LLVMValueRef gen_ffi(compile_t* c, ast_t* ast)
{
AST_GET_CHILDREN(ast, id, typeargs, args, named_args, can_err);
bool err = (ast_id(can_err) == TK_QUESTION);
// Get the function name, +1 to skip leading @
const char* f_name = ast_name(id) + 1;
// Get the return type.
ast_t* type = ast_type(ast);
reach_type_t* t = reach_type(c->reach, type);
pony_assert(t != NULL);
// Get the function.
LLVMValueRef func = LLVMGetNamedFunction(c->module, f_name);
if(func == NULL)
{
// If we have no prototype, declare one.
ast_t* decl = (ast_t*)ast_data(ast);
if(decl != NULL)
{
// Define using the declared types.
AST_GET_CHILDREN(decl, decl_id, decl_ret, decl_params, decl_err);
err = (ast_id(decl_err) == TK_QUESTION);
func = declare_ffi(c, f_name, t, decl_params, err, false);
} else if(!strncmp(f_name, "llvm.", 5)) {
// Intrinsic, so use the exact types we supply.
func = declare_ffi(c, f_name, t, args, err, true);
} else {
// Make it varargs.
func = declare_ffi_vararg(c, f_name, t, err);
}
}
// Generate the arguments.
int count = (int)ast_childcount(args);
size_t buf_size = count * sizeof(LLVMValueRef);
LLVMValueRef* f_args = (LLVMValueRef*)ponyint_pool_alloc_size(buf_size);
LLVMTypeRef f_type = LLVMGetElementType(LLVMTypeOf(func));
LLVMTypeRef* f_params = NULL;
bool vararg = (LLVMIsFunctionVarArg(f_type) != 0);
if(!vararg)
{
f_params = (LLVMTypeRef*)ponyint_pool_alloc_size(buf_size);
LLVMGetParamTypes(f_type, f_params);
}
ast_t* arg = ast_child(args);
for(int i = 0; i < count; i++)
{
f_args[i] = gen_expr(c, arg);
if(!vararg)
f_args[i] = cast_ffi_arg(c, f_args[i], f_params[i]);
if(f_args[i] == NULL)
{
ponyint_pool_free_size(buf_size, f_args);
return NULL;
}
arg = ast_sibling(arg);
}
// If we can error out and we have an invoke target, generate an invoke
// instead of a call.
LLVMValueRef result;
codegen_debugloc(c, ast);
if(err && (c->frame->invoke_target != NULL))
result = invoke_fun(c, func, f_args, count, "", false);
else
result = LLVMBuildCall(c->builder, func, f_args, count, "");
codegen_debugloc(c, NULL);
ponyint_pool_free_size(buf_size, f_args);
if(!vararg)
ponyint_pool_free_size(buf_size, f_params);
// Special case a None return value, which is used for void functions.
if(is_none(type))
return t->instance;
return result;
}
LLVMValueRef gen_ffi(compile_t* c, ast_t* ast)
{
AST_GET_CHILDREN(ast, id, typeargs, args, named_args, can_err);
bool err = (ast_id(can_err) == TK_QUESTION);
// Get the function name, +1 to skip leading @
const char* f_name = ast_name(id) + 1;
deferred_reification_t* reify = c->frame->reify;
// Get the return type.
ast_t* type = deferred_reify(reify, ast_type(ast), c->opt);
reach_type_t* t = reach_type(c->reach, type);
pony_assert(t != NULL);
ast_free_unattached(type);
// Get the function. First check if the name is in use by a global and error
// if it's the case.
ffi_decl_t* ffi_decl;
bool is_func = false;
LLVMValueRef func = LLVMGetNamedGlobal(c->module, f_name);
if(func == NULL)
{
func = LLVMGetNamedFunction(c->module, f_name);
is_func = true;
}
if(func == NULL)
{
// If we have no prototype, declare one.
ast_t* decl = (ast_t*)ast_data(ast);
if(decl != NULL)
{
// Define using the declared types.
