Add $$vars, $$parms, $$locals

4 files changed, 109 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 1be62021..618ca96e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-08-04  Stan Cox  <scox@redhat.com>
+
+	* tapsets.cxx (dwarf_var_expanding_copy_visitor::visit_target_symbol): 
+	Add support for $$vars, $$parms, and $$locals.
+	* stapprobes.5.in: Likewise.
+	* doc/langref.tex: Likewise.
+
 2008-08-02  Frank Ch. Eigler  <fche@elastic.org>
 
 	* translate.h (translator_output::assert_0_indent): New function.
diff --git a/doc/langref.tex b/doc/langref.tex
index e2c630d4..a1b694f6 100644
--- a/doc/langref.tex
+++ b/doc/langref.tex
@@ -779,6 +779,17 @@ may be repeated to follow additional levels of pointers.
 \texttt{\$var{[}N]} indexes into an array. The index is given with a literal
 number.
 
+\texttt{\$\$vars} expands to a character string that is equivalent to
+sprintf("parm1=\%x ... parmN=\%x var1=\%x ... varN=\%x", parm1, ..., parmN,
+var1, ..., varN)
+
+\texttt{\$\$locals} expands to a character string that is equivalent to
+sprintf("var1=\%x ... varN=\%x", var1, ..., varN)
+
+\texttt{\$\$parms} expands to a character string that is equivalent to
+sprintf("parm1=\%x ... parmN=\%x", parm1, ..., parmN)
+
+
 \subsubsection{kernel.function, module().function}
 \index{kernel.function}
 \index{module().function}
diff --git a/stapprobes.5.in b/stapprobes.5.in
index fcc44df1..24075248 100644
--- a/stapprobes.5.in
+++ b/stapprobes.5.in
@@ -329,6 +329,19 @@ may be repeated to follow more levels of pointers.
 $var[N]
 indexes into an array.  The index is given with a
 literal number.
+.TP
+$$vars
+expands to a character string that is equivalent to
+sprintf("parm1=%x ... parmN=%x var1=%x ... varN=%x", parm1, ..., parmN,
+var1, ..., varN)
+.TP
+$$locals
+expands to a character string that is equivalent to
+sprintf("var1=%x ... varN=%x", var1, ..., varN)
+.TP
+$$parms
+expands to a character string that is equivalent to
+sprintf("parm1=%x ... parmN=%x", parm1, ..., parmN)
 .PP
 For ".return" probes, context variables other than the "$return"
 value itself are only available for the function call parameters.
diff --git a/tapsets.cxx b/tapsets.cxx
index 83463f85..ca91659b 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2534,7 +2534,7 @@ struct dwarf_query : public base_query
 // It arises because we sometimes try to fix up slightly-off
 // .statement() probes (something we find out in fairly low-level).
 //
-// An alternative would be to put some more intellgence into query_cu(),
+// An alternative would be to put some more intelligence into query_cu(),
 // and have it print additional suggestions after finding that
 // q->dw.iterate_over_srcfile_lines resulted in no new finished_results.
 
@@ -4248,6 +4248,83 @@ dwarf_var_expanding_copy_visitor::visit_target_symbol (target_symbol *e)
       return;
     }
 
+  if (e->base_name == "$$vars"
+      || e->base_name == "$$parms"
+      || e->base_name == "$$locals")
+    {
+      Dwarf_Die *scopes;
+      if (dwarf_getscopes_die (scope_die, &scopes) == 0)
+	return;
+	
+      target_symbol *tsym = new target_symbol;
+      print_format* pf = new print_format;
+
+      // Convert $$parms to sprintf of a list of parms and active local vars
+      // which we recursively evaluate
+      token* tmp_tok = new token;
+      tmp_tok->type = tok_identifier;
+      tmp_tok->content = "sprintf";
+      pf->tok = tmp_tok;
+      pf->print_to_stream = false;
+      pf->print_with_format = true;
+      pf->print_with_delim = false;
+      pf->print_with_newline = false;
+      pf->print_char = false;
+
+      Dwarf_Die result;
+      if (dwarf_child (&scopes[0], &result) == 0)
+	do
+	  {
+	    switch (dwarf_tag (&result))
+	      {
+	      case DW_TAG_variable:
+		if (e->base_name == "$$parms")
+		  continue;
+	      case DW_TAG_formal_parameter:
+		if (e->base_name == "$$locals")
+		  continue;
+		break;
+
+	      default:
+		continue;
+	      }
+
+	    const char *diename = dwarf_diename (&result);
+	    token* sym_tok = new token;
+	    sym_tok->location = e->get_tok()->location;
+	    sym_tok->type = tok_identifier;
+	    sym_tok->content = diename;
+	    tsym->tok = sym_tok;
+	    tsym->base_name = "$";
+	    tsym->base_name += diename;
+	    Dwarf_Attribute attr_mem;
+
+	    // Ignore any variable that isn't accessible.
+	    // dwarf_attr_integrate is checked by literal_stmt_for_local
+	    // dwarf_getlocation_addr is checked by translate_location
+	    // but if those fail we cannot catch semantic_error.
+	    if (dwarf_attr_integrate (&result, DW_AT_location, &attr_mem) != NULL)
+	      {
+		Dwarf_Op *expr;
+		size_t len;
+		if (dwarf_getlocation_addr (&attr_mem, addr - q.dw.module_bias,
+					    &expr, &len, 1) == 0)
+		  continue;
+		this->visit_target_symbol(tsym);
+		pf->raw_components += diename;
+		pf->raw_components += "=%#x ";
+		pf->args.push_back(*(expression**)this->targets.top());
+	      }
+	  }
+	while (dwarf_siblingof (&result, &result) == 0);
+
+      pf->raw_components += "\\n";
+      pf->components = print_format::string_to_components(pf->raw_components);
+      provide <print_format*> (this, pf);
+
+      return;
+    }
+
   // Synthesize a function.
   functiondecl *fdecl = new functiondecl;
   fdecl->tok = e->tok;