Merge remote-tracking branch 'origin/develop' into breaking

libyul/backends/wasm/BinaryTransform.cpp

@@ -305,13 +305,23 @@ bytes BinaryTransform::run(Module const& _module)
 	ret += exportSection(functionIDs);
 
 	map<string, pair<size_t, size_t>> subModulePosAndSize;
-	for (auto const& sub: _module.subModules)
+	for (auto const& [name, module]: _module.subModules)
 	{
 		// TODO should we prefix and / or shorten the name?
-		bytes data = BinaryTransform::run(sub.second);
-		size_t length = data.size();
-		ret += customSection(sub.first, move(data));
-		subModulePosAndSize[sub.first] = {ret.size() - length, length};
+		bytes data = BinaryTransform::run(module);
+		size_t const length = data.size();
+		ret += customSection(name, move(data));
+		// Skip all the previous sections and the size field of this current custom section.
+		size_t const offset = ret.size() - length;
+		subModulePosAndSize[name] = {offset, length};
+	}
+	for (auto const& [name, data]: _module.customSections)
+	{
+		size_t const length = data.size();
+		ret += customSection(name, data);
+		// Skip all the previous sections and the size field of this current custom section.
+		size_t const offset = ret.size() - length;
+		subModulePosAndSize[name] = {offset, length};
 	}
 
 	BinaryTransform bt(
@@ -663,9 +673,11 @@ bytes BinaryTransform::globalSection(vector<wasm::GlobalVariableDeclaration> con
 
 bytes BinaryTransform::exportSection(map<string, size_t> const& _functionIDs)
 {
-	bytes result = lebEncode(2);
+	bool hasMain = _functionIDs.count("main");
+	bytes result = lebEncode(hasMain ? 2 : 1);
 	result += encodeName("memory") + toBytes(Export::Memory) + lebEncode(0);
-	result += encodeName("main") + toBytes(Export::Function) + lebEncode(_functionIDs.at("main"));
+	if (hasMain)
+		result += encodeName("main") + toBytes(Export::Function) + lebEncode(_functionIDs.at("main"));
 	return makeSection(Section::EXPORT, move(result));
 }
 

libyul/backends/wasm/BinaryTransform.h

@@ -112,6 +112,8 @@ private:
 	std::map<std::string, size_t> const m_globalIDs;
 	std::map<std::string, size_t> const m_functionIDs;
 	std::map<std::string, size_t> const m_functionTypes;
+	/// The map of submodules, where the pair refers to the [offset, length]. The offset is
+	/// an absolute offset within the resulting assembled bytecode.
 	std::map<std::string, std::pair<size_t, size_t>> const m_subModulePosAndSize;
 
 	std::map<std::string, size_t> m_locals;

libyul/backends/wasm/TextTransform.cpp

@@ -44,6 +44,11 @@ string TextTransform::run(wasm::Module const& _module)
 			"    ;; sub-module \"" +
 			sub.first +
 			"\" will be encoded as custom section in binary here, but is skipped in text mode.\n";
+	for (auto const& data: _module.customSections)
+		ret +=
+			"    ;; custom-section \"" +
+			data.first +
+			"\" will be encoded as custom section in binary here, but is skipped in text mode.\n";
 	for (wasm::FunctionImport const& imp: _module.imports)
 	{
 		ret += "    (import \"" + imp.module + "\" \"" + imp.externalName + "\" (func $" + imp.internalName;
@@ -56,8 +61,13 @@ string TextTransform::run(wasm::Module const& _module)
 
 	// allocate one 64k page of memory and make it available to the Ethereum client
 	ret += "    (memory $memory (export \"memory\") 1)\n";
-	// export the main function
-	ret += "    (export \"main\" (func $main))\n";
+	for (auto const& f: _module.functions)
+		if (f.name == "main")
+		{
+			// export the main function
+			ret += "    (export \"main\" (func $main))\n";
+			break;
+		}
 
 	for (auto const& g: _module.globals)
 		ret += "    (global $" + g.variableName + " (mut " + encodeType(g.type) + ") (" + encodeType(g.type) + ".const 0))\n";

libyul/backends/wasm/WasmAST.h

@@ -21,6 +21,8 @@
 
 #pragma once
 
+#include <libsolutil/Common.h>
+
 #include <variant>
 #include <string>
 #include <vector>
@@ -108,6 +110,7 @@ struct Module
 	std::vector<FunctionImport> imports;
 	std::vector<FunctionDefinition> functions;
 	std::map<std::string, Module> subModules;
+	std::map<std::string, bytes> customSections;
 };
 
 }

libyul/backends/wasm/WasmObjectCompiler.cpp

@@ -51,8 +51,10 @@ wasm::Module WasmObjectCompiler::run(Object& _object)
 	for (auto& subNode: _object.subObjects)
 		if (Object* subObject = dynamic_cast<Object*>(subNode.get()))
 			module.subModules[subObject->name.str()] = run(*subObject);
+		else if (Data* subObject = dynamic_cast<Data*>(subNode.get()))
+			module.customSections[subObject->name.str()] = subObject->data;
 		else
-			yulAssert(false, "Data is not yet supported for Wasm.");
+			yulAssert(false, "");
 
 	return module;
 }