Add tests and allow user-defined functions with blobhash identifier for EVM versions pre cancun

Author: r0qs

libyul/backends/evm/EVMDialect.cpp

@@ -128,11 +128,22 @@ std::set<YulString> createReservedIdentifiers(langutil::EVMVersion _evmVersion)
 		return _instrName == "prevrandao" && _evmVersion < langutil::EVMVersion::paris();
 	};
 
+	// TODO remove this in 0.9.0. We allow creating functions or identifiers in Yul with the name
+	// blobhash for VMs before cancun.
+	auto blobHashException = [&](evmasm::Instruction _instr) -> bool
+	{
+		return _instr == evmasm::Instruction::BLOBHASH && _evmVersion < langutil::EVMVersion::cancun();
+	};
+
 	std::set<YulString> reserved;
 	for (auto const& instr: evmasm::c_instructions)
 	{
 		std::string name = toLower(instr.first);
-		if (!baseFeeException(instr.second) && !prevRandaoException(name))
+		if (
+			!baseFeeException(instr.second) &&
+			!prevRandaoException(name) &&
+			!blobHashException(instr.second)
+		)
 			reserved.emplace(name);
 	}
 	reserved += std::vector<YulString>{

test/libsolidity/semanticTests/inlineAssembly/blobhash_pre_cancun.sol

@@ -0,0 +1,22 @@
+contract C {
+    function f() public pure returns (uint ret) {
+        assembly {
+            let blobhash := 1
+            ret := blobhash
+        }
+    }
+    function g() public pure returns (uint ret) {
+        assembly {
+            function blobhash() -> r {
+                r := 1000
+            }
+            ret := blobhash()
+        }
+    }
+}
+// ====
+// EVMVersion: <=shanghai
+// compileViaYul: also
+// ----
+// f() -> 1
+// g() -> 1000

test/libsolidity/syntaxTests/inlineAssembly/blobhash.sol

@@ -0,0 +1,10 @@
+contract C {
+    function f() public view returns (bytes32 ret) {
+        assembly {
+            ret := blobhash(1)
+        }
+    }
+}
+// ====
+// EVMVersion: >=cancun
+// ----

test/libsolidity/syntaxTests/inlineAssembly/blobhash_pre_cancun.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() pure external returns (bytes32 ret) {
+        assembly {
+            ret := blobhash()
+        }
+    }
+}
+// ====
+// EVMVersion: =shanghai
+// ----
+// DeclarationError 4619: (106-114): Function "blobhash" not found.
+// DeclarationError 8678: (99-116): Variable count for assignment to "ret" does not match number of values (1 vs. 0)

test/libsolidity/syntaxTests/inlineAssembly/blobhash_reserved_cancun.sol

@@ -0,0 +1,14 @@
+contract C {
+    function f() public pure returns (uint ret) {
+        assembly {
+            function blobhash() -> r {
+                r := 1000
+            }
+            ret := blobhash()
+        }
+    }
+}
+// ====
+// EVMVersion: >=cancun
+// ----
+// ParserError 5568: (103-111): Cannot use builtin function name "blobhash" as identifier name.

test/libsolidity/syntaxTests/types/blobhash.sol

@@ -0,0 +1,12 @@
+contract C {
+    function f() public view returns (bytes32 ret) {
+        assembly {
+            ret := blobhash(1)
+        }
+    }
+}
+// ====
+// EVMVersion: <=shanghai
+// ----
+// DeclarationError 4619: (104-112): Function "blobhash" not found.
+// DeclarationError 8678: (97-115): Variable count for assignment to "ret" does not match number of values (1 vs. 0)

test/libsolidity/syntaxTests/viewPureChecker/blobhash_not_pure.sol

@@ -0,0 +1,9 @@
+contract C {
+    function f() public pure {
+        assembly { pop(blobhash(0)) }
+    }
+}
+// ====
+// EVMVersion: >=cancun
+// ----
+// TypeError 2527: (67-78): Function declared as pure, but this expression (potentially) reads from the environment or state and thus requires "view".

test/libyul/yulSyntaxTests/blobhash.yul

@@ -0,0 +1,7 @@
+{
+    function blobhash() {}
+}
+// ====
+// EVMVersion: >=cancun
+// ----
+// ParserError 5568: (15-23): Cannot use builtin function name "blobhash" as identifier name.

test/libyul/yulSyntaxTests/blobhash_pre_cancun.sol

@@ -0,0 +1,6 @@
+{
+    function blobhash() {}
+}
+// ====
+// EVMVersion: <=shanghai
+// ----