Merge pull request #5341 from ethereum/optimizeAssemblyCommandline

Apply the optimize commandline parameter to assembly mode.

Changelog.md

@@ -7,6 +7,7 @@ Language Features:
 Compiler Features:
  * Build System: LLL is not built anymore by default. Must configure it with CMake as `-DLLL=ON`.
  * Code generator: Do not perform redundant double cleanup on unsigned integers when loading from calldata.
+ * Commandline interface: Experimental ``--optimize`` option for assembly mode.
  * SMTChecker: SMTLib2 queries and responses passed via standard JSON compiler interface.
  * SMTChecker: Support ``msg``, ``tx`` and ``block`` member variables.
  * SMTChecker: Support ``gasleft()`` and ``blockhash()`` functions.

libsolidity/interface/AssemblyStack.cpp

@@ -34,6 +34,8 @@
 
 #include <libevmasm/Assembly.h>
 
+#include <libyul/optimiser/Suite.h>
+
 using namespace std;
 using namespace dev;
 using namespace langutil;
@@ -79,6 +81,13 @@ bool AssemblyStack::parseAndAnalyze(std::string const& _sourceName, std::string
 	return analyzeParsed();
 }
 
+void AssemblyStack::optimize()
+{
+	solAssert(m_language != Language::Assembly, "Optimization requested for loose assembly.");
+	yul::OptimiserSuite::run(*m_parserResult->code, *m_parserResult->analysisInfo);
+	solAssert(analyzeParsed(), "Invalid source code after optimization.");
+}
+
 bool AssemblyStack::analyzeParsed()
 {
 	solAssert(m_parserResult, "");

libsolidity/interface/AssemblyStack.h

@@ -69,6 +69,9 @@ public:
 	/// Multiple calls overwrite the previous state.
 	bool parseAndAnalyze(std::string const& _sourceName, std::string const& _source);
 
+	/// Run the optimizer suite. Can only be used with Yul or strict assembly.
+	void optimize();
+
 	/// Run the assembly step (should only be called after parseAndAnalyze).
 	MachineAssemblyObject assemble(Machine _machine) const;
 

solc/CommandLineInterface.cpp

@@ -626,15 +626,15 @@ Allowed options)",
 		)
 		(
 			g_argAssemble.c_str(),
-			"Switch to assembly mode, ignoring all options except --machine and assumes input is assembly."
+			"Switch to assembly mode, ignoring all options except --machine and --optimize and assumes input is assembly."
 		)
 		(
 			g_argYul.c_str(),
-			"Switch to Yul mode, ignoring all options except --machine and assumes input is Yul."
+			"Switch to Yul mode, ignoring all options except --machine and --optimize and assumes input is Yul."
 		)
 		(
 			g_argStrictAssembly.c_str(),
-			"Switch to strict assembly mode, ignoring all options except --machine and assumes input is strict assembly."
+			"Switch to strict assembly mode, ignoring all options except --machine and --optimize and assumes input is strict assembly."
 		)
 		(
 			g_argMachine.c_str(),
@@ -820,6 +820,7 @@ bool CommandLineInterface::processInput()
 		using Machine = AssemblyStack::Machine;
 		Input inputLanguage = m_args.count(g_argYul) ? Input::Yul : (m_args.count(g_argStrictAssembly) ? Input::StrictAssembly : Input::Assembly);
 		Machine targetMachine = Machine::EVM;
+		bool optimize = m_args.count(g_argOptimize);
 		if (m_args.count(g_argMachine))
 		{
 			string machine = m_args[g_argMachine].as<string>();
@@ -835,7 +836,18 @@ bool CommandLineInterface::processInput()
 				return false;
 			}
 		}
-		return assemble(inputLanguage, targetMachine);
+		if (optimize && inputLanguage == Input::Assembly)
+		{
+			serr() <<
+				"Optimizer cannot be used for loose assembly. Use --" <<
+				g_strStrictAssembly <<
+				" or --" <<
+				g_strYul <<
+				"." <<
+				endl;
+			return false;
+		}
+		return assemble(inputLanguage, targetMachine, optimize);
 	}
 	if (m_args.count(g_argLink))
 	{
@@ -1179,7 +1191,8 @@ string CommandLineInterface::objectWithLinkRefsHex(eth::LinkerObject const& _obj
 
 bool CommandLineInterface::assemble(
 	AssemblyStack::Language _language,
-	AssemblyStack::Machine _targetMachine
+	AssemblyStack::Machine _targetMachine,
+	bool _optimize
 )
 {
 	bool successful = true;
@@ -1191,6 +1204,8 @@ bool CommandLineInterface::assemble(
 		{
 			if (!stack.parseAndAnalyze(src.first, src.second))
 				successful = false;
+			else if (_optimize)
+				stack.optimize();
 		}
 		catch (Exception const& _exception)
 		{

solc/CommandLineInterface.h

@@ -59,7 +59,7 @@ private:
 	/// @returns the full object with library placeholder hints in hex.
 	static std::string objectWithLinkRefsHex(eth::LinkerObject const& _obj);
 
-	bool assemble(AssemblyStack::Language _language, AssemblyStack::Machine _targetMachine);
+	bool assemble(AssemblyStack::Language _language, AssemblyStack::Machine _targetMachine, bool _optimize);
 
 	void outputCompilationResults();
 

test/cmdlineTests.sh

@@ -262,11 +262,46 @@ SOLTMPDIR=$(mktemp -d)
 )
 rm -rf "$SOLTMPDIR"
 
-printTask "Testing assemble, yul, strict-assembly..."
+test_solc_assembly_output() {
+    local input="${1}"
+    local expected="${2}"
+    local solc_args="${3}"
+
+    local expected_object="object \"object\" { code "${expected}" }"
+
+    output=$(echo "${input}" | "$SOLC" - ${solc_args} 2>/dev/null)
+    empty=$(echo $output | sed -ne '/'"${expected_object}"'/p')
+    if [ -z "$empty" ]
+    then
+        printError "Incorrect assembly output. Expected: "
+        echo -e ${expected}
+        printError "with arguments ${solc_args}, but got:"
+        echo "${output}"
+        exit 1
+    fi
+}
+
+printTask "Testing assemble, yul, strict-assembly and optimize..."
+(
     echo '{}' | "$SOLC" - --assemble &>/dev/null
     echo '{}' | "$SOLC" - --yul &>/dev/null
     echo '{}' | "$SOLC" - --strict-assembly &>/dev/null
 
+    # Test options above in conjunction with --optimize.
+    # Using both, --assemble and --optimize should fail.
+    ! echo '{}' | "$SOLC" - --assemble --optimize &>/dev/null
+
+    # Test yul and strict assembly output
+    # Non-empty code results in non-empty binary representation with optimizations turned off,
+    # while it results in empty binary representation with optimizations turned on.
+    test_solc_assembly_output "{ let x:u256 := 0:u256 }" "{ let x:u256 := 0:u256 }" "--yul"
+    test_solc_assembly_output "{ let x:u256 := 0:u256 }" "{ }" "--yul --optimize"
+
+    test_solc_assembly_output "{ let x := 0 }" "{ let x := 0 }" "--strict-assembly"
+    test_solc_assembly_output "{ let x := 0 }" "{ }" "--strict-assembly --optimize"
+)
+
+
 printTask "Testing standard input..."
 SOLTMPDIR=$(mktemp -d)
 (