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-rw-r--r--mozglue/misc/Sprintf.h98
1 files changed, 98 insertions, 0 deletions
diff --git a/mozglue/misc/Sprintf.h b/mozglue/misc/Sprintf.h
new file mode 100644
index 0000000000..4b459de82d
--- /dev/null
+++ b/mozglue/misc/Sprintf.h
@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* Provides a safer sprintf for printing to fixed-size character arrays. */
+
+#ifndef mozilla_Sprintf_h_
+#define mozilla_Sprintf_h_
+
+#include <stdio.h>
+#include <stdarg.h>
+#include <algorithm>
+
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Printf.h"
+
+#ifdef __cplusplus
+
+# ifndef SPRINTF_H_USES_VSNPRINTF
+namespace mozilla {
+namespace detail {
+
+struct MOZ_STACK_CLASS SprintfAppend final : public mozilla::PrintfTarget {
+ explicit SprintfAppend(char* aBuf, size_t aBufLen)
+ : mBuf(aBuf), mBufLen(aBufLen) {}
+
+ bool append(const char* aStr, size_t aLen) override {
+ if (aLen == 0) {
+ return true;
+ }
+ // Don't copy more than what's left to use.
+ size_t copy = std::min(mBufLen, aLen);
+ if (copy > 0) {
+ memcpy(mBuf, aStr, copy);
+ mBuf += copy;
+ mBufLen -= copy;
+ }
+ return true;
+ }
+
+ private:
+ char* mBuf;
+ size_t mBufLen;
+};
+
+} // namespace detail
+} // namespace mozilla
+# endif // SPRINTF_H_USES_VSNPRINTF
+
+MOZ_FORMAT_PRINTF(3, 0)
+MOZ_MAYBE_UNUSED
+static int VsprintfBuf(char* buffer, size_t bufsize, const char* format,
+ va_list args) {
+ MOZ_ASSERT(format != buffer);
+# ifdef SPRINTF_H_USES_VSNPRINTF
+ int result = vsnprintf(buffer, bufsize, format, args);
+ buffer[bufsize - 1] = '\0';
+ return result;
+# else
+ mozilla::detail::SprintfAppend ss(buffer, bufsize);
+ ss.vprint(format, args);
+ size_t len = ss.emitted();
+ buffer[std::min(len, bufsize - 1)] = '\0';
+ return len;
+# endif
+}
+
+MOZ_FORMAT_PRINTF(3, 4)
+MOZ_MAYBE_UNUSED
+static int SprintfBuf(char* buffer, size_t bufsize, const char* format, ...) {
+ va_list args;
+ va_start(args, format);
+ int result = VsprintfBuf(buffer, bufsize, format, args);
+ va_end(args);
+ return result;
+}
+
+template <size_t N>
+MOZ_FORMAT_PRINTF(2, 0)
+int VsprintfLiteral(char (&buffer)[N], const char* format, va_list args) {
+ return VsprintfBuf(buffer, N, format, args);
+}
+
+template <size_t N>
+MOZ_FORMAT_PRINTF(2, 3)
+int SprintfLiteral(char (&buffer)[N], const char* format, ...) {
+ va_list args;
+ va_start(args, format);
+ int result = VsprintfLiteral(buffer, format, args);
+ va_end(args);
+ return result;
+}
+
+#endif
+#endif /* mozilla_Sprintf_h_ */