Switch to C++17 standard

CMakeLists.txt

@@ -201,12 +201,12 @@ enable_testing ()
 #   set (CPACK_PACKAGE_VERSION_PATCH ${CPACK_PACKAGE_VERSION_PATCH}-${__P4C_VERSION_RC})
 # endif ()
 
-# set (CMAKE_CXX_EXTENSIONS OFF) # prefer using -std=c++11 rather than -std=gnu++11
-# CMAKE_CXX_STANDARD was introduced in CMake 3.1, so for older versions of CMake, we use -std=gnu++11
+# set (CMAKE_CXX_EXTENSIONS OFF) # prefer using -std=c++17 rather than -std=gnu++17
+# CMAKE_CXX_STANDARD was introduced in CMake 3.1, so for older versions of CMake, we use -std=gnu++17
 if (CMAKE_VERSION VERSION_LESS "3.1")
-    set (CMAKE_CXX_FLAGS "-std=gnu++11 ${CMAKE_CXX_FLAGS}")
-elseif(NOT DEFINED CMAKE_CXX_STANDARD OR CMAKE_CXX_STANDARD LESS 11)
-    set (CMAKE_CXX_STANDARD 11)
+    set (CMAKE_CXX_FLAGS "-std=gnu++17 ${CMAKE_CXX_FLAGS}")
+elseif(NOT DEFINED CMAKE_CXX_STANDARD OR CMAKE_CXX_STANDARD LESS 17)
+    set (CMAKE_CXX_STANDARD 17)
 endif ()
 set (CMAKE_CXX_STANDARD_REQUIRED ON)
 

README.md

@@ -224,7 +224,7 @@ Ubuntu 20.04 is the officially supported platform for p4c. There's also
 unofficial support for macOS 10.12. Other platforms are untested; you can try to
 use them, but YMMV.
 
-- A C++11 compiler. GCC 4.9 or later or Clang 3.3 or later is required.
+- A C++17 compiler. GCC 9.1 or later or Clang 6.0 or later is required.
 
 - `git` for version control
 
@@ -370,7 +370,7 @@ We recommend using `clang++` with no optimizations for speeding up
 compilation and simplifying debugging.
 
 We recommend installing a new version of [gdb](http://ftp.gnu.org/gnu/gdb).,
-because older gdb versions do not always handle C++11 correctly.
+because older gdb versions do not always handle C++11 or newer correctly.
 
 We recommend exuberant ctags for navigating source code in Emacs and vi.  `sudo
 apt-get install exuberant-ctags.` The Makefile targets `make ctags` and `make

frontends/parsers/p4/p4lexer.ll

@@ -26,6 +26,7 @@ using Parser = P4::P4Parser;
 #pragma GCC diagnostic ignored "-Wtautological-undefined-compare"
 #ifdef __clang__
 #pragma clang diagnostic ignored "-Wnull-conversion"
+#pragma clang diagnostic ignored "-Wregister"
 #endif
 
 %}

frontends/parsers/v1/v1lexer.ll

@@ -22,6 +22,7 @@ using Parser = V1::V1Parser;
 #pragma GCC diagnostic ignored "-Wtautological-undefined-compare"
 #ifdef __clang__
 #pragma clang diagnostic ignored "-Wnull-conversion"
+#pragma clang diagnostic ignored "-Wregister"
 #endif
 
 %}

lib/gc.cpp

@@ -68,9 +68,15 @@ void operator delete(void *p) _GLIBCXX_USE_NOEXCEPT {
     gc::operator delete(p);
 }
 
+void operator delete(void *p, std::size_t) _GLIBCXX_USE_NOEXCEPT {
+    if (p >= emergency_pool && p < emergency_pool + sizeof(emergency_pool))
+        return;
+    gc::operator delete(p);
+}
+
 void *operator new[](std::size_t size) { return ::operator new(size); }
 void operator delete[](void *p) _GLIBCXX_USE_NOEXCEPT { ::operator delete(p); }
-
+void operator delete[](void *p, std::size_t) _GLIBCXX_USE_NOEXCEPT { ::operator delete(p); }
 
 namespace {
 

lib/hash.cpp

@@ -59,10 +59,10 @@ std::uint32_t murmur32(const void* data, std::uint32_t size) {
     switch (size) {
     case 3:
         result ^= static_cast<unsigned char>(raw[2]) << 16;
-        // fallthrough
+        [[fallthrough]];
     case 2:
         result ^= static_cast<unsigned char>(raw[1]) << 8;
-        // fallthrough
+        [[fallthrough]];
     case 1:
         result ^= static_cast<unsigned char>(raw[0]);
         result *= m;

tools/ir-generator/ir-generator-lex.l

@@ -10,6 +10,7 @@
 #pragma GCC diagnostic ignored "-Wsign-compare"
 #ifdef __clang__
 #pragma clang diagnostic ignored "-Wnull-conversion"
+#pragma clang diagnostic ignored "-Wregister"
 #endif