Improve stack trace printing

The stacktrace now removes leading paths from object files and common
source code prefixes. It also skips the first five frames which are always
inside the stacktrace printing code and the signal handler.

maxutils/maxbase/src/stacktrace.cc

@@ -56,7 +56,7 @@ static void get_command_output(char* output, size_t size, const char* format, ..
     }
 }
 
-static void extract_file_and_line(const char* symbols, char* cmd, size_t size)
+static void extract_file_and_line(char* symbols, char* cmd, size_t size)
 {
     const char* filename_end = strchr(symbols, '(');
     const char* symname_end = strchr(symbols, ')');
@@ -116,6 +116,30 @@ static void extract_file_and_line(const char* symbols, char* cmd, size_t size)
             snprintf(symname, sizeof(symname), "%.*s", (int)(symname_end - symname_start), symname_start);
             get_command_output(cmd, size, "addr2line -e %s %s", filename, symname);
         }
+
+        const char prefix[] = "MaxScale/";
+
+        // Remove common source prefix
+        if (char* str = strstr(cmd, prefix))
+        {
+            str += sizeof(prefix) - 1;
+            memmove(cmd, str, strlen(cmd) - (str - cmd) + 1);
+        }
+
+        // Strip the directory name from the symbols (could this be useful?)
+        if (char* str = strrchr(symbols, '/'))
+        {
+            ++str;
+            memmove(symbols, str, strlen(symbols) - (str - symbols) + 1);
+        }
+
+        // Remove the address where the symbol is in memory (i.e. the [0xdeadbeef] that follows the
+        // (main+0xa1) part), we're only interested where it is in the library.
+        if (char* str = strchr(symbols, '['))
+        {
+            str--;
+            *str = '\0';
+        }
     }
 }
 }
@@ -129,12 +153,21 @@ void dump_stacktrace(std::function<void(const char*, const char*)> handler)
     int count = backtrace(addrs, 128);
     char** symbols = backtrace_symbols(addrs, count);
 
+    int rc = system("/bin/test -f /bin/nm -a -f /bin/addr2line");
+    bool do_extract = WIFEXITED(rc) && WEXITSTATUS(rc) == 0;
+
     if (symbols)
     {
-        for (int n = 0; n < count; n++)
+        // Skip first five frames, they are inside the stacktrace printing function and signal handlers
+        for (int n = 4; n < count; n++)
         {
-            char cmd[PATH_MAX + 1024] = "<not found>";
-            extract_file_and_line(symbols[n], cmd, sizeof(cmd));
+            char cmd[PATH_MAX + 1024] = "<binutils not installed>";
+
+            if (do_extract)
+            {
+                extract_file_and_line(symbols[n], cmd, sizeof(cmd));
+            }
+
             handler(symbols[n], cmd);
         }
         free(symbols);