Adds support for the EVM version "Paris".

Deprecates `block.difficulty` and disallow `difficulty()` in inline assembly for EVM versions >= paris.
The change is due to the renaming introduced by EIP-4399 (see: https://eips.ethereum.org/EIPS/eip-4399).
Introduces `block.prevrandao` in Solidity and `prevrandao()` in inline assembly for EVM versions >= paris.

Co-authored-by: Alex Beregszaszi <alex@rtfs.hu>
Co-authored-by: Daniel <daniel@ekpyron.org>
Co-authored-by: matheusaaguiar <95899911+matheusaaguiar@users.noreply.github.com>
Co-authored-by: Nikola Matić <nikola.matic@ethereum.org>

test/cmdlineTests/evmasm_difficulty_post_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version paris

test/cmdlineTests/evmasm_difficulty_post_paris/err

@@ -0,0 +1,5 @@
+Warning: Since the VM version paris, "difficulty" was replaced by "prevrandao", which now returns a random number based on the beacon chain.
+ --> evmasm_difficulty_post_paris/input.sol:6:21:
+  |
+6 |         uint256 x = block.difficulty;
+  |                     ^^^^^^^^^^^^^^^^

test/cmdlineTests/evmasm_difficulty_post_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.difficulty;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_difficulty_post_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_difficulty_post_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, prevrandao)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+PREVRANDAO PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_difficulty_pre_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version london

test/cmdlineTests/evmasm_difficulty_pre_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.difficulty;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_difficulty_pre_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_difficulty_pre_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, difficulty)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+DIFFICULTY PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_prevrandao_post_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version paris

test/cmdlineTests/evmasm_prevrandao_post_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.prevrandao;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_prevrandao_post_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_prevrandao_post_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, prevrandao)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+PREVRANDAO PUSH1 0x0 SSTORE STOP INVALID 

test/cmdlineTests/evmasm_prevrandao_pre_paris/args

@@ -0,0 +1 @@
+--no-cbor-metadata --via-ir --optimize --opcodes --asm --debug-info none --evm-version london

test/cmdlineTests/evmasm_prevrandao_pre_paris/err

@@ -0,0 +1,5 @@
+Warning: "prevrandao" is not supported by the VM version and will be treated as "difficulty".
+ --> evmasm_prevrandao_pre_paris/input.sol:6:21:
+  |
+6 |         uint256 x = block.prevrandao;
+  |                     ^^^^^^^^^^^^^^^^

test/cmdlineTests/evmasm_prevrandao_pre_paris/input.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.0.0;
+
+contract C {
+    constructor() payable {
+        uint256 x = block.prevrandao;
+        assembly {
+            sstore(0, x)
+            stop()
+        }
+    }
+
+    fallback() external payable {
+        assembly {
+            stop()
+        }
+    }
+}

test/cmdlineTests/evmasm_prevrandao_pre_paris/output

@@ -0,0 +1,13 @@
+
+======= evmasm_prevrandao_pre_paris/input.sol:C =======
+EVM assembly:
+  sstore(0x00, difficulty)
+  stop
+stop
+
+sub_0: assembly {
+      stop
+}
+
+Opcodes:
+DIFFICULTY PUSH1 0x0 SSTORE STOP INVALID 

test/libevmasm/Assembler.cpp

@@ -20,6 +20,7 @@
  * @date 2018
  * Tests for the assembler.
  */
+#include <test/Common.h>
 
 #include <libevmasm/Assembly.h>
 #include <libsolutil/JSON.h>
@@ -59,15 +60,16 @@ BOOST_AUTO_TEST_CASE(all_assembly_items)
 		{ "sub.asm", 1 },
 		{ "verbatim.asm", 2 }
 	};
-	Assembly _assembly{false, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly _assembly{evmVersion, false, {}};
 	auto root_asm = make_shared<string>("root.asm");
 	_assembly.setSourceLocation({1, 3, root_asm});
 
-	Assembly _subAsm{false, {}};
+	Assembly _subAsm{evmVersion, false, {}};
 	auto sub_asm = make_shared<string>("sub.asm");
 	_subAsm.setSourceLocation({6, 8, sub_asm});
 
-	Assembly _verbatimAsm(true, "");
+	Assembly _verbatimAsm(evmVersion, true, "");
 	auto verbatim_asm = make_shared<string>("verbatim.asm");
 	_verbatimAsm.setSourceLocation({8, 18, verbatim_asm});
 
