Compile Crypto++ library for OS X Xcode project

Question

I have downloaded Crypto++ and I am trying to build it so that I can use it in a C++ Xcode project.

I compiled using just "make" command and included libcryptopp.a in my c++ project of my xcode. But it is giving errors:

Undefined symbols for architecture i386:   "CryptoPP::HashFilter::HashFilter(CryptoPP::HashTransformation&,
 CryptoPP::BufferedTransformation*, bool, int, std::__1::basic_string<char, std::__1::char_traits<char>,
 std::__1::allocator<char> > const&, std::__1::basic_string<char, std::__1::char_traits<char>,
 std::__1::allocator<char> > const&)", referenced from:
 ...

Answer 1

I compiled using just "make" command and included libcryptopp.a in my c++ project of my xcode. But it is giving errors ...

As @halfelf said, you need to use LLVM's runtime ( libc++ ) because that is what Xcode uses. Depending on the Crypto++ version you have, you may (or may not) be using GNU's runtime ( libstdc++ ).

The easiest way to fix this is to checkout Master. Its OK to work from Master because its mostly stable and only suffers an occasional break (most development occurs on a separate branch).

$ git clone https://github.com/weidai11/cryptopp
Cloning into 'cryptopp'...
remote: Counting objects: 9116, done.
remote: Total 9116 (delta 0), reused 0 (delta 0), pack-reused 9116
Receiving objects: 100% (9116/9116), 8.05 MiB | 6.53 MiB/s, done.
Resolving deltas: 100% (6406/6406), done.
Checking connectivity... done.

Using Master is required because older versions of Crypto++ did not honor user's CXX and CXXFLAGS . You used to have to edit the makefile to fix it.

Then, perform the following:

export CXXFLAGS="-DNDEBUG -g2 -O2 -stdlib=libc++"
$ CXX=clang++ make -j 4
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -fPIC -march=native -pipe -c cryptlib.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -fPIC -march=native -pipe -c cpu.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -fPIC -march=native -pipe -c shacal2.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -fPIC -march=native -pipe -c md5.cpp
...

You have to set Debug/Release build, Symbol level and Optimization level. The makefile will add the rest of the flags.

There's some hand waiving above since it only adds -stdlib=libc++ . You should use the CXXFLAGS that Xcode uses to ensure the most trouble-free link. Using different CXXFLAGS has caused a lot of trouble over the years.

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Crypto++ is fat-binary safe ( unlike cURL and OpenSSL ), so you should be able to perform the following. In fact, our test script tests this class of configurations (Intel and PPC fat binaries, including C++03 through C++17), so it should work out of the box for you:

export CXXFLAGS="-DNDEBUG -g2 -O2 -stdlib=libc++ -arch i386 -arch x86_64"
$ CXX=clang++ make -j 4
$ make -j 4
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -arch i386 -arch x86_64 -fPIC -march=native -pipe -c cryptlib.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -arch i386 -arch x86_64 -fPIC -march=native -pipe -c cpu.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -arch i386 -arch x86_64 -fPIC -march=native -pipe -c shacal2.cpp
clang++ -DNDEBUG -g2 -O2 -stdlib=libc++ -arch i386 -arch x86_64 -fPIC -march=native -pipe -c md5.cpp
...

Using both architectures will avoid Undefined symbols for architecture i386 and Undefined symbols for architecture x86_64 .

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Here are some related Crypto++ wiki pages, but they are for iOS, and not OS X. They mostly apply, but not exactly.

• IOS (Xcode)
• IOS (Command Line)

Here's a wiki article on building the library from the command line. You're actually hitting the pain point discussed under "Compilers and C++ Runtimes" , but its not readily apparent:

• GNUmakefile