AST_GET_CHILDREN(decl, decl_id, decl_ret, decl_params, decl_err);
err = (ast_id(decl_err) == TK_QUESTION);
func = declare_ffi(c, f_name, t, decl_params, false);
} else if(!strncmp(f_name, "llvm.", 5) || !strncmp(f_name, "internal.", 9)) {
// Intrinsic, so use the exact types we supply.
func = declare_ffi(c, f_name, t, args, true);
} else {
// Make it varargs.
func = declare_ffi_vararg(c, f_name, t);
}
size_t index = HASHMAP_UNKNOWN;
#ifndef PONY_NDEBUG
ffi_decl_t k;
k.func = func;
ffi_decl = ffi_decls_get(&c->ffi_decls, &k, &index);
pony_assert(ffi_decl == NULL);
#endif
ffi_decl = POOL_ALLOC(ffi_decl_t);
ffi_decl->func = func;
ffi_decl->decl = (decl != NULL) ? decl : ast;
ffi_decls_putindex(&c->ffi_decls, ffi_decl, index);
} else {
ffi_decl_t k;
k.func = func;
size_t index = HASHMAP_UNKNOWN;
ffi_decl = ffi_decls_get(&c->ffi_decls, &k, &index);
if((ffi_decl == NULL) && (!is_func || LLVMHasMetadataStr(func, "pony.abi")))
{
ast_error(c->opt->check.errors, ast, "cannot use '%s' as an FFI name: "
"name is already in use by the internal ABI", f_name);
return NULL;
}
pony_assert(is_func);
}
// Generate the arguments.
int count = (int)ast_childcount(args);
size_t buf_size = count * sizeof(LLVMValueRef);
LLVMValueRef* f_args = (LLVMValueRef*)ponyint_pool_alloc_size(buf_size);
LLVMTypeRef f_type = LLVMGetElementType(LLVMTypeOf(func));
LLVMTypeRef* f_params = NULL;
bool vararg = (LLVMIsFunctionVarArg(f_type) != 0);
if(!vararg)
{
if(count != (int)LLVMCountParamTypes(f_type))
{
ast_error(c->opt->check.errors, ast,
"conflicting declarations for FFI function: declarations have an "
"incompatible number of parameters");
if(ffi_decl != NULL)
ast_error_continue(c->opt->check.errors, ffi_decl->decl, "first "
"declaration is here");
return NULL;
}
f_params = (LLVMTypeRef*)ponyint_pool_alloc_size(buf_size);
LLVMGetParamTypes(f_type, f_params);
}
ast_t* arg = ast_child(args);
for(int i = 0; i < count; i++)
{
f_args[i] = gen_expr(c, arg);
if(!vararg)
f_args[i] = cast_ffi_arg(c, ffi_decl, ast, f_args[i], f_params[i],
"parameters");
if(f_args[i] == NULL)
{
ponyint_pool_free_size(buf_size, f_args);
return NULL;
}
arg = ast_sibling(arg);
}
// If we can error out and we have an invoke target, generate an invoke
// instead of a call.
LLVMValueRef result;
codegen_debugloc(c, ast);
if(err && (c->frame->invoke_target != NULL))
result = invoke_fun(c, func, f_args, count, "", false);
else
result = LLVMBuildCall(c->builder, func, f_args, count, "");
codegen_debugloc(c, NULL);
ponyint_pool_free_size(buf_size, f_args);
if(!vararg)
ponyint_pool_free_size(buf_size, f_params);
compile_type_t* c_t = (compile_type_t*)t->c_type;
// Special case a None return value, which is used for void functions.
bool isnone = is_none(t->ast);
bool isvoid = LLVMGetReturnType(f_type) == c->void_type;
if(isnone && isvoid)
{
result = c_t->instance;
} else if(isnone != isvoid) {
report_ffi_type_err(c, ffi_decl, ast, "return values");
return NULL;
}
result = cast_ffi_arg(c, ffi_decl, ast, result, c_t->use_type,
"return values");
result = gen_assign_cast(c, c_t->use_type, result, t->ast_cap);
return result;
}
