Support integrate 3rd-party toolchains into wamrc (#1237)

Support integrating 3rd-party toolchain llc compiler or asm compiler
into wamrc by setting environment variable WAMRC_LLC_COMPILER
or WAMRC_ASM_COMPILER, wamrc will use these tools to generate
object file from LLVM IR firstly, and then refactor the object file into
aot file.
This commit is contained in:
Xu Jun 2022-06-20 13:13:41 +08:00 committed by GitHub
parent bc6eda2803
commit 53b775aa4b
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8 changed files with 241 additions and 1 deletions

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@ -15,7 +15,9 @@
extern "C" {
#endif
#ifndef AOT_FUNC_PREFIX
#define AOT_FUNC_PREFIX "aot_func#"
#endif
typedef InitializerExpression AOTInitExpr;
typedef WASMType AOTFuncType;

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@ -2886,6 +2886,36 @@ aot_compile_wasm(AOTCompContext *comp_ctx)
return true;
}
#if !(defined(_WIN32) || defined(_WIN32_))
char *
aot_generate_tempfile_name(const char *prefix, const char *extension,
char *buffer, uint32 len)
{
int fd, name_len;
name_len = snprintf(buffer, len, "%s-XXXXXX", prefix);
if ((fd = mkstemp(buffer)) <= 0) {
aot_set_last_error("make temp file failed.");
return NULL;
}
/* close and remove temp file */
close(fd);
unlink(buffer);
/* Check if buffer length is enough */
/* name_len + '.' + extension + '\0' */
if (name_len + 1 + strlen(extension) + 1 > len) {
aot_set_last_error("temp file name too long.");
return NULL;
}
snprintf(buffer + name_len, len - name_len, ".%s", extension);
return buffer;
}
#endif /* end of !(defined(_WIN32) || defined(_WIN32_)) */
#if WASM_ENABLE_LAZY_JIT == 0
bool
aot_emit_llvm_file(AOTCompContext *comp_ctx, const char *file_name)
@ -2915,6 +2945,83 @@ aot_emit_object_file(AOTCompContext *comp_ctx, char *file_name)
bh_print_time("Begin to emit object file");
#if !(defined(_WIN32) || defined(_WIN32_))
if (comp_ctx->external_llc_compiler || comp_ctx->external_asm_compiler) {
char cmd[1024];
int ret;
if (comp_ctx->external_llc_compiler) {
char bc_file_name[64];
if (!aot_generate_tempfile_name("wamrc-bc", "bc", bc_file_name,
sizeof(bc_file_name))) {
return false;
}
if (LLVMWriteBitcodeToFile(comp_ctx->module, bc_file_name) != 0) {
aot_set_last_error("emit llvm bitcode file failed.");
return false;
}
snprintf(cmd, sizeof(cmd), "%s %s -o %s %s",
comp_ctx->external_llc_compiler,
comp_ctx->llc_compiler_flags ? comp_ctx->llc_compiler_flags
: "-O3 -c",
file_name, bc_file_name);
LOG_VERBOSE("invoking external LLC compiler:\n\t%s", cmd);
ret = system(cmd);
/* remove temp bitcode file */
unlink(bc_file_name);
if (ret != 0) {
aot_set_last_error("failed to compile LLVM bitcode to obj file "
"with external LLC compiler.");
return false;
}
}
else if (comp_ctx->external_asm_compiler) {
char asm_file_name[64];
if (!aot_generate_tempfile_name("wamrc-asm", "s", asm_file_name,
sizeof(asm_file_name))) {
return false;
}
if (LLVMTargetMachineEmitToFile(comp_ctx->target_machine,
comp_ctx->module, asm_file_name,
LLVMAssemblyFile, &err)
!= 0) {
if (err) {
LLVMDisposeMessage(err);
err = NULL;
}
aot_set_last_error("emit elf to assembly file failed.");
return false;
}
snprintf(cmd, sizeof(cmd), "%s %s -o %s %s",
comp_ctx->external_asm_compiler,
comp_ctx->asm_compiler_flags ? comp_ctx->asm_compiler_flags
: "-O3 -c",
file_name, asm_file_name);
LOG_VERBOSE("invoking external ASM compiler:\n\t%s", cmd);
ret = system(cmd);
/* remove temp assembly file */
unlink(asm_file_name);
if (ret != 0) {
aot_set_last_error("failed to compile Assembly file to obj "
"file with external ASM compiler.");
return false;
}
}
return true;
}
#endif /* end of !(defined(_WIN32) || defined(_WIN32_)) */
if (!strncmp(LLVMGetTargetName(target), "arc", 3))
/* Emit to assmelby file instead for arc target
as it cannot emit to object file */

