I'm building libcurl to use with a project i'm working on, and after reading a little on how to build it properly i've found 2 ways to do it.
Method 1:
(edited Makefile in root directory to change "VC=vc6" to "VC=vc10")
C:\dev\curl-7.25.0>set ZLIB_PATH=C:\dev\zlib-1.2.6
C:\dev\curl-7.25.0>nmake vc-zlib
Method 2:
(Put necessary files for zlib in ../deps & edit Makefile to make USE_IDN=no actually work)
C:\dev\curl-7.25.0\winbuild>nmake /f Makefile.vc mode=static VC=10 WITH_ZLIB=sta
tic DEBUG=no USE_IDN=no WITH_DEVEL=../deps
Both work with no errors.
The scary part is, the outputted libcurl.lib files are different sizes.
So is there any libcurl gurus out there that can tell me the difference between these 2 build methods, and which is recommended to be used?
So what I've figured out so far is method 1 requires you to link your application with Ws2_32.lib and Wldap32.lib, where method 2 doesn't (probably the reason for the additional size).
Also method 1 has a slightly smaller output executable.
I'm really curious if there are any other differences though.
Related
I'm a long time VB programmer, and pretty good with c#, but I'm dumb as a brick when it comes to c++. But nonetheless, I need to build the source code for GraphicsMagick.NET, specifically for .net 2.0 if I can, to try to see if I can convert it to a fully managed dll, so that I can import it into Unity3D (who cares why I need to build it?).
Anyway, without posting the entire project here, I realize it might be hard for anyone here to know exactly what is causing my error. But perhaps someone can give an educated guess? Edit: you can download a zip of the full source from https://graphicsmagick.codeplex.com/SourceControl/latest if you want to see all the code I'm working with that is giving me this error.
This project, I assume, is supposed to compile without errors right out of the box. But it doesn't. It has this line of code in the include.h file:
# if defined(HasBZLIB)
# pragma comment(lib, "CORE_RL_bzlib_.lib")
# endif
and as a result of this evil line, I'm getting this evil error:
LNK1104 cannot open file 'CORE_RL_coders_.lib'
GraphicsMagick.NET.net20
C:\Users\A\Downloads\graphicsmagick-d\GraphicsMagick.NET.net20\LINK 1
Being the good VB programmer, I searched my project folder extensively, and that _.lib file doesn't exist. But in the process of searching online, I learned that c++ sometimes generates .lib files when you build a project. So perhaps this file was supposed to be built first, before it was linked, but for whatever reason it didn't get built first? You can see how clueless I am with c++.
Of course I commented out the line. But then it simply generates an error on the next line, which is another .lib file missing. I assume it will generate an error on every _.lib file in the entire include.h file, and there are a fair number of them.
Why is this project, which is supposed to build, missing so many .lib files? Can anyone give an educated guess why? am I probably missing some dependency that the author of this project forgot to mention in the installation instructions? Or would it be more likely that these .lib files are supposed to be created by me somehow, and I'm just not building it right?
In the downloaded release under GraphicsMagick there are two script files called CopyLibsFromDropbox.cmd and CopyLibsToDropbox.cmd, the first of which contains
echo You can download the library files here: https://www.dropbox.com/sh/a8krszzmo76fqkt/AAAc9Jho29Jk3iLrKhsBmw-Ma?dl=0
goto done
In that dropbox, you will find all the lib files you need. Download the whole thing as a .zip and extract the thing inside the the \GraphicsMagick directory. Should look like that now:
Once the libs are inside that folder you can actually compile the code. The scripts are for copying them from your local dropbox directory to this directory, if you choose to "save this inside my dropbox" at the dropbox download page above. In the end, you should see something like
3> GraphicsMagick.NET.Web -> C:\Users\Maxi\Downloads\graphicsmagick-d1b5b1b28f26cdedf3ceeb555b94a87609286740\GraphicsMagick.NET.Web\bin\ReleaseQ16\x86\GraphicsMagick.NET.Web-x86.dll
3> Codeanalysis is beeing executed...
