2005-11-24 Frank Ch. Eigler <fche@redhat.com>

	PR 1903
	* parse.cxx (eval_pp_conditional): Support %( arch == "i686" %) form.
	* stap.1.in: Document it.
	* testsuite/parseok/fourteen.stp: Test it.
	* session.h (architecture): New field.
	* main.cxx (main): Initialize it.

6 files changed, 103 insertions, 47 deletions

diff --git a/ChangeLog b/ChangeLog
index f7b43b69..822a379a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2005-11-24  Frank Ch. Eigler  <fche@redhat.com>
 
+	PR 1903
+	* parse.cxx (eval_pp_conditional): Support %( arch == "i686" %) form.
+	* stap.1.in: Document it.
+	* testsuite/parseok/fourteen.stp: Test it.
+	* session.h (architecture): New field.
+	* main.cxx (main): Initialize it.
+
+2005-11-24  Frank Ch. Eigler  <fche@redhat.com>
+
 	PR 1917
 	* translate.cxx (emit_common_header, emit_module_init,
 	emit_module_exit): Switch context array to per-cpu kmalloc variant.
diff --git a/main.cxx b/main.cxx
index cd641588..1ecefa2e 100644
--- a/main.cxx
+++ b/main.cxx
@@ -118,6 +118,7 @@ main (int argc, char * const argv [])
   struct utsname buf;
   (void) uname (& buf);
   s.kernel_release = string (buf.release);
+  s.architecture = string (buf.machine);
   s.verbose = false;
   s.test_mode = false;
   s.guru_mode = false;
diff --git a/parse.cxx b/parse.cxx
index 2ceb6f5f..628fe420 100644
--- a/parse.cxx
+++ b/parse.cxx
@@ -133,10 +133,12 @@ parser::last ()
 
 // Here, we perform on-the-fly preprocessing.
 // The basic form is %( CONDITION %? THEN-TOKENS %: ELSE-TOKENS %)
-// where CONDITION is "kernel_v[r]" COMPARISON-OP "version-string", and
-// the %: ELSE-TOKENS part is optional.
+// where CONDITION is: kernel_v[r] COMPARISON-OP "version-string"
+//                 or: arch COMPARISON-OP "arch-string"
+// The %: ELSE-TOKENS part is optional.
 //
 // e.g. %( kernel_v > "2.5" %? "foo" %: "baz" %)
+// e.g. %( arch != "i686" %? "foo" %: "baz" %)
 //
 // Up to an entire %( ... %) expression is processed by a single call
 // to this function.  Tokens included by any nested conditions are
@@ -145,46 +147,67 @@ parser::last ()
 bool eval_pp_conditional (systemtap_session& s,
                           const token* l, const token* op, const token* r)
 {
-  if (! (l->type == tok_identifier && (l->content == "kernel_v" ||
-                                       l->content == "kernel_vr")))
-    throw parse_error ("expected 'kernel_v' or 'kernel_vr'", l);
-  string target_kernel_vr = s.kernel_release;
-  string target_kernel_v = target_kernel_vr;
-  // cut off any release code suffix
-  string::size_type dr = target_kernel_vr.rfind ('-');
-  if (dr > 0 && dr != string::npos)
-    target_kernel_v = target_kernel_vr.substr (0, dr);
-
-  if (! (r->type == tok_string))
-    throw parse_error ("expected string literal", r);
-  string query_kernel_vr = r->content;
-
-  // collect acceptable strverscmp results.
-  int rvc_ok1, rvc_ok2;
-  if (op->type == tok_operator && op->content == "<=")
-    { rvc_ok1 = -1; rvc_ok2 = 0; }
-  else if (op->type == tok_operator && op->content == ">=")
-    { rvc_ok1 = 1; rvc_ok2 = 0; }
-  else if (op->type == tok_operator && op->content == "<")
-    { rvc_ok1 = -1; rvc_ok2 = -1; }
-  else if (op->type == tok_operator && op->content == ">")
-    { rvc_ok1 = 1; rvc_ok2 = 1; }
-  else if (op->type == tok_operator && op->content == "==")
-    { rvc_ok1 = 0; rvc_ok2 = 0; }
-  else if (op->type == tok_operator && op->content == "!=")
-    { rvc_ok1 = -1; rvc_ok2 = 1; }
+  if (l->type == tok_identifier && (l->content == "kernel_v" ||
+                                    l->content == "kernel_vr"))
+    {
+      string target_kernel_vr = s.kernel_release;
+      string target_kernel_v = target_kernel_vr;
+      // cut off any release code suffix
+      string::size_type dr = target_kernel_vr.rfind ('-');
+      if (dr > 0 && dr != string::npos)
+        target_kernel_v = target_kernel_vr.substr (0, dr);
+      
+      if (! (r->type == tok_string))
+        throw parse_error ("expected string literal", r);
+      string query_kernel_vr = r->content;
+      
+      // collect acceptable strverscmp results.
+      int rvc_ok1, rvc_ok2;
+      if (op->type == tok_operator && op->content == "<=")
+        { rvc_ok1 = -1; rvc_ok2 = 0; }
+      else if (op->type == tok_operator && op->content == ">=")
+        { rvc_ok1 = 1; rvc_ok2 = 0; }
+      else if (op->type == tok_operator && op->content == "<")
+        { rvc_ok1 = -1; rvc_ok2 = -1; }
+      else if (op->type == tok_operator && op->content == ">")
+        { rvc_ok1 = 1; rvc_ok2 = 1; }
+      else if (op->type == tok_operator && op->content == "==")
+        { rvc_ok1 = 0; rvc_ok2 = 0; }
+      else if (op->type == tok_operator && op->content == "!=")
+        { rvc_ok1 = -1; rvc_ok2 = 1; }
+      else
+        throw parse_error ("expected comparison operator", op);
+      
+      int rvc_result = strverscmp ((l->content == "kernel_vr" ? 
+                                    target_kernel_vr.c_str() :
+                                    target_kernel_v.c_str()),
+                                   query_kernel_vr.c_str());
+      // normalize rvc_result
+      if (rvc_result < 0) rvc_result = -1;
+      if (rvc_result > 0) rvc_result = 1;
+      
+      return (rvc_result == rvc_ok1 || rvc_result == rvc_ok2);
+    }
+  else if (l->type == tok_identifier && l->content == "arch")
+    {
+      string target_architecture = s.architecture;
+      if (! (r->type == tok_string))
+        throw parse_error ("expected string literal", r);
+      string query_architecture = r->content;
+      
+      bool result;
+      if (op->type == tok_operator && op->content == "==")
+        result = target_architecture == query_architecture;
+      else if (op->type == tok_operator && op->content == "!=")
+        result = target_architecture != query_architecture;
+      else
+        throw parse_error ("expected '==' or '!='", op);
+      
+      return result;
+    }  
+  // XXX: support other forms?  "CONFIG_SMP" ?
   else
-    throw parse_error ("expected comparison operator", op);
-
-  int rvc_result = strverscmp ((l->content == "kernel_vr" ? 
-                                target_kernel_vr.c_str() :
-                                target_kernel_v.c_str()),
-                               query_kernel_vr.c_str());
-  // normalize rvc_result
-  if (rvc_result < 0) rvc_result = -1;
-  if (rvc_result > 0) rvc_result = 1;
-
-  return (rvc_result == rvc_ok1 || rvc_result == rvc_ok2);
+    throw parse_error ("expected 'arch' or 'kernel_v' or 'kernel_vr'", l);
 }
 
