[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/filesystem/makepath.cpp

@@ -0,0 +1,205 @@
+//
+// makepath.cpp
+//
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+//
+// Defines the makepath family of functions, which compose a path string.
+//
+#include <corecrt_internal_securecrt.h>
+#include <mbstring.h>
+#include <stdlib.h>
+
+
+
+static char const* previous_character(char const* const first, char const* const current) throw()
+{
+    return reinterpret_cast<char const*>(_mbsdec(
+        reinterpret_cast<unsigned char const*>(first),
+        reinterpret_cast<unsigned char const*>(current)));
+}
+
+static wchar_t const* previous_character(wchar_t const*, wchar_t const* const current) throw()
+{
+    return current - 1;
+}
+
+
+
+template <typename Character>
+static errno_t __cdecl cleanup_after_error(
+    _Out_writes_z_(count) Character* const buffer,
+    size_t                           const count) throw()
+{
+    // This is referenced only in the Debug CRT build
+    UNREFERENCED_PARAMETER(count);
+
+    _RESET_STRING(buffer, count);
+    _RETURN_BUFFER_TOO_SMALL(buffer, count);
+    return EINVAL; // This is unreachable
+}
+
+
+
+// These functions compose a path string from its component parts.  They
+// concatenate the drive, directory, file_name, and extension into the provided
+// result_buffer.  For the functions that do not have a buffer count parameter,
+// the buffer is assumed to be large enough to hold however many characters are
+// required.
+//
+// The drive may or may not contain a ':'.  The directory may or may not contain
+// a leading or trailing '/' or '\'.  The extension may or may not contain a
+// leading '.'.
+template <typename Character>
+static errno_t __cdecl common_makepath_s(
+    _Out_writes_z_(result_count) Character* const result_buffer,
+    _In_       size_t           const result_count,
+    _In_opt_z_ Character const* const drive,
+    _In_opt_z_ Character const* const directory,
+    _In_opt_z_ Character const* const file_name,
+    _In_opt_z_ Character const* const extension
+    ) throw()
+{
+    _VALIDATE_STRING(result_buffer, result_count);
+
+    Character*       result_it  = result_buffer;
+
+    // For the non-secure makepath functions, result_count is _CRT_UNBOUNDED_BUFFER_SIZE.
+    // In this case, we do not want to perform arithmetic with the result_count.  Instead,
+    // we set the result_end to nullptr:  result_it will never be a null pointer,
+    // and when we need to perform arithmetic with result_end we can check it for
+    // null first.
+    Character* const result_end = result_count != _CRT_UNBOUNDED_BUFFER_SIZE
+        ? result_buffer + result_count
+        : nullptr;
+
+    CRT_WARNING_DISABLE_PUSH(26015, "Silence prefast about overflow - covered by result_end for secure callers")
+
+    // Copy the drive:
+    if (drive && drive[0] != '\0')
+    {
+        if (result_end != nullptr && result_end - result_it < 2)
+            return cleanup_after_error(result_buffer, result_count);
+
+        *result_it++ = *drive;
+        *result_it++ = ':';
+    }
+
+    // Copy the directory:
+    if (directory && directory[0] != '\0')
+    {
+        Character const* source_it = directory;
+        while (*source_it != '\0')
+        {
+            if ((result_end != nullptr) && (result_it >= result_end))
+                return cleanup_after_error(result_buffer, result_count);
+
+            *result_it++ = *source_it++;
+        }
+
+        // Write a trailing backslash if there isn't one:
+        source_it = previous_character(directory, source_it);
+        if (*source_it != '/' && *source_it != '\\')
+        {
+            if ((result_end != nullptr) && (result_it >= result_end))
+                return cleanup_after_error(result_buffer, result_count);
+
+            *result_it++ = '\\';
+        }
+    }
+
+    // Copy the file name:
+    if (file_name)
+    {
+        Character const* source_it = file_name;
+        while (*source_it != '\0')
+        {
+            if ((result_end != nullptr) && (result_it >= result_end))
+                return cleanup_after_error(result_buffer, result_count);
+
+            *result_it++ = *source_it++;
+        }
+    }
+
+    // Copy the extension:
+    if (extension)
+    {
+        // Add a '.' if one is required:
+        if (extension[0] != '\0' && extension[0] != '.')
+        {
+            if ((result_end != nullptr) && (result_it >= result_end))
+                return cleanup_after_error(result_buffer, result_count);
+
+            *result_it++ = '.';
+        }
+
+        Character const* source_it = extension;
+        while (*source_it != '\0')
+        {
+            if ((result_end != nullptr) && (result_it >= result_end))
+                return cleanup_after_error(result_buffer, result_count);
+
+            *result_it++ = *source_it++;
+        }
+    }
+
+    // Copy the null terminator:
+    if ((result_end != nullptr) && (result_it >= result_end))
+        return cleanup_after_error(result_buffer, result_count);
+
+    *result_it++ = '\0';
+
+    CRT_WARNING_POP
+
+    _FILL_STRING(result_buffer, result_count, result_it - result_buffer);
+    return 0;
+}
+
+
+
+extern "C" void __cdecl _makepath(
+    char*       const result_buffer,
+    char const* const drive,
+    char const* const directory,
+    char const* const file_name,
+    char const* const extension
+    )
+{
+    _makepath_s(result_buffer, _CRT_UNBOUNDED_BUFFER_SIZE, drive, directory, file_name, extension);
+}
+
+extern "C" void __cdecl _wmakepath(
+    wchar_t*       const result_buffer,
+    wchar_t const* const drive,
+    wchar_t const* const directory,
+    wchar_t const* const file_name,
+    wchar_t const* const extension
+    )
+{
+    _wmakepath_s(result_buffer, _CRT_UNBOUNDED_BUFFER_SIZE, drive, directory, file_name, extension);
+}
+
+
+
+extern "C" errno_t __cdecl _makepath_s(
+    char*       const result_buffer,
+    size_t      const result_count,
+    char const* const drive,
+    char const* const directory,
+    char const* const file_name,
+    char const* const extension
+    )
+{
+    return common_makepath_s(result_buffer, result_count, drive, directory, file_name, extension);
+}
+
+extern "C" errno_t __cdecl _wmakepath_s(
+    wchar_t*       const result_buffer,
+    size_t         const result_count,
+    wchar_t const* const drive,
+    wchar_t const* const directory,
+    wchar_t const* const file_name,
+    wchar_t const* const extension
+    )
+{
+    return common_makepath_s(result_buffer, result_count, drive, directory, file_name, extension);
+}