@@ -215,6 +217,7 @@ BOOST_AUTO_TEST_CASE(all_assembly_items)
 
 BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 {
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
 	// Tests for 1, 2, 3 number of immutables.
 	for (int numImmutables = 1; numImmutables <= 3; ++numImmutables)
 	{
@@ -243,7 +246,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 				{ *subName, 1 }
 			};
 
-			auto subAsm = make_shared<Assembly>(false, string{});
+			auto subAsm = make_shared<Assembly>(evmVersion, false, string{});
 			for (char i = 0; i < numImmutables; ++i)
 			{
 				for (int r = 0; r < numActualRefs; ++r)
@@ -253,7 +256,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 				}
 			}
 
-			Assembly assembly{true, {}};
+			Assembly assembly{evmVersion, true, {}};
 			for (char i = 1; i <= numImmutables; ++i)
 			{
 				assembly.setSourceLocation({10*i, 10*i + 3+i, assemblyName});
@@ -270,7 +273,7 @@ BOOST_AUTO_TEST_CASE(immutables_and_its_source_maps)
 			auto const numberOfMappings = std::count(sourceMappings.begin(), sourceMappings.end(), ';');
 
 			LinkerObject const& obj = assembly.assemble();
-			string const disassembly = disassemble(obj.bytecode, "\n");
+			string const disassembly = disassemble(obj.bytecode, evmVersion, "\n");
 			auto const numberOfOpcodes = std::count(disassembly.begin(), disassembly.end(), '\n');
 
 			#if 0 // {{{ debug prints
@@ -302,11 +305,12 @@ BOOST_AUTO_TEST_CASE(immutable)
 		{ "root.asm", 0 },
 		{ "sub.asm", 1 }
 	};
-	Assembly _assembly{true, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly _assembly{evmVersion, true, {}};
 	auto root_asm = make_shared<string>("root.asm");
 	_assembly.setSourceLocation({1, 3, root_asm});
 
-	Assembly _subAsm{false, {}};
+	Assembly _subAsm{evmVersion, false, {}};
 	auto sub_asm = make_shared<string>("sub.asm");
 	_subAsm.setSourceLocation({6, 8, sub_asm});
 	_subAsm.appendImmutable("someImmutable");
@@ -395,10 +399,11 @@ BOOST_AUTO_TEST_CASE(immutable)
 
 BOOST_AUTO_TEST_CASE(subobject_encode_decode)
 {
-	Assembly assembly{true, {}};
+	EVMVersion evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	Assembly assembly{evmVersion, true, {}};
 
-	shared_ptr<Assembly> subAsmPtr = make_shared<Assembly>(false, string{});
-	shared_ptr<Assembly> subSubAsmPtr = make_shared<Assembly>(false, string{});
+	shared_ptr<Assembly> subAsmPtr = make_shared<Assembly>(evmVersion, false, string{});
+	shared_ptr<Assembly> subSubAsmPtr = make_shared<Assembly>(evmVersion, false, string{});
 
 	assembly.appendSubroutine(subAsmPtr);
 	subAsmPtr->appendSubroutine(subSubAsmPtr);

test/libevmasm/Optimiser.cpp

@@ -1250,8 +1250,18 @@ BOOST_AUTO_TEST_CASE(jumpdest_removal_subassemblies)
 	// tag unifications (due to block deduplication) is also
 	// visible at the super-assembly.
 
-	Assembly main{false, {}};
-	AssemblyPointer sub = make_shared<Assembly>(true, string{});
+	Assembly::OptimiserSettings settings;
+	settings.runInliner = false;
+	settings.runJumpdestRemover = true;
+	settings.runPeephole = true;
+	settings.runDeduplicate = true;
+	settings.runCSE = true;
+	settings.runConstantOptimiser = true;
+	settings.evmVersion = solidity::test::CommonOptions::get().evmVersion();
+	settings.expectedExecutionsPerDeployment = OptimiserSettings{}.expectedExecutionsPerDeployment;
+
+	Assembly main{settings.evmVersion, false, {}};
+	AssemblyPointer sub = make_shared<Assembly>(settings.evmVersion, true, string{});
 
 	sub->append(u256(1));
 	auto t1 = sub->newTag();
@@ -1277,16 +1287,6 @@ BOOST_AUTO_TEST_CASE(jumpdest_removal_subassemblies)
 	main.append(t1.toSubAssemblyTag(subId));
 	main.append(u256(8));
 
