Merge #481

481: Added context trampoline into runtime r=losfair a=syrusakbary

Based on #450 

Co-authored-by: losfair <[email protected]>

lib/runtime-c-api/src/lib.rs

@@ -95,6 +95,8 @@ pub mod instance;
 pub mod memory;
 pub mod module;
 pub mod table;
+#[cfg(all(unix, target_arch = "x86_64"))]
+pub mod trampoline;
 pub mod value;
 
 #[allow(non_camel_case_types)]

lib/runtime-c-api/src/trampoline.rs

@@ -0,0 +1,84 @@
+//! Trampoline emitter for transforming function calls.
+
+use std::ffi::c_void;
+use std::mem;
+use wasmer_runtime_core::trampoline::*;
+
+#[repr(C)]
+pub struct wasmer_trampoline_buffer_builder_t;
+
+#[repr(C)]
+pub struct wasmer_trampoline_buffer_t;
+
+#[repr(C)]
+pub struct wasmer_trampoline_callable_t;
+
+/// Creates a new trampoline builder.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub extern "C" fn wasmer_trampoline_buffer_builder_new() -> *mut wasmer_trampoline_buffer_builder_t
+{
+    Box::into_raw(Box::new(TrampolineBufferBuilder::new())) as *mut _
+}
+
+/// Adds a context trampoline to the builder.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_buffer_builder_add_context_trampoline(
+    builder: *mut wasmer_trampoline_buffer_builder_t,
+    func: *const wasmer_trampoline_callable_t,
+    ctx: *const c_void,
+) -> usize {
+    let builder = &mut *(builder as *mut TrampolineBufferBuilder);
+    builder.add_context_trampoline(func as *const CallTarget, ctx as *const CallContext)
+}
+
+/// Adds a callinfo trampoline to the builder.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_buffer_builder_add_callinfo_trampoline(
+    builder: *mut wasmer_trampoline_buffer_builder_t,
+    func: *const wasmer_trampoline_callable_t,
+    ctx: *const c_void,
+    num_params: u32,
+) -> usize {
+    let builder = &mut *(builder as *mut TrampolineBufferBuilder);
+    builder.add_callinfo_trampoline(mem::transmute(func), ctx as *const CallContext, num_params)
+}
+
+/// Finalizes the trampoline builder into an executable buffer.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_buffer_builder_build(
+    builder: *mut wasmer_trampoline_buffer_builder_t,
+) -> *mut wasmer_trampoline_buffer_t {
+    let builder = Box::from_raw(builder as *mut TrampolineBufferBuilder);
+    Box::into_raw(Box::new(builder.build())) as *mut _
+}
+
+/// Destroys the trampoline buffer if not null.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_buffer_destroy(buffer: *mut wasmer_trampoline_buffer_t) {
+    if !buffer.is_null() {
+        Box::from_raw(buffer);
+    }
+}
+
+/// Returns the callable pointer for the trampoline with index `idx`.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_buffer_get_trampoline(
+    buffer: *const wasmer_trampoline_buffer_t,
+    idx: usize,
+) -> *const wasmer_trampoline_callable_t {
+    let buffer = &*(buffer as *const TrampolineBuffer);
+    buffer.get_trampoline(idx) as _
+}
+
+/// Returns the context added by `add_context_trampoline`, from within the callee function.
+#[no_mangle]
+#[allow(clippy::cast_ptr_alignment)]
+pub unsafe extern "C" fn wasmer_trampoline_get_context() -> *mut c_void {
+    get_context() as *const c_void as *mut c_void
+}

