static void trace_dynamic(compile_t* c, LLVMValueRef ctx, LLVMValueRef object,
ast_t* type, ast_t* orig, ast_t* tuple, LLVMBasicBlockRef next_block)
{
switch(ast_id(type))
{
case TK_UNIONTYPE:
case TK_ISECTTYPE:
trace_dynamic_union_or_isect(c, ctx, object, type, orig, tuple,
next_block);
break;
case TK_TUPLETYPE:
{
// This is a boxed tuple. Trace the box, then handle the elements.
trace_tag(c, ctx, object);
LLVMValueRef desc = gendesc_fetch(c, object);
LLVMValueRef ptr = gendesc_ptr_to_fields(c, object, desc);
trace_dynamic_tuple(c, ctx, ptr, desc, type, orig, tuple);
break;
}
case TK_NOMINAL:
trace_dynamic_nominal(c, ctx, object, type, orig, tuple, next_block);
break;
default: {}
}
}
static bool static_tuple(compile_t* c, LLVMValueRef value, ast_t* type,
ast_t* pattern, LLVMBasicBlockRef next_block)
{
switch(ast_id(type))
{
case TK_UNIONTYPE:
case TK_ISECTTYPE:
{
// Read the dynamic type and get a base pointer.
LLVMValueRef desc = gendesc_fetch(c, value);
LLVMValueRef ptr = gendesc_ptr_to_fields(c, value, desc);
return dynamic_tuple_ptr(c, ptr, desc, pattern, next_block);
}
case TK_TUPLETYPE:
return static_tuple_from_tuple(c, value, type, pattern, next_block);
case TK_ARROW:
return static_tuple(c, value, ast_childidx(type, 1), pattern,
next_block);
default: {}
}
// Can't match.
LLVMBuildBr(c->builder, next_block);
return true;
}
static bool dynamic_match_object(compile_t* c, LLVMValueRef object,
LLVMValueRef desc, ast_t* pattern, LLVMBasicBlockRef next_block)
{
switch(ast_id(pattern))
{
case TK_NONE:
return true;
case TK_MATCH_CAPTURE:
// Capture the match expression (or element thereof).
return dynamic_capture_object(c, object, desc, pattern, next_block);
case TK_TUPLE:
{
// Treat a one element tuple as its component expression.
ast_t* child = ast_child(pattern);
if(ast_sibling(child) == NULL)
return dynamic_match_object(c, object, desc, child, next_block);
// Build a base pointer that skips the object header.
LLVMValueRef ptr = gendesc_ptr_to_fields(c, object, desc);
// Destructure the match expression (or element thereof).
return dynamic_tuple_ptr(c, ptr, desc, pattern, next_block);
}
default:
// Test the match expression (or element thereof).
return dynamic_value_object(c, object, desc, pattern, next_block);
}
return true;
}
static bool check_tuple(compile_t* c, LLVMValueRef ptr, LLVMValueRef desc,
ast_t* pattern_type, LLVMBasicBlockRef next_block)
{
// First check cardinality.
size_t size = ast_childcount(pattern_type);
check_cardinality(c, desc, size, next_block);
// If we get here, the match expression has the right cardinality.
ast_t* pattern_child = ast_child(pattern_type);
for(int i = 0; pattern_child != NULL; i++)
{
// Get the field offset and field descriptor from the tuple descriptor.
LLVMValueRef field_info = gendesc_fieldinfo(c, desc, i);
LLVMValueRef field_ptr = gendesc_fieldptr(c, ptr, field_info);
LLVMValueRef field_desc = gendesc_fielddesc(c, field_info);
// If we have a null descriptor, load the object.
LLVMBasicBlockRef null_block = codegen_block(c, "null_desc");
LLVMBasicBlockRef nonnull_block = codegen_block(c, "nonnull_desc");
LLVMBasicBlockRef continue_block = codegen_block(c, "merge_desc");
LLVMValueRef test = LLVMBuildIsNull(c->builder, field_desc, "");
LLVMBuildCondBr(c->builder, test, null_block, nonnull_block);
// Load the object, load its descriptor, and continue from there.
LLVMPositionBuilderAtEnd(c->builder, null_block);
LLVMTypeRef ptr_type = LLVMPointerType(c->object_ptr, 0);
LLVMValueRef object_ptr = LLVMBuildIntToPtr(c->builder, field_ptr,
ptr_type, "");
LLVMValueRef object = LLVMBuildLoad(c->builder, object_ptr, "");
LLVMValueRef object_desc = gendesc_fetch(c, object);
object_ptr = gendesc_ptr_to_fields(c, object, object_desc);
if(!check_type(c, object_ptr, object_desc, pattern_child, next_block))
return false;
LLVMBuildBr(c->builder, continue_block);
// Continue with the pointer and descriptor.
LLVMPositionBuilderAtEnd(c->builder, nonnull_block);
if(!check_type(c, field_ptr, field_desc, pattern_child, next_block))
return false;
LLVMBuildBr(c->builder, continue_block);
// Merge the two branches.
LLVMPositionBuilderAtEnd(c->builder, continue_block);
pattern_child = ast_sibling(pattern_child);
}
return true;
}
static bool dynamic_value_object(compile_t* c, LLVMValueRef object,
LLVMValueRef desc, ast_t* pattern, LLVMBasicBlockRef next_block)
{
// Get the type of the right-hand side of the pattern's eq() function.
ast_t* param_type = eq_param_type(c, pattern);
// Build a base pointer that skips the object header.
LLVMValueRef ptr = gendesc_ptr_to_fields(c, object, desc);
// Check the runtime type. We pass a pointer to the fields because we may
// still need to match a tuple type inside a type expression.
if(!check_type(c, ptr, desc, param_type, next_block))
return false;
return check_value(c, pattern, param_type, object, next_block);
}
static bool dynamic_capture_object(compile_t* c, LLVMValueRef object,
LLVMValueRef desc, ast_t* pattern, LLVMBasicBlockRef next_block)
{
ast_t* pattern_type = ast_type(pattern);
// Build a base pointer that skips the object header.
LLVMValueRef ptr = gendesc_ptr_to_fields(c, object, desc);
// Check the runtime type. We pass a pointer to the fields because we may
// still need to match a tuple type inside a type expression.
if(!check_type(c, ptr, desc, pattern_type, next_block))
return false;
// As long as the type is correct, we can assign it, with gen_assign_value()
// handling boxing and unboxing. We pass the type of the pattern as the type
// of the object.
return gen_assign_value(c, pattern, object, pattern_type) != NULL;
}