From e90248c136765c2b7fc882d3472e777e797dfe9b Mon Sep 17 00:00:00 2001
From: Bhargava Shastry <bhargava.shastry@ethereum.org>
Date: Tue, 9 Feb 2021 16:46:16 +0100
Subject: [PATCH] Enable abi pragmas and fix formatting.

---
 test/tools/ossfuzz/SolidityGenerator.cpp | 19 ++++++++-----------
 test/tools/ossfuzz/SolidityGenerator.h   | 23 +++++++++++++++++++++++
 2 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/test/tools/ossfuzz/SolidityGenerator.cpp b/test/tools/ossfuzz/SolidityGenerator.cpp
index f5975b64e..6a1e534e8 100644
--- a/test/tools/ossfuzz/SolidityGenerator.cpp
+++ b/test/tools/ossfuzz/SolidityGenerator.cpp
@@ -133,15 +133,12 @@ string SourceUnitGenerator::visit()
 
 string PragmaGenerator::visit()
 {
-	static constexpr const char* preamble = R"(
-		pragma solidity >= 0.0.0;
-		pragma experimental SMTChecker;
-	)";
-	// Choose equally at random from coder v1 and v2
-	string abiPragma = "pragma abicoder v" +
-		to_string(uRandDist->distributionOneToN(2)) +
-		";\n";
-	return preamble + abiPragma;
+	set<string> pragmas = uRandDist->subset(s_genericPragmas);
+	// Choose either abicoder v1 or v2 but not both.
+	pragmas.insert(s_abiPragmas[uRandDist->distributionOneToN(s_abiPragmas.size()) - 1]);
+	ostringstream pragmaString;
+	copy(pragmas.begin(), pragmas.end(), ostream_iterator<string>(pragmaString, "\n"));
+	return pragmaString.str() + "\n";
 }
 
 string ImportGenerator::visit()
@@ -160,7 +157,7 @@ string ImportGenerator::visit()
 			os << "import "
 			   << "\""
 			   << state->randomPath()
-			   << "\";";
+			   << "\";\n";
 	}
 	else
 	{
@@ -169,7 +166,7 @@ string ImportGenerator::visit()
 		os << "import "
 			<< "\""
 			<< state->randomNonCurrentPath()
-			<< "\";";
+			<< "\";\n";
 	}
 	return os.str();
 }
diff --git a/test/tools/ossfuzz/SolidityGenerator.h b/test/tools/ossfuzz/SolidityGenerator.h
index 6b8a535f8..229fc04a0 100644
--- a/test/tools/ossfuzz/SolidityGenerator.h
+++ b/test/tools/ossfuzz/SolidityGenerator.h
@@ -77,6 +77,20 @@ struct UniformRandomDistribution
 		solAssert(_n > 0, "");
 		return distributionOneToN(_n) == 1;
 	}
+	/// @returns a subset whose elements are of type @param T
+	/// created from the set @param _container using
+	/// uniform selection.
+	template <typename T>
+	std::set<T> subset(std::set<T> const& _container)
+	{
+		size_t s = _container.size();
+		solAssert(s > 1, "");
+		std::set<T> subContainer;
+		for (auto const& item: _container)
+			if (probable(s))
+				subContainer.insert(item);
+		return subContainer;
+	}
 	std::unique_ptr<RandomEngine> randomEngine;
 };
 
@@ -231,6 +245,15 @@ public:
 	{}
 	std::string visit() override;
 	std::string name() override { return "Pragma generator"; }
+private:
+	std::set<std::string> const s_genericPragmas = {
+		R"(pragma solidity >= 0.0.0;)",
+		R"(pragma experimental SMTChecker;)",
+	};
+	std::vector<std::string> const s_abiPragmas = {
+		R"(pragma abicoder v1;)",
+		R"(pragma abicoder v2;)"
+	};
 };
 
 class ImportGenerator: public GeneratorBase