Support/PathV2: Implement get_magic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123544 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 5 insertions, 3 deletions

diff --git a/include/llvm/Support/FileSystem.h b/include/llvm/Support/FileSystem.h
index 960875e989..12f6d9b1d7 100644
--- a/include/llvm/Support/FileSystem.h
+++ b/include/llvm/Support/FileSystem.h
@@ -455,9 +455,11 @@ error_code has_magic(const Twine &path, const Twine &magic, bool &result);
 /// @param path Input path.
 /// @param len Number of magic bytes to get.
 /// @param result Set to the first \a len bytes in the file pointed to by
-///               \a path.
-/// @results errc::success if result has been successfully set, otherwise a
-///          platform specific error_code.
+///               \a path. Or the entire file if file_size(path) < len, in which
+///               case result.size() returns the size of the file.
+/// @results errc::success if result has been successfully set,
+///          errc::value_too_large if len is larger then the file pointed to by
+///          \a path, otherwise a platform specific error_code.
 error_code get_magic(const Twine &path, uint32_t len,
                      SmallVectorImpl<char> &result);