* layout.cc (Layout::layout_gnu_stack): Add warnings for executable

	stack.
	* layout.h (Layout::layout_gnu_stack): Add pointer to Object
	parameter; change all callers.
	* object.cc (Sized_relobj::do_layout): Adjust call to layout_gnu_stack.
	* options.h (warn_execstack): New option.

5 files changed, 33 insertions, 5 deletions

diff --git a/gold/ChangeLog b/gold/ChangeLog
index 7a5c36c..5febda7 100644
--- a/gold/ChangeLog
+++ b/gold/ChangeLog
@@ -1,3 +1,12 @@
+2010-12-09  Cary Coutant  <ccoutant@google.com>
+
+	* layout.cc (Layout::layout_gnu_stack): Add warnings for executable
+	stack.
+	* layout.h (Layout::layout_gnu_stack): Add pointer to Object
+	parameter; change all callers.
+	* object.cc (Sized_relobj::do_layout): Adjust call to layout_gnu_stack.
+	* options.h (warn_execstack): New option.
+
 2010-12-07  Doug Kwan  <dougkwan@google.com>
 
 	* arm.cc (Target_arm::Scan::get_reference_flags): Treat R_ARM_PREL31
diff --git a/gold/layout.cc b/gold/layout.cc
index 52120cc..9bf9a9f 100644
--- a/gold/layout.cc
+++ b/gold/layout.cc
@@ -1344,15 +1344,29 @@ Layout::expected_segment_count() const
 // object.  On some targets that will force an executable stack.
 
 void
-Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags)
+Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
+			 const Object* obj)
 {
   if (!seen_gnu_stack)
-    this->input_without_gnu_stack_note_ = true;
+    {
+      this->input_without_gnu_stack_note_ = true;
+      if (parameters->options().warn_execstack()
+	  && parameters->target().is_default_stack_executable())
+	gold_warning(_("%s: missing .note.GNU-stack section"
+		       " implies executable stack"),
+		     obj->name().c_str());
+    }
   else
     {
       this->input_with_gnu_stack_note_ = true;
       if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0)
-	this->input_requires_executable_stack_ = true;
+	{
+	  this->input_requires_executable_stack_ = true;
+	  if (parameters->options().warn_execstack()
+	      || parameters->options().is_stack_executable())
+	    gold_warning(_("%s: requires executable stack"),
+			 obj->name().c_str());
+	}
     }
 }
 
diff --git a/gold/layout.h b/gold/layout.h
index 6e817ca..cfbb9f0 100644
--- a/gold/layout.h
+++ b/gold/layout.h
@@ -470,7 +470,8 @@ class Layout
   // .note.GNU-stack section.  GNU_STACK_FLAGS is the section flags
   // from that section if there was one.
   void
-  layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags);
+  layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags,
+		   const Object*);
 
   // Add an Output_section_data to the layout.  This is used for
   // special sections like the GOT section.  ORDER is where the
diff --git a/gold/object.cc b/gold/object.cc
index bde89f6..466d26f 100644
--- a/gold/object.cc
+++ b/gold/object.cc
@@ -1429,7 +1429,7 @@ Sized_relobj<size, big_endian>::do_layout(Symbol_table* symtab,
     }
 
   if (!is_gc_pass_two)
-    layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags);
+    layout->layout_gnu_stack(seen_gnu_stack, gnu_stack_flags, this);
 
   // When doing a relocatable link handle the reloc sections at the
   // end.  Garbage collection  and Identical Code Folding is not 
diff --git a/gold/options.h b/gold/options.h
index 7a694a9..8f240f0 100644
--- a/gold/options.h
+++ b/gold/options.h
@@ -1035,6 +1035,10 @@ class General_options
   DEFINE_bool(warn_constructors, options::TWO_DASHES, '\0', false,
 	      N_("Ignored"), N_("Ignored"));
 
+  DEFINE_bool(warn_execstack, options::TWO_DASHES, '\0', false,
+	      N_("Warn if the stack is executable"),
+	      N_("Do not warn if the stack is executable (default)"));
+
   DEFINE_bool(warn_mismatch, options::TWO_DASHES, '\0', true,
 	      NULL, N_("Don't warn about mismatched input files"));