[llvm-bugs] [Bug 37771] New: Incorrect clang warning -Wconstant-conversion on unsigned types

[via llvm-bugs]

https://bugs.llvm.org/show_bug.cgi?id=37771

            Bug ID: 37771
           Summary: Incorrect clang warning -Wconstant-conversion on
                    unsigned types
           Product: clang
           Version: trunk
          Hardware: PC
                OS: Linux
            Status: NEW
          Severity: enhancement
          Priority: P
         Component: -New Bugs
          Assignee: unassignedclangbugs at nondot.org
          Reporter: manojgupta at google.com
                CC: llvm-bugs at lists.llvm.org, rtrieu at google.com

Found when building Linux kernel 4.14 with clang:
(https://bugs.chromium.org/p/chromium/issues/detail?id=849780).

Reduced test cases:

unsigned char test_char(void)
{
  const unsigned char w = 128;

  return ~w;
}

../build/char_warn.c:5:10: error: implicit conversion from 'int' to 'unsigned
char' changes value from -129 to 127
      [-Werror,-Wconstant-conversion]
  return ~w;


unsigned short test_short(void)
{
  const unsigned short w = 0x8000;

  return ~w;
}

../build/short_warn.c:5:10: error: implicit conversion from 'int' to 'unsigned
short' changes value from -32769 to 32767
      [-Werror,-Wconstant-conversion]
  return ~w;

-- 
You are receiving this mail because:
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-bugs/attachments/20180611/34a2f4ea/attachment.html>