3> Codeanalysis finished -- 0 Errors, 0 Warning(s)
========== Build: 2 successfull, 0 failed, 0 recent, 1 skipped ==========
(who cares why I need to build it?)
I do. You can already include managed dlls to Unity, and GraphicsMagick.NET already gives you a .NET dll which you should be able to use within Unity, or did you have any particular problems with that? Need some image processing functionality from that library?
I would like to visualize the code flow for a C++ project that I need to modify. The code compiles and runs fine.
Background:
Actually I am modifying an MRI sequence code. The framework is being called idea (SIEMENS). It somehow combines visual studio 2008 and cygwin to call customized command line inputs. Even the strucutre of makefile is different from usual makefile that I usually use for C++ project. (Disclaimer: I do not understand much about makefile and its customization nor do I know much about use of cygwin.)
1) I have access to dll and .so files
2) Also, path to include files are somehow abbreviated.
Abbreviated include statement:
#include "MrServers/MrMeasSrv/SeqIF/csequence.h"
Full include statement
#include "C:/MIDEA/N4_VD13A_LATEST_20120616/n4/pkg/MrServers/MrMeasSrv/SeqIF/csequence.h"
3) My project does not start with main(); but, it starts with init() and then it pass to prep(), check(), run(). Prep stage becomes particularly complicated.
4) The IDEA framework is designed in combination with cygwin for command line use only. So, I can not place break point.
Could someone suggest me how to visualize the code flow?
Very recently, I had this idea to start using Mozilla NSS and to learn to use it, so that somewhere in the future, i can use it, or can atleast start contributing to it.
So i went to its Website and cloned it source code into a director "NSS" using mercurial
Then I used
make nss_build_all
instead of
gmake nss_build_all
Note : I don't know, if it makes a difference, gmake is just GNU Make
This make command created a dist folder outside the nss folder. So, Now my NSS folder has 3 folders nss,nspr,dist.
In .bashrc i added a line at the end
export LD_LIBRARY_PATH=/home/ayusun/workspace/NSS/dist/Linux3.5_x86_glibc_PTH_DBG.OBJ/lib
Then i went over to this Sample code, did a copy paste and saved it in my NSS Folder.
And then i tried to compile it, but it failed, stating it couldn't find iostream.h, I went over and changed the location of header files
So
<iostream.h> became <iostream>
"pk11pub.h" became "nss/lib/pk11wrap/pk11pub.h"
"keyhi.h" became "nss/lib/cryptohi/keyhi.h"
"nss.h" became "nss/lib/nss/nss.h"
I tried compiling again but this time error came, that it couldn't find "planera.h"
which is actually present in dist/*.OBJ/include/ which is a link to a file planeras.h in nspr
And so i don't know, how to include these files anymore.
I always have trouble when it comes to include 3rd party header files.
Thanks
This is an old question, but I'll answer it anyway for future reference.
The simplest way is just to use the NSS package for your operating system.
Then you can use things like nss-config --cflags, nss-config --libs, nspr-config --cflags and nspr-config --libs and add that to your CFLAGS and LDFLAGS as appropriate.
For those who do decide to compile their own NSS, I'll give the quick overview.
The NSS headers are in dist/public. Add -I/path/to/dist/public to your compiler command line. The NSPR headers are in dist/Debug/include¹ so add -I/path/to/dist/Debug/include to your comiler command line.
Now you can use #include <nspr/prio.h> and #include <nss/nss.h> and friends.
The NSS code relies on directly uncluding the NSPR headers, so you'll need to add -I/path/to/dist/Debug/include/nspr for it to find things like plarena.h. Or you could do the same and not prefix your includes like I did above. It's up to you.
Now add -L/path/to/dist/Debug/lib and -lnss3 -lnspr4 to your linker command line. You may want to also add -rpath /path/to/dist/Debug/lib for the runtime link path, or copy them to a system directory or use LD_LIBRARY_PATH.
I hope this gets you started.
¹ This actually depends on your operating system and build type. I hope you can figure out the name of the actual Debug directory in your case.
