From ad2371cfaec238e26a16ad406ef71eff32d9a7c3 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Tue, 19 Jul 2016 15:40:52 +0000
Subject: [PATCH] Unix: compatibility with platforms where backtrace() is not
 in libc.

Also, don't depend on backtrace() when built as libslvs; it is not
the responsbility of the library to use it.
---
 CMakeLists.txt            | 1 +
 src/CMakeLists.txt        | 5 +++++
 src/platform/unixutil.cpp | 2 ++
 3 files changed, 8 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index cdb0dc9..5dd1844 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -187,6 +187,7 @@ elseif(APPLE)
     find_package(Freetype REQUIRED)
     find_library(APPKIT_LIBRARY AppKit REQUIRED)
 else() # Linux and compatible systems
+    find_package(Backtrace)
     find_package(SpaceWare)
 
     # Use freedesktop's pkg-config to locate everything.
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9ec43b9..4de85d1 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -216,6 +216,11 @@ if(SPACEWARE_FOUND)
         ${SPACEWARE_LIBRARIES})
 endif()
 
+if(Backtrace_FOUND)
+    target_link_libraries(solvespace
+        ${Backtrace_LIBRARIES})
+endif()
+
 if(APPLE)
     foreach(lib ${platform_BUNDLED_LIBS})
         get_filename_component(name ${lib} NAME)
diff --git a/src/platform/unixutil.cpp b/src/platform/unixutil.cpp
index 31366dd..ed0789a 100644
--- a/src/platform/unixutil.cpp
+++ b/src/platform/unixutil.cpp
@@ -31,6 +31,7 @@ void assert_failure(const char *file, unsigned line, const char *function,
     fprintf(stderr, "File %s, line %u, function %s:\n", file, line, function);
     fprintf(stderr, "Assertion '%s' failed: ((%s) == false).\n", message, condition);
 
+#ifndef LIBRARY
     static void *ptrs[1024] = {};
     size_t nptrs = backtrace(ptrs, sizeof(ptrs) / sizeof(ptrs[0]));
     char **syms = backtrace_symbols(ptrs, nptrs);
@@ -45,6 +46,7 @@ void assert_failure(const char *file, unsigned line, const char *function,
             fprintf(stderr, "%2zu: %p\n", i, ptrs[i]);
         }
     }
+#endif
 
     abort();
 }