Ada import functions not in index

The cooked index does not currently contain entries for Ada import
functions.  This means that whether or not these are visible to
"break" depends on which CUs were previously expanded -- clearly a
bug.

This patch fixes the issue.  I think the comments in the patch explain
the fix reasonably well.

Perhaps one to-do item here is to change GNAT to use
DW_TAG_imported_declaration for these imports.  This may eventually
let us remove some of the current hacks.

This version includes a fix from Simon to initialize the new member.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32511
Acked-By: Simon Marchi <simon.marchi@efficios.com>

6 files changed, 43 insertions, 23 deletions

diff --git a/gdb/dwarf2/abbrev.c b/gdb/dwarf2/abbrev.c
index 5cfff69..e3c268e 100644
--- a/gdb/dwarf2/abbrev.c
+++ b/gdb/dwarf2/abbrev.c
@@ -108,6 +108,8 @@ abbrev_table::read (struct dwarf2_section_info *section,
       cur_abbrev->has_children = read_1_byte (abfd, abbrev_ptr);
       abbrev_ptr += 1;
 
+      cur_abbrev->maybe_ada_import = false;
+
       unsigned int size = 0;
       unsigned int sibling_offset = -1;
       bool is_csize = true;
@@ -242,7 +244,12 @@ abbrev_table::read (struct dwarf2_section_info *section,
 	}
       else if (has_hardcoded_declaration
 	       && (cur_abbrev->tag != DW_TAG_variable || !has_external))
-	cur_abbrev->interesting = false;
+	{
+	  cur_abbrev->interesting = false;
+	  if (cur_abbrev->tag == DW_TAG_subprogram && has_name
+	      && has_linkage_name)
+	    cur_abbrev->maybe_ada_import = true;
+	}
       else if (!tag_interesting_for_index (cur_abbrev->tag))
 	cur_abbrev->interesting = false;
       else
diff --git a/gdb/dwarf2/abbrev.h b/gdb/dwarf2/abbrev.h
index 6fc61b1..a36bb8c 100644
--- a/gdb/dwarf2/abbrev.h
+++ b/gdb/dwarf2/abbrev.h
@@ -51,6 +51,14 @@ struct abbrev_info
   /* True if the DIE has children.  */
   bool has_children;
   bool interesting;
+  /* In Ada, an imported subprogram DIE will be marked as a
+     declaration, but will have both a name and a linkage name.  This
+     declaration may be the only spot where that name is associated
+     with an object, so it has to show up in the index.  But, because
+     abbrevs are CU-independent, we can't check the language when
+     computing them and instead we keep a separate flag to indicate
+     that the scanner should check this DIE.  */
+  bool maybe_ada_import;
   unsigned short size_if_constant;
   unsigned short sibling_offset;
   /* Number of attributes.  */
diff --git a/gdb/dwarf2/cooked-indexer.c b/gdb/dwarf2/cooked-indexer.c
index d4557c45..ef88325 100644
--- a/gdb/dwarf2/cooked-indexer.c
+++ b/gdb/dwarf2/cooked-indexer.c
@@ -20,6 +20,7 @@
 #include "dwarf2/cooked-indexer.h"
 #include "dwarf2/cooked-index-worker.h"
 #include "dwarf2/error.h"
+#include "dwarf2/read.h"
 
 /* See cooked-indexer.h.  */
 
@@ -297,7 +298,7 @@ cooked_indexer::scan_attributes (dwarf2_per_cu *scanning_per_cu,
 	   || abbrev->tag == DW_TAG_namespace)
 	  && abbrev->has_children)
 	*flags |= IS_TYPE_DECLARATION;
-      else
+      else if (!is_ada_import_or_export (reader->cu (), *name, *linkage_name))
 	{
 	  *linkage_name = nullptr;
 	  *name = nullptr;
@@ -506,7 +507,8 @@ cooked_indexer::index_dies (cutu_reader *reader,
       /* If a DIE parent is a DW_TAG_subprogram, then the DIE is only
 	 interesting if it's a DW_TAG_subprogram or a DW_TAG_entry_point.  */
       bool die_interesting
-	= (abbrev->interesting
+	= ((abbrev->interesting
+	    || (m_language == language_ada && abbrev->maybe_ada_import))
 	   && (parent_entry == nullptr
 	       || parent_entry->tag != DW_TAG_subprogram
 	       || abbrev->tag == DW_TAG_subprogram
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index c76086f..69b1330 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -981,9 +981,6 @@ static void queue_comp_unit (dwarf2_per_cu *per_cu,
 
 static void process_queue (dwarf2_per_objfile *per_objfile);
 
