Release Notes

emmtrix LLVM Tools

Release 2022.10

emmtrix C++-to-C compiler

New language features

• Switched to C++14 language standard
• Significantly improved template compatibility
• Unions
• Anonymous unions within functions
• Enums with fixed underlying type (e.g. enum e : int)
• Scoped enums
• if/switch statements with variable and/or initializer (e.g. if (int a = ...; int b = ...))
• User-defined literals
• wchar_t, char16_t and char32_t data types
• Lambda expressions
• Pointers to members (preliminary)
• Pointers to data members as well as the .* and ->* operators
• Pointers to member functions as well as the .* and ->* operators
• Derived-to-base casts of pointers to member functions is not full supported
• Variadic functions with no explicit parameters that are forbidden in C (e.g. void func(...))
• Using-declaration in class/struct definitions
• Ref-qualified member functions (e.g. void mf2() &)
• Volatile qualified member functions (e.g. void mf2() volatile)
• Binary conditional operator (a ?: b)
• sizeof... operator
• __underlying_type operator
• Placement new operator
• alignof operator
• Anonymous namespaces
• thread_local variables
• C++11-style attributes (e.g. [[maybe_unused]])
• Replacing [[noreturn]] attributes by _Noreturn keyword
• Removing [[fallthrough]] attributes
• Replacing other attributes by gcc-style attributes (e.g. __attribute__((deprecated)))
• Explicit template instantiation (e.g. template T<int>;)
• Complex list initialization of structs/classes (e.g STRUCT s = {0, g, 1})
• int{} and int{val} initialization of fundamental data types
• Functional casts with braced init lists (e.g. T{x, y})
• __func__, __FUNCTION__ and __PRETTY_FUNCTION__ macros
• __builtin_FUNCTION, __builtin_FILE, __builtin_LINE and __builtin_COLUMN builtin functions
• __builtin_constant_p builtin function
• __builtin_addressof builtin function
• __builtin_operator_delete and __builtin_operator_new builtin functions

Command line options

• Added command line option -output-min-record-size-attr to enable min_record_size attribute in output code
• Added command line option -output-nonnull-attr=false to disable nonnull attribute in output code
• Added command line option -output-linkage-attr to enable linkage attribute in output code

Misc

• Supporting attributed functions (e.g. __stdcall)
• Supporting nested decltype and auto return type expressions
• Correctly generating array size cookie for new[] expressions with non-trivial destructors
• Bugfix: Constant global variables with initializer containing comma operator
• Avoiding nested struct declarations in generated C code
• Supporting constexpr function calls as case labels
• Fixed handling of static class/struct member variables
• Supporting nested template classes
• Supporting zero length arrays and flexible array members
• Adding names for anonymous structs
• Using nonnull attribute for function arguments that were previously references
• Supporting correct generation of empty structs/classes (by using custom min_record_size attribute)
• Improved generation of temporaries and copy elision
• Ensuring that enum enumerators are unique (e.g. after removing namespaces)
• Supporting nested structs/classes with the same name by applying mangling to record names

emx-clang / emx-clang++

• Added linkage attribute to explicitly specify the LLVM linkage type of global variables and functions
• Added min_record_size attribute to specify the minimum size of a record