-	Assembly::OptimiserSettings settings;
-	settings.runInliner = false;
-	settings.runJumpdestRemover = true;
-	settings.runPeephole = true;
-	settings.runDeduplicate = true;
-	settings.runCSE = true;
-	settings.runConstantOptimiser = true;
-	settings.evmVersion = solidity::test::CommonOptions::get().evmVersion();
-	settings.expectedExecutionsPerDeployment = OptimiserSettings{}.expectedExecutionsPerDeployment;
-
 	main.optimise(settings);
 
 	AssemblyItems expectationMain{

test/libsolidity/SolidityOptimizer.cpp

@@ -109,7 +109,7 @@ public:
 		bytes realCode = bytecodeSansMetadata(_bytecode);
 		BOOST_REQUIRE_MESSAGE(!realCode.empty(), "Invalid or missing metadata in bytecode.");
 		size_t instructions = 0;
-		evmasm::eachInstruction(realCode, [&](Instruction _instr, u256 const&) {
+		evmasm::eachInstruction(realCode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 			if (!_which || *_which == _instr)
 				instructions++;
 		});
@@ -287,7 +287,7 @@ BOOST_AUTO_TEST_CASE(retain_information_in_branches)
 
 	bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "c", true);
 	size_t numSHA3s = 0;
-	eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) {
+	eachInstruction(optimizedBytecode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 		if (_instr == Instruction::KECCAK256)
 			numSHA3s++;
 	});
@@ -330,7 +330,7 @@ BOOST_AUTO_TEST_CASE(store_tags_as_unions)
 
 	bytes optimizedBytecode = compileAndRunWithOptimizer(sourceCode, 0, "test", true);
 	size_t numSHA3s = 0;
-	eachInstruction(optimizedBytecode, [&](Instruction _instr, u256 const&) {
+	eachInstruction(optimizedBytecode, m_evmVersion, [&](Instruction _instr, u256 const&) {
 		if (_instr == Instruction::KECCAK256)
 			numSHA3s++;
 	});

test/libsolidity/analysis/FunctionCallGraph.cpp

@@ -1860,6 +1860,7 @@ BOOST_AUTO_TEST_CASE(builtins)
 				block.chainid;
 				block.coinbase;
 				block.difficulty;
+				block.prevrandao;
 				block.gaslimit;
 				block.number;
 				block.timestamp;

test/libsolidity/semanticTests/inlineAssembly/difficulty.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (uint ret) {
+        assembly {
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: <paris
+// ----
+// f() -> 200000000

test/libsolidity/semanticTests/inlineAssembly/prevrandao.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (uint ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: >=paris
+// ----
+// f() -> 0xa86c2e601b6c44eb4848f7d23d9df3113fbcac42041c49cbed5000cb4f118777

test/libsolidity/semanticTests/state/block_prevrandao.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: >=paris
+// ----
+// f() -> 0xa86c2e601b6c44eb4848f7d23d9df3113fbcac42041c49cbed5000cb4f118777

test/libsolidity/semanticTests/state/block_prevrandao_pre_paris.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+}
+// ====
+// compileToEwasm: also
+// EVMVersion: <paris
+// ----
+// f() -> 200000000

test/libsolidity/syntaxTests/inlineAssembly/difficulty_builtin_pre_paris.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.difficulty;
+    }
+
+    function g() public view returns (uint256 ret) {
+        assembly {
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/difficulty_disallowed_function_pre_paris.sol

@@ -0,0 +1,21 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let difficulty := sload(0)
+            ret := difficulty
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function difficulty() -> r {
+                r := 1000
+            }
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// ParserError 5568: (101-111): Cannot use builtin function name "difficulty" as identifier name.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_magic_block_warn_post_paris.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.difficulty;
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// Warning 8417: (77-93): Since the VM version paris, "difficulty" was replaced by "prevrandao", which now returns a random number based on the beacon chain.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_nobuiltin_post_paris.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// DeclarationError 4619: (74-84): Function "difficulty" not found.
+// TypeError 3950: (74-86): Expected expression to evaluate to one value, but got 0 values instead.

test/libsolidity/syntaxTests/inlineAssembly/difficulty_reserved_post_paris.sol

@@ -0,0 +1,22 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let difficulty := sload(0)
+            ret := difficulty
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function difficulty() -> r {
+                r := 1000
+            }
+            ret := difficulty()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// DeclarationError 5017: (101-111): The identifier "difficulty" is reserved and can not be used.
+// DeclarationError 5017: (255-323): The identifier "difficulty" is reserved and can not be used.

