From 4ecdb70424a7c057bf6858027abc3a0f59454210 Mon Sep 17 00:00:00 2001
From: Petr Hosek <phosek@chromium.org>
Date: Mon, 28 Jan 2019 20:55:12 +0000
Subject: [PATCH] Revert "[libunwind] Drop the dependency on <algorithm>, add
 placement new inline"

This reverts commit r352384: this broke on ARM as UnwindCursor.hpp
still has some C++ library dependencies.

llvm-svn: 352427
---
 libunwind/CMakeLists.txt       | 25 ++++++++++++++++++++++---
 libunwind/src/Unwind-seh.cpp   |  4 ----
 libunwind/src/UnwindCursor.hpp |  1 +
 libunwind/src/libunwind.cpp    |  8 ++++----
 4 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/libunwind/CMakeLists.txt b/libunwind/CMakeLists.txt
index 46e7ce146e72..b03adaa5ab0f 100644
--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -287,9 +287,6 @@ unwind_append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_EHSC_FLAG -EHsc)
 
 unwind_append_if(LIBUNWIND_C_FLAGS LIBUNWIND_HAS_FUNWIND_TABLES -funwind-tables)
 
-# Ensure that we don't depend on C++ standard library.
-unwind_append_if(LIBUNWIND_CXX_FLAGS LIBUNWIND_HAS_NOSTDINCXX_FLAG -nostdinc++)
-
 # Assert
 string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
 if (LIBUNWIND_ENABLE_ASSERTIONS)
@@ -344,6 +341,28 @@ endif()
 
 include_directories(include)
 
+find_path(
+  LIBUNWIND_LIBCXX_INCLUDES_INTERNAL
+  __libcpp_version
+  PATHS ${LLVM_MAIN_SRC_DIR}/projects/libcxx/include
+        ${LLVM_MAIN_SRC_DIR}/runtimes/libcxx/include
+        ${LLVM_MAIN_SRC_DIR}/../libcxx/include
+  NO_DEFAULT_PATH
+  NO_CMAKE_FIND_ROOT_PATH
+  )
+if ((NOT LIBUNWIND_STANDALONE_BUILD OR HAVE_LIBCXX) AND
+    IS_DIRECTORY "${LIBUNWIND_LIBCXX_INCLUDES_INTERNAL}")
+  set(LIBUNWIND_CXX_INCLUDE_PATHS_DEFAULT "${LIBUNWIND_LIBCXX_INCLUDES_INTERNAL}")
+endif()
+
+set(LIBUNWIND_CXX_INCLUDE_PATHS "${LIBUNWIND_CXX_INCLUDE_PATHS_DEFAULT}" CACHE PATH
+    "Paths to C++ header directories separated by ';'.")
+
+if (NOT LIBUNWIND_CXX_INCLUDE_PATHS STREQUAL "")
+  list(APPEND LIBUNWIND_CXX_FLAGS -nostdinc++)
+  include_directories("${LIBUNWIND_CXX_INCLUDE_PATHS}")
+endif()
+
 add_subdirectory(src)
 
 if (LIBUNWIND_INCLUDE_DOCS)
diff --git a/libunwind/src/Unwind-seh.cpp b/libunwind/src/Unwind-seh.cpp
index 26eb0ef262bb..f55d62423a61 100644
--- a/libunwind/src/Unwind-seh.cpp
+++ b/libunwind/src/Unwind-seh.cpp
@@ -49,10 +49,6 @@ using namespace libunwind;
 /// Class of foreign exceptions based on unrecognized SEH exceptions.
 static const uint64_t kSEHExceptionClass = 0x434C4E4753454800; // CLNGSEH\0
 
-// libunwind does not and should not depend on C++ library which means that we
-// need our own declaration of global placement new.
-void *operator new(size_t, void*);
-
 /// Exception cleanup routine used by \c _GCC_specific_handler to
 /// free foreign exceptions.
 static void seh_exc_cleanup(_Unwind_Reason_Code urc, _Unwind_Exception *exc) {
diff --git a/libunwind/src/UnwindCursor.hpp b/libunwind/src/UnwindCursor.hpp
index 62efe771babb..497ff84552de 100644
--- a/libunwind/src/UnwindCursor.hpp
+++ b/libunwind/src/UnwindCursor.hpp
@@ -11,6 +11,7 @@
 #ifndef __UNWINDCURSOR_HPP__
 #define __UNWINDCURSOR_HPP__
 
+#include <algorithm>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
diff --git a/libunwind/src/libunwind.cpp b/libunwind/src/libunwind.cpp
index cfa9112a6336..a2496a06de9a 100644
--- a/libunwind/src/libunwind.cpp
+++ b/libunwind/src/libunwind.cpp
@@ -11,6 +11,10 @@
 
 #include <libunwind.h>
 
+#ifndef NDEBUG
+#include <cstdlib> // getenv
+#endif
+
 #include "libunwind_ext.h"
 #include "config.h"
 
@@ -23,10 +27,6 @@
 
 using namespace libunwind;
 
-// libunwind does not and should not depend on C++ library which means that we
-// need our own declaration of global placement new.
-void *operator new(size_t, void*);
-
 /// internal object to represent this processes address space
 LocalAddressSpace LocalAddressSpace::sThisAddressSpace;