clang-format: Allman option does not work reliably

[Quuxplusone]

Bugzilla Link	PR22104
Status	REOPENED
Importance	P normal
Reported by	Steven Evergreen (evergreenthrowaway@gmail.com)
Reported on	2015-01-06 09:56:52 -0800
Last modified on	2019-09-30 12:36:32 -0700
Version	unspecified
Hardware	Macintosh MacOS X
CC	djasper@google.com, evergreenthrowaway@gmail.com, klimek@google.com, llvm-bugs@lists.llvm.org, mydeveloperday@gmail.com
Fixed by commit(s)
Attachments
Blocks
Blocked by
See also

According to the documentation, Allman enforces "Always break before braces"

Unfortunately, it doesn't seem to be doing that for if statements or for loops
(see below).

Repros with 3.5.0 and http://llvm.org/git/clang.git
d287557ca022716d56a6ff4e7f8ba44a08ef9737

Thanks!

INPUT
void function() {
    for (unsigned i = 0; i < 5; i++) {
        if (YES) {
        }
        else {
        }
    }
}

OUTPUT
void function()
{
    for (unsigned i = 0; i < 5; i++) {
        if (YES) {
        }
        else
        {
        }
    }
}

[Quuxplusone]

On current trunk:
echo 'void f(){for(;;){if(a){}else{}}}' |./bin/clang-format -
style='{"BasedOnStyle": "LLVM", "BreakBeforeBraces": "Allman"}'
void f()
{
  for (;;)
  {
    if (a)
    {
    }
    else
    {
    }
  }
}

[Quuxplusone]

Repros with

echo 'void f(){for(;;){if(a){}else{}}}' |./bin/clang-format -style='{"BasedOnStyle": "LLVM", "BreakBeforeBraces": "Allman", "AllowShortBlocksOnASingleLine" : "true", "AllowShortIfStatementsOnASingleLine" : "true", "AllowShortLoopsOnASingleLine" : "true"}'

[Quuxplusone]

I realize this is a very old issue, but incase anyone is listening were you
concerned about the "if"?

Surely this comes from the AllowShortBlocksOnASingleLine, are you expecting the
"Allman" setting to override this?

Just trying to assess if this is something we still need to consider?

MyDeveloperDay

$ echo 'void f(){for(;;){if(a){}else{}}}' |./bin/clang-format -
style='{"BasedOnStyle": "LLVM", "BreakBeforeBraces": "Allman",
"AllowShortBlocksOnASingleLine" : "true", "AllowShortIfStatementsOnASingleLine"
: "true", "AllowShortLoopsOnASingleLine" : "true"}'
void f()
{
  for (;;)
  {
    if (a) {}
    else
    {
    }
  }
}

vs

$ echo 'void f(){for(;;){if(a){}else{}}}' |./bin/clang-format -
style='{"BasedOnStyle": "LLVM", "BreakBeforeBraces": "Allman",
"AllowShortBlocksOnASingleLine" : "false",
"AllowShortIfStatementsOnASingleLine" : "true", "AllowShortLoopsOnASingleLine"
: "true"}'
void f()
{
  for (;;)
  {
    if (a)
    {
    }
    else
    {
    }
  }
}