-static bool is_ada_import_or_export (dwarf2_cu *cu, const char *name,
-				     const char *linkagename);
-
 /* Class, the destructor of which frees all allocated queue entries.  This
    will only have work to do if an error was thrown while processing the
    dwarf.  If no error was thrown then the queue entries should have all
@@ -15977,14 +15974,14 @@ add_ada_export_symbol (struct symbol *orig, const char *new_name,
   add_symbol_to_list (copy, list_to_add);
 }
 
-/* A helper function that decides if a given symbol is an Ada Pragma
-   Import or Pragma Export.  */
+/* See read.h.  */
 
-static bool
+bool
 is_ada_import_or_export (dwarf2_cu *cu, const char *name,
 			 const char *linkagename)
 {
   return (cu->lang () == language_ada
+	  && name != nullptr
 	  && linkagename != nullptr
 	  && !streq (name, linkagename)
 	  /* The following exclusions are necessary because symbols
diff --git a/gdb/dwarf2/read.h b/gdb/dwarf2/read.h
index b9be541..469e68a 100644
--- a/gdb/dwarf2/read.h
+++ b/gdb/dwarf2/read.h
@@ -1382,4 +1382,10 @@ extern struct dwarf2_section_info *get_debug_line_section
 extern void dwarf2_start_subfile (dwarf2_cu *cu, const file_entry &fe,
 				  const line_header &lh);
 
+/* A helper function that decides if a given symbol is an Ada Pragma
+   Import or Pragma Export.  */
+
+extern bool is_ada_import_or_export (dwarf2_cu *cu, const char *name,
+				     const char *linkagename);
+
 #endif /* GDB_DWARF2_READ_H */
diff --git a/gdb/testsuite/gdb.ada/import.exp b/gdb/testsuite/gdb.ada/import.exp
index ab3a1c9..51ce7fa 100644
--- a/gdb/testsuite/gdb.ada/import.exp
+++ b/gdb/testsuite/gdb.ada/import.exp
@@ -54,6 +54,9 @@ gdb_test "print pkg.imported_var_ada" " = 42"
 gdb_test "print pkg.exported_var_ada" " = 99"
 gdb_test "print exported_var_ada" " = 99"
 
+gdb_breakpoint "local_imported_func" message
+gdb_test "print copy" " = 42"
+
 # This passes with gcc 10 but fails with gcc 9.  With gcc 9, we have:
 #   <1><1659>: Abbrev Number: 4 (DW_TAG_subprogram)
 #      <165a>   DW_AT_external    : 1
@@ -76,19 +79,16 @@ gdb_test "print exported_var_ada" " = 99"
 # The fact that things start to work when adding the DW_AT_declaration is
 # consistent with what is described in commit ff9baa5f1c5, so xfail this
 # (without pinpointing it to a specific gcc PR or commit).
-if { [gcc_major_version] < 10 } {
-    setup_xfail *-*-*
-}
-gdb_breakpoint "pkg.imported_func_ada" message
-gdb_breakpoint "imported_func" message
-if { [gcc_major_version] < 10 } {
-    setup_xfail *-*-*
+foreach func {"pkg.imported_func_ada" "imported_func"} {
+    clean_restart $testfile
+    if { [gcc_major_version] < 10 } {
+	setup_xfail *-*-*
+    }
+    gdb_breakpoint $func message
 }
-gdb_breakpoint "imported_func_ada" message
 
-gdb_breakpoint "local_imported_func" message
-gdb_breakpoint "pkg.exported_func_ada" message
-gdb_breakpoint "exported_func_ada" message
-gdb_breakpoint "exported_func" message
-
-gdb_test "print copy" " = 42"
+foreach func {"imported_func_ada" "pkg.exported_func_ada" \
+		  "exported_func_ada" "exported_func"} {
+    clean_restart $testfile
+    gdb_breakpoint $func message
+}