[wasm] Generate source position information

src/wasm/ast-decoder.cc

 // 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.
 
 #include "src/signature.h"
 
 #include "src/bit-vector.h"
 #include "src/flags.h"
 #include "src/handles.h"
 #include "src/zone-containers.h"
@@ skipping 617 matching lines @@
         if (pc_ >= limit_) {
           // End of code reached or exceeded.
           if (pc_ > limit_ && ok()) {
             error("Beyond end of code");
           }
           return;
         }
         continue;  // back to decoding loop.
       }
 
+      DCHECK_EQ(pc_ - start_, static_cast<int>(pc_ - start_));
+      if (builder_)
+        builder_->SetCurrentSourcePosition(static_cast<int>(pc_ - start_));
+
       switch (opcode) {
         case kExprNop:
           Leaf(kAstStmt);
           break;
         case kExprBlock: {
           BlockCountOperand operand(this, pc_);
           if (operand.count < 1) {
             Leaf(kAstStmt);
           } else {
             Shift(kAstEnd, operand.count);
@@ skipping 1139 matching lines @@
 BitVector* AnalyzeLoopAssignmentForTesting(Zone* zone, size_t num_locals,
                                            const byte* start, const byte* end) {
   FunctionBody body = {nullptr, nullptr, nullptr, start, end};
   SR_WasmDecoder decoder(zone, nullptr, body);
   return decoder.AnalyzeLoopAssignmentForTesting(start, num_locals);
 }
 
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8