PR2949: listings mode (stap -l PROBE)

2008-04-10  Frank Ch. Eigler  <fche@elastic.org>

	PR 2949.
	* session.h (listing_mode): New field.
	* main.cxx (main): Test it.  Enjoy it.
	(usage): Document it.
	* stap.1.in, stapex.5.in: Ditto.
	* elaborate.cxx (print_error): Disable error messages in listing mode.

2008-04-10  Frank Ch. Eigler  <fche@elastic.org>

	PR 2949
	* systemtap.base/cmd_parse.exp: Add "-l" listing test.

10 files changed, 183 insertions, 66 deletions

diff --git a/ChangeLog b/ChangeLog
index e35c3f71..720d5534 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2008-04-10  Frank Ch. Eigler  <fche@elastic.org>
 
+	PR 2949.
+	* session.h (listing_mode): New field.
+	* main.cxx (main): Test it.  Enjoy it.
+	(usage): Document it.
+	* stap.1.in, stapex.5.in: Ditto.
+	* elaborate.cxx (print_error): Disable error messages in listing mode.
+
+2008-04-10  Frank Ch. Eigler  <fche@elastic.org>
+
 	PR 6393 cont'd.
 	* Makefile.am: Also copy RadeonHD.am fragment to force
 	git_version.h regeneration at every make, and also special
diff --git a/NEWS b/NEWS
index fd9df29d..d794cd86 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,15 @@
+* What's new in version 0.7
+
+- A probe listing mode is available.
+  % stap -l vm.*
+  vm.brk
+  vm.mmap
+  vm.munmap
+  vm.oom_kill
+  vm.pagefault
+  vm.write_shared
+
+
 * What's new in version 0.6
 
 - A copy of the systemtap tutorial and language reference guide
diff --git a/elaborate.cxx b/elaborate.cxx
index 2d9fa7bc..1c41df64 100644
--- a/elaborate.cxx
+++ b/elaborate.cxx
@@ -1214,6 +1214,9 @@ systemtap_session::print_error (const semantic_error& e)
   string message_str;
   stringstream message;
 
+  // NB: we don't print error messages during listing mode.
+  if (listing_mode) return;
+
   message << "semantic error: " << e.what ();
   if (e.tok1 || e.tok2)
     message << ": ";
diff --git a/elaborate.h b/elaborate.h
index fc8fbbcb..30bf5bce 100644
--- a/elaborate.h
+++ b/elaborate.h
@@ -114,6 +114,8 @@ struct derived_probe: public probe
   derived_probe (probe* b, probe_point* l);
   probe* base; // the original parsed probe
   virtual probe* basest () { return base->basest(); }
+  // XXX: might be helpful for listing and stepwise expansion, but aliases/wildcards don't show up right
+  // virtual probe* almost_basest () { probe* bb = base->basest(); return (bb == base) ? this : bb; }
   virtual ~derived_probe () {}
   virtual void join_group (systemtap_session& s) = 0;
   virtual probe_point* sole_location () const;
diff --git a/main.cxx b/main.cxx
index 98c1711b..03021d8c 100644
--- a/main.cxx
+++ b/main.cxx
@@ -65,9 +65,11 @@ usage (systemtap_session& s, int exitcode)
     << endl
     << "   or: stap [options] -e SCRIPT    Run given script."
     << endl
+    << "   or: stap [options] -l PROBE     List matching probes."
+    << endl
     << endl
     << "Options:" << endl
-    << "   --         no more options after this" << endl
+    << "   --         end of translator options, script options follow" << endl
     << "   -v         increase verbosity [" << s.verbose << "]" << endl
     << "   -h         show help" << endl
     << "   -V         show version" << endl
@@ -117,75 +119,118 @@ usage (systemtap_session& s, int exitcode)
 static void
 printscript(systemtap_session& s, ostream& o)
 {
-  if (s.embeds.size() > 0)
-    o << "# global embedded code" << endl;
-  for (unsigned i=0; i<s.embeds.size(); i++)
+  if (s.listing_mode)
     {
-      embeddedcode* ec = s.embeds[i];
-      ec->print (o);
-      o << endl;
-    }
+      // We go through some heroic measures to produce clean output.
+      set<string> seen;
 
