0012-xtensa-Configurable-exception-emergency-pool-size.patch

From a39da3dc47b6e88daa20f5ef435a0fb3979c18f8 Mon Sep 17 00:00:00 2001
From: Alexey Gerenkov <alexey@espressif.com>
Date: Thu, 16 Nov 2017 15:06:35 +0300
Subject: [PATCH 12/18] xtensa: Configurable exception emergency pool size

---
 libstdc++-v3/libsupc++/eh_alloc.cc | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/libstdc++-v3/libsupc++/eh_alloc.cc b/libstdc++-v3/libsupc++/eh_alloc.cc
index 7ddd2b746d8..aca2e37799a 100644
--- a/libstdc++-v3/libsupc++/eh_alloc.cc
+++ b/libstdc++-v3/libsupc++/eh_alloc.cc
@@ -73,6 +73,13 @@ using namespace __cxxabiv1;
 # define EMERGENCY_OBJ_COUNT	4
 #endif
 
+static const size_t DEFAULT_ARENA_SIZE = EMERGENCY_OBJ_SIZE * EMERGENCY_OBJ_COUNT * sizeof (__cxa_dependent_exception);
+
+extern "C" size_t __cxx_eh_arena_size_get() __attribute__((weak));
+extern "C" size_t __cxx_eh_arena_size_get()
+{
+    return DEFAULT_ARENA_SIZE;
+}
 
 namespace
 {
@@ -112,9 +119,11 @@ namespace
     {
       // Allocate the arena - we could add a GLIBCXX_EH_ARENA_SIZE environment
       // to make this tunable.
-      arena_size = (EMERGENCY_OBJ_SIZE * EMERGENCY_OBJ_COUNT
-		    + EMERGENCY_OBJ_COUNT * sizeof (__cxa_dependent_exception));
-      arena = (char *)malloc (arena_size);
+      arena = NULL;
+      arena_size = __cxx_eh_arena_size_get();
+      if (arena_size > 0) {
+        arena = (char *)malloc (arena_size);
+      }
       if (!arena)
 	{
 	  // If the allocation failed go without an emergency pool.
-- 
2.21.0 (Apple Git-122)