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@ -371,6 +371,10 @@ aot_emit_aot_file_buf(AOTCompContext *comp_ctx, AOTCompData *comp_data,
bool
aot_emit_object_file(AOTCompContext *comp_ctx, char *file_name);
char *
aot_generate_tempfile_name(const char *prefix, const char *extension,
char *buffer, uint32 len);
#ifdef __cplusplus
} /* end of extern "C" */
#endif

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@ -2692,8 +2692,41 @@ aot_obj_data_create(AOTCompContext *comp_ctx)
memset(obj_data, 0, sizeof(AOTObjectData));
bh_print_time("Begin to emit object file");
if (comp_ctx->external_llc_compiler || comp_ctx->external_asm_compiler) {
#if defined(_WIN32) || defined(_WIN32_)
aot_set_last_error("external toolchain not supported on Windows");
goto fail;
#else
/* Generate a temp file name */
int ret;
char obj_file_name[64];
if (!strncmp(LLVMGetTargetName(target), "arc", 3)) {
if (!aot_generate_tempfile_name("wamrc-obj", "o", obj_file_name,
sizeof(obj_file_name))) {
goto fail;
}
if (!aot_emit_object_file(comp_ctx, obj_file_name)) {
goto fail;
}
/* create memory buffer from object file */
ret = LLVMCreateMemoryBufferWithContentsOfFile(
obj_file_name, &obj_data->mem_buf, &err);
/* remove temp object file */
unlink(obj_file_name);
if (ret != 0) {
if (err) {
LLVMDisposeMessage(err);
err = NULL;
}
aot_set_last_error("create mem buffer with file failed.");
goto fail;
}
#endif /* end of defined(_WIN32) || defined(_WIN32_) */
}
else if (!strncmp(LLVMGetTargetName(target), "arc", 3)) {
#if defined(_WIN32) || defined(_WIN32_)
aot_set_last_error("emit object file on Windows is unsupported.");
goto fail;

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@ -1660,6 +1660,51 @@ aot_create_comp_context(AOTCompData *comp_data, aot_comp_option_t option)
opt_level = option->opt_level;
size_level = option->size_level;
/* verify external llc compiler */
comp_ctx->external_llc_compiler = getenv("WAMRC_LLC_COMPILER");
if (comp_ctx->external_llc_compiler) {
#if defined(_WIN32) || defined(_WIN32_)
comp_ctx->external_llc_compiler = NULL;
LOG_WARNING("External LLC compiler not supported on Windows.");
#else
if (access(comp_ctx->external_llc_compiler, X_OK) != 0) {
LOG_WARNING("WAMRC_LLC_COMPILER [%s] not found, fallback to "
"default pipeline",
comp_ctx->external_llc_compiler);
comp_ctx->external_llc_compiler = NULL;
}
else {
comp_ctx->llc_compiler_flags = getenv("WAMRC_LLC_FLAGS");
LOG_VERBOSE("Using external LLC compiler [%s]",
comp_ctx->external_llc_compiler);
}
#endif
}
/* verify external asm compiler */
if (!comp_ctx->external_llc_compiler) {
comp_ctx->external_asm_compiler = getenv("WAMRC_ASM_COMPILER");
if (comp_ctx->external_asm_compiler) {
#if defined(_WIN32) || defined(_WIN32_)
comp_ctx->external_asm_compiler = NULL;
LOG_WARNING("External ASM compiler not supported on Windows.");
#else
if (access(comp_ctx->external_asm_compiler, X_OK) != 0) {
LOG_WARNING(
"WAMRC_ASM_COMPILER [%s] not found, fallback to "
"default pipeline",
comp_ctx->external_asm_compiler);
comp_ctx->external_asm_compiler = NULL;
}
else {
comp_ctx->asm_compiler_flags = getenv("WAMRC_ASM_FLAGS");
LOG_VERBOSE("Using external ASM compiler [%s]",
comp_ctx->external_asm_compiler);
}
#endif
}
}
if (arch) {
/* Add default sub-arch if not specified */
if (!strcmp(arch, "arm"))