How to get from C/C++ extension source code to a pyd file for windows (or other item that I could import to Python)?
edit: The specific library that I wanted to use (BRISK) was included in OpenCV 2.4.3 so my need for this skill went away for the time being. In case you came here looking for BRISK, here is a simple BRISK in Python demo that I posted.
I have the Brisk source code (download) that I would like to build and use in my python application. I got as far as generating a brisk.pyd file... but it was 0 bytes. If there is a better / alternative way to aiming for a brisk.pyd file, then of course I am open to that as well.
edit: Please ignore all the attempts in my original question below and see my answer which was made possible by obmarg's detailed walkthrough
Where am I going wrong?
Distutils without library path: First I tried to build the source as is with distutils and the following setup.py (I have just started learning distutils so this is a shot in the dark). The structure of the BRISK source code is at the bottom of this question for reference.
from distutils.core import setup, Extension
module1 = Extension('brisk',
include_dirs = ['include', 'C:/opencv2.4/build/include', 'C:/brisk/thirdparty/agast/include'],
#libraries = ['agast_static', 'brisk_static'],
#library_dirs = ['win32/lib'],
sources = ['src/brisk.cpp'])
setup (name = 'BriskPackage',
ext_modules = [module1])
That instantly gave me the following lines and a 0 byte brisk.pyd somewhere in the build folder. So close?
running build
running build_ext
Distutils with library path: Scratch that attempt. So I added the two library lines that are commented out in the above setup.py. That seemed to go ok until I got this linking error:
creating build\lib.win32-2.7
C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe /DLL /nologo /INCREMENTAL:NO /LIBPATH:win32/lib /LIB
PATH:C:\Python27_32bit\libs /LIBPATH:C:\Python27_32bit\PCbuild agast_static.lib brisk_static.lib /EXPORT:initbrisk build
\temp.win32-2.7\Release\src/brisk.obj /OUT:build\lib.win32-2.7\brisk.pyd /IMPLIB:build\temp.win32-2.7\Release\src\brisk.
lib /MANIFESTFILE:build\temp.win32-2.7\Release\src\brisk.pyd.manifest
LINK : error LNK2001: unresolved external symbol initbrisk
build\temp.win32-2.7\Release\src\brisk.lib : fatal error LNK1120: 1 unresolved externals
error: command '"C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\BIN\link.exe"' failed with exit status 1120
Uncontrolled flailing: I thought maybe the libraries needed to be built, so I did a crash course (lots of crashing) with cmake + mingw - mingw + vc++ express 2010 as follows:
cmake gui: source: c:/brisk, build: c:/brisk/build
cmake gui: configure for Visual Studio 10
cmake gui: use default options and generate (CMAKE_BACKWARDS_COMPATIBILITY, CMAKE_INSTALL_PREFIX, EXECUTABLE_OUTPUT_PATH, LIBRARY_OUTPUT_PATH)
VC++ Express 10: Change to Release and build the solution generated by cmake and get about 20 pages of what look like non-critical warnings followed by all succeeded. Note - no dlls are generated by this. It does generate the following libraries of similar size to the ones included with the download:
win32/lib/Release/
agast_static.lib
brisk_static.lib
Further flailing.
Relevant BRISK source file structure for reference:
build/ (empty)
include/brisk/
brisk.h
hammingsse.hpp
src
brisk.cpp
demo.cpp
thirdparty/agast/
include/agast/
agast5_8.h ....
cvWrapper.h
src/
agast5_8.cc ...
CMakeLists.txt
win32/
bin/
brisk.mexw32
opencv_calib3d220.dll ...
lib/
agast_static.lib
brisk_static.lib
CMakeLists.txt
FindOpenCV.cmake
Makefile
Are you sure that this brisk library even exports python bindings? I can't see any reference to it in the source code - it doesn't even seem to import python header files. This would certainly explain why you've not had much success so far - you can't just compile plain C++ code and expect python to interface with it.