-  if (s.globals.size() > 0)
-    o << "# globals" << endl;
-  for (unsigned i=0; i<s.globals.size(); i++)
-    {
-      vardecl* v = s.globals[i];
-      v->printsig (o);
-      if (s.verbose && v->init)
+      for (unsigned i=0; i<s.probes.size(); i++)
         {
-          o << " = ";
-          v->init->print(o);
+          derived_probe* p = s.probes[i];
+          // NB: p->basest() is not so interesting;
+          // p->almost_basest() doesn't quite work, so ...
+          vector<probe*> chain;
+          p->collect_derivation_chain (chain);
+          probe* second = (chain.size()>1) ? chain[chain.size()-2] : chain[0];
+
+          #if 0
+          cerr << "\tchain[" << chain.size() << "]:" << endl;
+          for (unsigned i=0; i<chain.size(); i++)
+            { cerr << "\t"; chain[i]->printsig(cerr); cerr << endl; }
+          #endif
+
+          stringstream tmps;
+          second->printsig (tmps);
+          string tmp = tmps.str();
+          // trim anything other than the "head" of the probe point signature:
+          // alias1 *CUT* = exp1, exp2
+          // probe1 *CUT* /* pc=0xdeadbeef */ /* <- foo */
+          string::size_type space_pos = tmp.find(' ');
+          assert (space_pos != string::npos);
+          string pp = tmp.substr (0, space_pos);
+
+          // Now duplicate-eliminate.  An alias may have expanded to
+          // several actual derived probe points, but we only want to
+          // print the alias head name once.
+          if (seen.find (pp) == seen.end())
+            {
+              o << pp << endl;
+              seen.insert (pp);
+            }
         }
-      o << endl;
     }
-
-  if (s.functions.size() > 0)
-    o << "# functions" << endl;
-  for (unsigned i=0; i<s.functions.size(); i++)
+  else
     {
-      functiondecl* f = s.functions[i];
-      f->printsig (o);
-      o << endl;
-      if (f->locals.size() > 0)
-	o << "  # locals" << endl;
-      for (unsigned j=0; j<f->locals.size(); j++)
+      if (s.embeds.size() > 0)
+        o << "# global embedded code" << endl;
+      for (unsigned i=0; i<s.embeds.size(); i++)
         {
-	  vardecl* v = f->locals[j];
-	  o << "  ";
-	  v->printsig (o);
-	  o << endl;
-	}
-      if (s.verbose)
+          embeddedcode* ec = s.embeds[i];
+          ec->print (o);
+          o << endl;
+        }
+      
+      if (s.globals.size() > 0)
+        o << "# globals" << endl;
+      for (unsigned i=0; i<s.globals.size(); i++)
         {
-	  f->body->print (o);
-	  o << endl;
-	}
-    }
-
-  if (s.probes.size() > 0)
-    o << "# probes" << endl;
-  for (unsigned i=0; i<s.probes.size(); i++)
-    {
-      derived_probe* p = s.probes[i];
-      p->printsig (o);
-      o << endl;
-      if (p->locals.size() > 0)
-        o << "  # locals" << endl;
-      for (unsigned j=0; j<p->locals.size(); j++)
+          vardecl* v = s.globals[i];
+          v->printsig (o);
+          if (s.verbose && v->init)
+            {
+              o << " = ";
+              v->init->print(o);
+            }
+          o << endl;
+        }
+      
+      if (s.functions.size() > 0)
+        o << "# functions" << endl;
+      for (unsigned i=0; i<s.functions.size(); i++)
         {
-	  vardecl* v = p->locals[j];
-	  o << "  ";
-	  v->printsig (o);
-	  o << endl;
-	}
-      if (s.verbose)
+          functiondecl* f = s.functions[i];
+          f->printsig (o);
+          o << endl;
+          if (f->locals.size() > 0)
+            o << "  # locals" << endl;
+          for (unsigned j=0; j<f->locals.size(); j++)
+            {
+              vardecl* v = f->locals[j];
+              o << "  ";
+              v->printsig (o);
+              o << endl;
+            }
+          if (s.verbose)
+            {
+              f->body->print (o);
+              o << endl;
+            }
+        }
+      
+      if (s.probes.size() > 0)
+        o << "# probes" << endl;
+      for (unsigned i=0; i<s.probes.size(); i++)
         {
-	  p->body->print (o);
-	  o << endl;
-	}
+          derived_probe* p = s.probes[i];
+          p->printsig (o);
+          o << endl;
+          if (p->locals.size() > 0)
+            o << "  # locals" << endl;
+          for (unsigned j=0; j<p->locals.size(); j++)
+            {
+              vardecl* v = p->locals[j];
+              o << "  ";
+              v->printsig (o);
+              o << endl;
+            }
+          if (s.verbose)
+            {
+              p->body->print (o);
+              o << endl;
+            }
+        }
+    }
     }
-}
 
 
 int pending_interrupts;
@@ -225,6 +270,7 @@ main (int argc, char * const argv [])
   s.bulk_mode = false;
   s.unoptimized = false;
   s.suppress_warnings = false;
+  s.listing_mode = false;
 
