From ff9d7741d4b9d5255bc809a7505225216ecc7b86 Mon Sep 17 00:00:00 2001 From: Arthur Cohen Date: Mon, 12 Sep 2022 16:26:46 +0200 Subject: [PATCH] gccrs: const generics: Forbid default values in Functions, Traits and Impls gcc/rust/ChangeLog: * checks/errors/rust-const-checker.cc (ConstChecker::ctx_to_str): Allow getting an error string from a specific constant context. (ConstChecker::ctx_allows_default): New function, check if a context allows default values for Const generics. (ConstChecker::visit): Call into `ctx_allows_default`. * checks/errors/rust-const-checker.h: Declare `ctx_allows_default`. gcc/testsuite/ChangeLog: * rust/compile/const_generics_8.rs: New test. --- gcc/rust/checks/errors/rust-const-checker.cc | 97 ++++++++++++++++++++++++-- gcc/rust/checks/errors/rust-const-checker.h | 25 +++++++ gcc/testsuite/rust/compile/const_generics_8.rs | 12 ++++ 3 files changed, 128 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/rust/compile/const_generics_8.rs diff --git a/gcc/rust/checks/errors/rust-const-checker.cc b/gcc/rust/checks/errors/rust-const-checker.cc index 0c1b743..2fa9614 100644 --- a/gcc/rust/checks/errors/rust-const-checker.cc +++ b/gcc/rust/checks/errors/rust-const-checker.cc @@ -52,6 +52,67 @@ ConstChecker::is_const_extern_fn (HIR::ExternalFunctionItem &fn) }); } +const char * +ConstChecker::ctx_to_str (ConstGenericCtx ctx) +{ + switch (ctx) + { + case ConstGenericCtx::Function: + return "function"; + case ConstGenericCtx::TypeAlias: + return "type alias"; + case ConstGenericCtx::Struct: + return "struct"; + case ConstGenericCtx::Enum: + return "enum"; + case ConstGenericCtx::Union: + return "union"; + case ConstGenericCtx::Trait: + return "trait"; + case ConstGenericCtx::Impl: + return "impl"; + default: + gcc_unreachable (); + } +} + +bool +ConstChecker::ctx_allows_default (ConstGenericCtx ctx) +{ + switch (ctx) + { + case ConstGenericCtx::TypeAlias: + case ConstGenericCtx::Struct: + case ConstGenericCtx::Enum: + case ConstGenericCtx::Trait: + return true; + default: + return false; + } +} + +void +ConstChecker::check_default_const_generics ( + std::vector> ¶ms, ConstGenericCtx context) +{ + if (ctx_allows_default (context)) + return; + + for (auto ¶m : params) + { + if (param->get_kind () == GenericParam::GenericKind::CONST) + { + auto const_param = static_cast (param.get ()); + if (const_param->has_default_expression ()) + rust_error_at ( + param->get_locus (), + "default values for const generic parameters are not " + "allowed in %qs items", + ctx_to_str (context)); + } + } +} + void ConstChecker::visit (Lifetime &lifetime) {} @@ -560,6 +621,9 @@ ConstChecker::visit (Function &function) if (const_fn) const_context.enter (function.get_mappings ().get_hirid ()); + check_default_const_generics (function.get_generic_params (), + ConstGenericCtx::Function); + for (auto ¶m : function.get_function_params ()) param.get_type ()->accept_vis (*this); @@ -571,18 +635,27 @@ ConstChecker::visit (Function &function) void ConstChecker::visit (TypeAlias &type_alias) -{} +{ + check_default_const_generics (type_alias.get_generic_params (), + ConstGenericCtx::TypeAlias); +} void ConstChecker::visit (StructStruct &struct_item) -{} +{ + check_default_const_generics (struct_item.get_generic_params (), + ConstGenericCtx::Struct); +} void ConstChecker::visit (TupleStruct &tuple_struct) -{} +{ + check_default_const_generics (tuple_struct.get_generic_params (), + ConstGenericCtx::Struct); +} void -ConstChecker::visit (EnumItem &item) +ConstChecker::visit (EnumItem &enum_item) {} void @@ -605,11 +678,17 @@ ConstChecker::visit (EnumItemDiscriminant &item) void ConstChecker::visit (Enum &enum_item) -{} +{ + check_default_const_generics (enum_item.get_generic_params (), + ConstGenericCtx::Enum); +} void ConstChecker::visit (Union &union_item) -{} +{ + check_default_const_generics (union_item.get_generic_params (), + ConstGenericCtx::Union); +} void ConstChecker::visit (ConstantItem &const_item) @@ -652,6 +731,9 @@ ConstChecker::visit (TraitItemType &item) void ConstChecker::visit (Trait &trait) { + check_default_const_generics (trait.get_generic_params (), + ConstGenericCtx::Trait); + for (auto &item : trait.get_trait_items ()) item->accept_vis (*this); } @@ -659,6 +741,9 @@ ConstChecker::visit (Trait &trait) void ConstChecker::visit (ImplBlock &impl) { + check_default_const_generics (impl.get_generic_params (), + ConstGenericCtx::Impl); + for (auto &item : impl.get_impl_items ()) item->accept_vis (*this); } diff --git a/gcc/rust/checks/errors/rust-const-checker.h b/gcc/rust/checks/errors/rust-const-checker.h index ca86b49..13cf44b 100644 --- a/gcc/rust/checks/errors/rust-const-checker.h +++ b/gcc/rust/checks/errors/rust-const-checker.h @@ -46,6 +46,31 @@ private: */ void check_function_call (HirId fn_id, Location locus); + /* All possible const contexts */ + enum class ConstGenericCtx + { + Function, + TypeAlias, + Struct, + Enum, + Union, + Trait, + Impl + }; + + /* Get the string representation of a const context */ + const char *ctx_to_str (ConstGenericCtx ctx); + + /* Check if a const context allows default values */ + bool ctx_allows_default (ConstGenericCtx ctx); + + /** + * Check that const generic parameters only contains defaults in allowed + * contexts + */ + void check_default_const_generics ( + std::vector> ¶m, ConstGenericCtx context); + StackedContexts const_context; Resolver::Resolver &resolver; Analysis::Mappings &mappings; diff --git a/gcc/testsuite/rust/compile/const_generics_8.rs b/gcc/testsuite/rust/compile/const_generics_8.rs new file mode 100644 index 0000000..b0bb262 --- /dev/null +++ b/gcc/testsuite/rust/compile/const_generics_8.rs @@ -0,0 +1,12 @@ +struct Bidule {} +enum Bidoule {} + +// Note - missing generic parameter - needs name resolution on const generics +type Bipboupe = Bidule; +trait Fooable {} + +union Bidoulepe {} // { dg-error "default values for const generic parameters are not allowed in .union. items" } +fn const_default() {} // { dg-error "default values for const generic parameters are not allowed in .function. items" } + +// Note - missing generic parameter - needs name resolution on const generics +impl Bidule {} // { dg-error "default values for const generic parameters are not allowed in .impl. items" } -- 2.7.4