compiler: rationalize external symbol names

    
    Encode all external symbol names using only ASCII alphanumeric
    characters, underscore, and dot.  Use a scheme that can be reliably
    demangled to a somewhat readable version as described in the long
    comment in names.cc.
    
    A minor cleanup discovered during this was that we were treating
    function types as different if one had a NULL parameters_ field and
    another has a non-NULL parameters_ field that has no parameters.  This
    worked because we mangled them slightly differently.  We now mangle
    them the same, so we treat them as equal, as we should anyhow.
    
    Reviewed-on: https://go-review.googlesource.com/89555

	* go.go-torture/execute/names-1.go: New test.

From-SVN: r257033

1 files changed, 6 insertions, 5 deletions

diff --git a/libgo/runtime/go-callers.c b/libgo/runtime/go-callers.c
index 9f376c7..2eaac68 100644
--- a/libgo/runtime/go-callers.c
+++ b/libgo/runtime/go-callers.c
@@ -68,13 +68,14 @@ callback (void *data, uintptr_t pc, const char *filename, int lineno,
     {
       const char *p;
 
-      p = __builtin_strchr (function, '.');
-      if (p != NULL && __builtin_strncmp (p + 1, "$thunk", 6) == 0)
+      p = function + __builtin_strlen (function);
+      while (p > function && p[-1] >= '0' && p[-1] <= '9')
+	--p;
+      if (p - function > 7 && __builtin_strncmp (p - 7, "..thunk", 7) == 0)
 	return 0;
-      p = __builtin_strrchr (function, '$');
-      if (p != NULL && __builtin_strcmp(p, "$recover") == 0)
+      if (p - function > 3 && __builtin_strcmp (p - 3, "..r") == 0)
 	return 0;
-      if (p != NULL && __builtin_strncmp(p, "$stub", 5) == 0)
+      if (p - function > 6 && __builtin_strcmp (p - 6, "..stub") == 0)
 	return 0;
     }