[patch] Add namespace aliasing support.

Sami Wagiaalla swagiaal@redhat.com
Fri Jan 29 16:27:00 GMT 2010


gdb/7935

This patch adds support for namespace aliasing.
Eg.

namespace A{
   int x;
}

void foo(){
   namespace B=A
}

...

(gdb) p B::x

PR gdb/7935:
2010-01-29  Sami Wagiaalla  <swagiaal@redhat.com>

    * cp-support.h: Added char* alias element to using_direct data
    struct.
    (cp_add_using): Added char* alias argument.
    (cp_add_using_directive): Ditto.
    * cp-namespace.c: Updated with the above changes.
    (cp_lookup_symbol_imports): Check for aliases.
    * dwarf2read.c (read_import_statement): Figure out local alias
    for the import and pass it on to cp_add_using.
    (read_namespace): Pass alias argument to cp_add_using.
        
2010-01-29  Sami Wagiaalla  <swagiaal@redhat.com>

    * gdb.cp/namespace-using.exp: Removed kfail; bug has been fixed.


diff --git a/gdb/cp-namespace.c b/gdb/cp-namespace.c
index 8ca9c20..a6ecb26 100644
--- a/gdb/cp-namespace.c
+++ b/gdb/cp-namespace.c
@@ -117,7 +117,7 @@ cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
  		 anonymous namespace.  So add symbols in it to the
  		 namespace given by the previous component if there is
  		 one, or to the global namespace if there isn't.  */
-	      cp_add_using_directive (dest, src);
+	      cp_add_using_directive (dest, src, "");
  	    }
  	  /* The "+ 2" is for the "::".  */
  	  previous_component = next_component + 2;
@@ -132,7 +132,7 @@ cp_scan_for_anonymous_namespaces (const struct symbol *symbol)
     has already been added, don't add it twice.  */
  
  void
-cp_add_using_directive (const char *dest, const char *src)
+cp_add_using_directive (const char *dest, const char *src, const char* alias)
  {
    struct using_direct *current;
    struct using_direct *new;
@@ -146,7 +146,7 @@ cp_add_using_directive (const char *dest, const char *src)
  	return;
      }
  
-  using_directives = cp_add_using (dest, src, using_directives);
+  using_directives = cp_add_using (dest, src, alias, using_directives);
  
  }
  
@@ -198,8 +198,10 @@ cp_is_anonymous (const char *namespace)
  	  != NULL);
  }
  
-/* Create a new struct using direct which imports the namespace SRC
-   into the scope DEST.
+/* Create a new struct using direct which imports the namespace SRC into the
+   scope DEST. ALIAS is the name of the imported namespace in the current
+   scope. If ALIAS is an empty string  then the namespace is known by its
+   original name.
     Set its next member in the linked list to NEXT; allocate all memory
     using xmalloc.  It copies the strings, so NAME can be a temporary
     string.  */
@@ -207,6 +209,7 @@ cp_is_anonymous (const char *namespace)
  struct using_direct *
  cp_add_using (const char *dest,
                const char *src,
+              const char *alias,
  	      struct using_direct *next)
  {
    struct using_direct *retval;
@@ -214,6 +217,8 @@ cp_add_using (const char *dest,
    retval = xmalloc (sizeof (struct using_direct));
    retval->import_src = savestring (src, strlen(src));
    retval->import_dest = savestring (dest, strlen(dest));
+  retval->alias = savestring (alias, strlen(alias));
+
    retval->next = next;
    retval->searched = 0;
  
@@ -344,13 +349,28 @@ cp_lookup_symbol_imports (const char *scope,
  	current->searched = 1;
  	searched_cleanup = make_cleanup (reset_directive_searched, current);
  
-	sym = cp_lookup_symbol_namespace (current->import_src,
+	if (strcmp (name, current->alias) == 0)
+	  /* If the import is creating an alias and the alias matches the
+	     sought name. Pass current->import_src as the NAME to direct the
+	     search towards the aliased namespace.   */
+	  {
+	    sym = cp_lookup_symbol_in_namespace (scope,
+	                                         current->import_src,
+	                                         linkage_name,
+	                                         block,
+	                                         domain);
+	  }
+	else if (strcmp ("", current->alias) == 0)
+	  {
+	  /* If this import statement creates no alias, pass current->inner as
+	     NAMESPACE to direct the search towards the imported namespace.  */
+	  sym = cp_lookup_symbol_imports (current->import_src,
  	                                  name,
  	                                  linkage_name,
  	                                  block,
  	                                  domain,
  	                                  0);
-
+	  }
  	current->searched = 0;
  	discard_cleanups (searched_cleanup);
  
diff --git a/gdb/cp-support.h b/gdb/cp-support.h
index 33b1b44..5d28bf9 100644
--- a/gdb/cp-support.h
+++ b/gdb/cp-support.h
@@ -38,14 +38,20 @@ struct demangle_component;
  
