Writing a C++ Assignment Configuration
This is a quick-start guide to writing your own C++ Assignment Configuration YAML. Note that this document is by no means comprehensive; The Grader is much more extensible than what is advertised here.
Template
A starting template can be found here. The file will contain a one-liner
description of which required option does. Alternatively, an unannotated version can be found
here.
The following sections will all use the above template to briefly explain the meaning of each configuration option. Always refer to configuration-specific documents for more details on how to use each stage!
Settings
The _settings block is used to configure global grading options.
_settings:
lang: cpp/g++:8
use_template: FILENAMES
template:
- do_not_include.txt
use_skeleton: true
use_provided: true
stage_wait_duration_secs: 10
cpus: 1.0
mem_gb: 2.0
enable_features:
network: false
Available languages and compilers are explained below. More info about other configuration keys are available in Writing an Assignment Configuration.
lang
This key determines the programming language which this grading pipeline is targeted for.
Certain stages, such as Compile and StdioTest, contain custom language-specific logic. By setting this key, it allows those stages to adapt its execution for the specified language.
The currently supported combinations are:
cpp/g++:<gcc_version>Supports any GCC version 8 or above
<gcc_version>can be the full version (9.3.0), major+minor version (9.3), or major version only (9)
cpp/clang:<clang_version>Supports any clang version 8 or above
Suggested Structure
Here is a minimum suggested structure for setting up the pipeline to grade a C++ assignment:
fileStructureValidation: {}
diffWithSkeleton: {}
compile:
# ...
stdioTest:
# ...
score:
# ...
To include more than one compilation stage, see Multiple Stages of Same Type.
Pre-Grading Stages
Pre-Grading Stages are pipeline stages which are performed before compilation and/or test execution. These stages are generally language-agnostic in nature.
fileStructureValidation
File Structure Validation is a stage which checks whether files submitted by the students matches the expected list of files that students should submit. If the student submission does not contain certain files, or the student submission contains additional files, this stage will emit a warning for students.
Note that in order to use this stage, _settings.use_template must not be null.
diffWithSkeleton
Diff With Skeleton is a stage which checks whether students have inadvertently submitted certain files from the skeleton code. If there are any files in the student submission which are identical to those in the skeleton code, this stage will emit a warning for students.
Note that in order to use this stage, _settings.use_skeleton must be true.
Grading Stages
Grading Stages are pipeline stages which are performed to either prepare or execute grading tasks. Some of these stages have the additional ability to be score-generating, i.e. a score can be generated from the stage based on its correctness.
Note that the following sections are not an exhaustive list of all supported stages. Refer to this page for a comprehensive list of supported stages and their configuration.
Necessary/Recommended
Compile
The Compile stage is a language-agnostic stage which can be used in any pipeline with a supported _settings.lang.
This allows you to only need to specify the input, output, and optionally the compilation flags to compile
file(s) using the compiler. Here are the default flags that are used for C++:
[“-std=c++11”, “-pedantic”, “-Wall”, “-Wextra”, “-g”]
compile:
input: "[String]" # full set of files needed for compilation
output: String? # name of the compiled target executable
flags: "[String]?" # flags used for compilation. These will be fed into specific compilation commands of the language. [default: <according to specific langauges>]
additional_packages: "[String]?" # any additional package to install as dependency to the container [default: []]
StdioTest
The Stdio Test stage is a language-agnostic stage which is used to perform testing using Standard I/O (i.e. stdout
and stderr) streams.
stdioTest:
testCases:
- file: String # file to run
id: Int # id for this case
args: "[String]?" # optional command line arguments
stdin: String? # optional standard input
file_stdin: String? # optional helper file for providing standard input
expected: String? # optional expected output of the case
file_expected: String? # optional helper file for providing expected output
visibility: Visiblity # visibility of the result of this case
score: Double? # scores for passing this case, if any (if not specified, scoring is disabled for this test case)
valgrind: Valgrind? # test case-specific override for Valgrind [default: null (following the `valgrind` key)]
diff_ignore_flags: "[DiffIgnoreFlag]?" # list of diff ignore flags to be used for comparing standard output against expected output
C++
Make
Ths Make stage is a stage which invokes GNU Make on Makefile for easier compilation.
Valgrind
The Valgrind stage is a stage which invokes Valgrind on an executable.
Note that the specification for Valgrind does not contain individual test cases. Instead, the Valgrind configuration is
designed to be applied to all test cases within all stdioTest blocks. Fine-grained overrides can be configured using
the stdioTest.testCases.valgrind key.
GTest
The GTest stage is a stage which compiles files containing GTest test cases and executes them.
Post-Grading Stages
Score
The Score stage performs aggregation on all score-generating stages preceding it.
Note
If this stage is not specified, an overall score will not be generated for submissions.