Support external toolchain on Windows for aot compiler (#3911)

allowing custom ARC toolchain on Windows

Author: TianlongLiang

build-scripts/build_llvm.py

@@ -102,12 +102,27 @@ def build_llvm(llvm_dir, platform, backends, projects, use_clang=False, extra_fl
         "default": [],
     }
 
+    experimental_backends = ["ARC", "Xtensa"]
+    normal_backends = [s for s in backends if s not in experimental_backends]
+
     LLVM_TARGETS_TO_BUILD = [
-        '-DLLVM_TARGETS_TO_BUILD:STRING="' + ";".join(backends) + '"'
-        if backends
+        '-DLLVM_TARGETS_TO_BUILD:STRING="' + ";".join(normal_backends) + '"'
+        if normal_backends
         else '-DLLVM_TARGETS_TO_BUILD:STRING="AArch64;ARM;Mips;RISCV;X86"'
     ]
 
+    # if not on ARC platform, but want to add expeirmental backend ARC as target
+    if platform != "ARC" and "ARC" in backends: 
+        LLVM_TARGETS_TO_BUILD.extend(
+            LLVM_EXTRA_COMPILE_OPTIONS["arc"]
+        )
+
+    if platform != "Xtensa" and "Xtensa" in backends:
+        print(
+            "Currently it's not supported to build Xtensa backend on non-Xtensa platform"
+        )
+        return None
+
     LLVM_PROJECTS_TO_BUILD = [
         '-DLLVM_ENABLE_PROJECTS:STRING="' + ";".join(projects) + '"' if projects else ""
     ]
@@ -240,6 +255,7 @@ def main():
             "X86",
             "Xtensa",
         ],
+        default=[],
         help="identify LLVM supported backends, separate by space, like '--arch ARM Mips X86'",
     )
     parser.add_argument(

core/iwasm/compilation/aot_compiler.c

@@ -4093,39 +4093,6 @@ 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;
-}
-#else
-
-errno_t
-_mktemp_s(char *nameTemplate, size_t sizeInChars);
-
 char *
 aot_generate_tempfile_name(const char *prefix, const char *extension,
                            char *buffer, uint32 len)
@@ -4134,7 +4101,8 @@ aot_generate_tempfile_name(const char *prefix, const char *extension,
 
     name_len = snprintf(buffer, len, "%s-XXXXXX", prefix);
 
-    if (_mktemp_s(buffer, name_len + 1) != 0) {
+    if (!bh_mkstemp(buffer, name_len + 1)) {
+        aot_set_last_error("make temp file failed.");
         return NULL;
     }
 
@@ -4148,7 +4116,6 @@ aot_generate_tempfile_name(const char *prefix, const char *extension,
     snprintf(buffer + name_len, len - name_len, ".%s", extension);
     return buffer;
 }
-#endif /* end of !(defined(_WIN32) || defined(_WIN32_)) */
 
 bool
 aot_emit_llvm_file(AOTCompContext *comp_ctx, const char *file_name)
@@ -4227,7 +4194,6 @@ 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;
@@ -4270,7 +4236,7 @@ aot_emit_object_file(AOTCompContext *comp_ctx, char *file_name)
                      file_name, bc_file_name);
             LOG_VERBOSE("invoking external LLC compiler:\n\t%s", cmd);
 
-            ret = system(cmd);
+            ret = bh_system(cmd);
             /* remove temp bitcode file */
             unlink(bc_file_name);
 
@@ -4323,7 +4289,7 @@ aot_emit_object_file(AOTCompContext *comp_ctx, char *file_name)
                      file_name, asm_file_name);
             LOG_VERBOSE("invoking external ASM compiler:\n\t%s", cmd);
 
-            ret = system(cmd);
+            ret = bh_system(cmd);
             /* remove temp assembly file */
             unlink(asm_file_name);
 
@@ -4336,7 +4302,6 @@ aot_emit_object_file(AOTCompContext *comp_ctx, char *file_name)
 
         return true;
     }
-#endif /* end of !(defined(_WIN32) || defined(_WIN32_)) */
 
     if (!strncmp(LLVMGetTargetName(target), "arc", 3))
         /* Emit to assembly file instead for arc target

core/iwasm/compilation/aot_emit_aot_file.c

@@ -4292,10 +4292,6 @@ aot_obj_data_create(AOTCompContext *comp_ctx)
 
     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];
@@ -4323,27 +4319,18 @@ aot_obj_data_create(AOTCompContext *comp_ctx)
             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;
-#else
         /* Emit to assembly file instead for arc target
            as it cannot emit to object file */
         char file_name[] = "wasm-XXXXXX", buf[128];
-        int fd, ret;
+        int ret;
 
