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/include/llvm/Support/FileSystem.h b/include/llvm/Support/FileSystem.h
index 960875e..12f6d9b 100644
--- a/include/llvm/Support/FileSystem.h
+++ b/include/llvm/Support/FileSystem.h
@@ -455,9 +455,11 @@
/// @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);
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
diff --git a/lib/Support/Windows/PathV2.inc b/lib/Support/Windows/PathV2.inc
index c618dbf..f4629a1 100644
--- a/lib/Support/Windows/PathV2.inc
+++ b/lib/Support/Windows/PathV2.inc
@@ -616,6 +616,48 @@
return success;
}
+error_code get_magic(const Twine &path, uint32_t len,
+ SmallVectorImpl<char> &result) {
+ SmallString<128> path_storage;
+ SmallVector<wchar_t, 128> path_utf16;
+ result.set_size(0);
+
+ // Convert path to UTF-16.
+ if (error_code ec = UTF8ToUTF16(path.toStringRef(path_storage),
+ path_utf16))
+ return ec;
+
+ // Open file.
+ HANDLE file = ::CreateFileW(c_str(path_utf16),
+ GENERIC_READ,
+ FILE_SHARE_READ,
+ NULL,
+ OPEN_EXISTING,
+ FILE_ATTRIBUTE_READONLY,
+ NULL);
+ if (file == INVALID_HANDLE_VALUE)
+ return windows_error(::GetLastError());
+
+ // Allocate buffer.
+ result.reserve(len);
+
+ // Get magic!
+ DWORD bytes_read = 0;
+ BOOL read_success = ::ReadFile(file, result.data(), len, &bytes_read, NULL);
+ error_code ec = windows_error(::GetLastError());
+ ::CloseHandle(file);
+ if (!read_success || (bytes_read != len)) {
+ // Set result size to the number of bytes read if it's valid.
+ if (bytes_read >= 0 && bytes_read <= len)
+ result.set_size(bytes_read);
+ // ERROR_HANDLE_EOF is mapped to errc::value_too_large.
+ return ec;
+ }
+
+ result.set_size(len);
+ return success;
+}
+
error_code directory_iterator_construct(directory_iterator &it, StringRef path){
SmallVector<wchar_t, 128> path_utf16;
diff --git a/lib/Support/Windows/system_error.inc b/lib/Support/Windows/system_error.inc
index 73304d5..64753d0 100644
--- a/lib/Support/Windows/system_error.inc
+++ b/lib/Support/Windows/system_error.inc
@@ -79,6 +79,7 @@
MAP_ERR_TO_COND(ERROR_FILE_EXISTS, file_exists);
MAP_ERR_TO_COND(ERROR_FILE_NOT_FOUND, no_such_file_or_directory);
MAP_ERR_TO_COND(ERROR_HANDLE_DISK_FULL, no_space_on_device);
+ MAP_ERR_TO_COND(ERROR_HANDLE_EOF, value_too_large);
MAP_ERR_TO_COND(ERROR_INVALID_ACCESS, permission_denied);
MAP_ERR_TO_COND(ERROR_INVALID_DRIVE, no_such_device);
MAP_ERR_TO_COND(ERROR_INVALID_FUNCTION, function_not_supported);