I think your second distutils example is closest to correct - it's obviously compiling things and getting to the linker stage, but then you encounter this error. That error just means it can't find a function named initbrisk which I'm guessing would be the top level init function for the module. Again this suggests that you're trying to compile a python module from code that isn't meant for it.
If you want to wrap the C++ code in a python wrapper yourself you could have a look at the official documentation on writing c/c++ extensions. Alternatively you could have a look into boost::python, SIP or shiboken which try to somewhat (or completely) automate the process of making python extensions from C++ code.
EDIT: Since you seem to have made a decent amount of effort to solve the problem yourself and have posted a good question, I've decided to give a more detailed response on how to go about doing this.
Quick Tutorial On Wrapping C++ Libraries Using boost::python
Personally I've only ever used boost::python for stuff like this, so I'll try and give you a good summary of how to go about doing that. I'm going to assume that you're using Visual C++ 2010. I'm also going to assume that you've got a 32bit version of python installed, as I believe the boost pro libraries only provide 32bit binaries.
Installing boost
First you'll need to grab a copy of the boost library. The easiest way to do this is to download an installer from the boost pro website. These should install all the header files and binary files that are required for using the boost c++ library on windows. Take note of where you install these files to, as you'll need them later on - it might be best to install to a path without a space in it. For easyness I'm going to assume you put these files in C:\boost but you can substitute that for the path you actually used.
Alternatively, you can follow these instructions to build boost from source. I'm not 100% sure, but it might be the case that you need to do this in order to get a version of boost::python that is compatible with the version of python you have installed.
Setting up a visual studio project
Next, you'll want to setup a visual studio project for brisk.pyd. If you open visual studio, go to New -> Project then find the option for Win32 Project. Set up your location etc. and click ok. In the wizard that appears select a DLL project type, and then tick the empty project checkbox.
Now that you've created your project, you'll need to set up the include & library paths to allow you to use python, boost::python and the brisk.lib file.
In Visual Studios solution explorer, right click on your project, and select properties from the menu that appears. This should open up the property pages for your project. Go to the Linker -> General section and look for the Additional Library Directories section. You'll need to fill this in with the paths to the .lib files for boost, python and your brisk_static.lib. Generally these can be found in lib (or libs) subdirectories of
wherever you've installed the libraries. Paths are seperated with semicolons. I've attached a screenshot of my settings below:
Next, you'll need to get visual studio to link to the .lib files. These sections can be found in the Additional Dependencies field of the Linker -> Input section of the properties. Again it's a semicolon delimited list. You should need to add in libraries for python (in my case this is python27.lib but this will vary by version) and brisk_static.lib. These do not require the full path as you added that in the previous stage. Again, here's a screenshot:
You may also need to add the boost_python library file but I think boost uses some header file magic to save you the trouble. If I'm incorrect then have a look in you boost library path for a file named similar to boost_python-vc100-mt.lib and add that in.
Finally, you'll need to setup the include paths to allow your project to include the relevant C++ header files. To get the relevant settings to appear in project properties, you'll need to add a .cpp file to your project. Right click the source files folder in your solution explorer, and then go to add new item. Select a C++ File (.cpp) and name it main.cpp (or whatever else you want).
Next, go back to your project properties and go to C/C++ -> General. Under the additional libraries directory you need to add the include paths for brisk, python and boost. Again, semicolons for seperators, and again here's a screenshot:
I suspect that you might need to update these settings to include the opencv2 & agast libraries as well but I'll leave that as a task for you to figure out - it should be much the same process.
Wrapping existing c++ classes with boost::python.
Now comes the slightly trickier bit - actually writing C++ to wrap your brisk library in boost python. You can find a tutorial for this here but i'll try and go over it a bit as well.
This will be taking place in the main.cpp file you created earlier. First, add the relevant include statements you'll need at the top of the file:
#include <brisk/brisk.h>
#include <Python.h>
#include <boost/python.hpp>
Next, you'll need to declare your python module. I'm assuming you'd want this to be called brisk, so you do something like this:
BOOST_PYTHON_MODULE(brisk)
{
}
This should tell boost::python to create a python module named brisk.
