From 0e874252a859ef44e1554e4c609efacf5a570945 Mon Sep 17 00:00:00 2001
From: Ludovic 'Archivist' Lagouardette
 <archivist@172-0-0-153.lightspeed.brhmal.sbcglobal.net>
Date: Tue, 28 Apr 2020 12:08:42 +0200
Subject: [PATCH] Optional typesafety (found bug with asan)

---
 Makefile                |  5 ++-
 include/gp/memory.hpp   |  4 +-
 include/gp/optional.hpp | 90 +++++++++++++++++++++++++++++++----------
 3 files changed, 75 insertions(+), 24 deletions(-)

diff --git a/Makefile b/Makefile
index c112d61..5e8d9e0 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,12 @@
 CXX= clang++-8
-CXXFLAGS= --std=c++17 -O0 -pthread -DFUZZ_STRENGTH=500000 \
+CXXFLAGS= --std=c++17 -O0 -pthread -DFUZZ_STRENGTH=500000 -pedantic -Werror \
+ -fsanitize=address -fno-omit-frame-pointer \
  -Wno-unknown-attributes \
  -g -fprofile-instr-generate -fcoverage-mapping
 all: tests
 
 tests: bin/tests
-	LLVM_PROFILE_FILE="./bin/tests.profraw" ./bin/tests
+	LLVM_PROFILE_FILE="./bin/tests.profraw" ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer ./bin/tests
 	@llvm-profdata merge -sparse ./bin/tests.profraw -o ./bin/tests.profdata
 	@llvm-cov report ./bin/tests -instr-profile=./bin/tests.profdata include/*.hpp include/gp/*.hpp include/gp/algorithm/*.hpp include/gp/allocator/*.hpp
 	@llvm-cov report ./bin/tests -instr-profile=./bin/tests.profdata include/*.hpp include/gp/*.hpp include/gp/algorithm/*.hpp include/gp/allocator/*.hpp | tail -n 1 | tr -s " " | sed -e 's/ /,/g' -- | awk -F "," '{print $$9}' | sed -e 's/^/Untested lines: /g'
diff --git a/include/gp/memory.hpp b/include/gp/memory.hpp
index 0aae5cc..793b2e3 100644
--- a/include/gp/memory.hpp
+++ b/include/gp/memory.hpp
@@ -4,6 +4,7 @@
 #include <type_traits>
 // XXX: THIS FILE SHOULD BE REMOVED, AS SHOULD ALL DEPENDENCIES ON THE C-ALLOCATOR AS IS
 
+/*
 namespace gp{
 	template<class T, typename I = std::enable_if_t<gp_config::memory_module::is_ok,int>>
 	class default_memory_allocator
@@ -54,4 +55,5 @@ void* operator new(size_t sz)
 void operator delete (void* ptr) noexcept
 {
 	gp_config::memory_module::memory_deallocator<gp_config::memory_module::memory_mode>(ptr);
-}
\ No newline at end of file
+}
+*/
\ No newline at end of file
diff --git a/include/gp/optional.hpp b/include/gp/optional.hpp
index 000ec54..5bc585a 100644
--- a/include/gp/optional.hpp
+++ b/include/gp/optional.hpp
@@ -39,7 +39,7 @@ namespace gp{
 			new(buffer) T(gp::move(value));
 		}
 
-		optional operator=(nullopt_t) {
+		optional& operator=(nullopt_t) {
 			if(ready) {
 				((T*)buffer)->~T();
 				ready = false;
@@ -47,7 +47,7 @@ namespace gp{
 			return *this;
 		}
 
-		optional operator=(T& value) {
+		optional& operator=(T& value) {
 			if(ready) {
 				*(T*)buffer = value;
 			} else {
@@ -57,7 +57,7 @@ namespace gp{
 			return *this;
 		}
 
-		optional operator=(T&& value) {
+		optional& operator=(T&& value) {
 			if(ready) {
 				*(T*)buffer = gp::move(value);
 			} else {
@@ -92,7 +92,7 @@ namespace gp{
 	template<typename T>
 	class optional<T,false>{
 		bool ready = false;
-		void* ptr;
+		T* ptr;
 	public:
 		constexpr optional()
 		: ready{false}
@@ -102,50 +102,92 @@ namespace gp{
 		: ready{false}
 		{}
 
-		// TODO: Add typesafe generic assignment
-		constexpr optional(T& value)
+		template<typename U>
+		constexpr optional(U& value)
 		: ready{true}
 		{
-			ptr = (void*)new T(value); // TODO: Use allocators
+			ptr = new U(value); // TODO: Use allocators
 		}
 
-		// TODO: Add typesafe generic assignment
-		constexpr optional(T&& value)
+		template<typename U>
+		constexpr optional(U&& value)
 		: ready{true}
 		{
-			ptr = (void*)new T(gp::move(value)); // TODO: Use allocators
+			ptr = new U(gp::move(value)); // TODO: Use allocators
 		}
 
-		optional operator=(nullopt_t) {
+		optional& operator=(nullopt_t) {
 			if(ready) {
-				delete (T*)ptr;
+				delete ptr;
 				ready = false;
 			}
 			return *this;
 		}
 
-		// TODO: Add typesafe generic assignment
-		optional operator=(T& value) {
+		template<typename U>
+		optional& operator=(U& value) {
 			if(ready) {
-				*(T*)ptr = value;
+				if constexpr (std::is_same_v<T, U>) {
+					*ptr = value;
+				} else {
+					delete ptr; // TODO: Use allocators
+					ptr = new U(value); // TODO: Use allocators
+				}
 			} else {
 				ready = true;
-				ptr = (void*)new T(value); // TODO: Use allocators
+				ptr = new U(value); // TODO: Use allocators
 			}
 			return *this;
 		}
 
-		// TODO: Add typesafe generic assignment
-		optional operator=(T&& value) {
+		template<typename U>
+		optional& operator=(U&& value) {
 			if(ready) {
-				*(T*)ptr = gp::move(value);
+				if constexpr (std::is_same_v<T, U>) {
+					*ptr = gp::move(value);
+				} else {
+					delete ptr; // TODO: Use allocators
+					ptr = new U(gp::move(value)); // TODO: Use allocators
+				}
 			} else {
 				ready = true;
-				ptr = (void*)new T(gp::move(value)); // TODO: Use allocators
+				ptr = new U(gp::move(value)); // TODO: Use allocators
 			}
 			return *this;
 		}
 
+		template<>
+		optional& operator=<optional>(optional& value) {
+			if(ready) {
+					*ptr = value;
+			} else {
+				ready = true;
+				ptr = new optional(value.value()); // TODO: Use allocators
+			}
+			return *this;
+		}
+
+		template<>
+		optional& operator=<optional>(optional&& value){
+			if(ready) {
+					delete ptr; // TODO: Use allocators
+			}
+			if(value.ready) {
+				ptr = value.ptr;
+				value.ready = false;
+				ready = true;
+				return *this;
+			} else {
+				ready = false;
+				return *this;
+			}
+		}
+
+		operator T&() {
+			gp_config::assertion(ready, "bad optional access");
+			return *ptr;
+		}
+
 		constexpr bool has_value()
 		{
 			return ready;
@@ -162,7 +204,13 @@ namespace gp{
 			} else {
 				gp_config::assertion(ready, "bad optional access");
 			}
-			return *reinterpret_cast<T*>(ptr);
+			return *ptr;
+		}
+
+		~optional() {
+			if(ready) {
+				delete ptr; // TODO: Use allocators
+			}
 		}
 	};
 }
\ No newline at end of file