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Adhemerval Zanella dad55c2218 [ARM] [ELF] Fix ARMMaterializeGV for Indirect calls
Recent shouldAssumeDSOLocal changes (introduced by 961f31d8ad)
do not take in consideration the relocation model anymore.  The ARM
fast-isel pass uses the function return to set whether a global symbol
is loaded indirectly or not, and without the expected information
llvm now generates an extra load for following code:

```
$ cat test.ll
@__asan_option_detect_stack_use_after_return = external global i32
define dso_local i32 @main(i32 %argc, i8** %argv) #0 {
entry:
  %0 = load i32, i32* @__asan_option_detect_stack_use_after_return,
align 4
  %1 = icmp ne i32 %0, 0
  br i1 %1, label %2, label %3

2:
  ret i32 0

3:
  ret i32 1
}

attributes #0 = { noinline optnone }

$ lcc test.ll -o -
[...]
main:
        .fnstart
[...]
        movw    r0, :lower16:__asan_option_detect_stack_use_after_return
        movt    r0, :upper16:__asan_option_detect_stack_use_after_return
        ldr     r0, [r0]
        ldr     r0, [r0]
        cmp     r0, #0
[...]
```

And without 'optnone' it produces:
```
[...]
main:
        .fnstart
[...]
        movw    r0, :lower16:__asan_option_detect_stack_use_after_return
        movt    r0, :upper16:__asan_option_detect_stack_use_after_return
        ldr     r0, [r0]
        clz     r0, r0
        lsr     r0, r0, #5
        bx      lr

[...]
```

This triggered a lot of invalid memory access in sanitizers for
arm-linux-gnueabihf.  I checked this patch both a stage1 built with
gcc and a stage2 bootstrap and it fixes all the Linux sanitizers
issues.

Reviewed By: MaskRay

Differential Revision: https://reviews.llvm.org/D95379
2021-01-26 15:57:55 -03:00
.github [github] Move repo lockdown config into llvm-project repo 2021-01-11 16:20:08 -08:00
clang [OpenMP][deviceRTLs] Build the deviceRTLs with OpenMP instead of target dependent language 2021-01-26 12:28:47 -05:00
clang-tools-extra [clangd] Add std::size_t to StdSymbol mapping 2021-01-26 17:53:07 +01:00
compiler-rt [scudo][standalone] Enable death tests on Fuchsia 2021-01-25 09:19:10 -08:00
debuginfo-tests [DebugInfo][dexter] Tweak dexter test for merged values 2021-01-19 12:45:31 +00:00
flang Revert "[flang] Search for #include "file" in right directory" 2021-01-26 13:07:14 +00:00
libc [libc] Distinguish compiler and run failures 2021-01-21 15:27:34 -08:00
libclc libclc: Use find_package to find Python 3 and require it 2020-10-01 22:31:33 +02:00
libcxx [libcxx] random_device, for OpenBSD specify optimal entropy properties 2021-01-25 20:55:09 -05:00
libcxxabi [libc++] Set CMAKE_FOLDER. NFC. 2021-01-25 09:51:16 +01:00
libunwind [CMake] Remove dead code setting policies to NEW 2021-01-19 17:19:36 +02:00
lld [LLD][ELF][AArch64] Add support for R_AARCH64_LD64_GOTPAGE_LO15 relocation 2021-01-26 12:01:38 +00:00
lldb [lldb][NFC] Another attempt to fix GCC 5.x compilation 2021-01-26 19:13:12 +01:00
llvm [ARM] [ELF] Fix ARMMaterializeGV for Indirect calls 2021-01-26 15:57:55 -03:00
mlir [mlir] sret and byval now require a type argument when constructed. 2021-01-26 10:47:19 -08:00
openmp [OpenMP][deviceRTLs] Build the deviceRTLs with OpenMP instead of target dependent language 2021-01-26 12:28:47 -05:00
parallel-libs Reapply "Try enabling -Wsuggest-override again, using add_compile_options instead of add_compile_definitions for disabling it in unittests/ directories." 2020-07-22 17:50:19 -07:00
polly [Polly] Track defined behavior for PHI predecessor computation. 2021-01-23 13:03:49 -06:00
pstl [pstl] Replace direct use of assert() with _PSTL_ASSERT 2020-11-02 18:35:54 -05:00
runtimes [MSVC] Don't add -nostdinc++ -isystem to runtimes builds 2021-01-15 13:22:07 -08:00
utils/arcanist Fix arc lint's clang-format rule: only format the file we were asked to format. 2020-10-11 14:24:23 -07:00
.arcconfig Set the target branch for `arc land` to main 2020-12-07 21:57:32 +00:00
.arclint PR46997: don't run clang-format on clang's testcases. 2020-08-04 17:53:25 -07:00
.clang-format
.clang-tidy - Update .clang-tidy to ignore parameters of main like functions for naming violations in clang and llvm directory 2020-01-31 16:49:45 +00:00
.git-blame-ignore-revs NFC: Add whitespace-changing revisions to .git-blame-ignore-revs 2020-09-21 20:17:24 -04:00
.gitignore [NFC] Add CMakeUserPresets.json filename to .gitignore 2021-01-22 12:45:29 +01:00
CONTRIBUTING.md
README.md Revert "This is a test commit" 2020-10-21 09:34:15 +08:00