  /* This struct is designed to store data from using directives.  It
     says that names from namespace IMPORT_SRC should be visible within
-   namespace IMPORT_DEST. IMPORT_DEST should always be a strict initial
-   substring of IMPORT_SRC. These form a linked list; NEXT is the next element
-   of the list.  */
+   namespace IMPORT_DEST. These form a linked list; NEXT is the next element
+   of the list. ALIAS is set to a non empty string if the imported namespace
+   has been aliased.
+   Eg:
+       namespace C=A::B;
+*/
  
  struct using_direct
  {
    char *import_src;
    char *import_dest;
+
+  char *alias;
+
    struct using_direct *next;
  
    /* Used during import search to temporarily mark this node as searched.  */
@@ -82,10 +88,12 @@ extern int cp_validate_operator (const char *input);
  extern int cp_is_anonymous (const char *namespace);
  
  extern void cp_add_using_directive (const char *dest,
-                                    const char *src);
+                                    const char *src,
+                                    const char *alias);
  
  extern struct using_direct *cp_add_using (const char *dest,
                                            const char *src,
+                                          const char *alias,
  					  struct using_direct *next);
  
  extern void cp_initialize_namespace (void);
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 2f671ca..ae089eb 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -3385,6 +3385,8 @@ read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
    struct dwarf2_cu *imported_cu;
    const char *imported_name;
    const char *imported_name_prefix;
+  char *import_alias;
+
    const char *import_prefix;
    char *canonical_name;
  
@@ -3436,7 +3438,12 @@ read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
        return;
      }
  
-  /* FIXME: dwarf2_name (die); for the local name after import.  */
+  /* Figure out the local name after import.  */
+  import_alias = dwarf2_name (die, cu);
+  if (import_alias == NULL)
+    {
+    import_alias = "";
+    }
  
    /* Figure out where the statement is being imported to.  */
    import_prefix = determine_prefix (die, cu);
@@ -3447,7 +3454,8 @@ read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
  
    if (strlen (imported_name_prefix) > 0)
      {
-      canonical_name = alloca (strlen (imported_name_prefix) + 2 + strlen (imported_name) + 1);
+      canonical_name = alloca (strlen (imported_name_prefix)
+                               + 2 + strlen (imported_name) + 1);
        strcpy (canonical_name, imported_name_prefix);
        strcat (canonical_name, "::");
        strcat (canonical_name, imported_name);
@@ -3458,7 +3466,10 @@ read_import_statement (struct die_info *die, struct dwarf2_cu *cu)
        strcpy (canonical_name, imported_name);
      }
  
-  using_directives = cp_add_using (import_prefix,canonical_name, using_directives);
+  using_directives = cp_add_using (import_prefix,
+                                   canonical_name,
+                                   import_alias,
+                                   using_directives);
  }
  
  static void
@@ -5616,7 +5627,7 @@ read_namespace (struct die_info *die, struct dwarf2_cu *cu)
        if (is_anonymous)
  	{
  	  const char *previous_prefix = determine_prefix (die, cu);
-	  cp_add_using_directive (previous_prefix, TYPE_NAME (type));
+	  cp_add_using_directive (previous_prefix, TYPE_NAME (type), "");
  	}
      }
  
diff --git a/gdb/testsuite/gdb.cp/nsusing.exp b/gdb/testsuite/gdb.cp/nsusing.exp
index bd115c4..72a616e 100644
--- a/gdb/testsuite/gdb.cp/nsusing.exp
+++ b/gdb/testsuite/gdb.cp/nsusing.exp
@@ -116,14 +116,11 @@ if ![runto marker2] then {
      continue
  }
  
-setup_kfail "gdb/7935" "*-*-*"
  gdb_test "print B::_a" "= 1"
  
-setup_kfail "gdb/7935" "*-*-*"
  gdb_test "print _a" "No symbol \"_a\" in current context." \
      "print _a in namespace alias scope"
  
-setup_kfail "gdb/7935" "*-*-*"
  gdb_test "print x" "No symbol \"x\" in current context." \
      "print x in namespace alias scope"
  
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