[PATCH] D93844: [clang-format] Add possibility to be based on parent directory

[Zhao Wei Liew via Phabricator via cfe-commits]

zwliew added inline comments.


================
Comment at: clang/lib/Format/Format.cpp:3067
+  if (!ChildFormatTextToApply.empty()) {
+    assert(ChildFormatTextToApply.size() == 1);
+
----------------
HazardyKnusperkeks wrote:
> zwliew wrote:
> > Is there a reason behind limiting the number of children configs to 1 in this case? When the fallback is not used, more than 1 children configs are allowed (line 3036).
> > 
> > Sorry for digging this up, I came across this seemingly arbitrary decision when working on some changes to https://reviews.llvm.org/D72326
> Yeah but it doesn't happen, there is at most only one `.clang-format` in the parent directory path which is found. So we assert on that and then don't need to loop over what is exactly one element big.
Thanks for the reply. However, I don't think that's true. Yes, it's only possible to find one `.clang-format` file in the first parent directory. But if it has `BasedOnStyle: InheritParentConfig` set, then we could find another `.clang-format` file in the "grandparent" directory. In this case, we'll have 2 elements in `ChildFormatTextToApply`, but only the very first one will actually be applied.

To illustrate, suppose we have the following file structure:
```
- .clang-format
- foo
  |- .clang-format
  |- input.cpp
```

Both `.clang-format` files have `BasedOnStyle: InheritParentConfig` set. When running `clang-format --style=file foo/input.cpp`, only the inner config is applied on the fallback style, while the outer config is ignored. When testing on a debug build, I encountered a crash due to the failed assert. When removing the assert, and using a loop to apply the configs, both the inner and outer configs are applied, which I believe is the expected behaviour.



Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93844/new/

https://reviews.llvm.org/D93844