Visual Studio build fails

[matthewgertner]

Since you added a call to snprintf, npm is no longer able to build buffertools using Visual Studio:

..\buffertools.cc(431): error C3861: 'snprintf': identifier not found

Believe it or not, even Visual Studio 2013 does not appear to support snprintf.

The suggested workaround is:

#if _MSC_VER
#define snprintf _snprintf
#endif

[bnoordhuis]

Right, I kind of knew that in the back of my head, I fixed the same issue in joyent/node a while ago. Does this patch help?

diff --git a/buffertools.cc b/buffertools.cc
index c3b49f4..34ba18d 100644
--- a/buffertools.cc
+++ b/buffertools.cc
@@ -20,8 +20,10 @@
 #include "v8.h"

 #include <algorithm>
-#include <cstring>
+#include <stdarg.h>
 #include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
 #include <string>

 namespace {
@@ -97,6 +99,24 @@ using v8::Value;
     v8::ThrowException(v8::String::New(message))
 #endif  // NODE_MAJOR_VERSION > 0 || NODE_MINOR_VERSION > 10

+#if defined(_WIN32)
+// Emulate snprintf() on windows, _snprintf() doesn't zero-terminate
+// the buffer on overflow.
+inline int snprintf(char* buf, size_t size, const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  const int len = _vsprintf_p(buf, size, fmt, ap);
+  va_end(ap);
+  if (len < 0) {
+    abort();
+  }
+  if (static_cast<unsigned>(len) >= size && size > 0) {
+    buf[size - 1] = '\0';
+  }
+  return len;
+}
+#endif
+
 // this is an application of the Curiously Recurring Template Pattern
 template <class Derived> struct UnaryAction {
   Local<Value> apply(Local<Object> buffer,

[matthewgertner]

Well it builds of course. I'll have to do some more testing to verify that it runs properly (though I don't doubt that it does). The main problem is that buffertools is being installed and built by npm inside a deep tree of packages, so I need to figure out how to get it to use the patched version.

[bnoordhuis]

You can npm link it in your top-level node_modules directory and then you just delete all lower-down buffertools directories.

[matthewgertner]

The problem is that it runs on our CI server with a fresh npm install every time, so it's pulling and building without any obvious possibility to get in there and patch something. I dealt with it for now by dropping your snprintf implementation into stdio.h.

[bnoordhuis]

Okay, if you can confirm that it works for you, I'll land it and publish a new release.

[matthewgertner]

I guess you don't have a test that triggers that error message? I have everything built but will have to write a testcase if you don't have one.

[bnoordhuis]

Well, there's not much to test for - the module either builds or it doesn't. The confirmation I'm looking for is whether it builds for you. :-)

[vineet89]

I can confirm that @matthewgertner 's solution worked and I was able to build packages with buffertools as their dependency(by using npm link). Git threw some fatal errors when I tried to apply the above patch, I will try to add the lines manually and revert in some time.

Thanks to both of you for the fix

[matthewgertner]

@bnoordhuis Ah okay I thought you wanted me to test that the snprintf function works. I can confirm that it does build.

[bnoordhuis]

Cheers, fixed in 70732be and published as v2.1.2.

[matthewgertner]

Awesome, thanks @bnoordhuis.