xref: /freebsd/contrib/llvm-project/libcxx/src/filesystem/format_string.h (revision 59c8e88e72633afbc47a4ace0d2170d00d51f7dc)
1 //===----------------------------------------------------------------------===////
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===////
8 
9 #ifndef FILESYSTEM_FORMAT_STRING_H
10 #define FILESYSTEM_FORMAT_STRING_H
11 
12 #include <__assert>
13 #include <__config>
14 #include <array>
15 #include <cstdarg>
16 #include <cstddef>
17 #include <cstdio>
18 #include <string>
19 
20 #if defined(_LIBCPP_WIN32API)
21 #  define PATHSTR(x) (L##x)
22 #  define PATH_CSTR_FMT "\"%ls\""
23 #else
24 #  define PATHSTR(x) (x)
25 #  define PATH_CSTR_FMT "\"%s\""
26 #endif
27 
28 _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
29 
30 namespace detail {
31 
32 inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 0) string vformat_string(const char* msg, va_list ap) {
33   array<char, 256> buf;
34 
35   va_list apcopy;
36   va_copy(apcopy, ap);
37   int ret = ::vsnprintf(buf.data(), buf.size(), msg, apcopy);
38   va_end(apcopy);
39 
40   string result;
41   if (static_cast<size_t>(ret) < buf.size()) {
42     result.assign(buf.data(), static_cast<size_t>(ret));
43   } else {
44     // we did not provide a long enough buffer on our first attempt. The
45     // return value is the number of bytes (excluding the null byte) that are
46     // needed for formatting.
47     size_t size_with_null = static_cast<size_t>(ret) + 1;
48     result.__resize_default_init(size_with_null - 1);
49     ret = ::vsnprintf(&result[0], size_with_null, msg, ap);
50     _LIBCPP_ASSERT_UNCATEGORIZED(static_cast<size_t>(ret) == (size_with_null - 1), "TODO");
51   }
52   return result;
53 }
54 
55 inline _LIBCPP_ATTRIBUTE_FORMAT(__printf__, 1, 2) string format_string(const char* msg, ...) {
56   string ret;
57   va_list ap;
58   va_start(ap, msg);
59 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
60   try {
61 #endif // _LIBCPP_HAS_NO_EXCEPTIONS
62     ret = detail::vformat_string(msg, ap);
63 #ifndef _LIBCPP_HAS_NO_EXCEPTIONS
64   } catch (...) {
65     va_end(ap);
66     throw;
67   }
68 #endif // _LIBCPP_HAS_NO_EXCEPTIONS
69   va_end(ap);
70   return ret;
71 }
72 
73 } // end namespace detail
74 
75 _LIBCPP_END_NAMESPACE_FILESYSTEM
76 
77 #endif // FILESYSTEM_FORMAT_STRING_H
78