Avoid emitting duplicated decls in abixml

This patch avoids emitting the same decl twice in the same ABI corpus
or corpus_group.  For the purpose of this duplication detection, a
decl is designated by its pretty representation.

The patch helps to reduce the size of the abixml files drastically by
cutting some of them, especially those representing the KMI of the
linux kernel in more than half.

	* src/abg-writer.cc (write_context::m_emitted_decls_map): New data
	member.
	(write_context::{decl_name_is_emitted, record_decl_as_emitted}):
	Define new memeber functions.
	(write_translation_unit): Do not emit a decl that has already been
	emitted.
	(write_var_decl, write_function): Record the decl as emitted.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>

diff --git a/src/abg-writer.cc b/src/abg-writer.cc
index 268d845529442e6e1fb85c6362b3a84a57e02b92..716ff1ba4edf9fddc9b621fed274f06bf49c2159 100644 (file)
--- a/src/abg-writer.cc
+++ b/src/abg-writer.cc
@@ -170,6 +170,9 @@ class write_context
   class_tmpl_shared_ptr_map            m_class_tmpl_id_map;
   string_elf_symbol_sptr_map_type      m_fun_symbol_map;
   string_elf_symbol_sptr_map_type      m_var_symbol_map;
+  mutable unordered_map<interned_string,
+                       bool,
+                       hash_interned_string> m_emitted_decls_map;
 
   write_context();
 
@@ -502,6 +505,35 @@ public:
     return type_id_is_emitted(id);
   }
 
+  /// Test if the name of a given decl has been written out to the XML
+  /// output.
+  ///
+  /// @param the decl to consider.
+  ///
+  /// @return true if the decl has already been emitted, false
+  /// otherwise.
+  bool
+  decl_name_is_emitted(const interned_string& name) const
+  {return m_emitted_decls_map.find(name) != m_emitted_decls_map.end();}
+
+  /// Test if a given decl has been written out to the XML output.
+  ///
+  /// @param the decl to consider.
+  ///
+  /// @return true if the decl has already been emitted, false
+  /// otherwise.
+  bool
+  decl_is_emitted(decl_base_sptr& decl) const
+  {
+    if (is_type(decl))
+      return false;
+
+    string repr = get_pretty_representation(decl, true);
+    interned_string irepr = decl->get_environment()->intern(repr);
+    bool is_emitted = decl_name_is_emitted(irepr);
+    return is_emitted;
+  }
+
   /// Record a declaration-only class as being emitted.
   ///
   /// For now, this function expects a declaration-only class,
@@ -557,6 +589,18 @@ public:
   clear_emitted_types_map()
   {m_emitted_type_id_map.clear();}
 
+  /// Record a declaration as emitted in the abixml output.
+  ///
+  /// @param decl the decl to consider.
+  void
+  record_decl_as_emitted(const decl_base_sptr &decl)const
+  {
+
+    string repr = get_pretty_representation(decl, true);
+    interned_string irepr = decl->get_environment()->intern(repr);
+    m_emitted_decls_map[irepr] = true;
+  }
+
   /// Clear the map that contains the IDs of the types that has been
   /// recorded as having been written out to the XML output.
   void
@@ -1653,6 +1697,11 @@ write_translation_unit(const translation_unit&   tu,
          // This type has already been written out to the current
          // translation unit, so do not emit it again.
          continue;
+
+      if (decl_base_sptr d = is_decl(*i))
+       if (ctxt.decl_is_emitted(d))
+         continue;
+
       o << "\n";
       write_decl(*i, ctxt, indent + c.get_xml_element_indent());
     }
@@ -2568,6 +2617,8 @@ write_var_decl(const var_decl_sptr& decl, write_context& ctxt,
 
   o << "/>";
 
+  ctxt.record_decl_as_emitted(decl);
+
   return true;
 }
 
@@ -2665,6 +2716,8 @@ write_function_decl(const function_decl_sptr& decl, write_context& ctxt,
   do_indent(o, indent);
   o << "</function-decl>";
 
+  ctxt.record_decl_as_emitted(decl);
+
   return true;
 }