[all-commits] [llvm/llvm-project] dccfaf: Revert "[BuildLibcalls, Attrs] Support more varian...

[Richard Smith via All-commits]

  Branch: refs/heads/release/12.x
  Home:   https://github.com/llvm/llvm-project
  Commit: dccfafaf8cc1085724331a8427f656d7636679ba
      https://github.com/llvm/llvm-project/commit/dccfafaf8cc1085724331a8427f656d7636679ba
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   2021-02-12 (Fri, 12 Feb 2021)

  Changed paths:
    M llvm/lib/Transforms/Utils/BuildLibCalls.cpp
    M llvm/test/Transforms/InferFunctionAttrs/annotate.ll

  Log Message:
  -----------
  Revert "[BuildLibcalls, Attrs] Support more variants of C++'s new, add attributes for C++'s delete"

Several of the new attributes here were incorrect, and even the ones
that are generally correct were being added even to nobuiltin calls.

This reverts commit bb3f169b59e1c8bd7fd70097532220bbd11e9967.

(cherry picked from commit 1484ad4137b5d627573672bad48b03785f8fdefd)


  Commit: 97dd9224f1033b1d6313ae80047e48ff964ca77d
      https://github.com/llvm/llvm-project/commit/97dd9224f1033b1d6313ae80047e48ff964ca77d
  Author: Richard Smith <richard at metafoo.co.uk>
  Date:   2021-02-12 (Fri, 12 Feb 2021)

  Changed paths:
    M llvm/lib/Transforms/Utils/BuildLibCalls.cpp
    M llvm/test/Transforms/InferFunctionAttrs/annotate.ll

  Log Message:
  -----------
  Don't infer attributes on '::operator new'.

These attributes were all incorrect or inappropriate for LLVM to infer:
- inaccessiblememonly is generally wrong; user replacement operator new
  can access memory that's visible to the caller, as can a new_handler
  function.
- willreturn is generally wrong; a custom new_handler is not guaranteed
  to terminate.
- noalias is inappropriate: Clang has a flag to determine whether this
  attribute should be present and adds it itself when appropriate.
- noundef and nonnull on the return value should be specified by the
  frontend on all 'operator new' functions if we want them, not here.

In any case, inferring attributes on functions declared 'nobuiltin' (as
these are when Clang emits them) seems questionable.

(cherry picked from commit ab243efb261ba7e27f4b14e1a6fbbff15a79c0bf)


Compare: https://github.com/llvm/llvm-project/compare/a67a4346f78d...97dd9224f103