Add possibility to build CDT in debug mode

[mikelik]

Change Description

Add possibility to build CDT in debug mode.
Do not change CMAKE_BUILD_TYPE if provided, which allows to build project in Debug mode.
Only LLVM is needed in Release - otherwise unit tests are failing because of assertion failure.

To build in debug mode cmake command should look like:

cmake -DCMAKE_BUILD_TYPE="Debug" -DTOOLS_BUILD_TYPE="Debug" -DLIBS_BUILD_TYPE="Debug" ..

Now almost everything is built in Debug mode:

mikel@msi:~/repo/cdt/debug$ find . -type f -name "CMakeCache.txt"|xargs grep BUILD_TYPE
./libraries/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Debug
./cdt-llvm/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Release
./tools/toolchain-tester/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=
./tools/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Debug
./tests/unit/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Debug
./tests/integration/CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Debug
./CMakeCache.txt:CMAKE_BUILD_TYPE:STRING=Debug
./CMakeCache.txt:LIBS_BUILD_TYPE:UNINITIALIZED=Debug
./CMakeCache.txt:TOOLS_BUILD_TYPE:UNINITIALIZED=Debug

Debug symbols are added, i.e.:

mikel@msi:~/repo/cdt/debug$ gdb /home/mikel/repo/cdt/debug/tests/unit/asset_tests 
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04.1) 9.2
(...)
(gdb) where
#0  eosio::cdt::output_stream::push (this=0x38c2c8 <std_err>, c=105 'i')
    at /home/mikel/repo/cdt/libraries/native/native/eosio/crt.hpp:15
#1  0x00000000003540bc in _prints (cstr=0x2024df "invalid symbol name", which=1 '\001')
    at /home/mikel/repo/cdt/libraries/native/crt.cpp:61
(...)

If no CMAKE_BUILD_TYPE is provided then "Release" is assumed (the same as before).

API Changes

• API Changes

Documentation Additions

• Documentation Additions

[dimas1185]

tested local debug. looks good to me