[ARROW-7604] [C++] Avoid duplicate object file names

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/23858
• Assignee: Unassigned
• Reporter: Wes McKinney
• Created: 17/Jan/20 16:43
• Updated: 11/Jan/23 07:54
• Resolved: 27/Apr/20 02:47

Description

It seems that some linking tools (e.g. libtool Apple Inc. version cctools-949.0.1) will emit warnings of the following

```
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (options.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(options.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(options.cc.o) due to use of basename, truncation and blank padding
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (options.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(options.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(options.cc.o) due to use of basename, truncation and blank padding
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (parser.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(parser.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(parser.cc.o) due to use of basename, truncation and blank padding
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (reader.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(reader.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(reader.cc.o) due to use of basename, truncation and blank padding
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (reader.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(reader.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(reader.cc.o) due to use of basename, truncation and blank padding
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/libtool: warning same member name (util_internal.cc.o) in output file used for input files: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(util_internal.cc.o) and: /Users/wesm/code/arrow/cpp/build/debug/libarrow_unbundled.a(util_internal.cc.o) due to use of basename, truncation and blank padding
```

I found some Chromium bug reports seemingly related to the same issue

https://codereview.chromium.org/955263002

I don't know whether this problem is benign or not, but it suggests that we might want to avoid duplicated $NAME.cc.o names to be on the safe side