BytesParsing for calldata (#58)

* taking first stab at BytesParsing for calldata impl (untested)

* fix typo

* implement calldata parsing and testing for BytesParsing

* add forge runs parameter to BytesParsing test

* fix calldata prefixedSlice parsing impl

Author: nonergodic

gen/libraryTestWrapper.ts

@@ -1,10 +1,19 @@
 //Simple parser for .sol files that finds libraries defined in the file and creates a wrapper
-//  that converts all their internal functions to external functions so they can be tested
-//  in forge unit tests.
+//  that converts all their internal functions to external functions so they can be externally
+//  called in forge unit tests.
+//
+//Forge supports vm.expectRevert even for internal functions, so this wrapper is primarily
+//  helpful for libraries like BytesParsing (the original motivation for this script) where
+//  you have a large family of similar functions to test and you don't want to write a separate
+//  test for each one. So, it really mostly is a workaround for Solidity's lack of support for
+//  generics.
+
+//Regarding the implementation of this script:
 //Instead of properly parsing the full AST, we make our task of finding and transforming the
 //  relevant bits easier by making some basic assumptions about code formatting that any sane
-//  code should almost certainly adhere to regardless.
-
+//  code should almost certainly adhere to regardless, like closing braces of library definitions
+//  being on their own line with no leading whitespace, etc.
+//
 //Solidity language grammar:
 //  https://docs.soliditylang.org/en/latest/grammar.html
 
@@ -43,8 +52,22 @@ if (process.argv.length != 3) {
   process.exit(1);
 }
 
-const filename = process.argv[2];
-let fileCode = readFileSync("../src/" + filename + filename.endsWith(".sol") ? "" : ".sol", "utf8");
+//convenience for use with Makefile:
+//If no .sol file ending is specified, this script will use Wormhole Solidity SDK defaults for
+//  the file paths, the SPDX license header, the pragma version, and the import statement.
+const fullPath = (() => {
+  const filename = process.argv[2];
+  if (filename.endsWith(".sol"))
+    return filename;
+
+  console.log(
+    `// SPDX-License-Identifier: Apache 2\npragma solidity ^0.8.24;\n\n` +
+    `import "wormhole-sdk/${filename}.sol";\n`
+  );
+
+  return "../src/" + filename + ".sol";
+})();
+let fileCode = readFileSync(fullPath, "utf8");
 
 //we first remove all comments so we can be sure that everything we're parsing is actual code
 fileCode = removeComments(fileCode);
@@ -76,13 +99,13 @@ for (const libs of libMatches) {
     const [_, funcName, funcParasRaw, modsRaw, close] = funcs;
     if (close == ';')
       continue; //function pointer, not a function definition
-    
+
     if (!modsRaw.includes("internal"))
       continue; //not an internal function
 
     const retParasRegex = /returns\s*\(([\s\S]*?)\)/;
     const retParasRaw = modsRaw.match(retParasRegex);
-    
+
     const collapseSpaceRegex = /\s\s+/g;
     const paramsToArray = (paramList: string) =>
       paramList.replace(collapseSpaceRegex, ' ').trim().split(',').map(param => {
@@ -100,12 +123,7 @@ for (const libs of libMatches) {
   }
 }
 
-console.log(`// SPDX-License-Identifier: Apache 2
-pragma solidity ^0.8.24;
-
-//This file was auto-generated by libraryTestWrapper.ts
-
-import "wormhole-sdk/${filename}.sol";`);
+console.log(`// This file was auto-generated by wormhole-solidity-sdk gen/libraryTestWrapper.ts`);
 
 const pConcat = (paras: string[]) =>
   (paras.length > 2 ? "\n    " : "") +
@@ -121,7 +139,7 @@ const pNames = (paras: string[]) =>
 
 for (const [libName, funcs] of Object.entries(libraries)) {
   console.log(`\ncontract ${libName}TestWrapper {`);
-  const funcCode = [];  
+  const funcCode = [];
   for (const func of funcs)
     funcCode.push([
       `  function ${func.name}(${pConcat(func.paras)}) external ${func.stateMut}` +

src/constants/Common.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: Apache 2
+pragma solidity ^0.8.4;
+
+uint256 constant FREE_MEMORY_PTR = 0x40;
+uint256 constant WORD_SIZE = 32;
+//we can't define _WORD_SIZE_MINUS_ONE via _WORD_SIZE - 1 because of solc restrictions
+//  what constants can be used in inline assembly
+uint256 constant WORD_SIZE_MINUS_ONE = 31; //=0x1f=0b00011111
+
+//see section "prefer `< MAX + 1` over `<= MAX` for const comparison" in docs/Optimization.md
+uint256 constant WORD_SIZE_PLUS_ONE = 33;