README.md

The LLVM Compiler Infrastructure

This directory and its sub-directories contain source code for LLVM, a toolkit for the construction of highly optimized compilers, optimizers, and run-time environments.

The README briefly describes how to get started with building LLVM. For more information on how to contribute to the LLVM project, please take a look at the Contributing to LLVM guide.

Getting Started with the LLVM System

Taken from https://llvm.org/docs/GettingStarted.html.

Overview

Welcome to the LLVM project!

The LLVM project has multiple components. The core of the project is itself called "LLVM". This contains all of the tools, libraries, and header files needed to process intermediate representations and converts it into object files. Tools include an assembler, disassembler, bitcode analyzer, and bitcode optimizer. It also contains basic regression tests.

C-like languages use the Clang front end. This component compiles C, C++, Objective-C, and Objective-C++ code into LLVM bitcode -- and from there into object files, using LLVM.

Other components include: the libc++ C++ standard library, the LLD linker, and more.

Getting the Source Code and Building LLVM

The LLVM Getting Started documentation may be out of date. The Clang Getting Started page might have more accurate information.

This is an example work-flow and configuration to get and build the LLVM source:

  1. Checkout LLVM (including related sub-projects like Clang):

    • git clone https://github.com/llvm/llvm-project.git

    • Or, on windows, git clone --config core.autocrlf=false https://github.com/llvm/llvm-project.git

  2. Configure and build LLVM and Clang:

    • cd llvm-project

    • mkdir build

    • cd build

    • cmake -G <generator> [options] ../llvm

      Some common build system generators are:

      • Ninja --- for generating Ninja build files. Most llvm developers use Ninja.
      • Unix Makefiles --- for generating make-compatible parallel makefiles.
      • Visual Studio --- for generating Visual Studio projects and solutions.
      • Xcode --- for generating Xcode projects.

      Some Common options:

      • -DLLVM_ENABLE_PROJECTS='...' --- semicolon-separated list of the LLVM sub-projects you'd like to additionally build. Can include any of: clang, clang-tools-extra, libcxx, libcxxabi, libunwind, lldb, compiler-rt, lld, polly, or debuginfo-tests.

        For example, to build LLVM, Clang, libcxx, and libcxxabi, use -DLLVM_ENABLE_PROJECTS="clang;libcxx;libcxxabi".

      • -DCMAKE_INSTALL_PREFIX=directory --- Specify for directory the full path name of where you want the LLVM tools and libraries to be installed (default /usr/local).

      • -DCMAKE_BUILD_TYPE=type --- Valid options for type are Debug, Release, RelWithDebInfo, and MinSizeRel. Default is Debug.

      • -DLLVM_ENABLE_ASSERTIONS=On --- Compile with assertion checks enabled (default is Yes for Debug builds, No for all other build types).

    • cmake --build . [-- [options] <target>] or your build system specified above directly.

      • The default target (i.e. ninja or make) will build all of LLVM.

      • The check-all target (i.e. ninja check-all) will run the regression tests to ensure everything is in working order.

      • CMake will generate targets for each tool and library, and most LLVM sub-projects generate their own check-<project> target.

      • Running a serial build will be slow. To improve speed, try running a parallel build. That's done by default in Ninja; for make, use the option -j NNN, where NNN is the number of parallel jobs, e.g. the number of CPUs you have.

    • For more information see CMake

Consult the Getting Started with LLVM page for detailed information on configuring and compiling LLVM. You can visit Directory Layout to learn about the layout of the source code tree.