 #ifdef ENABLE_PROLOGUES
   s.prologue_searching = true;
@@ -296,7 +342,7 @@ main (int argc, char * const argv [])
   while (true)
     {
       // NB: also see find_hash(), usage(), switch stmt below, stap.1 man page
-      int grc = getopt (argc, argv, "hVMvtp:I:e:o:R:r:m:kgPc:x:D:bs:uqw");
+      int grc = getopt (argc, argv, "hVMvtp:I:e:o:R:r:m:kgPc:x:D:bs:uqwl:");
       if (grc < 0)
         break;
       switch (grc)
@@ -322,6 +368,11 @@ main (int argc, char * const argv [])
 	  break;
 
         case 'p':
+          if (s.listing_mode)
+            {
+              cerr << "Listing (-l) mode implies pass 2." << endl;
+              usage (s, 1);
+            }
           s.last_pass = atoi (optarg);
           if (s.last_pass < 1 || s.last_pass > 5)
             {
@@ -454,6 +505,19 @@ main (int argc, char * const argv [])
           usage (s, 0);
           break;
 
+        case 'l':
+          s.listing_mode = true;
+          s.last_pass = 2;
+          if (have_script)
+            {
+	      cerr << "Only one script can be given on the command line."
+		   << endl;
+	      usage (s, 1);
+            }
+          cmdline_script = string("probe ") + string(optarg) + " {}";
+          have_script = true;
+          break;
+
         default:
           usage (s, 1);
           break;
@@ -719,7 +783,7 @@ main (int argc, char * const argv [])
   // PASS 2: ELABORATION
   rc = semantic_pass (s);
 
-  if (rc == 0 && s.last_pass == 2)
+  if (s.listing_mode || (rc == 0 && s.last_pass == 2))
     printscript(s, cout);
 
   times (& tms_after);
@@ -768,7 +832,7 @@ main (int argc, char * const argv [])
 	}
     }
 
-  if (rc || s.last_pass == 2 || pending_interrupts) goto cleanup;
+  if (rc || s.listing_mode || s.last_pass == 2 || pending_interrupts) goto cleanup;
 
   // PASS 3: TRANSLATION
 
diff --git a/session.h b/session.h
index b06d9ecc..d8f3e38a 100644
--- a/session.h
+++ b/session.h
@@ -88,6 +88,7 @@ struct systemtap_session
   bool timing;
   bool keep_tmpdir;
   bool guru_mode;
+  bool listing_mode;
   bool bulk_mode;
   bool unoptimized;
   bool merge;
diff --git a/stap.1.in b/stap.1.in
index acfc64c3..db64748f 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -45,6 +45,15 @@ stap \- systemtap script translator/driver
 [
 .I ARGUMENTS
 ]
+.br
+.B stap
+[
+.I OPTIONS
+]
+.BI \-l " PROBE"
+[
+.I ARGUMENTS
+]
 
 .SH DESCRIPTION
 
@@ -153,6 +162,11 @@ Start the probes, run CMD, and exit when CMD finishes.
 .BI \-x " PID"
 Sets target() to PID. This allows scripts to be written that filter on 
 a specific process.
+.TP
+.BI \-l " PROBE"
+Instead of running a probe script, just list all available probe
+points matching the given pattern.  The pattern may include wildcards
+and aliases.
 
 .SH ARGUMENTS
 
diff --git a/stapex.5.in b/stapex.5.in
index 86e1c87b..2c9ecb60 100644
--- a/stapex.5.in
+++ b/stapex.5.in
@@ -101,11 +101,9 @@ probe kernel.function("sys_mkdir") { println ("enter") }
 probe kernel.function("sys_mkdir").return { println ("exit") }
 .ESAMPLE
 
-To list the probeable functions in the kernel, use the last-pass
-option to the translator.  That output needs to be filtered because
-each inlined function instance is listed separately.
+To list the probeable functions in the kernel, use the listings mode.
 .SAMPLE
-% stap \-p2 \-e \[aq]probe kernel.function("*") {}\[aq] | sort | uniq
+% stap \-l \[aq]kernel.function("*")\[aq]
 .ESAMPLE
 
 .SH SEE ALSO
diff --git a/testsuite/ChangeLog b/testsuite/ChangeLog
index 95c1f117..8bfb1ce4 100644
--- a/testsuite/ChangeLog
+++ b/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-04-10  Frank Ch. Eigler  <fche@elastic.org>
+
+	PR 2949
+	* systemtap.base/cmd_parse.exp: Add "-l" listing test.
+
 2008-04-04  Masami Hiramatsu <mhiramat@redhat.com>
 
 	PR 5528
diff --git a/testsuite/systemtap.base/cmd_parse.exp b/testsuite/systemtap.base/cmd_parse.exp
index ff347a9d..cbce0455 100644
--- a/testsuite/systemtap.base/cmd_parse.exp
+++ b/testsuite/systemtap.base/cmd_parse.exp
@@ -75,3 +75,12 @@ expect {
     eof {fail "cmd_parse7: unexpected EOF"}
 }
 wait
+
+spawn stap -l {vm.*}
+expect {
+    -timeout 60
+    -re "vm.*" {pass "cmd_parse8"}
+    timeout {fail "cmd_parse8: unexpected timeout"}
+    eof {fail "cmd_parse8: unexpected EOF"}
+}
+wait