[cfe-dev] [PATCH] Refactoring: fix making absolute FilePath in Replacement

[Steffen Prohaska]

On Sep 2, 2014, at 1:41 AM, Justin Bogner <mail at justinbogner.com> wrote:

> Justin Bogner <mail at justinbogner.com> writes:
>> Steffen Prohaska <prohaska at zib.de> writes:
>>> An std::error_code of 0 indicates success.  The condition must be reversed.
>>> 
>>> See diff below for http://llvm.org/svn/llvm-project/cfe/trunk
>>> ---
>>> 
>>> Hello,
>>> I'm unsure whether this is the right way to submit a patch.  Please let me
>>> know if I should prepare it in a different way.
>> 
>> Generally, we prefer patches to be sent to cfe-commits@, rather than
>> cfe-dev@, for future reference.
>> 
>> Additionally, we usually like to check in a test with bug fixes. This is
>> pretty obvious by inspection, but if you have a case where it fails and
>> can easily be reduced, submitting that as well would be appreciated.
> 
> On further inspection, fixing this opens a whole can of worms. It looks
> like we've been relying on it being broken for quite a while. I've sent
> an alternative patch to cfe-commits for review:
> 
>    http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20140901/113949.html

Hmm...  Your patch looks sane, but it doesn't solve my original problem.

Maybe the following is relevant.  I'm unsure, because I'm rather
unfamiliar with the clang codebase.

I've been working on a custom refactoring tool.  I tried to save the
replacements and then apply them with clang-apply-replacements.  I
wanted to collect replacements for several packages across a large
project.  The problem can be illustrated with clang-modernize.  

I created a compile_commands.json for a custom build system that uses
recursive make. Commands are executed in the subdirectory of the source
file:

    [
        {
            "directory": "/rootpath/src/package",
            "command": "clang++ ... file.cpp",
            "file": "file.cpp"
        },
        ...
    ]

I'd like to create serialized replacements similar to:

    clang-modernize --add-override --serialize-replacements \
        --serialize-dir=$(pwd)/replacements src/package/file.cpp

and then apply them with:

    clang-apply-replacements -format ./replacements

The setup seemed natural, and I expected it to work this way.  But it
fails, because the serialized replacements contain paths that are
relative to the directories in compile_commands.json (like
"FilePath: file.cpp").

With my fix that teaches Replacement to store absolute paths, it works
as expected, because the Replacements and therefore the YAML files then
contain absolute paths.

Best,
  Steffen