 
diff --git a/session.h b/session.h
index 6e507dd7..0c9a0082 100644
--- a/session.h
+++ b/session.h
@@ -62,6 +62,7 @@ struct systemtap_session
   std::vector<std::string> macros;
   std::vector<std::string> args;
   std::string kernel_release;
+  std::string architecture;
   std::string runtime_path;
   std::string module_name;
   std::string output_file;
diff --git a/stap.1.in b/stap.1.in
index fe954d10..28c20dd5 100644
--- a/stap.1.in
+++ b/stap.1.in
@@ -163,20 +163,31 @@ ternary operator:
 .BR %( " CONDITION " %? " TRUE-TOKENS " %)
 .BR %( " CONDITION " %? " TRUE-TOKENS " %: " FALSE-TOKENS " %)
 .ESAMPLE
-The CONDITION is a very limited expression consisting of three
-parts.  The first part is the identifier
+The CONDITION is a very limited expression whose format is determined
+by its first keyword.
+.PP
+If the first part is the identifier
 .BR kernel_vr " or " kernel_v
 to refer to the kernel version number, with ("2.6.13-1.322FC3smp") or
-without ("2.6.13") the release code suffix.
-The second part is one of the six standard numeric comparison operators
-.BR < ", " <= ", " == ", " != ", " > ", and " >= .
-The third part is a string literal that contains an RPM-style
+without ("2.6.13") the release code suffix, then
+the second part is one of the six standard numeric comparison operators
+.BR < ", " <= ", " == ", " != ", " > ", and " >= ,
+and the third part is a string literal that contains an RPM-style
 version-release value.  The condition is deemed satisfied if the
 version of the target kernel (as optionally overridden by the
 .BR \-r
 option) compares to the given version string.  The comparison is
 performed by the glibc function
 .BR strverscmp .
+.PP
+If, on the other hand, the first part is the identifier
+.BR arch
+to refer to the processor architecture, then the second part
+then the second part is one of the two string comparison operatorsn
+.BR == " or " != ,
+and the third part is a string literal for matching it.  This
+comparison is simple string (in)equality.
+.PP
 The TRUE-TOKENS and FALSE-TOKENS are zero or more general parser
 tokens (possibly including nested preprocessor conditionals), and are
 pasted into the input stream if the condition is true or false.  For
@@ -192,6 +203,10 @@ probe kernel.function (
      %( kernel_vr == "2.6.13-1.8273FC3smp" %? "do_page_fault" %:
         UNSUPPORTED %) %)
 ) { /* ... */ }
+
+%( arch == "ia64" %?
+   probe syscall.vliw = kernel.function("vliw_widget") {} 
+%)
 .ESAMPLE
 
 .SS VARIABLES
diff --git a/testsuite/parseok/fourteen.stp b/testsuite/parseok/fourteen.stp
index e68aa4fe..cc51b90b 100755
--- a/testsuite/parseok/fourteen.stp
+++ b/testsuite/parseok/fourteen.stp
@@ -8,3 +8,10 @@ global
       %: "FAIL2" %)
    %: "FAIL3" %)
 %: "FAIL4" %)
+
+global
+%( arch == "i386" %? i386
+%: %( arch == "i686" %? i686
+   %: %( arch != "x86_64" %? other %: x86_64 %) 
+   %)
+%)