[avr] port a subset of libstdc++ to the AVR platform

This will allow for using large parts of the C++ standard library inside modm.
Almost the complete implementation is copied from libstdc++ sources released
with GCC 8.2.0. Most headers do not require any modifications.

Some parts have been deliberately excluded because they are unavailable on
embedded platforms or the provided implementation is inherently unsuitable for
AVR and requires considerable porting efforts. For instance, the string conversion
functions contain kilobytes of static data that would be put into RAM.

IOStreams and std::string are also not available.
All stream-related code is removed from the supplied headers.

The following parts are included:

- Containers
- Algorithms (<algorithm>)
- Iterators library (<iterator>, except for iostream iterators)
- Numerics library (<complex>, <numeric>, <ratio>, <valarray>)
- Utilities library (<type_traits>, <any>, <optional>, <variant>, <tuple>, <utility>, <chrono>, …)
- Numeric limits (<limits>)
- C headers except for C99/C11 additions not supported by AVR libc (<c*>)
- Memory management (<new>, <memory>, <scoped_allocator>), except for std::shared_ptr
- String view (<string_view>)

Not included (may be incomplete):

- std::string and string conversions, regex
- Anything that requires an OS to work (threads, filesystem, locales, ...)
- Atomics
- iostreams and related headers
- Random number generation (<random>)
- std::shared_ptr (build on atomics, high porting effort)
- std::bitset
- Polymorphic allocators (<memory_resource>), experimental in libstdc++
- Exception headers
- RTTI headers

.gitmodules

@@ -13,3 +13,6 @@
 [submodule "ext/arm/cmsis"]
 	path = ext/arm/cmsis
 	url = https://github.com/modm-io/cmsis-5-partial.git
+[submodule "ext/gcc/libstdc++"]
+	path = ext/gcc/libstdc++
+	url = https://github.com/modm-io/avr-libstdcpp.git

ext/gcc/assert.cpp.in

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2018, Christopher Durand
+ *
+ * This file is part of the modm project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+// ----------------------------------------------------------------------------
+
+#include <cstdint>
+#include <bits/functexcept.h>
+#include <modm/utils/bit_constants.hpp>
+
+%% if options["use_modm_assert"]
+#include <modm/architecture/interface/assert.hpp>
+
+#define __modm_stdcpp_failure(failure) modm_assert(false, "stdc++", "stdc++", failure);__builtin_abort();
+%% else
+#define __modm_stdcpp_failure(failure) __builtin_abort();
+%% endif
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+	void
+	__throw_logic_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("logic_error"); }
+
+	void
+	__throw_domain_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("domain_error"); }
+
+	void
+	__throw_invalid_argument(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("invalid_argument"); }
+
+	void
+	__throw_length_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("length_error"); }
+
+	void
+	__throw_out_of_range(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("out_of_range"); }
+
+	void
+	__throw_runtime_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("runtime_error"); }
+
+	void
+	__throw_range_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("range_error"); }
+
+	void
+	__throw_overflow_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("overflow_error"); }
+
+	void
+	__throw_underflow_error(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("underflow_error"); }
+
+	void
+	__throw_bad_optional_access()
+	{ __modm_stdcpp_failure("bad_optional"); }
+
+	void
+	__throw_bad_variant_access(const char* __s __attribute__((unused)))
+	{ __modm_stdcpp_failure("bad_variant"); }
+
+	void
+	__throw_bad_function_call()
+	{ __modm_stdcpp_failure("bad_function_call"); }
+
+	void
+	__throw_bad_any_cast()
+	{ __modm_stdcpp_failure("bad_any_cast"); }
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace

src/stdc++/module.lb → ext/gcc/module.lb

@@ -3,6 +3,7 @@
 #
 # Copyright (c) 2016-2017, Niklas Hauser
 # Copyright (c) 2017-2018, Fabian Greif
+# Copyright (c) 2018, Christopher Durand
 #
 # This file is part of the modm project.
 #
@@ -21,11 +22,18 @@ def prepare(module, options):
     if target["platform"] != "avr":
         return False
 
+    module.add_option(
+        BooleanOption(
+            name="use_modm_assert",
+            description="Assert on error in stdlib. Set to False to save flash.",
+            default=True))
+
     return True
 
 
 def build(env):
-    env.add_metadata("include_path", "modm/src/stdc++")
+    env.add_metadata("include_path", "modm/ext/gcc/libstdc++/include")
 
-    env.outbasepath = "modm/src/stdc++"
-    env.copy(".")
+    env.outbasepath = "modm/ext/gcc"
+    env.copy(".", ignore=env.ignore_files("*.lb", "*.md", "*.in", "examples"))
+    env.template("assert.cpp.in", "assert.cpp")

src/modm/platform/core/avr/newdelete.cpp

@@ -49,6 +49,18 @@ operator new[](size_t size, modm::MemoryTraits)
 	return ptr;
 }
 
+void*
+operator new(std::size_t size, const std::nothrow_t&) noexcept
+{
+	return modm::platform::allocateMemory(size);
+}
+
+void*
+operator new[](std::size_t size, const std::nothrow_t&) noexcept
+{
+	return modm::platform::allocateMemory(size);
+}
+
 void
 operator delete(void* ptr)
 {
@@ -72,3 +84,15 @@ operator delete[](void* ptr, size_t)
 {
 	modm::platform::freeMemory(ptr);
 }
+
+void
+operator delete(void* ptr, const std::nothrow_t&) noexcept
+{
+	modm::platform::freeMemory(ptr);
+}
+
+void
+operator delete[](void* ptr, const std::nothrow_t&) noexcept
+{
+	modm::platform::freeMemory(ptr);
+}