Next it's just a case of going through all the classes & structs that you want to wrap and declaring boost python classes with them. The declerations of the classes should all be contained in brisk.h. You should only wrap the public members of a class, not any protected or private members. As a quick example, I've done a couple of the structs here:
BOOST_PYTHON_MODULE(brisk)
{
using namespace boost::python;
class_< cv::BriskPatternPoint >( "BriskPatternPoint" )
.def_readwrite("x", &cv::BriskPatternPoint::x)
.def_readwrite("y", &cv::BriskPatternPoint::y)
.def_readwrite("sigma", &cv::BriskPatternPoint::sigma);
class< cv::BriskScaleSpace >( "BriskScaleSpace", init< uint8_t >() )
.def( "constructPyramid", &cv::BriskScaleSpace::constructPyramid );
}
Here I have wrapped the cv::BriskPatternPoint structure and the cv::BriskScaleSpace class. Some quick explanations:
class_< cv::BriskPatternPoint >( "BriskPatternPoint" ) tells boost::python to declare a class, using the cv::BriskPatternPoint C++ class, and expose it as BriskPatternPoint in python.
.def_readwrite("y", &cv::BriskPatternPoint::y) adds a readable & writeable property to the BriskPatternPoint class. The property is named y, and will map to the BriskPatternPoint::y c++ field.
class< cv::BriskScaleSpace >( "BriskScaleSpace", init< uint8_t >() ) declares another class, this time BriskScaleSpace but also provides a constructor that accepts a uint8_t (an unsigned byte - which should just map to an integer in python, but I'd be careful to not pass in one greater than 255 bytes - I don't know what would happen in that situation)
The following .def line just declares a function - boost::python should (I think) be able to determine the argument types of functions automatically, so you don't need to provide them.
It's probably worth noting that I haven't actually compiled any of these examples - they might well not work at all.
Anyway, to get this fully working in python it should just be a case of doing similar for every structure, class, property & function that you want accessible from python - which is potentially quite a time consuming task!
If you want to see another example of this in action, I did this here to wrap up this class
Building & using the extension
Visual studio should take care of building the extension - then using it is just a case of taking the .DLL and renaming it to .pyd (you can get VS to do this for you, but I'll leave that up to you).
Then you just need to copy your python file to somewhere on your python path (site-packages for example), import it and use it!
import brisk
patternPoint = brisk.BriskPatternPoint()
....
Anyway, I have spent a good hour or so writing this out - so I'm going to stop here. Apologies if I've left anything out or if anything isn't clear, but I'm doing this mostly from memory. Hopefully it's been of some help to you. If you need anything clarified please just leave a comment, or ask another question.
In case someone needs it, this what I have so far. Basically a BriskFeatureDetector that can be created in Python and then have detect called. Most of this is just confirming/copying what obmarg showed me, but I have added the details that get all the way to the pyd library.
The detect method is still incomplete for me though since it does not convert data types. Anyone who knows a good way to improve this, please do! I did find, for example, this library which seems to convert a numpy ndarray to a cv::Mat, but I don't have the time to figure out how to integrate it now. There are also other data types that need to be converted.
Install OpenCV 2.2
for the setup below, I installed to C:\opencv2.2
Something about the API or implementation has changed by version 2.4 that gave me problems (maybe the new Algorithm object?) so I stuck with 2.2 which BRISK was developed with.