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_allowed_function_pre_paris.sol

@@ -0,0 +1,20 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let prevrandao := sload(0)
+            ret := prevrandao
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function prevrandao() -> r {
+                r := 1000
+            }
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_builtin_post_paris.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.prevrandao;
+    }
+
+    function g() public view returns (uint256 ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_disallowed_function_post_paris.sol

@@ -0,0 +1,21 @@
+contract C {
+    function f() public view returns (uint256 ret) {
+        assembly {
+            let prevrandao := sload(0)
+            ret := prevrandao
+        }
+    }
+
+    function g() public pure returns (uint256 ret) {
+        assembly {
+            function prevrandao() -> r {
+                r := 1000
+            }
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// ParserError 5568: (101-111): Cannot use builtin function name "prevrandao" as identifier name.

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_magic_block_warn_pre_paris.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public view returns (uint256) {
+        return block.prevrandao;
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// Warning 9432: (77-93): "prevrandao" is not supported by the VM version and will be treated as "difficulty".

test/libsolidity/syntaxTests/inlineAssembly/prevrandao_nobuitin_pre_paris.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(prevrandao())
+        }
+    }
+}
+// ====
+// EVMVersion: <paris
+// ----
+// DeclarationError 4619: (74-84): Function "prevrandao" not found.
+// TypeError 3950: (74-86): Expected expression to evaluate to one value, but got 0 values instead.

test/libsolidity/syntaxTests/tryCatch/low_level_homestead.sol

@@ -8,6 +8,6 @@ contract C {
     }
 }
 // ====
-// EVMVersion: <byzantium
+// EVMVersion: =homestead
 // ----
 // TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (homestead). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/low_level_spuriousDragon.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch (bytes memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =spuriousDragon
+// ----
+// TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (spuriousDragon). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/low_level_tangerineWhistle.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch (bytes memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =tangerineWhistle
+// ----
+// TypeError 9908: (73-106): This catch clause type cannot be used on the selected EVM version (tangerineWhistle). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_homestead.sol

@@ -8,6 +8,6 @@ contract C {
     }
 }
 // ====
-// EVMVersion: <byzantium
+// EVMVersion: =homestead
 // ----
 // TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (homestead). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_spuriousDragon.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch Error(string memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =spuriousDragon
+// ----
+// TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (spuriousDragon). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/tryCatch/structured_tangerineWhistle.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public {
+        try this.f() {
+
+        } catch Error(string memory) {
+
+        }
+    }
+}
+// ====
+// EVMVersion: =tangerineWhistle
+// ----
+// TypeError 1812: (73-112): This catch clause type cannot be used on the selected EVM version (tangerineWhistle). You need at least a Byzantium-compatible EVM or use `catch { ... }`.

test/libsolidity/syntaxTests/types/magic_block_istanbul.sol

@@ -3,15 +3,12 @@ contract C {
         return block.coinbase;
     }
     function g() public view returns (uint) {
-        return block.difficulty;
-    }
-    function h() public view returns (uint) {
         return block.gaslimit;
     }
-    function i() public view returns (uint) {
+    function h() public view returns (uint) {
         return block.timestamp;
     }
-    function j() public view returns (uint) {
+    function i() public view returns (uint) {
         return block.chainid;
     }
 }

test/libsolidity/syntaxTests/types/magic_block_paris.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public view returns (uint) {
+        return block.prevrandao;
+    }
+    function g() public view returns (uint ret) {
+        assembly {
+            ret := prevrandao()
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed.sol

@@ -73,7 +73,7 @@ contract C {
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
+            pop(prevrandao())
             pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled
@@ -83,7 +83,7 @@ contract C {
     }
 }
 // ====
-// EVMVersion: >=london
+// EVMVersion: >=paris
 // ----
 // Warning 5740: (89-1716): Unreachable code.
 // Warning 5740: (1729-1741): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_london.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: <=london
+// ----
+// Warning 2018: (17-103): Function state mutability can be restricted to view