lib/runtime-c-api/tests/test-import-function-callinfo.c

@@ -0,0 +1,132 @@
+#include <stdio.h>
+#include "../wasmer.h"
+#include <assert.h>
+#include <stdint.h>
+#include <string.h>
+
+static bool print_str_called = false;
+static int memory_len = 0;
+static int ptr_len = 0;
+static char actual_str[14] = {};
+static int actual_context_data_value = 0;
+
+typedef struct {
+  int value;
+} context_data;
+
+struct print_str_context {
+    int call_count;
+};
+
+void print_str(struct print_str_context *local_context, uint64_t *args)
+{
+    local_context->call_count++;
+
+    wasmer_instance_context_t *ctx = (void *) args[0];
+    int32_t ptr = args[1];
+    int32_t len = args[2];
+
+    const wasmer_memory_t *memory = wasmer_instance_context_memory(ctx, 0);
+    uint32_t mem_len = wasmer_memory_length(memory);
+    uint8_t *mem_bytes = wasmer_memory_data(memory);
+    for (int32_t idx = 0; idx < len; idx++)
+    {
+        actual_str[idx] = mem_bytes[ptr + idx];
+    }
+    actual_str[13] = '\0';
+    printf("In print_str, memory len: %d, ptr_len: %d\n, str %s", mem_len, len, actual_str);
+    print_str_called = true;
+    memory_len = mem_len;
+    ptr_len = len;
+
+    actual_context_data_value = ((context_data *) wasmer_instance_context_data_get(ctx))->value;
+}
+
+int main()
+{
+    wasmer_value_tag params_sig[] = {WASM_I32, WASM_I32};
+    wasmer_value_tag returns_sig[] = {};
+    struct print_str_context local_context = {
+        .call_count = 0
+    };
+
+    printf("Creating trampoline buffer\n");
+    wasmer_trampoline_buffer_builder_t *tbb = wasmer_trampoline_buffer_builder_new();
+    unsigned long print_str_idx = wasmer_trampoline_buffer_builder_add_callinfo_trampoline(
+        tbb,
+        (wasmer_trampoline_callable_t *) print_str,
+        (void *) &local_context,
+        3
+    );
+    wasmer_trampoline_buffer_t *tb = wasmer_trampoline_buffer_builder_build(tbb);
+    const wasmer_trampoline_callable_t *print_str_callable = wasmer_trampoline_buffer_get_trampoline(tb, print_str_idx);
+
+    printf("Creating new func\n");
+    wasmer_import_func_t *func = wasmer_import_func_new((void (*)(void *)) print_str_callable, params_sig, 2, returns_sig, 0);
+    wasmer_import_t import;
+
+    char *module_name = "env";
+    wasmer_byte_array module_name_bytes;
+    module_name_bytes.bytes = (const uint8_t *) module_name;
+    module_name_bytes.bytes_len = strlen(module_name);
+    char *import_name = "print_str";
+    wasmer_byte_array import_name_bytes;
+    import_name_bytes.bytes = (const uint8_t *) import_name;
+    import_name_bytes.bytes_len = strlen(import_name);
+
+    import.module_name = module_name_bytes;
+    import.import_name = import_name_bytes;
+    import.tag = WASM_FUNCTION;
+    import.value.func = func;
+    wasmer_import_t imports[] = {import};
+
+    // Read the wasm file bytes
+    FILE *file = fopen("assets/wasm_sample_app.wasm", "r");
+    fseek(file, 0, SEEK_END);
+    long len = ftell(file);
+    uint8_t *bytes = malloc(len);
+    fseek(file, 0, SEEK_SET);
+    fread(bytes, 1, len, file);
+    fclose(file);
+
+    printf("Instantiating\n");
+    wasmer_instance_t *instance = NULL;
+    wasmer_result_t compile_result = wasmer_instantiate(&instance, bytes, len, imports, 1);
+    printf("Compile result:  %d\n", compile_result);
+
+    assert(compile_result == WASMER_OK);
+
+    context_data* context_data = malloc(sizeof(context_data));
+    int context_data_value = 42;
+    context_data->value = context_data_value;
+    wasmer_instance_context_data_set(instance, context_data);
+
+    wasmer_value_t params[] = {};
+    wasmer_value_t results[] = {};
+    wasmer_result_t call_result = wasmer_instance_call(instance, "hello_wasm", params, 0, results, 0);
+    printf("Call result:  %d\n", call_result);
+
+    int error_len = wasmer_last_error_length();
+    printf("Error len: `%d`\n", error_len);
+    char *error_str = malloc(error_len);
+    wasmer_last_error_message(error_str, error_len);
+    printf("Error str: `%s`\n", error_str);
+
+    assert(call_result == WASMER_OK);
+
+    assert(print_str_called);
+    assert(memory_len == 17);
+    assert(ptr_len == 13);
+    assert(0 == strcmp(actual_str, "Hello, World!"));
+    assert(context_data_value == actual_context_data_value);
+    assert(local_context.call_count == 1);
+
+    printf("Destroying trampoline buffer\n");
+    wasmer_trampoline_buffer_destroy(tb);
+    printf("Destroying func\n");
+    wasmer_import_func_destroy(func);
+    printf("Destroy instance\n");
+    wasmer_instance_destroy(instance);
+    free(context_data);
+    return 0;
+}

