diff options
Diffstat (limited to 'fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/doc/source_debugging.md')
| -rw-r--r-- | fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/doc/source_debugging.md | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/doc/source_debugging.md b/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/doc/source_debugging.md new file mode 100644 index 00000000..a9fa0930 --- /dev/null +++ b/fluent-bit/lib/wasm-micro-runtime-WAMR-1.2.2/doc/source_debugging.md @@ -0,0 +1,224 @@ +# WAMR source debugging + +References: +- [Blog: WAMR source debugging basic](https://bytecodealliance.github.io/wamr.dev/blog/wamr-source-debugging-basic/) +- [Blog: Debugging wasm with VSCode](https://bytecodealliance.github.io/wamr.dev/blog/debugging-wasm-with-vscode/) + +WAMR supports source level debugging based on DWARF (normally used in C/C++/Rust), source map (normally used in AssemblyScript) is not supported. + +**The lldb's ability to debug wasm application is based on the patch [Add class WasmProcess for WebAssembly debugging](https://reviews.llvm.org/D78801). Thanks very much to the author @paolosev for such a great work!** + +## Build wasm application with debug information +To debug your application, you need to compile them with debug information. You can use `-g` option when compiling the source code if you are using wasi-sdk (also work for emcc and rustc): +``` bash +/opt/wasi-sdk/bin/clang -g test.c -o test.wasm +``` + +Then you will get `test.wasm` which is a WebAssembly module with embedded DWARF sections. Further, you can use `llvm-dwarfdump` to check if the generated wasm file contains DWARF information: +``` bash +llvm-dwarfdump-12 test.wasm +``` + +## Debugging with interpreter +1. Install dependent libraries +``` bash +apt update && apt install cmake make g++ libxml2-dev -y +``` + +2. Build iwasm with source debugging feature +``` bash +cd ${WAMR_ROOT}/product-mini/platforms/linux +mkdir build && cd build +cmake .. -DWAMR_BUILD_DEBUG_INTERP=1 +make +``` +> Note: On MacOS M1 environment, pass the additional `-DWAMR_DISABLE_HW_BOUND_CHECK=1` cmake configuration. + +3. Execute iwasm with debug engine enabled +``` bash +iwasm -g=127.0.0.1:1234 test.wasm +# Use port = 0 to allow a random assigned debug port +``` + +4. Build customized lldb +``` bash +git clone --branch release/13.x --depth=1 https://github.com/llvm/llvm-project +cd llvm-project +git apply ${WAMR_ROOT}/build-scripts/lldb-wasm.patch +mkdir build-lldb +cmake -S ./llvm -B build-lldb \ + -G Ninja \ + -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_PROJECTS="clang;lldb" \ + -DLLVM_TARGETS_TO_BUILD:STRING="X86;WebAssembly" \ + -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DLLVM_BUILD_BENCHMARKS:BOOL=OFF \ + -DLLVM_BUILD_DOCS:BOOL=OFF -DLLVM_BUILD_EXAMPLES:BOOL=OFF \ + -DLLVM_BUILD_LLVM_DYLIB:BOOL=OFF -DLLVM_BUILD_TESTS:BOOL=OFF \ + -DLLVM_ENABLE_BINDINGS:BOOL=OFF -DLLVM_INCLUDE_BENCHMARKS:BOOL=OFF \ + -DLLVM_INCLUDE_DOCS:BOOL=OFF -DLLVM_INCLUDE_EXAMPLES:BOOL=OFF \ + -DLLVM_INCLUDE_TESTS:BOOL=OFF -DLLVM_ENABLE_LIBXML2:BOOL=ON +cmake --build build-lldb --target lldb --parallel $(nproc) +# The lldb is generated under build-lldb/bin/lldb +``` +> Note: If using `CommandLineTools` on MacOS, make sure only one SDK is present in `/Library/Developer/CommandLineTools/SDKs`. + +> You can download pre-built `wamr-lldb` binaries from [here](https://github.com/bytecodealliance/wasm-micro-runtime/releases). + +5. Launch customized lldb and connect to iwasm +``` bash +lldb +(lldb) process connect -p wasm connect://127.0.0.1:1234 +``` +Then you can use lldb commands to debug your applications. Please refer to [lldb document](https://lldb.llvm.org/use/tutorial.html) for command usage. + +## Debugging with AOT + +> Note: AOT debugging is experimental and only a few debugging capabilities are supported. + +1. Build lldb (assume you have already built llvm) +``` bash +cd ${WAMR_ROOT}/core/deps/llvm/build +cmake ../llvm -DLLVM_ENABLE_PROJECTS="clang;lldb" -DLLDB_INCLUDE_TESTS=OFF +make -j $(nproc) +``` + +2. Build wamrc with debugging feature +``` bash +cd ${WAMR_ROOT}/wamr-compiler +mkdir build && cd build +cmake .. -DWAMR_BUILD_DEBUG_AOT=1 +make -j $(nproc) +``` + +3. Build iwasm with debugging feature +``` bash +cd ${WAMR_ROOT}/product-mini/platforms/linux +mkdir build && cd build +cmake .. -DWAMR_BUILD_DEBUG_AOT=1 +make +``` + +4. Compile wasm module to AOT module +``` bash +wamrc -o test.aot test.wasm +``` + +5. Execute iwasm using lldb + + Then you can