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_pure.sol

@@ -73,7 +73,6 @@ contract C {
             //pop(coinbase())
             //pop(timestamp())
             //pop(number())
-            //pop(difficulty())
             //pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_view.sol

@@ -73,7 +73,7 @@ contract C {
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
+            pop(prevrandao())
             pop(gaslimit())
 
             // NOTE: msize() is allowed only with optimizer disabled
@@ -83,7 +83,7 @@ contract C {
     }
 }
 // ====
-// EVMVersion: >=london
+// EVMVersion: >=paris
 // ----
 // Warning 5740: (94-1733): Unreachable code.
 // Warning 5740: (1746-1758): Unreachable code.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_allowed_view_london.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: <=london
+// ----

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure.sol

@@ -6,33 +6,26 @@ contract C {
             pop(gas())
             pop(address())
             pop(balance(0))
-            pop(selfbalance())
             pop(caller())
             pop(callvalue())
             pop(extcodesize(0))
             extcodecopy(0, 1, 2, 3)
-            pop(extcodehash(0))
             pop(create(0, 1, 2))
-            pop(create2(0, 1, 2, 3))
             pop(call(0, 1, 2, 3, 4, 5, 6))
             pop(callcode(0, 1, 2, 3, 4, 5, 6))
             pop(delegatecall(0, 1, 2, 3, 4, 5))
-            pop(staticcall(0, 1, 2, 3, 4, 5))
             selfdestruct(0)
             log0(0, 1)
             log1(0, 1, 2)
             log2(0, 1, 2, 3)
             log3(0, 1, 2, 3, 4)
             log4(0, 1, 2, 3, 4, 5)
-            pop(chainid())
-            pop(basefee())
             pop(origin())
             pop(gasprice())
             pop(blockhash(0))
             pop(coinbase())
             pop(timestamp())
             pop(number())
-            pop(difficulty())
             pop(gaslimit())
 
             // These two are disallowed too but the error suppresses other errors.
@@ -41,40 +34,31 @@ contract C {
         }
     }
 }
-// ====
-// EVMVersion: >=london
 // ----
-// Warning 5740: (672-1083): Unreachable code.
+// Warning 5740: (526-853): Unreachable code.
 // TypeError 2527: (79-87): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 8961: (101-113): Function cannot be declared as pure because this expression (potentially) modifies the state.
 // TypeError 2527: (130-135): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 2527: (153-162): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
 // TypeError 2527: (180-190): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (208-221): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (239-247): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (265-276): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (294-308): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (322-345): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (362-376): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 8961: (394-409): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (427-446): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (464-489): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (507-536): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (554-584): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 2527: (602-630): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 8961: (644-659): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (672-682): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (695-708): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (721-737): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (750-769): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 8961: (782-804): Function cannot be declared as pure because this expression (potentially) modifies the state.
-// TypeError 2527: (821-830): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (848-857): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (875-883): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (901-911): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (929-941): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (959-969): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (987-998): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1016-1024): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1042-1054): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
-// TypeError 2527: (1072-1082): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (208-216): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (234-245): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (263-277): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (291-314): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (331-346): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (364-389): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (407-436): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (454-484): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (498-513): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (526-536): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (549-562): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (575-591): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (604-623): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 8961: (636-658): Function cannot be declared as pure because this expression (potentially) modifies the state.
+// TypeError 2527: (675-683): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (701-711): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (729-741): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (759-769): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (787-798): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (816-824): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (842-852): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_byzantium.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(staticcall(0, 1, 2, 3, 4, 5))
+        }
+    }
+}
+// ====
+// EVMVersion: >=byzantium
+// ----
+// TypeError 2527: (79-107): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_constantinople.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(extcodehash(0))
+            pop(create2(0, 1, 2, 3))
+        }
+    }
+}
+// ====
+// EVMVersion: >=constantinople
+// ----
+// TypeError 2527: (79-93): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 8961: (111-130): Function cannot be declared as pure because this expression (potentially) modifies the state.