Install Boost with Boost Python
for the setup below, I installed to C:\boost\boost_1_47
Create a Visual Studio 10 Project:
new project --> win32
for the setup below, I named it brisk
next --> DLL application type; empty project --> finished
at the top, change from Debug Win32 to Release Win32
Create main.cpp in Source Files
Do this before the project settings so the C++ options become available in the project settings
#include <boost/python.hpp>
#include <opencv2/opencv.hpp>
#include <brisk/brisk.h>
BOOST_PYTHON_MODULE(brisk)
{
using namespace boost::python;
//this long mess is the only way I could get the overloaded signatures to be accepted
void (cv::BriskFeatureDetector::*detect_1)(const cv::Mat&,
std::vector<cv::KeyPoint, std::allocator<cv::KeyPoint>>&,
const cv::Mat&) const
= &cv::BriskFeatureDetector::detect;
void (cv::BriskFeatureDetector::*detect_vector)(const std::vector<cv::Mat, std::allocator<cv::Mat>>&,
std::vector< std::vector< cv::KeyPoint, std::allocator<cv::KeyPoint>>, std::allocator< std::vector<cv::KeyPoint, std::allocator<cv::KeyPoint>>>>&,
const std::vector<cv::Mat, std::allocator<cv::Mat>>&) const
= &cv::BriskFeatureDetector::detect;
class_< cv::BriskFeatureDetector >( "BriskFeatureDetector", init<int, int>())
.def( "detect", detect_1)
;
}
Project Settings (right-click on the project --> properties):
Includes / Headers
Configuration Properties --> C/C++ --> General
add to Additional Include Directories (adjust to your own python / brisk / etc. base paths):
C:\opencv2.2\include;
C:\boost\boost_1_47;
C:\brisk\include;C:\brisk\thirdparty\agast\include;
C:\python27\include;
Libraries (linker)
Configuration Properties --> Linker --> General
add to Additional Library Directories (adjust to your own python / brisk / etc. base paths):
C:\opencv2.2\lib;
C:\boost\boost_1_47\lib;
C:\brisk\win32\lib;
C:\python27\Libs;
Configuration Properties --> Linker --> Input
add to Additional Dependencies (adjust to your own python / brisk / etc. base paths):
opencv_imgproc220.lib;opencv_core220.lib;opencv_features2d220.lib;
agast_static.lib; brisk_static.lib;
python27.lib;
.pyd output instead of .dll
Configuration Properties --> General
change Target Extension to .pyd
Build and rename if necessary
Right-click on the solution and build/rebuild
you may need to rename the output from "Brisk.pyd" to "brisk.pyd" or else python will give you errors about not being able to load the DLL
Make brisk.pyd available to python by putting it in site packages or by putting a .pth file that links to its path
Update Path environment variable
In windows settings, make sure the following are included in your path (again, adjust to your paths):
`C:\boost\boost_1_47\lib;C:\brisk\win32\bin`
I have been trying to set up an EDE project for C++ (emacs24 + builtin CEDET) and I'm starting to get desperate because I can't seem to find the way I want the makefiles to be generated. I'm relatively new to Emacs.
I'll try to describe what I'm doing:
I have a toy project set like so:
main.cpp
other/
Utils.cpp
Utils.h
CGrabBuffer.cpp
CGrabBuffer.h
main.cpp includes both .h's inside the "other/" directory. These are the steps I follow to set up an EDE project with this simple directory setup:
Open main.cpp in emacs and do M-x ede-new ; type: Make ; name: main-proj.
Open one of the files in the "other" directory and do M-x ede-new ; type: Make ; name: aux-proj.
Now it's time to create the targets (which I believe are three in this case):
On the main.cpp buffer: M-x ede-new-target ; name: main ; type: program. When prompted, I add the main.cpp to this target.
I repeat the same for the other two targets (Utils which has Utils.cpp and Utils.h and CGrabBuffer which has CGrabBuffer.cpp and CGrabBuffer.h). Here I find the first problem. What type do these two targets have to be? I only want them to generate .o files.
Once this is done, I type M-x ede-customize-current-target to all three targets and I add some include paths, some libraries, etc.
After this, if I call M-x ede-compile-project it doesn't compile because:
It tries to compile main.cpp first; I have no idea how to specify (using EDE) that both Utils.o and CGrabBuffer.o are needed before attempting to build main.cpp.
If I manually change the order (editing the Makefile), it's not able to link main.cpp because it can't find Utils.o and CGrabBuffer.o.
As you can see, I am in the middle of a great mess. Maybe I'm not even understanding what "target" means in EDE. I have also read about the existence of ede-cpp-root-project which has to be specified inside the .emacs file. I haven't tried it because what I think it does is just help with the semantics. It doesn't generate Makefiles, does it? Can I have (or do I need) an EDE project built with Project.el's and the same thing using ede-cpp-root-project for the semantics? Or is it redundant?