use lldb commands to debug both wamr runtime and your wasm application in ***current terminal***. + + ``` bash + % lldb iwasm -- test.aot + (lldb) target create "iwasm" + Current executable set to 'iwasm' (x86_64). + (lldb) settings set -- target.run-args "test.aot" + (lldb) settings set plugin.jit-loader.gdb.enable on + (lldb) b main + Breakpoint 1: where = iwasm`main + 48 at main.c:294:11, address = 0x0000000100001020 + (lldb) run + Process 27954 launched: '/tmp/bin/iwasm' (x86_64) + Process 27954 stopped + * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.1 + frame #0: 0x0000000100001020 iwasm`main(argc=2, argv=0x00007ff7bfeff678) at main.c:294:11 + 291 int + 292 main(int argc, char *argv[]) + 293 { + -> 294 int32 ret = -1; + 295 char *wasm_file = NULL; + 296 const char *func_name = NULL; + 297 uint8 *wasm_file_buf = NULL; + Target 0: (iwasm) stopped. + (lldb) c + Process 27954 resuming + 1 location added to breakpoint 1 + error: need to add support for DW_TAG_base_type 'void' encoded with DW_ATE = 0x0, bit_size = 0 + Process 27954 stopped + * thread #1, queue = 'com.apple.main-thread', stop reason = breakpoint 1.2 + frame #0: 0x00000001002980a0 JIT(0x100298004)`main(exenv=0x0000000301808200) at hello.c:6:9 + 3 int + 4 main(void) + 5 { + -> 6 printf("hello\n"); + 7 + 8 return 0; + 9 } + Target 0: (iwasm) stopped. + (lldb) br l + Current breakpoints: + 1: name = 'main', locations = 2, resolved = 2, hit count = 2 + 1.1: where = iwasm`main + 48 at main.c:294:11, address = 0x0000000100001020, resolved, hit count = 1 + 1.2: where = JIT(0x100298004)`main + 12 at hello.c:6:9, address = 0x00000001002980a0, resolved, hit count = 1 + + (lldb) + ``` + + * In the above example, + + * The first `main` function, which is in `main.c`, is the main + function of the iwasm command. + + * The second `main` function, which is in `hello.c`, is the main + function of the AOT-compiled wasm module. + + * WAMR AOT debugging uses the GDB JIT loader mechanism to load + the debug info of the debugee module. + On some platforms including macOS, you need to enable it explicitly. + (`settings set plugin.jit-loader.gdb.enable on`) + + References: + + * https://github.com/llvm/llvm-project/blob/main/llvm/docs/DebuggingJITedCode.rst + * https://sourceware.org/gdb/current/onlinedocs/gdb/JIT-Interface.html + +## Enable debugging in embedders (for interpreter) + +There are three steps to enable debugging in embedders + +1. Set the debug parameters when initializing the runtime environment: + ``` c + RuntimeInitArgs init_args; + memset(&init_args, 0, sizeof(RuntimeInitArgs)); + + /* ... */ + strcpy(init_args.ip_addr, "127.0.0.1"); + init_args.instance_port = 1234; + /* + * Or set port to 0 to use a port assigned by os + * init_args.instance_port = 0; + */ + + if (!wasm_runtime_full_init(&init_args)) { + return false; + } + ``` + +2. Use `wasm_runtime_start_debug_instance` to create the debug instance: + ``` c + /* + initialization, loading and instantiating + ... + */ + exec_env = wasm_runtime_create_exec_env(module_inst, stack_size); + uint32_t debug_port = wasm_runtime_start_debug_instance(exec_env); + ``` + +3. Enable source debugging features during building + + You can use `-DWAMR_BUILD_DEBUG_INTERP=1` during cmake configuration + + Or you can set it directly in `cmake` files: + ``` cmake + set (WAMR_BUILD_DEBUG_INTERP 1) + ``` + +### Attentions +- Debugging `multi-thread wasm module` is not supported, if your wasm module use pthread APIs (see [pthread_library.md](./pthread_library.md)), or the embedder use `wasm_runtime_spawn_thread` to create new wasm threads, then there may be **unexpected behaviour** during debugging. + + > Note: This attention is about "wasm thread" rather than native threads. Executing wasm functions in several different native threads will **not** affect the normal behaviour of debugging feature. + +- When using source debugging features, **don't** create multiple `wasm_instance` from the same `wasm_module`, because the debugger may change the bytecode (set/unset breakpoints) of the `wasm_module`. If you do need several instance from the same bytecode, you need to copy the bytecode to a new butter, then load a new `wasm_module`, and then instantiate the new wasm module to get the new instance. + +- If you are running `lldb` on non-linux platforms, please use `platform select remote-linux` command in lldb before connecting to the runtime: + ``` + (lldb) platform select remote-linux + (lldb) process connect -p wasm connect://127.0.0.1:1234 + ``` |