[wasm] Remove non-const arguments from decoder

R=ahaas@chromium.org

Bug: v8:9429, v8:9396
Change-Id: I79e5d707f6c3970c96eb2186604d8b26fda787e5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1687897Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62556}

src/wasm/function-body-decoder.cc

@@ -45,7 +45,7 @@ BytecodeIterator::BytecodeIterator(const byte* start, const byte* end,
 DecodeResult VerifyWasmCode(AccountingAllocator* allocator,
                             const WasmFeatures& enabled,
                             const WasmModule* module, WasmFeatures* detected,
-                            FunctionBody& body) {  // NOLINT(runtime/references)
+                            const FunctionBody& body) {
   Zone zone(allocator, ZONE_NAME);
   WasmFullDecoder<Decoder::kValidate, EmptyInterface> decoder(
       &zone, module, enabled, detected, body);

src/wasm/function-body-decoder.h

@@ -34,10 +34,11 @@ struct FunctionBody {
       : sig(sig), offset(offset), start(start), end(end) {}
 };
 
-V8_EXPORT_PRIVATE DecodeResult
-VerifyWasmCode(AccountingAllocator* allocator, const WasmFeatures& enabled,
-               const WasmModule* module, WasmFeatures* detected,
-               FunctionBody& body);  // NOLINT(runtime/references)
+V8_EXPORT_PRIVATE DecodeResult VerifyWasmCode(AccountingAllocator* allocator,
+                                              const WasmFeatures& enabled,
+                                              const WasmModule* module,
+                                              WasmFeatures* detected,
+                                              const FunctionBody& body);
 
 enum PrintLocals { kPrintLocals, kOmitLocals };
 V8_EXPORT_PRIVATE

src/wasm/module-compiler.cc

@@ -1921,7 +1921,7 @@ bool AsyncStreamingProcessor::ProcessSection(SectionCode section_code,
   if (section_code == SectionCode::kUnknownSectionCode) {
     Decoder decoder(bytes, offset);
     section_code = ModuleDecoder::IdentifyUnknownSection(
-        decoder, bytes.begin() + bytes.length());
+        &decoder, bytes.begin() + bytes.length());
     if (section_code == SectionCode::kUnknownSectionCode) {
       // Skip unknown sections that we do not know how to handle.
       return true;

src/wasm/module-decoder.h

@@ -139,14 +139,12 @@ class ModuleDecoder {
 
   // Translates the unknown section that decoder is pointing to to an extended
   // SectionCode if the unknown section is known to decoder.
-  // The decoder is expected to point after the section lenght and just before
+  // The decoder is expected to point after the section length and just before
   // the identifier string of the unknown section.
   // If a SectionCode other than kUnknownSectionCode is returned, the decoder
   // will point right after the identifier string. Otherwise, the position is
   // undefined.
-  static SectionCode IdentifyUnknownSection(
-      Decoder& decoder,  // NOLINT(runtime/references)
-      const byte* end);
+  static SectionCode IdentifyUnknownSection(Decoder* decoder, const byte* end);
 
  private:
   const WasmFeatures enabled_features_;

src/wasm/wasm-result.cc

@@ -18,29 +18,29 @@ namespace wasm {
 namespace {
 
 PRINTF_FORMAT(3, 0)
-void VPrintFToString(std::string& str,  // NOLINT(runtime/references)
-                     size_t str_offset, const char* format, va_list args) {
-  DCHECK_LE(str_offset, str.size());
+void VPrintFToString(std::string* str, size_t str_offset, const char* format,
+                     va_list args) {
+  DCHECK_LE(str_offset, str->size());
   size_t len = str_offset + strlen(format);
   // Allocate increasingly large buffers until the message fits.
   for (;; len = base::bits::RoundUpToPowerOfTwo64(len + 1)) {
     DCHECK_GE(kMaxInt, len);
-    str.resize(len);
+    str->resize(len);
     va_list args_copy;
     va_copy(args_copy, args);
-    int written = VSNPrintF(Vector<char>(&str.front() + str_offset,
+    int written = VSNPrintF(Vector<char>(&str->front() + str_offset,
                                          static_cast<int>(len - str_offset)),
                             format, args_copy);
     va_end(args_copy);
     if (written < 0) continue;  // not enough space.
-    str.resize(str_offset + written);
+    str->resize(str_offset + written);
     return;
   }
 }
 
 PRINTF_FORMAT(3, 4)
-void PrintFToString(std::string& str,  // NOLINT(runtime/references)
-                    size_t str_offset, const char* format, ...) {
+void PrintFToString(std::string* str, size_t str_offset, const char* format,
+                    ...) {
   va_list args;
   va_start(args, format);
   VPrintFToString(str, str_offset, format, args);
@@ -52,7 +52,7 @@ void PrintFToString(std::string& str,  // NOLINT(runtime/references)
 // static
 std::string WasmError::FormatError(const char* format, va_list args) {
   std::string result;
-  VPrintFToString(result, 0, format, args);
+  VPrintFToString(&result, 0, format, args);
   return result;
 }
 
@@ -63,10 +63,10 @@ void ErrorThrower::Format(ErrorType type, const char* format, va_list args) {
 
   size_t context_len = 0;
   if (context_) {
-    PrintFToString(error_msg_, 0, "%s: ", context_);
+    PrintFToString(&error_msg_, 0, "%s: ", context_);
     context_len = error_msg_.size();
   }
-  VPrintFToString(error_msg_, context_len, format, args);
+  VPrintFToString(&error_msg_, context_len, format, args);
   error_type_ = type;
 }