Support/PathV2: Implement get_magic.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123544 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Unix/PathV2.inc b/lib/Support/Unix/PathV2.inc
index 80e75ec..056708a 100644
--- a/lib/Support/Unix/PathV2.inc
+++ b/lib/Support/Unix/PathV2.inc
@@ -462,6 +462,37 @@
return success;
}
+error_code get_magic(const Twine &path, uint32_t len,
+ SmallVectorImpl<char> &result) {
+ SmallString<128> PathStorage;
+ StringRef Path = path.toNullTerminatedStringRef(PathStorage);
+ result.set_size(0);
+
+ // Open path.
+ std::FILE *file = std::fopen(Path.data(), "rb");
+ if (file == 0)
+ return error_code(errno, system_category());
+
+ // Reserve storage.
+ result.reserve(len);
+
+ // Read magic!
+ size_t size = std::fread(result.data(), 1, len, file);
+ if (std::ferror(file) != 0) {
+ std::fclose(file);
+ return error_code(errno, system_category());
+ } else if (size != result.size()) {
+ if (std::feof(file) != 0) {
+ std::fclose(file);
+ result.set_size(size);
+ return make_error_code(errc::value_too_large);
+ }
+ }
+ std::fclose(file);
+ result.set_size(len);
+ return success;
+}
+
} // end namespace fs
} // end namespace sys
} // end namespace llvm