lib/runtime-c-api/tests/test-import-function.c

@@ -14,8 +14,15 @@ typedef struct {
   int value;
 } context_data;
 
+struct print_str_context {
+    int call_count;
+};
+
 void print_str(wasmer_instance_context_t *ctx, int32_t ptr, int32_t len)
 {
+    struct print_str_context *local_context = wasmer_trampoline_get_context();
+    local_context->call_count++;
+
     const wasmer_memory_t *memory = wasmer_instance_context_memory(ctx, 0);
     uint32_t mem_len = wasmer_memory_length(memory);
     uint8_t *mem_bytes = wasmer_memory_data(memory);
@@ -36,9 +43,22 @@ int main()
 {
     wasmer_value_tag params_sig[] = {WASM_I32, WASM_I32};
     wasmer_value_tag returns_sig[] = {};
+    struct print_str_context local_context = {
+        .call_count = 0
+    };
+
+    printf("Creating trampoline buffer\n");
+    wasmer_trampoline_buffer_builder_t *tbb = wasmer_trampoline_buffer_builder_new();
+    unsigned long print_str_idx = wasmer_trampoline_buffer_builder_add_context_trampoline(
+        tbb,
+        (wasmer_trampoline_callable_t *) print_str,
+        (void *) &local_context
+    );
+    wasmer_trampoline_buffer_t *tb = wasmer_trampoline_buffer_builder_build(tbb);
+    const wasmer_trampoline_callable_t *print_str_callable = wasmer_trampoline_buffer_get_trampoline(tb, print_str_idx);
 
     printf("Creating new func\n");
-    wasmer_import_func_t *func = wasmer_import_func_new((void (*)(void *)) print_str, params_sig, 2, returns_sig, 0);
+    wasmer_import_func_t *func = wasmer_import_func_new((void (*)(void *)) print_str_callable, params_sig, 2, returns_sig, 0);
     wasmer_import_t import;
 
     char *module_name = "env";
@@ -95,7 +115,10 @@ int main()
     assert(ptr_len == 13);
     assert(0 == strcmp(actual_str, "Hello, World!"));
     assert(context_data_value == actual_context_data_value);
+    assert(local_context.call_count == 1);
 
+    printf("Destroying trampoline buffer\n");
+    wasmer_trampoline_buffer_destroy(tb);
     printf("Destroying func\n");
     wasmer_import_func_destroy(func);
     printf("Destroy instance\n");

lib/runtime-c-api/wasmer.h

@@ -133,6 +133,18 @@ typedef struct {
 
 } wasmer_serialized_module_t;
 
+typedef struct {
+
+} wasmer_trampoline_buffer_builder_t;
+
+typedef struct {
+
+} wasmer_trampoline_callable_t;
+
+typedef struct {
+
+} wasmer_trampoline_buffer_t;
+
 /**
  * Creates a new Module from the given wasm bytes.
  * Returns `wasmer_result_t::WASMER_OK` upon success.
@@ -584,6 +596,47 @@ uint32_t wasmer_table_length(wasmer_table_t *table);
  */
 wasmer_result_t wasmer_table_new(wasmer_table_t **table, wasmer_limits_t limits);
 
