/PhysX/v2.8.1/libPhysXCore.so.1 /usr/lib/libPhysXCore.so.1
Now, using Eclipse, I have specified the following libraries (-l):
libNxCharacter.so.1
libNxCooking.so.1
libPhysXCore.so.1
And the following search paths just in case (-L):
/usr/lib/PhysX/v2.8.1
/usr/lib
Also, as Gerald Kaszuba suggested, I added the following include paths (-I):
/usr/lib/PhysX/v2.8.1
/usr/lib
Then, I attempted to compile the following code:
#include "NxPhysics.h"
NxPhysicsSDK* gPhysicsSDK = NULL;
NxScene* gScene = NULL;
NxVec3 gDefaultGravity(0,-9.8,0);
void InitNx()
{
gPhysicsSDK = NxCreatePhysicsSDK(NX_PHYSICS_SDK_VERSION);
if (!gPhysicsSDK)
{
std::cout<<"Error"<<std::endl;
return;
}
NxSceneDesc sceneDesc;
sceneDesc.gravity = gDefaultGravity;
gScene = gPhysicsSDK->createScene(sceneDesc);
}
int main(int arc, char** argv)
{
InitNx();
return 0;
}
The first error I get is:
NxPhysics.h: No such file or directory
Which tells me that the project is obviously not linking properly. Can anyone tell me what I have done wrong, or what else I need to do to get my project to compile? I am using the GCC C++ Compiler. Thanks in advance!
It looks like you're confusing header files with library files. NxPhysics.h is a source code header file. Header files are needed when compiling source code (not when linking). It's probably located in a place like /usr/include or /usr/include/PhysX/v2.8.1, or similar. Find the real location of this file and make sure you use the -I option to tell the compiler where it is, as Gerald Kaszuba suggests.
The libraries are needed when linking the compiled object files (and not when compiling). You'll need to deal with this later with the -L and -l options.
Note: depending on how you invoke gcc, you can have it do compiling and then linking with a single invocation, but behind the scenes it still does a compile step then a link step.
EDIT: Extra explanation added...
When building a binary using a C/C++ compiler, the compiler reads the source code (.c or .cpp files). While reading it, there are frequently #include statements that are used to read .h files. The #include statements give the names of files that must be loaded. Those exact files must exist in the include path. In your case, a file with the exact name "NxPhysics.h" must be found somewhere in the include path. Typically, /usr/include is in the path by default, and so is the current directory. If the headers are somewhere else such as a subdirectory of /usr/include, then you always need to explicitly tell the compiler where to look using the -I command-line switches (or sometimes with environment variables or other system configuration methods).
A .h header file typically includes data structure declarations, inline function definitions, function and class declarations, and #define macros. When the compilation is done, a .o object file is created. The compiler does not know about .so or .a libraries and cannot use them in any way, other than to embed a little bit of helper information for the linker. Note that the compiler also embeds some "header" information in the object files. I put "header" in quotes because the information only roughly corresponds to what may or may not be found in the .h files. It includes a binary representation of all exported declarations. No macros are found there. I believe that inline functions are omitted as well (though I could be wrong there).
Once all of the .o files exist, it is time for another program to take over: the linker. The linker knows nothing of source code files or .h header files. It only cares about binary libraries and object files. You give it a collection of libraries and object files. In their "headers" they list what things (data types, functions, etc.) they define and what things they need someone else to define. The linker then matches up requests for definitions from one module with actual definitions for other modules. It checks to make sure there aren't multiple conflicting definitions, and if building an executable, it makes sure that all requests for definitions are fulfilled.
There are some notable caveats to the above description. First, it is possible to call gcc once and get it to do both compiling and linking, e.g.
gcc hello.c -o hello
will first compile hello.c to memory or to a temporary file, then it will link against the standard libraries and write out the hello executable. Even though it's only one call to gcc, both steps are still being performed sequentially, as a convenience to you. I'll skip describing some of the details of dynamic libraries for now.
If you're a Java programmer, then some of the above might be a little confusing. I believe that .net works like Java, so the following discussion should apply to C# and the other .net languages. Java is syntactically a much simpler language than C and C++. It lacks macros and it lacks true templates (generics are a very weak form of templates). Because of this, Java skips the need for separate declaration (.h) and definition (.c) files. It is also able to embed all the relevant information in the object file (.class for Java). This makes it so that both the compiler and the linker can use the .class files directly.
The problem was indeed with my include paths. Here is the relevant command:
g++ -I/usr/include/PhysX/v2.8.1/SDKs/PhysXLoader/include -I/usr/include -I/usr/include/PhysX/v2.8.1/LowLevel/API/include -I/usr/include/PhysX/v2.8.1/LowLevel/hlcommon/include -I/usr/include/PhysX/v2.8.1/SDKs/Foundation/include -I/usr/include/PhysX/v2.8.1/SDKs/Cooking/include -I/usr/include/PhysX/v2.8.1/SDKs/NxCharacter/include -I/usr/include/PhysX/v2.8.1/SDKs/Physics/include -O0 -g3 -DNX_DISABLE_FLUIDS -DLINUX -Wall -c -fmessage-length=0 -MMD -MP -MF"main.d" -MT"main.d" -o"main.o" "../main.cpp"
Also, for the linker, only "PhysXLoader" was needed (same as Windows). Thus, I have:
g++ -o"PhysXSetupTest" ./main.o -lglut -lPhysXLoader
While installing I got the following error
*
dpkg: dependency problems prevent configuration of libphysx-dev-2.8.1:
libphysx-dev-2.8.1 depends on libphysx-2.8.1 (= 2.8.1-4); however:
Package libphysx-2.8.1 is not configured yet.
dpkg: error processing libphysx-dev-2.8.1 (--install):
dependency problems - leaving unconfigured
Errors were encountered while processing:
*
So I reinstalled *libphysx-2.8.1_4_i386.deb*
sudo dpkg -i libphysx-2.8.1_4_i386.deb

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