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[FIX] Add support for multi-level pointers #93

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[FIX] Add support for multi-level pointers #93

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6 changes: 3 additions & 3 deletions regression-tests/test-results/mixed-lifetime-safety-and-null-contracts.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -15,7 +15,7 @@ auto null_from_cpp1() -> int* { return nullptr; }

auto try_pointer_stuff() -> void;
#line 21 "mixed-lifetime-safety-and-null-contracts.cpp2"
auto call_my_framework(cpp2::in<const char *> msg) -> void;
auto call_my_framework(cpp2::in<const char*> msg) -> void;

//=== Cpp2 definitions ==========================================================

Expand All @@ -29,12 +29,12 @@ auto call_my_framework(cpp2::in<const char *> msg) -> void;
#line 14 "mixed-lifetime-safety-and-null-contracts.cpp2"

auto try_pointer_stuff() -> void{
int* p { null_from_cpp1() };
int * p { null_from_cpp1() };
*p = 42; // deliberate null dereference
// to show -n
}

auto call_my_framework(cpp2::in<const char *> msg) -> void {
auto call_my_framework(cpp2::in<const char*> msg) -> void {
std::cout
<< "sending error to my framework... ["
<< msg << "]\n"; }
2 changes: 1 addition & 1 deletion regression-tests/test-results/mixed-type-safety-1.cpp
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Expand Up @@ -44,7 +44,7 @@ auto print(cpp2::in<std::string> msg, cpp2::in<bool> b) -> void
print( "1 is int? ", cpp2::is<int>(1));

auto c { cpp2_new<Circle>() }; // safe by construction
Shape* s { CPP2_UFCS_0(get, c) }; // safe by Lifetime
Shape * s { CPP2_UFCS_0(get, c) }; // safe by Lifetime
print("\ns* is Shape? ", cpp2::is<Shape>(*s));
print( "s* is Circle? ", cpp2::is<Circle>(*s));
print( "s* is Square? ", cpp2::is<Square>(*s));
Expand Down
27 changes: 17 additions & 10 deletions source/cppfront.cpp
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Expand Up @@ -1071,6 +1071,10 @@ class cppfront
assert(n.identifier);
emit(*n.identifier);

for (auto _ : n.pointer_declarators) {
printer.print_cpp2("*", n.position());
}

if (!n.template_args.empty()) {
printer.print_cpp2("<", n.open_angle);
auto first = true;
Expand Down Expand Up @@ -1572,9 +1576,19 @@ class cppfront
auto& unqual = std::get<id_expression_node::unqualified>(id->id);
assert(unqual);
auto decl = sema.get_local_declaration_of(*unqual->identifier);
// TODO: Generalize this -- for now we detect only cases of the form "p: *int = ...;"
// We don't recognize pointer types that are deduced, multi-level, or from Cpp1
if (decl && decl->declaration && decl->declaration->pointer_declarator) {

bool is_pointer = false;
if (decl && decl->declaration) {
if (auto* obj_id_expr = std::get_if<declaration_node::object>(&decl->declaration->type)) {
if (auto* unqual = std::get_if<id_expression_node::unqualified>(&(*obj_id_expr)->id)){
is_pointer = !(*unqual)->pointer_declarators.empty();
}
}
}

// TODO: Generalize this -- for now we detect only multi-level cases of the form "p: ***int = ...;"
// We don't recognize pointer types that are deduced or from Cpp1
if (!unqual->pointer_declarators.empty() || is_pointer) {
if (n.ops.empty()) {
last_postfix_expr_was_pointer = true;
}
Expand Down Expand Up @@ -2155,10 +2169,6 @@ class cppfront
}
else {
emit( id_expr );
if (n.declaration->pointer_declarator) {
printer.print_cpp2(" ", n.declaration->pointer_declarator->position());
emit(*n.declaration->pointer_declarator);
}
}

// Then any suffix
Expand Down Expand Up @@ -2538,9 +2548,6 @@ class cppfront
}
printer.preempt_position(n.position());
emit( *type );
if (n.pointer_declarator) {
printer.print_cpp2("*", n.position());
}
// one pointer is enough for now, pointer-to-function fun can be later
if (!n.initializer) {
printer.print_cpp2( ">", n.position() );
Expand Down
28 changes: 13 additions & 15 deletions source/parse.h
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Expand Up @@ -364,6 +364,7 @@ struct unqualified_id_node
{
token const* const_qualifier = {}; // optional
token const* identifier = {}; // required
std::vector<token const*> pointer_declarators = {}; // optional

enum active { empty=0, expression, id_expression };

Expand Down Expand Up @@ -846,8 +847,6 @@ struct declaration_node
source_position pos;
std::unique_ptr<unqualified_id_node> identifier;

token const* pointer_declarator = nullptr;

enum active { function, object };
std::variant<
std::unique_ptr<function_type_node>,
Expand Down Expand Up @@ -1771,13 +1770,19 @@ class parser
{
// Handle the identifier
if (curr().type() != lexeme::Identifier &&
curr().type() != lexeme::Keyword) // 'const', and fundamental types that are keywords
curr().type() != lexeme::Keyword && // 'const', and fundamental types that are keywords
curr().type() != lexeme::Multiply ) // pointer declarators
{
return {};
}

auto n = std::make_unique<unqualified_id_node>();

while (curr().type() == lexeme::Multiply) {
n->pointer_declarators.push_back(&curr());
next();
}

if (curr().type() == lexeme::Keyword && curr() == "const") {
n->const_qualifier = &curr();
next();
Expand Down Expand Up @@ -2784,6 +2789,7 @@ class parser
auto unnamed_declaration(source_position pos, bool semicolon_required = true, bool captures_allowed = false) -> std::unique_ptr<declaration_node>
{
auto deduced_type = false;
auto pointer_declaration = false;

// The next token must be :
if (curr().type() != lexeme::Colon) {
Expand All @@ -2809,19 +2815,11 @@ class parser
n->type = std::move(t);
assert (n->type.index() == declaration_node::function);
}

// Or a pointer to a type, declaring a pointer object
else if (curr().type() == lexeme::Multiply) {
n->pointer_declarator = &curr();
next();
if (auto t = id_expression()) {
n->type = std::move(t);
assert (n->type.index() == declaration_node::object);
}
}

// Or just a type, declaring a non-pointer object
else if (auto t = id_expression()) {
if(auto* unqual = std::get_if<id_expression_node::unqualified>(&t->id)) {
pointer_declaration = !(*unqual)->pointer_declarators.empty();
}
n->type = std::move(t);
assert (n->type.index() == declaration_node::object);
}
Expand Down Expand Up @@ -2866,7 +2864,7 @@ class parser
n->equal_sign = curr().position();
next();

if (n->pointer_declarator) {
if (pointer_declaration) {
if (curr() == "nullptr" ||
isdigit(std::string_view(curr())[0]) ||
(curr() == "(" && peek(1) && *peek(1) == ")")
Expand Down