[ARROW-5849] [C++] Compiler warnings on mingw-w64

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.14.0
• Fix Version/s: 0.14.1, 0.15.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/22268
• Assignee: Antoine Pitrou
• Reporter: Jeroen
• Created: 04/Jul/19 12:17
• Updated: 11/Jan/23 07:43
• Resolved: 05/Jul/19 13:02

Description

In mingw64 we see the following warnings:

[ 54%] Building CXX object src/arrow/CMakeFiles/arrow_static.dir/util/io-util.cc.obj
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/decimal.cc: In static member function 'static arrow::Status arrow::Decimal128::FromString(const string_view&, arrow::Decimal128*, int32_t*, int32_t*)':
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/decimal.cc:313:35: warning: 'dec.arrow::{anonymous}::DecimalComponents::exponent' may be used uninitialized in this function [-Wmaybe-uninitialized]
       *scale = -adjusted_exponent + len - 1;
                ~~~~~~~~~~~~~~~~~~~^~~~

[ 56%] Building CXX object src/arrow/CMakeFiles/arrow_static.dir/util/string_builder.cc.obj
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/io-util.cc: In static member function 'static arrow::Status arrow::internal::TemporaryDir::Make(const string&, std::unique_ptr<arrow::internal::TemporaryDir>*)':
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/io-util.cc:897:3: warning: 'created' may be used uninitialized in this function [-Wmaybe-uninitialized]
   if (!created) {
   ^~

And on mingw32 we also see these:

In file included from C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/io/file.cc:25:
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/io/mman.h: In function 'void* mmap(void*, size_t, int, int, int, off_t)':
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/io/mman.h:94:62: warning: right shift count >= width of type [-Wshift-count-overflow]
   const DWORD dwMaxSizeHigh = static_cast<DWORD>((maxSize >> 32) & 0xFFFFFFFFL);
                                                              ^~

 54%] Building CXX object src/arrow/CMakeFiles/arrow_static.dir/util/logging.cc.obj
In file included from C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/io-util.cc:63:
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/io/mman.h: In function 'void* mmap(void*, size_t, int, int, int, off_t)':
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/io/mman.h:94:62: warning: right shift count >= width of type [-Wshift-count-overflow]
   const DWORD dwMaxSizeHigh = static_cast<DWORD>((maxSize >> 32) & 0xFFFFFFFFL);
                                                              ^~
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/io-util.cc: In function 'arrow::Status arrow::internal::MemoryMapRemap(void*, size_t, size_t, int, void**)':
C:/msys64/home/mingw-packages/mingw-w64-arrow/src/arrow/cpp/src/arrow/util/io-util.cc:568:55: warning: right shift count >= width of type [-Wshift-count-overflow]
   LONG new_size_high = static_cast<LONG>((new_size >> 32) & 0xFFFFFFFFL);
                                 

Issue Links

• links to: GitHub Pull Request #4804