llvm-project/clang
Philip Reames f549176ad9 [funcattrs] Add the maximal set of implied attributes to definitions
Have funcattrs expand all implied attributes into the IR. This expands the infrastructure from D100400, but for definitions not declarations this time.

Somewhat subtly, this mostly isn't semantic. Because the accessors did the inference, any client which used the accessor was already getting the stronger result. Clients that directly checked presence of attributes (there are some), will see a stronger result now.

The old behavior can end up quite confusing for two reasons:
* Without this change, we have situations where function-attrs appears to fail when inferring an attribute (as seen by a human reading IR), but that consuming code will see that it should have been implied. As a human trying to sanity check test results and study IR for optimization possibilities, this is exceeding error prone and confusing. (I'll note that I wasted several hours recently because of this.)
* We can have transforms which trigger without the IR appearing (on inspection) to meet the preconditions. This change doesn't prevent this from happening (as the accessors still involve multiple checks), but it should make it less frequent.

I'd argue in favor of deleting the extra checks out of the accessors after this lands, but I want that in it's own review as a) it's purely stylistic, and b) I already know there's some disagreement.

Once this lands, I'm also going to do a cleanup change which will delete some now redundant duplicate predicates in the inference code, but again, that deserves to be a change of it's own.

Differential Revision: https://reviews.llvm.org/D100226
2021-04-16 14:22:19 -07:00
..
INPUTS
bindings
cmake Ship `llvm-cxxfilt` in the toolchain. 2021-04-13 11:58:33 -07:00
docs [clang-format] Inconsistent behavior regarding line break before access modifier 2021-04-16 10:39:13 +02:00
examples
include DeclContext: Fix iterator category 2021-04-16 20:59:36 +02:00
lib [WebAssembly] Remove saturating fp-to-int target intrinsics 2021-04-16 12:11:20 -07:00
runtime [compiler-rt] Fix stale incremental builds when using `LLVM_BUILD_EXTERNAL_COMPILER_RT=ON`. 2021-03-10 09:42:24 -08:00
test [funcattrs] Add the maximal set of implied attributes to definitions 2021-04-16 14:22:19 -07:00
tools [SystemZ][z/OS] Add IsText Argument to GetFile and GetFileOrSTDIN 2021-04-16 10:08:36 -04:00
unittests [clang-format] Inconsistent behavior regarding line break before access modifier 2021-04-16 10:39:13 +02:00
utils [RISCV][Clang] Add RVV miscellaneous intrinsic functions. 2021-04-16 09:41:19 -07:00
www [C++2b] Support size_t literals 2021-03-31 13:36:23 +00:00
.clang-format
.clang-tidy
.gitignore Remove .gitignore entries not relevant in the monorepo. 2021-04-07 12:25:02 -07:00
CMakeLists.txt [clang][cli] Round-trip cc1 arguments in assert builds 2021-03-27 17:24:03 +01:00
CODE_OWNERS.TXT
INSTALL.txt
LICENSE.TXT
ModuleInfo.txt
NOTES.txt
README.txt

README.txt

//===----------------------------------------------------------------------===//
// C Language Family Front-end
//===----------------------------------------------------------------------===//

Welcome to Clang.  This is a compiler front-end for the C family of languages
(C, C++, Objective-C, and Objective-C++) which is built as part of the LLVM
compiler infrastructure project.

Unlike many other compiler frontends, Clang is useful for a number of things
beyond just compiling code: we intend for Clang to be host to a number of
different source-level tools.  One example of this is the Clang Static Analyzer.

If you're interested in more (including how to build Clang) it is best to read
the relevant web sites.  Here are some pointers:

Information on Clang:             http://clang.llvm.org/
Building and using Clang:         http://clang.llvm.org/get_started.html
Clang Static Analyzer:            http://clang-analyzer.llvm.org/
Information on the LLVM project:  http://llvm.org/

If you have questions or comments about Clang, a great place to discuss them is
on the Clang development mailing list:
  http://lists.llvm.org/mailman/listinfo/cfe-dev

If you find a bug in Clang, please file it in the LLVM bug tracker:
  http://llvm.org/bugs/