[llvm-dev] How can I fix the error "Inline asm not supported [...] because we don't have an asm parser for this target"?

[Alex Susu via llvm-dev]

   Hello.
     Can somebody please help me with the error reported in this thread?
     It seems that some changes were made from LLVM 8 (from 2019) to the current LLVM, 
such that there is no longer a default(?) MCTargetAsmParser and I need to implement one in 
my back end.

     There is one more issue that I wrote of in the previous message also: I create inline 
assembly expressions in the back end to print some special strings (like "N/M", which is 
an arithmetic expression), which actually do not represent assembler instructions of the 
processor. Therefore, I guess I should have an Asm Parser that should not bother to parse 
the arithmetic expression strings because they do not contains assembler mnemonics.

   Thank you very much,
     Alex

On 2/21/2021 10:08 PM, Alex Susu wrote:
>    Hello.
>      I am trying to build against the latest LLVM source from GitHub (from Jan 23 2021) my 
> research processor back end, which is mostly inspired from the BPF LLVM back end. While 
> trying this, I got this error that I didn't encounter until now:
>       <<LLVM ERROR: Inline asm not supported by this streamer because we don't have an asm 
> parser for this target"
>        ...
>        llvm::AsmPrinter::emitInlineAsm(llvm::StringRef, llvm::MCSubtargetInfo const&, 
> llvm::MCTargetOptions const&, llvm::MDNode const*, llvm::InlineAsm::AsmDialect) const 
> llvm/lib/CodeGen/AsmPrinter/AsmPrinterInlineAsm.cpp:156:9>>
> 
>      Again, this is the first time I encounter this error. It is true I am using quite a 
> bit inline assembly expressions to print some special strings which actually do not 
> represent assembler instructions of the processor.
> 
>    My back end is inspired heavily from the BPF back end but in 2015, when I started my 
> back end, BPF did not have an AsmParser folder. Do you recommend to get inspired from the 
> the current AsmParser folder of the BPF back end?
>    Any suggestion is warmly welcome.
> 
>    If ever, my LLVM back end can be found here: 
> https://sites.google.com/site/alexsusu/myfilecabinet/Connex_be.zip .
> 
>    Just to mention, I found some documentation about AsmParser from around 2012: 
> https://www.embecosm.com/appnotes/ean10/ean10-howto-llvmas-1.0.html#idp86952 .
> 
>    Thank you very much,
>      Alex