diff options
| -rw-r--r-- | docs/contracts.rst | 6 | ||||
| -rw-r--r-- | test/libsolidity/SolidityEndToEndTest.cpp | 25 |
2 files changed, 30 insertions, 1 deletions
diff --git a/docs/contracts.rst b/docs/contracts.rst index faef3fc2..0d1b029b 100644 --- a/docs/contracts.rst +++ b/docs/contracts.rst @@ -485,7 +485,11 @@ Functions can be declared ``view`` in which case they promise not to modify the .. note:: If the compiler's EVM target is Byzantium or newer (default) the opcode ``STATICCALL`` is used for ``view`` functions which enforces the state - to stay unmodified as part of the EVM execution. + to stay unmodified as part of the EVM execution. For library ``view`` functions + ``DELEGATECALL`` is used, because there is no combined ``DELEGATECALL`` and ``STATICCALL``. + This means library ``view`` functions do not have run-time checks that prevent state + modifications. This should not impact security negatively because library code is + usually known at compile-time and the static checker performs compile-time checks. The following statements are considered modifying the state: diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp index f65c8b27..7a496e64 100644 --- a/test/libsolidity/SolidityEndToEndTest.cpp +++ b/test/libsolidity/SolidityEndToEndTest.cpp @@ -4519,6 +4519,31 @@ BOOST_AUTO_TEST_CASE(library_call_protection) ABI_CHECK(callContractFunction("pu()"), encodeArgs(2)); } + +BOOST_AUTO_TEST_CASE(library_staticcall_delegatecall) +{ + char const* sourceCode = R"( + library Lib { + function x() public view returns (uint) { + return 1; + } + } + contract Test { + uint t; + function f() public returns (uint) { + t = 2; + return this.g(); + } + function g() public view returns (uint) { + return Lib.x(); + } + } + )"; + compileAndRun(sourceCode, 0, "Lib"); + compileAndRun(sourceCode, 0, "Test", bytes(), map<string, Address>{{"Lib", m_contractAddress}}); + ABI_CHECK(callContractFunction("f()"), encodeArgs(1)); +} + BOOST_AUTO_TEST_CASE(store_bytes) { // this test just checks that the copy loop does not mess up the stack |