-        if ((fd = mkstemp(file_name)) <= 0) {
+        if (!bh_mkstemp(file_name, sizeof(file_name))) {
             aot_set_last_error("make temp file failed.");
             goto fail;
         }
 
-        /* close and remove temp file */
-        close(fd);
-        unlink(file_name);
-
         snprintf(buf, sizeof(buf), "%s%s", file_name, ".s");
         if (LLVMTargetMachineEmitToFile(comp_ctx->target_machine,
                                         comp_ctx->module, buf, LLVMAssemblyFile,
@@ -4364,7 +4351,7 @@ aot_obj_data_create(AOTCompContext *comp_ctx)
                  "/opt/zephyr-sdk/arc-zephyr-elf/bin/arc-zephyr-elf-gcc ",
                  "-mcpu=arcem -o ", file_name, ".o -c ", file_name, ".s");
         /* TODO: use try..catch to handle possible exceptions */
-        ret = system(buf);
+        ret = bh_system(buf);
         /* remove temp assembly file */
         snprintf(buf, sizeof(buf), "%s%s", file_name, ".s");
         unlink(buf);
@@ -4391,7 +4378,6 @@ aot_obj_data_create(AOTCompContext *comp_ctx)
             aot_set_last_error("create mem buffer with file failed.");
             goto fail;
         }
-#endif /* end of defined(_WIN32) || defined(_WIN32_) */
     }
     else {
         if (LLVMTargetMachineEmitToMemoryBuffer(

core/iwasm/compilation/aot_llvm.c

@@ -2746,10 +2746,6 @@ aot_create_comp_context(const AOTCompData *comp_data, aot_comp_option_t option)
         /* 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",
@@ -2761,17 +2757,12 @@ aot_create_comp_context(const AOTCompData *comp_data, aot_comp_option_t option)
                 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 "
@@ -2784,7 +2775,6 @@ aot_create_comp_context(const AOTCompData *comp_data, aot_comp_option_t option)
                     LOG_VERBOSE("Using external ASM compiler [%s]",
                                 comp_ctx->external_asm_compiler);
                 }
-#endif
             }
         }
 

core/iwasm/compilation/aot_llvm.h

@@ -37,6 +37,18 @@
 #include "aot_orc_extra.h"
 #include "aot_comp_option.h"
 
+#if defined(_WIN32) || defined(_WIN32_)
+#include <io.h>
+#define access _access
+/* On windows there is no X_OK flag to check for executablity, only check for
+ * existence */
+#ifdef X_OK
+#undef X_OK
+#endif
+#define X_OK 00
+#define unlink _unlink
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif

core/shared/utils/bh_common.c

@@ -165,3 +165,53 @@ wa_strdup(const char *s)
     }
     return s1;
 }
+
+#if WASM_ENABLE_WAMR_COMPILER != 0 || WASM_ENABLE_JIT != 0
+int
+bh_system(const char *cmd)
+{
+    int ret;
+
+#if !(defined(_WIN32) || defined(_WIN32_))
+    ret = system(cmd);
+#else
+    ret = _spawnlp(_P_WAIT, "cmd.exe", "/c", cmd, NULL);
+#endif
+
+    return ret;
+}
+
+#if defined(_WIN32) || defined(_WIN32_)
+errno_t
+_mktemp_s(char *nameTemplate, size_t sizeInChars);
+#endif
+
+bool
+bh_mkstemp(char *file_name, size_t name_len)
+{
+    int fd;
+
+#if !(defined(_WIN32) || defined(_WIN32_))
+    (void)name_len;
+    /* On Linux, it generates a unique temporary filename from template, creates
+     * and opens the file, and returns an open file descriptor for the file. */
+    if ((fd = mkstemp(file_name)) <= 0) {
+        goto fail;
+    }
+
+    /* close and remove temp file */
+    close(fd);
+    unlink(file_name);
+#else
+    /* On Windows, it generates a unique temporary file name but does not create
+     * or open the file */
+    if (_mktemp_s(file_name, name_len) != 0) {
+        goto fail;
+    }
+#endif
+
+    return true;
+fail:
+    return false;
+}
+#endif /* End of WASM_ENABLE_WAMR_COMPILER != 0 || WASM_ENABLE_JIT != 0 */

core/shared/utils/bh_common.h

@@ -66,6 +66,16 @@ bh_strdup(const char *s);
 char *
 wa_strdup(const char *s);
 
+#if WASM_ENABLE_WAMR_COMPILER != 0 || WASM_ENABLE_JIT != 0
+/* Executes a system command in bash/cmd.exe */
+int
+bh_system(const char *cmd);
+
+/* Tests whether can create a temporary file with the given name */
+bool
+bh_mkstemp(char *filename, size_t name_len);
+#endif
+
 #ifdef __cplusplus
 }
 #endif