llvm-project/clang
Roman Lebedev 7892c37455 [clang][UBSan] Sanitization for alignment assumptions.
Summary:
UB isn't nice. It's cool and powerful, but not nice.
Having a way to detect it is nice though.
[[ https://wg21.link/p1007r3 | P1007R3: std::assume_aligned ]] / http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1007r2.pdf says:
```
We propose to add this functionality via a library function instead of a core language attribute.
...
If the pointer passed in is not aligned to at least N bytes, calling assume_aligned results in undefined behaviour.
```

This differential teaches clang to sanitize all the various variants of this assume-aligned attribute.

Requires D54588 for LLVM IRBuilder changes.
The compiler-rt part is D54590.

Reviewers: ABataev, craig.topper, vsk, rsmith, rnk, #sanitizers, erichkeane, filcab, rjmccall

Reviewed By: rjmccall

Subscribers: chandlerc, ldionne, EricWF, mclow.lists, cfe-commits, bkramer

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D54589

llvm-svn: 351105
2019-01-14 19:09:27 +00:00
..
INPUTS
bindings [python] Make the collections import future-proof 2019-01-05 12:07:36 +00:00
cmake [CMake] Use hidden visibility for static libc++ in Fuchsia 2019-01-06 08:23:56 +00:00
docs [clang][UBSan] Sanitization for alignment assumptions. 2019-01-14 19:09:27 +00:00
examples cmake: Remove uses of add_llvm_loadable_module macro 2018-12-20 22:04:36 +00:00
include [WebAssembly] Remove old builtins 2019-01-14 18:28:10 +00:00
lib [clang][UBSan] Sanitization for alignment assumptions. 2019-01-14 19:09:27 +00:00
runtime Fix check-hwasan with LLVM_BUILD_EXTERNAL_COMPILER_RT=ON 2019-01-03 22:50:45 +00:00
test [clang][UBSan] Sanitization for alignment assumptions. 2019-01-14 19:09:27 +00:00
tools [analyzer][CrossTU][NFC] Generalize to external definitions instead of external functions 2019-01-10 17:44:04 +00:00
unittests [AST] Fix double-traversal of code in top-level lambdas in RAV(implicit = yes). 2019-01-14 17:16:00 +00:00
utils Implement Attr dumping in terms of visitors 2019-01-11 19:16:01 +00:00
www Implementation Feature Test Macros for P0722R3 2019-01-11 17:09:22 +00:00
.arcconfig
.clang-format
.clang-tidy
.gitignore NFC: Add .vscode to .gitignore 2018-12-03 22:51:07 +00:00
CMakeLists.txt inhereit LLVM_ENABLE_LIBXML2 2018-11-29 14:57:14 +00:00
CODE_OWNERS.TXT Add myself as code owner for OpenBSD driver 2018-11-30 21:42:34 +00:00
INSTALL.txt
LICENSE.TXT Update copyright year to 2018. 2018-06-18 12:22:17 +00:00
ModuleInfo.txt
NOTES.txt PTH-- Remove feature entirely- 2018-12-04 14:34:09 +00:00
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/