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@ -14,6 +14,7 @@
#include "llvm-c/Object.h"
#include "llvm-c/ExecutionEngine.h"
#include "llvm-c/Analysis.h"
#include "llvm-c/BitWriter.h"
#include "llvm-c/Transforms/Utils.h"
#include "llvm-c/Transforms/Scalar.h"
#include "llvm-c/Transforms/Vectorize.h"
@ -350,6 +351,20 @@ typedef struct AOTCompContext {
uint32 func_ctx_count;
char **custom_sections_wp;
uint32 custom_sections_count;
/* 3rd-party toolchains */
/* External llc compiler, if specified, wamrc will emit the llvm-ir file and
* invoke the llc compiler to generate object file.
* This can be used when we want to benefit from the optimization of other
* LLVM based toolchains */
const char *external_llc_compiler;
const char *llc_compiler_flags;
/* External asm compiler, if specified, wamrc will emit the text-based
* assembly file (.s) and invoke the llc compiler to generate object file.
* This will be useful when the upstream LLVM doesn't support to emit object
* file for some architecture (such as arc) */
const char *external_asm_compiler;
const char *asm_compiler_flags;
} AOTCompContext;
enum {

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@ -330,6 +330,36 @@ Examples: wamrc -o test.aot test.wasm
wamrc --target=i386 --format=object -o test.o test.wasm
```
## AoT compilation with 3rd-party toolchains
`wamrc` uses LLVM to compile wasm bytecode to AoT file, this works for most of the architectures, but there may be circumstances where you want to use 3rd-party toolchains to take over some steps of the compilation pipeline, e.g.
1. The upstream LLVM doesn't support generating object file for your CPU architecture (such as ARC), then we may need some other assembler to do such things.
2. You may get some other LLVM-based toolchains which may have better optimizations for the specific target, then you may want your toolchain to take over all optimization steps.
`wamrc` provides two environment variables to achieve these:
- `WAMRC_LLC_COMPILER`
When specified, `wamrc` will emit the optimized LLVM-IR (.bc) to a file, and invoke `$WAMRC_LLC_COMPILER` with ` -c -O3 ` to generate the object file.
Optionally, you can use environment variable `WAMRC_LLC_FLAGS` to overwrite the default flags.
- `WAMRC_ASM_COMPILER`
When specified, `wamrc` will emit the text based assembly file (.s), and invoke `$WAMRC_ASM_COMPILER` with ` -c -O3 ` to generate the object file.
Optionally, you can use environment variable `WAMRC_ASM_FLAGS` to overwrite the default flags.
### Usage example
``` bash
WAMRC_LLC_COMPILER=<path/to/your/compiler/driver> ./wamrc -o test.aot test.wasm
```
> Note: `wamrc` will verify whether the specified file exists and executable. If verification failed, `wamrc` will report a warning and fallback to normal pipeline. Since the verification is based on file, you **must specify the absolute path to the binary** even if it's in `$PATH`
> Note: `WAMRC_LLC_COMPILER` has higher priority than `WAMRC_ASM_COMPILER`, if `WAMRC_LLC_COMPILER` is set and verified, then `WAMRC_ASM_COMPILER` will be ignored.
> Note: the `LLC` and `ASM` in the env name just means this compiler will be used to compile the `LLVM IR file`/`assembly file` to object file, usually passing the compiler driver is the simplest way. (e.g. for LLVM toolchain, you don't need to pass `/usr/bin/llc`, using `/usr/bin/clang` is OK)
Run WASM app in WAMR mini product build
=======================================

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@ -41,6 +41,10 @@ if (WAMR_BUILD_LLVM_LEGACY_PM EQUAL 1)
add_definitions(-DWASM_ENABLE_LLVM_LEGACY_PM=1)
endif()
if (DEFINED WAMR_BUILD_AOT_FUNC_PREFIX)
add_definitions(-DAOT_FUNC_PREFIX="${WAMR_BUILD_AOT_FUNC_PREFIX}")
endif ()
# Set WAMR_BUILD_TARGET, currently values supported:
# "X86_64", "AMD_64", "X86_32", "ARM_32", "MIPS_32", "XTENSA_32"
if (NOT WAMR_BUILD_TARGET)