build: linux does not always have execinfo.h (#7101)

Closes #7099

CMakeLists.txt

@@ -192,6 +192,16 @@ if(CMAKE_EXE_LINKER_FLAGS MATCHES "--sort-common" OR
   string(REGEX REPLACE "-Wl($| )" "" CMAKE_MODULE_LINKER_FLAGS "${CMAKE_MODULE_LINKER_FLAGS}")
 endif()
 
+check_c_source_compiles("
+#include <execinfo.h>
+int main(void)
+{
+  void *trace[1];
+  int trace_size = backtrace(trace, 1);
+  return 0;
+}
+" HAVE_EXECINFO_BACKTRACE)
+
 if(MSVC)
   # XXX: /W4 gives too many warnings. #3241
   add_definitions(/W3 -D_CRT_SECURE_NO_WARNINGS -D_CRT_NONSTDC_NO_DEPRECATE)
@@ -324,7 +334,6 @@ main(void)
   return MSGPACK_OBJECT_FLOAT32;
 }
 " MSGPACK_HAS_FLOAT32)
-
 if(MSGPACK_HAS_FLOAT32)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DNVIM_MSGPACK_HAS_FLOAT32")
 endif()

config/config.h.in

@@ -68,4 +68,6 @@
 #cmakedefine ORDER_BIG_ENDIAN
 #define ENDIAN_INCLUDE_FILE <@ENDIAN_INCLUDE_FILE@>
 
+#cmakedefine HAVE_EXECINFO_BACKTRACE
+
 #endif  // AUTO_CONFIG_H

src/nvim/log.c

@@ -25,6 +25,10 @@ static uv_mutex_t mutex;
 # include "log.c.generated.h"
 #endif
 
+#ifdef HAVE_EXECINFO_BACKTRACE
+# include <execinfo.h>
+#endif
+
 static bool log_try_create(char *fname)
 {
   if (fname == NULL || fname[0] == '\0') {
@@ -173,8 +177,7 @@ FILE *open_log_file(void)
   return stderr;
 }
 
-#if defined(__linux__)
-# include <execinfo.h>
+#ifdef HAVE_EXECINFO_BACKTRACE
 void log_callstack(const char *const func_name, const int line_num)
 {
   void *trace[100];

src/nvim/log.h

@@ -61,7 +61,7 @@
                            __VA_ARGS__)
 #endif
 
-#if defined(__linux__)
+#ifdef HAVE_EXECINFO_BACKTRACE
 # define LOG_CALLSTACK() log_callstack(__func__, __LINE__)
 #endif