cxxrtl: preserve interior memory pointers across reset.

Before this commit, values, wires, and memories with an initializer
were value-initialized in emitted C++ code. After this commit, all
values, wires, and memories are default-initialized, and the default
constructor of generated modules calls the reset() method, which
assigns the members that have an initializer.

1 files changed, 3 insertions, 21 deletions

diff --git a/backends/cxxrtl/cxxrtl.h b/backends/cxxrtl/cxxrtl.h
index 923146eba..3e1357498 100644
--- a/backends/cxxrtl/cxxrtl.h
+++ b/backends/cxxrtl/cxxrtl.h
@@ -738,24 +738,6 @@ struct memory {
 		return *this;
 	}
 
-	// The only way to get the compiler to put the initializer in .rodata and do not copy it on stack is to stuff it
-	// into a plain array. You'd think an std::initializer_list would work here, but it doesn't, because you can't
-	// construct an initializer_list in a constexpr (or something) and so if you try to do that the whole thing is
-	// first copied on the stack (probably overflowing it) and then again into `data`.
-	template<size_t Size>
-	struct init {
-		size_t offset;
-		value<Width> data[Size];
-	};
-
-	template<size_t... InitSize>
-	explicit memory(size_t depth, const init<InitSize> &...init) : depth(depth), data(new value<Width>[depth]) {
-		// This utterly reprehensible construct is the most reasonable way to apply a function to every element
-		// of a parameter pack, if the elements all have different types and so cannot be cast to an initializer list.
-		auto _ = {std::move(std::begin(init.data), std::end(init.data), &data[init.offset])...};
-		(void)_;
-	}
-
 	// An operator for direct memory reads. May be used at any time during the simulation.
 	const value<Width> &operator [](size_t index) const {
 		assert(index < depth);
@@ -1051,9 +1033,9 @@ struct debug_items {
 	}
 };
 
-// Tag class to disambiguate module move constructor and module constructor that takes black boxes
-// out of another instance of the module.
-struct adopt {};
+// Tag class to disambiguate the default constructor used by the toplevel module that calls reset(),
+// and the constructor of interior modules that should not call it.
+struct interior {};
 
 struct module {
 	module() {}