This repo has scripts to help C and C++ programmers drag unwilling legacy C and C++ into a test harness.
The recipe for getting legacy C/C++ is described in TDD How-to: Get your Legacy C Into a Test Harness
In your local build directory add a file like this
LEGACY_BUILD=~/repos/github/legacy-build/legacy-build.sh
INCLUDE_ROOT=.
BUILD_DIR=.
BUILD_COMMAND=make
bash $LEGACY_BUILD $BUILD_DIR $INCLUDE_ROOT $BUILD_COMMAND
Runs MY_BUILD_COMMAND in the working directory, captures the
output, passes it to legacy-suggest which may make a suggestion about how
to solve the current problem. If you use CppUTest, some suggestions can be cut and pasted into your makefile.
Finally, when you get to linker errors, legacy-build will
generate eploding fakes to get you past linker problems and on to running your code.
Set your build so that it fails on the first error.
For gcc and clang -Wfatal-errors.
So far, this has been tested on
- ubuntu gcc version 9.3.0.
- mac osx gcc version 7.4.0
Takes a gcc compiler error output, and filters the error, and makes a suggestion.
The suggestions handle a couple common legacy code test-build problems, like missing includes and linker errors.
Generate exploding fakes from c/c++ linker error output (used for unit testing).
gen-xfakes.sh produces three files with the supplied basename xfakes
tmp-xfakes-c.c |
C linkage fakes, ready to add to your build |
tmp-xfakes-cpp.cpp |
C++ linkage fakes, edits needed |
tmp-xfakes-cpp-globals.cpp |
C++ undefined globals, edits needed |
For C linker errors, the resutling file can be added to the build and those link errors go away. They later turn into runtime errors as exit the test runner whenever your code executes and exploding fake. Usually when you hit an exploding fake, you want the fake to do nothing, or possible you will need a smarter fake.
For C++ errors, you need to do some editing. tmp-xfakes-cpp.cpp will contain a fair guess at what the missing function is that you need. You'll need to add include files and adjust function signatures.
- g++ linker output
- clang
- Visual Studio -- best guess
- Feel free to give me a contribution
- All these compilers are moving target, so you may have to fiddle with it.
See test/example-output/gcc-link-errors.txt for example input. The output files
are found in test/golden.
A full explanation of how to use gen-xfakes is on my blog here.
Clone everying including the tests
$ git clone <repo>
$ git submodule update --init
Run the tests
cd tests
./all-tests.sh