[wasm] Implement AST printing into an ostream

src/wasm/ast-decoder.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_WASM_AST_DECODER_H_
 #define V8_WASM_AST_DECODER_H_
 
 #include "src/signature.h"
 #include "src/wasm/decoder.h"
 #include "src/wasm/wasm-opcodes.h"
@@ skipping 195 matching lines @@
 
 // All of the various data structures necessary to decode a function body.
 struct FunctionBody {
   ModuleEnv* module;  // module environment
   FunctionSig* sig;   // function signature
   const byte* base;   // base of the module bytes, for error reporting
   const byte* start;  // start of the function body
   const byte* end;    // end of the function body
 };
 
+static inline FunctionBody FunctionBodyForTesting(const byte* start,
+                                                  const byte* end) {
+  return {nullptr, nullptr, start, start, end};
+}
+
 struct Tree;
 typedef Result<Tree*> TreeResult;
 
 std::ostream& operator<<(std::ostream& os, const Tree& tree);
 
 TreeResult VerifyWasmCode(base::AccountingAllocator* allocator,
                           FunctionBody& body);
 TreeResult BuildTFGraph(base::AccountingAllocator* allocator,
                         TFBuilder* builder, FunctionBody& body);
-void PrintAst(base::AccountingAllocator* allocator, FunctionBody& body);
+bool PrintAst(base::AccountingAllocator* allocator, const FunctionBody& body,
+              std::ostream& os,
+              std::vector<std::tuple<uint32_t, int, int>>* offset_table);
 
 // A simplified form of AST printing, e.g. from a debugger.
 void PrintAstForDebugging(const byte* start, const byte* end);
 
 inline TreeResult VerifyWasmCode(base::AccountingAllocator* allocator,
                                  ModuleEnv* module, FunctionSig* sig,
                                  const byte* start, const byte* end) {
   FunctionBody body = {module, sig, nullptr, start, end};
   return VerifyWasmCode(allocator, body);
 }
@@ skipping 29 matching lines @@
 int OpcodeLength(const byte* pc, const byte* end);
 
 // Computes the arity (number of sub-nodes) of the opcode at the given address.
 int OpcodeArity(const byte* pc, const byte* end);
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_AST_DECODER_H_