[ORC-1732] [C++] Can't detect Protobuf installed by Homebrew on macOS

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.1.0, 2.0.2
• Component/s: C++
• Assignee: Hao Zou
• Reporter: Kouhei Sutou
• Created: 22/Jun/24 22:39
• Updated: 15/Aug/24 16:31
• Resolved: 11/Jul/24 15:44

Description

Downstream issue: https://github.com/apache/arrow/issues/42149

We can use system Protobuf if we specify one of them:

• PROTOBUF_HOME environment variable
• Protobuf_ROOT CMake variable
• Protobuf_ROOT environment variable
• PROTOBUF_ROOT CMake variable
• PROTOBUF_ROOT environment variable

See also:

• https://github.com/apache/orc/blob/8003801e78ff6156a1f18ec62b631d6ba4768b00/cmake_modules/ThirdpartyToolchain.cmake#L466
• https://github.com/apache/orc/blob/8003801e78ff6156a1f18ec62b631d6ba4768b00/cmake_modules/ThirdpartyToolchain.cmake#L80-L90

If system Protobuf CMake package is found, we extract include directory from libprotobuf::protoc CMake target:
https://github.com/apache/orc/blob/8003801e78ff6156a1f18ec62b631d6ba4768b00/cmake_modules/FindProtobuf.cmake#L66

But libprotobuf::protoc CMake target doesn't have include directory configuration:
https://github.com/protocolbuffers/protobuf/blob/0302c4c43821ac893e8f1071576f80edef5c6398/cmake/libprotoc.cmake#L19-L20

If we can't extract include directory, system Protobuf detection is failed:
https://github.com/apache/orc/blob/8003801e78ff6156a1f18ec62b631d6ba4768b00/cmake_modules/FindProtobuf.cmake#L101-L107

So we never detect system Protobuf by system Protobuf CMake package.

FYI: We can extract include directory from protobuf::libprotobuf (not ...::libprotoc) CMake target:

diff --git a/cmake_modules/FindProtobuf.cmake b/cmake_modules/FindProtobuf.cmake
index 82429a23..ab73195c 100644
--- a/cmake_modules/FindProtobuf.cmake
+++ b/cmake_modules/FindProtobuf.cmake
@@ -63,7 +63,7 @@ if (Protobuf_FOUND)
         set (PROTOC_STATIC_LIB protobuf::libprotoc)
     endif ()
 
-    get_target_property (PROTOBUF_INCLUDE_DIR protobuf::libprotoc INTERFACE_INCLUDE_DIRECTORIES)
+    get_target_property (PROTOBUF_INCLUDE_DIR protobuf::libprotobuf INTERFACE_INCLUDE_DIRECTORIES)
 
 else()
     find_path (PROTOBUF_INCLUDE_DIR google/protobuf/io/zero_copy_stream.h HINTS

But there is a test failure with Protobuf 27.1:

[ RUN      ] TestFileScan.testErrorHandling
/Users/runner/work/orc/orc/tools/test/TestFileScan.cc:211: Failure
Expected: (std::string::npos) != (error.find(errorMsg)), actual: 18446744073709551615 vs 18446744073709551615
Caught exception in /Users/runner/work/orc/orc/examples/corrupt/stripe_footer_bad_column_encodings.orc: bad StripeFooter from zlib(/Users/runner/work/orc/orc/examples/corrupt/stripe_footer_bad_column_encodings.orc from 336 for 79)

[  FAILED  ] TestFileScan.testErrorHandling (126 ms)

See also:

• The above change + minimal CI configuration on macOS used when I looked at this: https://github.com/apache/orc/compare/main...kou:orc:cpp-protobuf?expand=1
• A CI result: https://github.com/kou/orc/actions/runs/9628707685/job/26557240526#step:6:126

Issue Links

• links to: GitHub Pull Request #1963