Merge pull request #287 from WebAssembly/vs2015_fixes

VS2015 fixes

1 files changed, 8 insertions, 2 deletions

diff --git a/src/support/file.cpp b/src/support/file.cpp
index 8813750d4..c93086990 100644
--- a/src/support/file.cpp
+++ b/src/support/file.cpp
@@ -17,6 +17,7 @@
 #include "support/file.h"
 
 #include <cstdlib>
+#include <limits>
 
 template <typename T>
 T wasm::read_file(const std::string &filename, bool debug) {
@@ -27,8 +28,13 @@ T wasm::read_file(const std::string &filename, bool debug) {
     exit(EXIT_FAILURE);
   }
   infile.seekg(0, std::ios::end);
-  size_t insize = infile.tellg();
-  T input(insize + 1, '\0');
+  std::streampos insize = infile.tellg();
+  if (size_t(insize) >= std::numeric_limits<size_t>::max()) {
+    // Building a 32-bit executable where size_t == 32 bits, we are not able to create strings larger than 2^32 bytes in length, so must abort here.
+    std::cerr << "Failed opening '" << filename << "': Input file too large: " << insize << " bytes. Try rebuilding in 64-bit mode." << std::endl;
+    exit(EXIT_FAILURE);
+  }
+  T input(size_t(insize) + 1, '\0');
   infile.seekg(0);
   infile.read(&input[0], insize);
   return input;