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_istanbul.sol

@@ -0,0 +1,13 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(selfbalance())
+            pop(chainid())
+        }
+    }
+}
+// ====
+// EVMVersion: >=istanbul
+// ----
+// TypeError 2527: (79-92): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".
+// TypeError 2527: (110-119): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_london.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(basefee())
+        }
+    }
+}
+// ====
+// EVMVersion: >=london
+// ----
+// TypeError 2527: (79-88): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_paris.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(prevrandao())
+        }
+    }
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// TypeError 2527: (79-91): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libsolidity/syntaxTests/viewPureChecker/inline_assembly_instructions_disallowed_pure_pre_paris.sol

@@ -0,0 +1,11 @@
+contract C {
+    function f() public pure {
+        assembly {
+            pop(difficulty())
+        }
+    }
+}
+// ====
+// EVMVersion: <=london
+// ----
+// TypeError 2527: (79-91): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libyul/EVMCodeTransformTest.cpp

@@ -19,6 +19,8 @@
 #include <test/libyul/EVMCodeTransformTest.h>
 #include <test/libyul/Common.h>
 
+#include <test/Common.h>
+
 #include <libyul/YulStack.h>
 #include <libyul/backends/evm/EthAssemblyAdapter.h>
 #include <libyul/backends/evm/EVMObjectCompiler.h>
@@ -66,7 +68,7 @@ TestCase::TestResult EVMCodeTransformTest::run(ostream& _stream, string const& _
 		return TestResult::FatalError;
 	}
 
-	evmasm::Assembly assembly{false, {}};
+	evmasm::Assembly assembly{solidity::test::CommonOptions::get().evmVersion(), false, {}};
 	EthAssemblyAdapter adapter(assembly);
 	EVMObjectCompiler::compile(
 		*stack.parserResult(),

test/libyul/ObjectCompilerTest.cpp

@@ -20,6 +20,8 @@
 
 #include <test/libsolidity/util/SoltestErrors.h>
 
+#include <test/Common.h>
+
 #include <libsolutil/AnsiColorized.h>
 
 #include <libyul/YulStack.h>
@@ -101,7 +103,7 @@ TestCase::TestResult ObjectCompilerTest::run(ostream& _stream, string const& _li
 				"Bytecode: " +
 				util::toHex(obj.bytecode->bytecode) +
 				"\nOpcodes: " +
-				boost::trim_copy(evmasm::disassemble(obj.bytecode->bytecode)) +
+				boost::trim_copy(evmasm::disassemble(obj.bytecode->bytecode, solidity::test::CommonOptions::get().evmVersion())) +
 				"\nSourceMappings:" +
 				(obj.sourceMappings->empty() ? "" : " " + *obj.sourceMappings) +
 				"\n";

test/libyul/YulInterpreterTest.cpp

@@ -98,7 +98,7 @@ string YulInterpreterTest::interpret()
 	{
 		Interpreter::run(
 			state,
-			EVMDialect::strictAssemblyForEVMObjects(langutil::EVMVersion{}),
+			EVMDialect::strictAssemblyForEVMObjects(solidity::test::CommonOptions::get().evmVersion()),
 			*m_ast,
 			/*disableExternalCalls=*/ !m_simulateExternalCallsToSelf,
 			/*disableMemoryTracing=*/ false

test/libyul/ewasmTranslationTests/difficulty.yul

@@ -1,6 +1,8 @@
 {
   sstore(0, difficulty())
 }
+// ====
+// EVMVersion: <paris
 // ----
 // Trace:
 // Memory dump:

test/libyul/yulInterpreterTests/difficulty.yul

@@ -0,0 +1,10 @@
+{
+  sstore(0, difficulty())
+}
+// ====
+// EVMVersion: <paris
+// ----
+// Trace:
+// Memory dump:
+// Storage dump:
+//   0000000000000000000000000000000000000000000000000000000000000000: 0000000000000000000000000000000000000000000000000000000009999999

test/libyul/yulInterpreterTests/prevrandao.yul

@@ -0,0 +1,10 @@
+{
+  sstore(0, prevrandao())
+}
+// ====
+// EVMVersion: >=paris
+// ----
+// Trace:
+// Memory dump:
+// Storage dump:
+//   0000000000000000000000000000000000000000000000000000000000000000: 0000000000000000000000000000000000000000000000010000000000000001

test/tools/fuzzer_common.cpp

@@ -189,7 +189,7 @@ void FuzzerUtil::testConstantOptimizer(string const& _input, bool _quiet)
 
 	for (bool isCreation: {false, true})
 	{
-		Assembly assembly{isCreation, {}};
+		Assembly assembly{langutil::EVMVersion{}, isCreation, {}};
 		for (u256 const& n: numbers)
 		{
 			if (!_quiet)

test/tools/yulInterpreter/EVMInstructionInterpreter.cpp

@@ -98,7 +98,7 @@ u256 EVMInstructionInterpreter::eval(
 	using namespace solidity::evmasm;
 	using evmasm::Instruction;
 
