Error when using option "-emit-llvm"

[here4thee]

Hi,

I was trying to get LLVM IR for optimization and analysis when using the option "-emit-llvm" with the tool "eosio-cpp" to compile the source code. But I met an error during the LLVM code generation. Does anyone know how to correctly use the "-emit-llvm" option?

Thanks!

Following is the error information:

$ eosio-cpp -emit-llvm addressbook.cpp

Error while trying to load a compilation database:

Could not auto-detect compilation database for file "addressbook.cpp"

No compilation database found in path/contracts/addressbook or any parent directory

fixed-compilation-database: Error while opening fixed database: No such file or directory

json-compilation-database: Error while opening JSON database: No such file or directory

Running without flags.

path/contracts/addressbook/addressbook.cpp:1:10: fatal error: 'eosio/eosio.hpp' file not found

#include <eosio/eosio.hpp>

         ^~~~~~~~~~~~~~~~~

Warning, action <notify> does not have a ricardian contract

1 error generated.

Error while processing path/contracts/addressbook/addressbook.cpp.

abigen error

[here4thee]

I found a piece of code in "/eosio.cdt/tools/cc/eosio-cpp.cpp.in" telling the compiler where to search the header files. Then I copied all the include/library directories and files to the right path (with the same directory hierachy), but the tool eosio-cpp still can't find 'eosio/eosio.hpp' file.

[here4thee]

@jeffreyssmith2nd
Hi, have you solved this bug?

[mtabz]

I haven't tried yet to use the emit-llvm option, however you can get CMake to automatically generate the compilation database. See here for more context

1. Initialise a CMake project using eosio-init
2. Generate the makefiles using cmake
3. Go into the src/ directory and edit the CMakeLists.txt file and add this line set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
4. Run make and you should then have a compilation database named compile_commands.json in your build tree.
5. Copy the compile_commands.json into your src/ directory and try building the file again.

[mtabz]

Update: I tried with -emit-llvm and I got past the request for compilation database. It now fails with the following error:

error: unknown argument: '-contract'
error: unable to handle compilation, expected exactly one compiler job in ' "/usr/bin/eosio-cpp"
<<snip>>

[here4thee]

I tried to set the FrontendOption of the CompilerInstance with the value of "ProgramAction == EmitLLVM", but got a Segmentation fault (core dumped). It seems that eosio-cpp doesn't store the LLVM IR in VM's memory.

Following is the code I modified in ~\eosio.cdt\tools\include\eosio\codegen.hpp

And the error information when compiling a contract.

[here4thee]

@mtabz
Hi, thanks for your response. I read the blog about generating user-defined compilation database, but I found if the flags are added between "clang" and "--", then there is no need to generate a json compilation database.

Following is the description of a "fixed" compilation database in the blog.

A "fixed" compilation database allows us to pass the compilation flags to a tool on the command-line, following a special token --. So providing compilation commands to tools on the command-line is easy. However, if you want to run analyses/transformations over larger projects for which some sort of build system already exists, you'll probably find a real compilation database more useful.

So I added two options "-emit-llvm" and "-c" between "eosio-cpp" and "--". However, I still got an error during linking process. I searched for this error but it seems no one has ever encountered this problem.

And here is the error infomation.

/usr/local/eosio.cdt/bin/wasm-ld: error: fatal failure: contract with no actions and trying to create dispatcher