Files
codeql/cpp/ql/test
Andrew Eisenberg 6a47fcaf1f Packaging: Normalize all qlpack.yml files for all languages
This commit ensures consistency among all of our qlpacks. Here are the
changes:

1. Ensure only modern references are used (codeql-{lang} is converted to
   codeql/{lang}-all or codeql/{lang}-queries where appropriate).
2. Use consistent version numbers. All languages are at 0.0.2 except
   javascript, which is 0.0.3.
3. Convert all `libraryPathDependencies` to `dependencies` with version
   constraints
4. Dependencies from query packs to other packs are always `"*"` since
   these dependencies are always from source and we should get the
   latest.
5. Dependencies from codeql/{lang}-lib to codeql/{lang}-upgrades must
   be strict since there is a tight connection between the libary
   and its relevant upgrades.
2021-09-03 11:53:28 -07:00
..
2020-10-07 13:14:54 -04:00
2021-02-09 15:20:03 +00:00

C/C++ CodeQL tests

This document provides additional information about the C/C++ CodeQL tests located in cpp/ql/test. The principles under "Copying code", below, also apply to any other C/C++ code in this repository, such as examples linked from query .qhelp files in cpp/ql/src. For more general information about contributing to this repository, see Contributing to CodeQL.

The tests can be run through Visual Studio Code. Advanced users may also use the codeql test run command.

Contributing to the tests

We are keen to have unit tests for all of our QL code.

Every query in cpp/ql/src (outside of cpp/ql/src/experimental) should have a test in the corresponding subdirectory of cpp/ql/test/query-tests. At a minimum, each query test should contain one case that should be detected by the query, and one related case that should not.

For example a simple test for the "Memory is never freed" (cpp/memory-never-freed) query might contain the following cases:

int *array1, *array2;

array1 = (int *)malloc(sizeof(int) * 100); // BAD: never freed

array2 = (int *)malloc(sizeof(int) * 100); // GOOD
free(array2);

Features of the QL libraries in cpp/ql/src should also have test coverage, in cpp/ql/test/library-tests.

Copying code

The contents of cpp/ql/test should be original - nothing should be copied from other sources. In particular do not copy-paste C/C++ code from third-party projects, your own projects, or the standard C/C++ library implementation of your compiler (regardless of the associated license). As an exception, required declarations may be taken from the following sources where necessary:

  • ISO/IEC Programming languages - C (all versions)
  • ISO/IEC Programming languages - C++ (all versions)
  • Code from existing queries and tests in this repository. This includes 'translating QL to C++', that is, writing C/C++ declarations from the information such as parameter names and positions specified in QL classes (when there is enough information to do so).
  • Code in the public domain

For example the test above for the "Memory is never freed" (cpp/memory-never-freed) query requires the following declarations, taken from ISO/IEC 9899:2018 - Programming languages - C:

void *malloc(size_t size);
void free(void *ptr);

We also need to write our own definition of size_t. Any unsigned integral type will do for our purposes:

typedef unsigned int size_t;

Including files

Standard and third-party library header files should not be included in tests by means of #include or similar mechanisms. This is because the tests should be independent of platform and library versions installed on the running machine. Standard library declarations may be inserted directly where necessary (see the rules in the section above), but it is generally better to avoid using the standard library at all when possible.

#include may be used to include files from the same directory within cpp/ql/test. For example the test for "Include header files only" (cpp/include-non-header) includes other files in the test directory:

#include "test.H"
#include "test.xpm"
#include "test2.c"