add the initial version

.gitignore

@@ -0,0 +1,13 @@
+# IntelliJ
+.idea
+.vscode
+*.iml
+
+# MacOS folder metadata
+.DS_Store
+
+# Text writing
+*.scriv
+
+# Webassembly generated files
+*.wasm

Makefile

@@ -0,0 +1,20 @@
+TARGET = hello_world
+CC = clang
+SYSROOT = --sysroot=/tmp/wasi-sdk/
+TARGET_TRIPLE = --target=wasm32-unknown-wasi
+CFLAGS = -nostartfiles -fvisibility=hidden -Wl,--no-entry,--demangle,--allow-undefined
+EXPORT_FUNCS = -Wl,--export=allocate,--export=deallocate,--export=invoke
+SDK = sdk/allocator.c sdk/logger.c
+
+.PHONY: default all clean
+
+default: $(TARGET)
+all: default
+
+$(TARGET): main.c $(SDK)
+	$(CC) $(SYSROOT) $(TARGET_TRIPLE) $(CFLAGS) $(EXPORT_FUNCS) $^ -o $@.wasm
+
+.PRECIOUS: $(TARGET)
+
+clean:
+	-rm -f $(TARGET).wasm

main.c

@@ -0,0 +1,6 @@
+#include "sdk/allocator.h"
+#include "sdk/logger.h"
+
+char *invoke(const char *str, int length) {
+
+}

sdk/allocator.c

@@ -0,0 +1,13 @@
+#include "allocator.h"
+#include <stdlib.h>
+
+#define UNUSED(x) (void)(x)
+
+void *allocate(size_t size) {
+    return malloc(size);
+}
+
+void deallocate(void *ptr, size_t size) {
+    UNUSED(size);
+    free(ptr);
+}

sdk/allocator.h

@@ -0,0 +1,12 @@
+#ifndef FLUENCE_C_SDK_ALLOCATOR_H
+#define FLUENCE_C_SDK_ALLOCATOR_H
+
+#include <stddef.h> // for size_t
+
+// used by Wasm VM for byte array passing (should be exported from module)
+void *allocate(size_t size);
+
+// used by Wasm VM for freeing previous memory allocated by allocate function
+void deallocate(void *ptr, size_t size);
+
+#endif //FLUENCE_C_SDK_ALLOCATOR_H

sdk/logger.c

@@ -0,0 +1,15 @@
+#include "logger.h"
+
+#define __LOGGER_IMPORT(name) \
+    __attribute__((__import_module__("logger"), __import_name__(#name)))
+
+void __write(char ch) __LOGGER_IMPORT(write);
+void __flush() __LOGGER_IMPORT(flush);
+
+void wasm_log(const char *str, int len) {
+    for(int byteId = 0; byteId < len; ++byteId) {
+        __write(str[byteId]);
+    }
+
+    __flush();
+}

sdk/logger.h

@@ -0,0 +1,7 @@
+#ifndef FLUENCE_C_SDK_LOGGER_H
+#define FLUENCE_C_SDK_LOGGER_H
+
+// writes provided string to Wasm VM logger
+void wasm_log(const char *str, int len);
+
+#endif //FLUENCE_C_SDK_LOGGER_H