llvm | Compiler Course -

I am working in an environment where I cannot use heap memory but only stack memory. To not be constrained by the #[no_std] enviroment I tried to use stack memory as heap memory with the linked-list-allocator crate. This was my approach.

I tried to compile a .so library using Visual Studio 2019 along with OpenCV Android in order to use this library in Unity. There are some answers on how to configure Visual Studio to use OpenCV Android (here or here) but none of these work for me. Below you can see my configurations.

Visual Studio 2019 (running on Windows 10)

android-ndk-r21e // also tried with android-ndk-r15c android-ndk-r16b and android-ndk-r17c

OpenCV Android 4.5.2 // also tried with OpenCV Android 4.0.0, 4.0.1 and 4.1.0

My settings in Visual Studio 2019 look as follows:

Configuration Properties

- General

• Platform Toolset Clang 5.0 (also tried Clang 3.8 or GCC 4.9)

• Configuration Type Dynamic Library (.so)

• Target API Level Nougat 7.0 (android-24) (also tried different versions)

• Use STL LLVM libc++ static library (c++_static) (also tried "GNU STL static library (gnustl_static)")

C/C++

- General

• Additional Include Directories "Path to OpenCV_4_5_2_Android\sdk\native\jni\include"

• Code Generation Enable C++ Exceptions "Yes(-fexceptions)"

• Language C++17(-std=c++1z)

• Precompiled Headers Not using Precompiled Headers

Linker

- General

• Additional Library Directories Path to OpenCV_4_5_2_Android\sdk\native\libs\armeabi-v7a

- Input

• Additional Dependencies Path to OpenCV_4_5_2_Android\sdk\native\libs\armeabi-v7a\libopencv_java4.so

My Source.cpp I try to compile is just a single function for testing purposes

I am trying to build LLVM using MinGW-w64 (GCC 8.1.0). After cmake .. -G"Mingw Makefiles" and mingw32-make it started building, but after a while this error hapenned:

I'm cross compiling bare metal 32-bit code for x86 with Rust and I'm facing the problem, that the final object file is empty, if the entry function is not exactly called _start; the linker throws all code away because it sees it as dead. I'm familiar with the fact, that _start is a well-known entry point name, but the question is still:

What part in Rust, LLVM or Linker forces this? Also attributes like extern "C" fn ..., #[no_mangle] or #[export_name = "foobar"] do not work (get thrown away by the linker). My guess is, that it's not the Rust compiler but the linker. As you can see, I use rust-lld as linker and ld.lld as linker-flavor in my case (see below).

1. Where does the required _start-come from? Why does the linker throw my other code away?
2. Whats the best option to specify my custom entry point to the linker?

x86-unknown-bare_metal.json

I'm currently having a bit of trouble with CGAL's Polyline Simplification.

More specifically, for the following example, PS::simplify(ct, Cost(), Stop(0.2)) results in a self-intersecting polyline. In the image below, the blue polyline is the input polyline into PS::simplify() while the green polyline is the resulting (output) polyline. The red arrow points to the self-intersection in the resulting polyline.

Further below, I have copied and pasted my code from 2 files simplify_test.cpp and CMakeLists.txt. With the required libraries installed, to run this example, you may place them in the same directory, cd to that directory, and run the following in your terminal:

so I have created a

I'm writing Rust code and need to get the value that is currently stored inside "ebx" register (x86).

My code [0] looks like this:

I am trying to use OMPTrace which is a tool for tracing and visualizing OpenMP program execution as shown here https://github.com/passlab/omptrace. The codes given in the examples is written in C. (jacobi.c and axpy.c) The library is well installed in /home/hakim/llvm-openmp/BUILD/omptrace/build/libomptrace.so. I created a makefile as following:

I successfully compiled boost 1.70 for Android armeabiv7a with NDK r21b.

I used user-config.jam: