LLVM/Clang AVR cross compiler

[bstaletic]

AVR support should be there since LLVM 5.0, which the following link confirms:
http://llvm.org/svn/llvm-project/llvm/t ... arget/AVR/

i don't see AVR in LLVM_TARGETS, so I'm wondering if this is just a gentoo packaging problem or do I need to jump through some hoops to get "clang -t avr foo.c" to work.

Thanks in advance.

[bstaletic]

Looking at the llvm/lib/Target, Gentoo is not only lacking AVR, but also ARC, Nios2, RISCV and WebAssembly.

Here's the output of "equery u llvm" after I added those targets to LLVM_TARGETS in my local overlay:

Code: Select all

 * Found these USE flags for sys-devel/llvm-6.0.0-r1:
 U I
 - - debug                    : Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see
                                https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
 - - doc                      : Build and install the HTML documentation and regenerate the man pages
 - - gold                     : Build the gold linker plugin
 - - libedit                  : Use the libedit library (replacement for readline)
 + + libffi                   : Enable support for Foreign Function Interface library
 + + llvm_targets_AArch64     : AArch64 CPU target (arm64 in Gentoo)
 - - llvm_targets_AMDGPU      : AMDGPU target (supports R600 and GCN GPUs)
 - - llvm_targets_ARC         : <unknown>
 + + llvm_targets_ARM         : ARM CPU target
 + - llvm_targets_AVR         : 8-bit Atmel AVR microcontroller target [EXPERIMENTAL]
 - - llvm_targets_BPF         : Berkeley Packet Filter target
 - - llvm_targets_Hexagon     : Qualcomm Hexagon DSP target
 - - llvm_targets_Lanai       : Lanai CPU target
 - - llvm_targets_MSP430      : MSP430 CPU target (experimental)
 - - llvm_targets_Mips        : MIPS CPU target (includes MIPS64)
 - - llvm_targets_NVPTX       : NVIDIA PTX (GPU) target (32-bit and 64-bit)
 - - llvm_targets_Nios2       : Nios2 CPU target [EXPERIMENTAL]
 - - llvm_targets_PowerPC     : PowerPC CPU target (PPC32 and PPC64)
 - - llvm_targets_RISCV       : RISC-V CPU target [EXPERIMENTAL]
 - - llvm_targets_Sparc       : Sparc CPU target
 - - llvm_targets_SystemZ     : SystemZ (s390x) CPU target
 - - llvm_targets_WebAssembly : WebAssembly backend [EXPERIMENTAL]
 - - llvm_targets_XCore       : XCore CPU target
 + + ncurses                  : Support querying terminal properties using ncurses' terminfo
 - - test                     : Workaround to pull in packages needed to run with FEATURES=test. Portage-2.1.2 handles this internally, so don't set it in make.conf/package.use anymore
 - - xar                      : Support dumping LLVM bitcode sections in Mach-O files (uses app-arch/xar)
 - - xml                      : Add support for XML files

As you can see, all five missing targets have a description and are marked [EXPERIMENTAl]. Should I open a bug report to request the new LLVM_TARGETS?

[Hu]

Have you built an llvm with those targets enabled and verified that they work correctly?