Extension of the solidity compiler to support smart contract verification.

Code related to code generation, and the solidity AST, may be found in libsolidity/. The generated code relies on a runtime library, found within libverify/. These components are integrated within solc/ to build solc, the solidity compiler.

Tests for these libraries may be found under test/libsolidity. The libsolidity testsuite is accessible for scripts/solctests.sh.

Before building solc, ensure that the latest version of cmake is installed. When compiling a development solc build for the first time, run

mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=run

Once cmake has finished, simply run,

make
make install

This will populate solc, along with all of its dependencies, within build/run/. To run solc, execute build/run/bin/solc.

If needed, refer to the official build documentation

After making the project, you should find ./build/run/bin/solc. This is our modified version of the solidity compiler.

To generate a model, run <PATH_TO_SOLC> <SRC1> [SRC2] ... [SRCn] --c-model --output-dir=<A_FRESH_DIRECTORY>. This will populate a CMake project.

There two integer models supported: those from cstdint, and those from boost multiprecision. To select one of these models pass -DINT_MODEL:STRING=USE_STDINT (resp. -DINT_MODEL:STRING=USE_BOOST_MP) to cmake. The model also expects the directory in which seahorn lives, given as -DSEA_PATH=<SEAHORN_DIR>. If seahorn is found within your search path, this step may be skipped.

Additionally, you may pass -DSEA_ARGS=arg1;arg2;... to Seahorn. For instance, to compile a bit-precise counter-example, run -DSEA_ARGS=--cex=cex.ll;--bv-cex.

After running cmake, you may then generate an interactive model by running make icmodel. You may invoke seahorn by running make verify. To produce a counterexample, run make cex. If a counterexample exists, it will be populated in cex.ll.

As a full example,

mkdir example
./build/run/bin/solc contract.sol --c-model --output-dir=example
cd exmaple
mkdir build
cd build
cmake .. -DINT_MODEL:STRING=USE_STDINT -DSEA_ARGS=--bv-cex
make icmodel
make verify
make cex

Regression tests operate on Solidity contracts which have previously shown to work with some pipeline. These tests will run said contracts through the modified solc compiler, and then attempt to use their project directories. To see all integration tests, refer to test/regression.

Integration tests are powered by lit and CheckOutput. Before running any integration tests, first install pipe and then run,

pip install lit
pip install CheckOutput

With these tools in place, simply run lit, from test/regression. In this test suite, lit expects a SEA_PATH environment variable to sea's parent directory, should this directory not be in $PATH. This setup also accepts the absolute path to tooling, where supported variables are CMAKE and SOLC. For example, a common command might be,

SEA_PATH=<PATH_TO_SEA_BINDIR> SOLC=<PATH_TO_REPO>/build/solc/solc lit . 

To add a new file to libsolidity/, its path must be added to libsolidity/CMakeLists.txt. For each module added, some test cases should also be introduced. Unlike the libraries, the test CMake files need only be updated if a new directory is added.

The libsolidity testsuite is built on top of Boost's unit testing framework. A simply testsuite will be of the form,

BOOST_AUTO_TEST_SUITE(SuiteName);

...

BOOST_AUTO_TEST_CASE(test_name)
{
    ...
}

...

BOOST_AUTO_TEST_SUITE_END()

It is recommended that test cases use test/libsolidity/AnalysisFramework.h. This provides a test fixture which allows solidity to AST compiling within a testcase. By using solidity code within the test, the scope of each test becomes more evident.

The script scripts/solctests.sh will execute tests only from libsolidity. The test script will use the latest version of solctest found under build/test. By default, all tests related to Z3 and aneth will be executed. These are not needed in this project, and may be bypassed with the following command.

/script/solctests.sh --no-smt --no-ipc

For more information on the libsolidity testsuite, or to learn how to test other modules, refer to Running the compiler tests from the official developer documents.

The Solidity compiler can be configured to output JSON-formatted AST's. This tool proves useful when debugging end-to-end issues. The following command will consume a source unit through STDIN, and dump the AST to STDOUT.

solc --ast -

Comprehensive documentation for solidity compiler development may be found in the Developer's Guide

The original README.md for solidity has be renamed to solidity.md. This file provides useful information on other aspects of the solidity project.