Do not add an extra null character when reading files

src/support/file.cpp

@@ -71,7 +71,8 @@ T wasm::read_file(const std::string& filename, Flags::BinaryOption binary) {
             << "': Input file too large: " << insize
             << " bytes. Try rebuilding in 64-bit mode.";
   }
-  T input(size_t(insize) + (binary == Flags::Binary ? 0 : 1), '\0');
+  // Zero-initialize the string or vector with the expected size.
+  T input(size_t(insize), '\0');
   if (size_t(insize) == 0) {
     return input;
   }
@@ -82,8 +83,7 @@ T wasm::read_file(const std::string& filename, Flags::BinaryOption binary) {
     // Truncate size to the number of ASCII characters actually read in text
     // mode (which is generally less than the number of bytes on Windows, if
     // \r\n line endings are present)
-    input.resize(chars + 1);
-    input[chars] = '\0';
+    input.resize(chars);
   }
   return input;
 }

src/tools/wasm-ctor-eval.cpp

@@ -1436,8 +1436,6 @@ int main(int argc, const char* argv[]) {
                     });
   options.parse(argc, argv);
 
-  auto input(read_file<std::string>(options.extra["infile"], Flags::Text));
-
   Module wasm;
   options.applyFeatures(wasm);
 

src/tools/wasm-metadce.cpp

@@ -485,8 +485,6 @@ int main(int argc, const char* argv[]) {
     Fatal() << "no graph file provided.";
   }
 
-  auto input(read_file<std::string>(options.extra["infile"], Flags::Text));
-
   Module wasm;
   options.applyFeatures(wasm);
 

src/tools/wasm2js.cpp

@@ -976,8 +976,7 @@ int main(int argc, const char* argv[]) {
       ModuleReader reader;
       reader.read(input, wasm, "");
     } else {
-      auto input(
-        read_file<std::vector<char>>(options.extra["infile"], Flags::Text));
+      auto input(read_file<std::string>(options.extra["infile"], Flags::Text));
       if (options.debug) {
         std::cerr << "s-parsing..." << std::endl;
       }

src/wasm/wasm-io.cpp

@@ -39,8 +39,7 @@ bool useNewWATParser = false;
 
 static void readTextData(std::string& input, Module& wasm, IRProfile profile) {
   if (useNewWATParser) {
-    std::string_view in(input.c_str());
-    if (auto parsed = WATParser::parseModule(wasm, in);
+    if (auto parsed = WATParser::parseModule(wasm, input);
         auto err = parsed.getErr()) {
       Fatal() << err->msg;
     }