Continuation of long lines aligns with start of line instead of start of instruction


Bugzilla Link	PR47097
Status	NEW
Importance	P normal
Reported by	Waris Boonyasiriwat (waris.boonyasiriwat@gmail.com)
Reported on	2020-08-10 12:27:17 -0700
Last modified on	2020-08-10 12:30:17 -0700
Version	10.0
Hardware	PC Linux
CC	djasper@google.com, klimek@google.com, llvm-bugs@lists.llvm.org, waris.boonyasiriwat@gmail.com
Fixed by commit(s)
Attachments	`bugreport.zip` (2930 bytes, application/zip)
Blocks
Blocked by
See also

Created attachment 23838
3 files: (1) the dummy test file (2) .clang-format for v10 (3) .clang-format
for v6

Version:
clang-format version 10.0.0-4ubuntu1~18.04.2

Overview:
Continuation of long lines seem to align with the start of line instead of
start of instruction. This behaviour did not exist in clang-format-6.0.

Steps to reproduce:
Run clang-format with ColumnLimit of 120 and ContinuationIndentWidth of 2 on
this snippet (also attached).

void foo()
{
    if (SUCCESS_CONSTANT
        == a_really_really_really_long_function_name(
               reinterpret_cast<uint8_t*>(a_somewhat_long_argument), a_somewhat_long_argument,
               reinterpret_cast<uint16_t*>(a_really_really_really_really_really_long_argument),
               reinterpret_cast<uint32_t*>(a_really_really_really_really_really_long_argument)))
    {
        // do stuff
    }
}

Expected Result (what I got with clang-format-6.0):

void foo()
{
    if (SUCCESS_CONSTANT
        == a_really_really_really_long_function_name(
             reinterpret_cast<uint8_t*>(a_somewhat_long_argument), a_somewhat_long_argument,
             reinterpret_cast<uint16_t*>(a_really_really_really_really_really_long_argument),
             reinterpret_cast<uint32_t*>(a_really_really_really_really_really_long_argument)))
    {
        // do stuff
    }
}

Actual Result (what I got with clang-format-10):

void foo()
{
    if (SUCCESS_CONSTANT
        == a_really_really_really_long_function_name(
          reinterpret_cast<uint8_t*>(a_somewhat_long_argument), a_somewhat_long_argument,
          reinterpret_cast<uint16_t*>(a_really_really_really_really_really_long_argument),
          reinterpret_cast<uint32_t*>(a_really_really_really_really_really_long_argument)))
    {
        // do stuff
    }
}

Notice how the continued line is aligned to the left of the function name. I
tried tweaking many other rules but did not seem to help. This led me to
believe that the alignment reference for long line continuation has been
changed from "start of instruction" to "start of line"

Quuxplusone / LLVMBugzillaTest

Continuation of long lines aligns with start of line instead of start of instruction #46066