+/**
+ * Adds a callinfo trampoline to the builder.
+ */
+uintptr_t wasmer_trampoline_buffer_builder_add_callinfo_trampoline(wasmer_trampoline_buffer_builder_t *builder,
+                                                                   const wasmer_trampoline_callable_t *func,
+                                                                   const void *ctx,
+                                                                   uint32_t num_params);
+
+/**
+ * Adds a context trampoline to the builder.
+ */
+uintptr_t wasmer_trampoline_buffer_builder_add_context_trampoline(wasmer_trampoline_buffer_builder_t *builder,
+                                                                  const wasmer_trampoline_callable_t *func,
+                                                                  const void *ctx);
+
+/**
+ * Finalizes the trampoline builder into an executable buffer.
+ */
+wasmer_trampoline_buffer_t *wasmer_trampoline_buffer_builder_build(wasmer_trampoline_buffer_builder_t *builder);
+
+/**
+ * Creates a new trampoline builder.
+ */
+wasmer_trampoline_buffer_builder_t *wasmer_trampoline_buffer_builder_new(void);
+
+/**
+ * Destroys the trampoline buffer if not null.
+ */
+void wasmer_trampoline_buffer_destroy(wasmer_trampoline_buffer_t *buffer);
+
+/**
+ * Returns the callable pointer for the trampoline with index `idx`.
+ */
+const wasmer_trampoline_callable_t *wasmer_trampoline_buffer_get_trampoline(const wasmer_trampoline_buffer_t *buffer,
+                                                                            uintptr_t idx);
+
+/**
+ * Returns the context added by `add_context_trampoline`, from within the callee function.
+ */
+void *wasmer_trampoline_get_context(void);
+
 /**
  * Returns true for valid wasm bytes and false for invalid bytes
  */

lib/runtime-c-api/wasmer.hh

@@ -131,6 +131,18 @@ struct wasmer_serialized_module_t {
 
 };
 
+struct wasmer_trampoline_buffer_builder_t {
+
+};
+
+struct wasmer_trampoline_callable_t {
+
+};
+
+struct wasmer_trampoline_buffer_t {
+
+};
+
 extern "C" {
 
 /// Creates a new Module from the given wasm bytes.
@@ -458,6 +470,33 @@ uint32_t wasmer_table_length(wasmer_table_t *table);
 /// and `wasmer_last_error_message` to get an error message.
 wasmer_result_t wasmer_table_new(wasmer_table_t **table, wasmer_limits_t limits);
 
+/// Adds a callinfo trampoline to the builder.
+uintptr_t wasmer_trampoline_buffer_builder_add_callinfo_trampoline(wasmer_trampoline_buffer_builder_t *builder,
+                                                                   const wasmer_trampoline_callable_t *func,
+                                                                   const void *ctx,
+                                                                   uint32_t num_params);
+
+/// Adds a context trampoline to the builder.
+uintptr_t wasmer_trampoline_buffer_builder_add_context_trampoline(wasmer_trampoline_buffer_builder_t *builder,
+                                                                  const wasmer_trampoline_callable_t *func,
+                                                                  const void *ctx);
+
+/// Finalizes the trampoline builder into an executable buffer.
+wasmer_trampoline_buffer_t *wasmer_trampoline_buffer_builder_build(wasmer_trampoline_buffer_builder_t *builder);
+
+/// Creates a new trampoline builder.
+wasmer_trampoline_buffer_builder_t *wasmer_trampoline_buffer_builder_new();
+
+/// Destroys the trampoline buffer if not null.
+void wasmer_trampoline_buffer_destroy(wasmer_trampoline_buffer_t *buffer);
+
+/// Returns the callable pointer for the trampoline with index `idx`.
+const wasmer_trampoline_callable_t *wasmer_trampoline_buffer_get_trampoline(const wasmer_trampoline_buffer_t *buffer,
+                                                                            uintptr_t idx);
+
+/// Returns the context added by `add_context_trampoline`, from within the callee function.
+void *wasmer_trampoline_get_context();
+
 /// Returns true for valid wasm bytes and false for invalid bytes
 bool wasmer_validate(const uint8_t *wasm_bytes, uint32_t wasm_bytes_len);