Merge pull request #14591 from ethereum/old-evm-deprecation-warning

Deprecate support for `byzantium` and older EVM versions

Author: cameel

Changelog.md

@@ -7,6 +7,7 @@ Language Features:
 Compiler Features:
  * Commandline Interface: Add ``--no-import-callback`` option that prevents the compiler from loading source files not given explicitly on the CLI or in Standard JSON input.
  * Commandline Interface: Use proper severity and coloring also for error messages produced outside of the compilation pipeline.
+ * EVM: Deprecate support for "homestead", "tangerineWhistle", "spuriousDragon" and "byzantium" EVM versions.
  * Parser: Remove the experimental error recovery mode (``--error-recovery`` / ``settings.parserErrorRecovery``).
  * SMTChecker: Support user-defined operators.
  * Yul Optimizer: If ``PUSH0`` is supported, favor zero literals over storing zero values in variables.

docs/using-the-compiler.rst

@@ -147,14 +147,14 @@ Target Options
 Below is a list of target EVM versions and the compiler-relevant changes introduced
 at each version. Backward compatibility is not guaranteed between each version.
 
-- ``homestead``
+- ``homestead`` (*support deprecated*)
    - (oldest version)
-- ``tangerineWhistle``
+- ``tangerineWhistle`` (*support deprecated*)
    - Gas cost for access to other accounts increased, relevant for gas estimation and the optimizer.
    - All gas sent by default for external calls, previously a certain amount had to be retained.
-- ``spuriousDragon``
+- ``spuriousDragon`` (*support deprecated*)
    - Gas cost for the ``exp`` opcode increased, relevant for gas estimation and the optimizer.
-- ``byzantium``
+- ``byzantium`` (*support deprecated*)
    - Opcodes ``returndatacopy``, ``returndatasize`` and ``staticcall`` are available in assembly.
    - The ``staticcall`` opcode is used when calling non-library view or pure functions, which prevents the functions from modifying state at the EVM level, i.e., even applies when you use invalid type conversions.
    - It is possible to access dynamic data returned from function calls.
@@ -175,7 +175,7 @@ at each version. Backward compatibility is not guaranteed between each version.
 - ``paris``
    - Introduces ``prevrandao()`` and ``block.prevrandao``, and changes the semantics of the now deprecated ``block.difficulty``, disallowing ``difficulty()`` in inline assembly (see `EIP-4399 <https://eips.ethereum.org/EIPS/eip-4399>`_).
 - ``shanghai`` (**default**)
-  - Smaller code size and gas savings due to the introduction of ``push0`` (see `EIP-3855 <https://eips.ethereum.org/EIPS/eip-3855>`_).
+   - Smaller code size and gas savings due to the introduction of ``push0`` (see `EIP-3855 <https://eips.ethereum.org/EIPS/eip-3855>`_).
 
 .. index:: ! standard JSON, ! --standard-json
 .. _compiler-api:
@@ -318,7 +318,7 @@ Input Description
         // Affects type checking and code generation. Can be homestead,
         // tangerineWhistle, spuriousDragon, byzantium, constantinople,
         // petersburg, istanbul, berlin, london, paris or shanghai (default)
-        "evmVersion": "byzantium",
+        "evmVersion": "shanghai",
         // Optional: Change compilation pipeline to go through the Yul intermediate representation.
         // This is false by default.
         "viaIR": true,

libsolidity/interface/StandardCompiler.cpp

@@ -787,6 +787,12 @@ std::variant<StandardCompiler::InputsAndSettings, Json::Value> StandardCompiler:
 		std::optional<langutil::EVMVersion> version = langutil::EVMVersion::fromString(settings["evmVersion"].asString());
 		if (!version)
 			return formatFatalError(Error::Type::JSONError, "Invalid EVM version requested.");
+		if (version < EVMVersion::constantinople())
+			ret.errors.append(formatError(
+				Error::Type::Warning,
+				"general",
+				"Support for EVM versions older than constantinople is deprecated and will be removed in the future."
+			));
 		ret.evmVersion = *version;
 	}
 

solc/CommandLineInterface.cpp

@@ -681,6 +681,12 @@ bool CommandLineInterface::parseArguments(int _argc, char const* const* _argv)
 
 void CommandLineInterface::processInput()
 {
+	if (m_options.output.evmVersion < EVMVersion::constantinople())
+		report(
+			Error::Severity::Warning,
+			"Support for EVM versions older than constantinople is deprecated and will be removed in the future."
+		);
+
 	switch (m_options.input.mode)
 	{
 	case InputMode::Help:

test/cmdlineTests.sh

@@ -240,9 +240,9 @@ EOF
         sed -i.bak -e 's/\(\\"version\\":[ ]*\\"\)[^"\\]*\(\\"\)/\1<VERSION REMOVED>\2/' "$stdout_path"
         rm "$stdout_path.bak"
     else
-        sed -i.bak -e '/^Warning: This is a pre-release compiler version, please do not use it in production./d' "$stderr_path"
+        sed -i.bak -e '/^Warning: This is a pre-release compiler version, please do not use it in production./,+1d' "$stderr_path"
         sed -i.bak -e '/^Compiler run successful, no output requested\.$/d' "$stderr_path"
-        sed -i.bak -e '/^Warning (3805): This is a pre-release compiler version, please do not use it in production./d' "$stderr_path"
+        sed -i.bak -e '/^Warning (3805): This is a pre-release compiler version, please do not use it in production./,+1d' "$stderr_path"
         sed -i.bak -e 's/\(^[ ]*auxdata: \)0x[0-9a-f]*$/\1<AUXDATA REMOVED>/' "$stdout_path"
         sed -i.bak -e 's/ Consider adding "pragma .*$//' "$stderr_path"
         sed -i.bak -e 's/\(Unimplemented feature error.* in \).*$/\1<FILENAME REMOVED>/' "$stderr_path"

test/cmdlineTests/ast_json_import_wrong_evmVersion/err

@@ -1 +1,2 @@
+Warning: Support for EVM versions older than constantinople is deprecated and will be removed in the future.
 Error: Failed to import AST: Imported tree evm version differs from configured evm version!

test/cmdlineTests/evm_version_byzantium/args

@@ -0,0 +1 @@
+--evm-version byzantium

test/cmdlineTests/evm_version_byzantium/err

@@ -0,0 +1,3 @@
+Warning: Support for EVM versions older than constantinople is deprecated and will be removed in the future.
+Warning: Source file does not specify required compiler version!
+--> evm_version_byzantium/input.sol

test/cmdlineTests/evm_version_byzantium/input.sol

@@ -0,0 +1 @@
+// SPDX-License-Identifier: GPL-3.0

test/cmdlineTests/evm_version_constantinople/args

@@ -0,0 +1 @@
+--evm-version constantinople