Example LLVM passes - based on LLVM 8-18, LLVM7- is not tested.

build

Build LLVM

cd /path/to/llvm
cmake -S llvm -B build -G Ninja -DLLVM_ENABLE_PROJECTS="clang;lld" -DCMAKE_BUILD_TYPE=Debug 
cmake --build build

Build Demo

cd /path/to/llvm-pass-hikari
export LLVM_DIR=/path/to/llvm/build/lib/cmake/llvm
cmake -B build --fresh
cmake --build build

Test

Test environment: MacOS 13.x

Test with clang

# for LLVM<=12      Legacy Pass
llvm12/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -Xclang -load -Xclang build/MyPassDemo12.dylib /tmp/1.cpp
# for LLVM<=12      Legacy Pass (Equal to above)
llvm12/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -fplugin=build/MyPassDemo12.dylib /tmp/1.cpp
# for LLVM=9/10/11  New Pass (O3 required)
llvm11/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -fexperimental-new-pass-manager -fpass-plugin=build/MyPassDemo11.dylib /tmp/1.cpp -O3
# for LLVM=12       New Pass
llvm12/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -fexperimental-new-pass-manager -fpass-plugin=build/MyPassDemo12.dylib /tmp/1.cpp
# for LLVM=13/14    Legacy Pass
llvm13/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -flegacy-pass-manager -fplugin=build/MyPassDemo13.dylib /tmp/1.cpp
# for LLVM=13/14    New Pass
llvm13/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -fpass-plugin=build/MyPassDemo13.dylib /tmp/1.cpp
# for LLVM>=15      New Pass
llvm15/build/bin/clang -isysroot `xcrun --sdk macosx --show-sdk-path` -fpass-plugin=build/MyPassDemo15.dylib /tmp/1.cpp

Test with opt

# for LLVM all versions
llvm8/build/bin/clang -emit-llvm -c -isysroot `xcrun --sdk macosx --show-sdk-path` -o /tmp/test.bc /tmp/test.cpp
llvm8/build/bin/opt -load-pass-plugin build/MyPassDemo8.dylib -passes all -S -o /tmp/test_new.bc /tmp/test.bc

NOTICE: opt support ll as input from LLVM15

llvm15/build/bin/clang -emit-llvm -S -isysroot `xcrun --sdk macosx --show-sdk-path` -o /tmp/test.ll /tmp/test.cpp
llvm15/build/bin/opt -load-pass-plugin build/MyPassDemo15.dylib -passes all -S -o /tmp/test_new.ll /tmp/test.ll 

compile

• c/cpp -> bc clang -emit-llvm -c
• c/cpp -> ll clang -emit-llvm -S
• c/cpp -> obj clang -c
• ll/bc -> obj/asm llc
• bc/obj -> bin lld
• ll/bc -> ll opt -S (ll -> ll in LLVM>=15)
• ll/bc -> bc opt (ll -> bc in LLVM>=15)
• ll -> bc llvm-as
• bc -> ll llvm-dis
• c/cpp/obj/asm -> bin clang