-	auto info = instructionInfo(_instruction);
+	auto info = instructionInfo(_instruction, m_evmVersion);
 	yulAssert(static_cast<size_t>(info.args) == _arguments.size(), "");
 
 	auto const& arg = _arguments;
@@ -268,8 +268,8 @@ u256 EVMInstructionInterpreter::eval(
 		return m_state.timestamp;
 	case Instruction::NUMBER:
 		return m_state.blockNumber;
-	case Instruction::DIFFICULTY:
-		return m_state.difficulty;
+	case Instruction::PREVRANDAO:
+		return (m_evmVersion < langutil::EVMVersion::paris()) ? m_state.difficulty : m_state.prevrandao;
 	case Instruction::GASLIMIT:
 		return m_state.gaslimit;
 	// --------------- memory / storage / logs ---------------
@@ -543,7 +543,7 @@ void EVMInstructionInterpreter::logTrace(
 )
 {
 	logTrace(
-		evmasm::instructionInfo(_instruction).name,
+		evmasm::instructionInfo(_instruction, m_evmVersion).name,
 		SemanticInformation::memory(_instruction) == SemanticInformation::Effect::Write,
 		_arguments,
 		_data

test/tools/yulInterpreter/EVMInstructionInterpreter.h

@@ -26,6 +26,8 @@
 #include <libsolutil/CommonData.h>
 #include <libsolutil/Numeric.h>
 
+#include <liblangutil/EVMVersion.h>
+
 #include <vector>
 
 namespace solidity::evmasm
@@ -74,7 +76,8 @@ struct InterpreterState;
 class EVMInstructionInterpreter
 {
 public:
-	explicit EVMInstructionInterpreter(InterpreterState& _state, bool _disableMemWriteTrace):
+	explicit EVMInstructionInterpreter(langutil::EVMVersion _evmVersion, InterpreterState& _state, bool _disableMemWriteTrace):
+		m_evmVersion(_evmVersion),
 		m_state(_state),
 		m_disableMemoryWriteInstructions(_disableMemWriteTrace)
 	{}
@@ -128,6 +131,7 @@ private:
 		return m_disableMemoryWriteInstructions;
 	}
 
+	langutil::EVMVersion m_evmVersion;
 	InterpreterState& m_state;
 	/// Flag to disable trace of instructions that write to memory.
 	bool m_disableMemoryWriteInstructions;

test/tools/yulInterpreter/EwasmBuiltinInterpreter.cpp

@@ -597,7 +597,7 @@ u256 EwasmBuiltinInterpreter::readU256(uint64_t _offset, size_t _croppedTo)
 
 void EwasmBuiltinInterpreter::logTrace(evmasm::Instruction _instruction, std::vector<u256> const& _arguments, bytes const& _data)
 {
-	logTrace(evmasm::instructionInfo(_instruction).name, _arguments, _data);
+	logTrace(evmasm::instructionInfo(_instruction, langutil::EVMVersion()).name, _arguments, _data);
 }
 
 void EwasmBuiltinInterpreter::logTrace(std::string const& _pseudoInstruction, std::vector<u256> const& _arguments, bytes const& _data)

test/tools/yulInterpreter/Interpreter.cpp

@@ -314,7 +314,7 @@ void ExpressionEvaluator::operator()(FunctionCall const& _funCall)
 	{
 		if (BuiltinFunctionForEVM const* fun = dialect->builtin(_funCall.functionName.name))
 		{
-			EVMInstructionInterpreter interpreter(m_state, m_disableMemoryTrace);
+			EVMInstructionInterpreter interpreter(dialect->evmVersion(), m_state, m_disableMemoryTrace);
 
 			u256 const value = interpreter.evalBuiltin(*fun, _funCall.arguments, values());
 

test/tools/yulInterpreter/Interpreter.h

@@ -94,6 +94,7 @@ struct InterpreterState
 	u256 timestamp = 0x88888888;
 	u256 blockNumber = 1024;
 	u256 difficulty = 0x9999999;
+	u256 prevrandao = (u256(1) << 64) + 1;
 	u256 gaslimit = 4000000;
 	u256 chainid = 0x01;
 	/// The minimum value of basefee: 7 wei.