2005-08-10 Frank Ch. Eigler <fche@elastic.org>

	PR translator/1186
	* elaborate.cxx (resolve_2types): Accept a flag to tolerate unresolved
	expression types.
	(visit_functioncall): Call it thusly.
	* translate.cxx (emit_function): Tolerate void functions.
	* stap.1.in: Document possibility of void functions.
	* tapset/builtin_{log,printk,warn}.stp: Make these void functions.
	* testsuite/buildok/nine.stp, semok/eighteen.stp: New tests.

9 files changed, 44 insertions, 16 deletions

diff --git a/ChangeLog b/ChangeLog
index 0553076a..f05ab027 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2005-08-10  Frank Ch. Eigler  <fche@elastic.org>
 
+	PR translator/1186
+	* elaborate.cxx (resolve_2types): Accept a flag to tolerate unresolved
+	expression types.
+	(visit_functioncall): Call it thusly.
+	* translate.cxx (emit_function): Tolerate void functions.
+	* stap.1.in: Document possibility of void functions.
+	* tapset/builtin_{log,printk,warn}.stp: Make these void functions.
+	* testsuite/buildok/nine.stp, semok/eighteen.stp: New tests.
+
+2005-08-10  Frank Ch. Eigler  <fche@elastic.org>
+
 	* tapsets.cxx: Correct hex/decimal misformatting of verbose messages.
 	* main.cxx: Add formal "-h" and "-V" options.
 	* stap.1.in: Document them.
diff --git a/elaborate.cxx b/elaborate.cxx
index 0cecab7e..de39b496 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -1252,7 +1252,7 @@ typeresolution_info::visit_ternary_expression (ternary_expression* e)
 
 template <class Referrer, class Referent>
 void resolve_2types (Referrer* referrer, Referent* referent,
-                    typeresolution_info* r, exp_type t)
+                    typeresolution_info* r, exp_type t, bool accept_unknown = false)
 {
   exp_type& re_type = referrer->type;
   const token* re_tok = referrer->tok;
@@ -1290,7 +1290,7 @@ void resolve_2types (Referrer* referrer, Referent* referent,
       r->resolved (te_tok, te_type);
       // catch re_type/t mismatch later
     }
-  else
+  else if (! accept_unknown)
     r->unresolved (re_tok);
 }
 
@@ -1361,7 +1361,7 @@ typeresolution_info::visit_functioncall (functioncall* e)
 {
   assert (e->referent != 0);
 
-  resolve_2types (e, e->referent, this, t);
+  resolve_2types (e, e->referent, this, t, true); // accept unknown type 
 
   if (e->type == pe_stats)
     invalid (e->tok, e->type);
diff --git a/stap.1.in b/stap.1.in
index 44359b68..afaf0c72 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -190,8 +190,9 @@ Exit or iterate the innermost nesting loop
 statement.
 .TP
 .BR return " EXP"
-Return EXP value from enclosing function.  A return value is mandatory,
-since void functions are not supported.
+Return EXP value from enclosing function.  If the function's value is
+not taken anywhere, then a return statement is not needed, and the
+function will have a special "unknown" type with no return value.
 .TP
 .BR next
 Return now from enclosing probe handler.
@@ -372,12 +373,9 @@ function thisfn (arg1, arg2) {
 .fi
 .RE
 Note the usual absence of type declarations, which are instead
-inferred by the translator.  Because a return value type is required,
-each function must contain at least one
-.I return
-statement.  Functions may call others or themselves recursively, up to
-a fixed nesting limit.  This limit is defined by a macro in the
-translated C code and is in the neighbourhood of 30.
+inferred by the translator.  Functions may call others or themselves
+recursively, up to a fixed nesting limit.  This limit is defined by
+a macro in the translated C code and is in the neighbourhood of 30.
 
 .SS EMBEDDED C
 When in guru mode, the translator accepts embedded code in the
diff --git a/tapset/builtin_log.stp b/tapset/builtin_log.stp
index 2932d66e..3d1a0aaf 100644
--- a/tapset/builtin_log.stp
+++ b/tapset/builtin_log.stp
@@ -3,5 +3,5 @@ function _log (msg) %{
 %}
 
 function log (msg) {
-    return 0 + _log (msg . "")
+   _log (msg . "")
 }
diff --git a/tapset/builtin_printk.stp b/tapset/builtin_printk.stp
index 3e456fb2..81826849 100644
--- a/tapset/builtin_printk.stp
+++ b/tapset/builtin_printk.stp
@@ -3,5 +3,5 @@ function _printk (msg) %{
 %}
 
 function printk (msg) {
-    return 0 + _printk (msg . "")
+    _printk (msg . "")
 }
diff --git a/tapset/builtin_warn.stp b/tapset/builtin_warn.stp
index 98fef7fe..97289ee0 100644
--- a/tapset/builtin_warn.stp
+++ b/tapset/builtin_warn.stp
@@ -3,5 +3,5 @@ function _warn (msg) %{
 %}
 
 function warn (msg) {
-    return 0 + _warn (msg . "")
+    _warn (msg . "")
 }
diff --git a/testsuite/buildok/nine.stp b/testsuite/buildok/nine.stp
new file mode 100755
index 00000000..d9a15276
--- /dev/null
+++ b/testsuite/buildok/nine.stp
@@ -0,0 +1,8 @@
+#! stap -p2
+
+function f () { }
+function g (arg) { }
+
+probe begin {
+  true ? f() : g(1);
+}
diff --git a/testsuite/semok/eighteen.stp b/testsuite/semok/eighteen.stp
new file mode 100755
index 00000000..1b05d89b
--- /dev/null
+++ b/testsuite/semok/eighteen.stp
@@ -0,0 +1,8 @@
+#! stap -p2
+
+function f () { }
+function g (arg) { }
+
+probe begin {
+  f(); g(1)
+}
diff --git a/translate.cxx b/translate.cxx
index 4add7b64..8806e502 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -765,8 +765,11 @@ c_unparser::emit_function (functiondecl* v)
     }
 
   // initialize return value, if any
-  var retvalue = var(true, v->type, "__retvalue");
-  o->newline() << retvalue.init();
+  if (v->type != pe_unknown)
+    {
+      var retvalue = var(true, v->type, "__retvalue");
+      o->newline() << retvalue.init();
+    }
 
   v->body->visit (this);
   this->current_function = 0;