Add replacement helpers for strncpy[_s]

Portable without vulnerabilities.

include/dusk/string.hpp

@@ -0,0 +1,52 @@
+#ifndef DUSK_STRING_HPP
+#define DUSK_STRING_HPP
+
+#include "global.h"
+#include <cstring>
+#include <dolphin/os.h>
+
+namespace dusk {
+
+/**
+ * Copy a string to a fixed-size array.
+ * Truncates if the destination is not large enough, always inserts a null terminator (padding the remainder of the buffer with zeroes.)
+ */
+template <size_t BufSize>
+void SafeStringCopyTruncate(char (&buffer)[BufSize], const char* src) {
+    static_assert(BufSize > 0, "Target buffer cannot be size zero");
+
+    // Can't just use strncpy as I can't figure out how to selectively mute the warnings on MSVC.
+    // And can't use strncpy_s on MSVC  as it doesn't fill the entire buffer.
+    constexpr size_t copyBufSize = BufSize - 1;
+    const auto srcLen = strlen(src);
+    const auto copyLen = srcLen > copyBufSize ? copyBufSize : srcLen;
+    memcpy(buffer, src, copyLen);
+    memset(buffer + copyLen, 0, BufSize - copyLen);
+}
+
+/**
+ * Copy a string to a fixed-size array.
+ * Aborts if the destination is not large enough, always inserts a null terminator (padding the remainder of the buffer with zeroes.)
+ */
+template <size_t BufSize>
+void SafeStringCopy(char (&buffer)[BufSize], const char* src) {
+    static_assert(BufSize > 0, "Target buffer cannot be size zero");
+    if (buffer == src) {
+        CRASH("Cannot copy string to same buffer");
+    }
+
+    // Can't just use strncpy as I can't figure out how to selectively mute the warnings on MSVC.
+    // And can't use strncpy_s on MSVC as it doesn't fill the entire buffer.
+    constexpr size_t copyBufSize = BufSize - 1;
+    const auto srcLen = strlen(src);
+    if (srcLen > copyBufSize) {
+        CRASH("Destination buffer too small!");
+    }
+
+    memcpy(buffer, src, srcLen);
+    memset(buffer + srcLen, 0, BufSize - srcLen);
+}
+
+}
+
+#endif  // DUSK_STRING_HPP