[PATCH] D72194: [MC][ELF] Ensure that mergeable globals with an explicit section are assigned to SHF_MERGE sections with compatible entsizes

[ben via Phabricator via llvm-commits]

bd1976llvm added a comment.

@nickdesaulniers and @MaskRay,

With regards to the diagnostic. The whole thing is a bit of a mess. Since I originally authored this patch the behaviour of report_fatal_error has been changed, see comments on: https://reviews.llvm.org/rG8cedf0e2994c1a258902ed931abdec5f94725a55. Currently, it is not possible to emit a warning or error using MCContext::reportWarning/Error. I have changed the code to use reportError. For now, this results in a call to report_fatal_error, which results in a call to abort, which necessitates the use of "not --crash" in the LIT test.

As @nickdesaulniers had reported the test was broken on Linux (although it did work on Windows). Looking at this failure I don't think there is a guarantee of how much stdout will be printed if report_fatal_error is called. Therefore, I have split the original testcase into two; first the error message is checked, second the suppression of mergeable section generation is checked.

With regards to whether we should emit a warning or an error. IMO It should be an error as: there is no way to turn off optimizing mergeable sections (in most linkers), warnings are often ignored, and we don't want to create broken output after linking.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72194/new/

https://reviews.llvm.org/D72194