Sorry If I misunderstood a lot of things but I'm very confused and being new to emacs makes things worse. Thanks for your patience!
EDIT: with some tinkering and the responses I received I have been able to figure out a lot of stuff, so thanks a lot. What I still don't understand is the use of the ede-cpp-root-project which has to be specified inside the .emacs file. Is it just for c++ semantics? Is it redundant to have the project with Project.el's AND also the elisp lines in .emacs?
EDE is designed to handle many different kinds of projects, usually of a type where the build system was written outside of Emacs in some other tool.
The EDE project type that creates Makefiles for you can do quite a few things, but you need to have some basic understanding of build systems for it to be helpful, and you really do need to customize the projects to get anything of any complexity working.
I've recently added a section to the EDE manual to help with basic project setups that autogenerate Automake files. You can check out the tutorial here:
http://www.randomsample.de/cedetdocs/ede/ede/Quick-Start.html
The same steps will apply for projects that just use Make instead, but Make based projects often have trouble with shared libraries due to the extra complexity.
Mike's answer is quite good, but I think it is ok to just add .h files to the same target as your .cpp sources. It will keep track of them separately.
Another useful trick is to use the whole project compile keystroke (C-c . C) which uses a capital C whenever you change something big. That will regenerate the Makefiles, rerun any needed Automake features, and start at the top.
EDIT: You only need one EDE project for a give project area. The ede-cpp-root project is useful when no other automatic project type works. That's when you create that in your .emacs file so that the other tools that need a project definition, like semantic's smart completion, and tag lookup, will work.
Well, I think I actually have it figured out this time, but it's ugly. Utils.cpp and CGrabBuffer.cpp should not get their own individual targets, because there doesn't seem to be an appropriate target type. Instead, you'll need to create an archive or library, which will automatically compile Utils.cpp and CGrabBuffer.cpp for you. Below, I'll assume you want static, but it's easy to change.
[For anyone to whom archives or libraries are not familiar, they basically just gather up .o files into a separate unit. It doesn't actually make the compilation harder. Read more here.]
1) Follow the first two and a half steps above (including making the main target, but not the other targets).
2) Switch to Utils.cpp and do M-x ede-new-target ; name: aux ; type: archive. When prompted, add Utils.cpp to this target.
3) Switch to CGrabBuffer.cpp and do C-c . a ; Target: aux .
4) Regenerate the Makefile with M-x ede-proj-regenerate. At this point, if you run make in the other subdirectory, you should get the archive libaux.a.
5) Switch back to main.cpp and do M-x ede-customize-current-target. This brings up an interactive emacs customization buffer, which allows you to edit details of the ede configuration. Under the Ldflags section, click [INS]. This pops out a new line that says Link Flag: and has some different-colored box for you to type in (mine is grey). Type -Lother -laux, so that other/libaux.a is included when compiling main. Then, at the top of the buffer, press [Accept], which should save that change and switch back to main.cpp.
6) Regenerate the Makefile with M-x ede-proj-regenerate.
Now, unfortunately, the Makefile makes the main target first, then descends into the other directory and makes that. Unfortunately, this means that a make from the top-level directory will not work on a clean tree. I don't know why this is, because it seems like that would never be what you want in any project that is ever made with EDE. I can't find any way to change that, except for this hack:
7) Do M-x customize-project; under Inference-Rules click [INS]. Then enter Target: all ; Dependencies: aux main ; Rules: [INS] ; String #: . (This last one is just to prevent an error on an empty rule with a tab; presumably an EDE bug.) Click [Accept], and regenerate the Makefiles.
So now, in your top directory, you can just run make, and main should be a working executable.
I'm quickly becoming convinced that EDE is not yet ready to be used by people other than its authors. Despite its size and the amount of effort they've clearly put into it, it is too buggy, too counterintuitive, and just not smart enough. That's a shame. Emacs needs something like this.