From 19fada966fb2cefe655458cce1c4395015fc3558 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kamil=20=C5=9Aliwak?= <kamil.sliwak@codepoets.it>
Date: Thu, 24 Jun 2021 13:29:01 +0200
Subject: [PATCH] Do not use \b, \v and \f escapes in string literals in
 generated Yul code

---
 libsolidity/codegen/ir/IRGeneratorForStatements.cpp  |  2 +-
 libsolutil/CommonData.cpp                            | 12 ++++--------
 libsolutil/CommonData.h                              |  2 +-
 libyul/AsmPrinter.cpp                                |  2 +-
 .../hex_string_with_non_printable_characters.sol     | 12 ++++++++++++
 .../hex_string_literal_non_printable_characters.yul  |  6 ++++++
 6 files changed, 25 insertions(+), 11 deletions(-)
 create mode 100644 test/libsolidity/semanticTests/literals/hex_string_with_non_printable_characters.sol
 create mode 100644 test/libyul/yulSyntaxTests/hex_string_literal_non_printable_characters.yul

diff --git a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
index e19e22f29..cd2b3805c 100644
--- a/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
+++ b/libsolidity/codegen/ir/IRGeneratorForStatements.cpp
@@ -3157,5 +3157,5 @@ bool IRGeneratorForStatements::visit(TryCatchClause const& _clause)
 string IRGeneratorForStatements::linkerSymbol(ContractDefinition const& _library) const
 {
 	solAssert(_library.isLibrary(), "");
-	return "linkersymbol(" + util::escapeAndQuoteString(_library.fullyQualifiedName()) + ")";
+	return "linkersymbol(" + util::escapeAndQuoteYulString(_library.fullyQualifiedName()) + ")";
 }
diff --git a/libsolutil/CommonData.cpp b/libsolutil/CommonData.cpp
index 1dc616836..c6688fee8 100644
--- a/libsolutil/CommonData.cpp
+++ b/libsolutil/CommonData.cpp
@@ -192,11 +192,13 @@ string solidity::util::formatAsStringOrNumber(string const& _value)
 		if (c <= 0x1f || c >= 0x7f || c == '"')
 			return "0x" + h256(_value, h256::AlignLeft).hex();
 
-	return escapeAndQuoteString(_value);
+	// The difference in escaping is only in characters below 0x1f and the string does not have them
+	// so this will work for Solidity strings too.
+	return escapeAndQuoteYulString(_value);
 }
 
 
-string solidity::util::escapeAndQuoteString(string const& _input)
+string solidity::util::escapeAndQuoteYulString(string const& _input)
 {
 	string out;
 
@@ -205,18 +207,12 @@ string solidity::util::escapeAndQuoteString(string const& _input)
 			out += "\\\\";
 		else if (c == '"')
 			out += "\\\"";
-		else if (c == '\b')
-			out += "\\b";
-		else if (c == '\f')
-			out += "\\f";
 		else if (c == '\n')
 			out += "\\n";
 		else if (c == '\r')
 			out += "\\r";
 		else if (c == '\t')
 			out += "\\t";
-		else if (c == '\v')
-			out += "\\v";
 		else if (!isprint(c, locale::classic()))
 		{
 			ostringstream o;
diff --git a/libsolutil/CommonData.h b/libsolutil/CommonData.h
index b33231a32..3c8b2d80c 100644
--- a/libsolutil/CommonData.h
+++ b/libsolutil/CommonData.h
@@ -554,7 +554,7 @@ std::string formatAsStringOrNumber(std::string const& _value);
 
 /// @returns a string with the usual backslash-escapes for non-ASCII
 /// characters and surrounded by '"'-characters.
-std::string escapeAndQuoteString(std::string const& _input);
+std::string escapeAndQuoteYulString(std::string const& _input);
 
 template<typename Container, typename Compare>
 bool containerEqual(Container const& _lhs, Container const& _rhs, Compare&& _compare)
diff --git a/libyul/AsmPrinter.cpp b/libyul/AsmPrinter.cpp
index 8c5f26178..e91208feb 100644
--- a/libyul/AsmPrinter.cpp
+++ b/libyul/AsmPrinter.cpp
@@ -57,7 +57,7 @@ string AsmPrinter::operator()(Literal const& _literal) const
 		break;
 	}
 
-	return escapeAndQuoteString(_literal.value.str()) + appendTypeName(_literal.type);
+	return escapeAndQuoteYulString(_literal.value.str()) + appendTypeName(_literal.type);
 }
 
 string AsmPrinter::operator()(Identifier const& _identifier) const
diff --git a/test/libsolidity/semanticTests/literals/hex_string_with_non_printable_characters.sol b/test/libsolidity/semanticTests/literals/hex_string_with_non_printable_characters.sol
new file mode 100644
index 000000000..5b703b614
--- /dev/null
+++ b/test/libsolidity/semanticTests/literals/hex_string_with_non_printable_characters.sol
@@ -0,0 +1,12 @@
+contract C {
+    function f() public pure returns (bytes32 result) {
+        assembly {
+            result := hex"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f"
+        }
+    }
+}
+// ====
+// compileToEwasm: also
+// compileViaYul: also
+// ----
+// f() -> 0x000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f
diff --git a/test/libyul/yulSyntaxTests/hex_string_literal_non_printable_characters.yul b/test/libyul/yulSyntaxTests/hex_string_literal_non_printable_characters.yul
new file mode 100644
index 000000000..4a28c44a7
--- /dev/null
+++ b/test/libyul/yulSyntaxTests/hex_string_literal_non_printable_characters.yul
@@ -0,0 +1,6 @@
+{
+    let name := hex"000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f"
+}
+// ====
+// dialect: evm
+// ----