[PATCH] D86360: Add new hidden option -print-changed which only reports changes to IR

[Yuanfang Chen via Phabricator via llvm-commits]

ychen added a comment.

In D86360#2282199 <https://reviews.llvm.org/D86360#2282199>, @jamieschmeiser wrote:

> @ychen, Why are the regexs not sufficient for testing?  I would rather not "check the common sub-string of GCC's and MSVC's output" because it has already been sufficiently demonstrated that this is fragile in the test.

"check the common sub-string of GCC's and MSVC's output" is not fragile because we only support GCC/Clang/MSVC as the host compiler. For PassID,  GCC and Clang produce similar if not identical results. Checking PassID for only one compiler is fragile yes.

> The important part of the test is captured in that the banner shows that the dump is either filtered, ignored, output, etc and that the portion of IR is correct.  This is the intent of the tests, rather than testing how different compilers construct a PassID.

That covers " dump is either filtered, ignored, output," functionality but it does not make sure that these functionalies are applied to the right pass and in the right order. Besides, {{.+}} makes it hard to understand the test.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86360/new/

https://reviews.llvm.org/D86360