dwarf2read: replace gdb::optional<bool> with enum

gdb::optional<bool> is dangerous, because it's easy to do:

  if (opt_bool)

when you actually meant

  if (*opt_bool)

or vice-versa.  The first checks if the optional is set, the second
checks if the wrapped bool is true.

Replace it with an enum that explicitly defines the three possible
states.

gdb/ChangeLog:

	* dwarf2read.c (dw2_debug_names_iterator::next): Use enum to
	represent whether the symbol is static, dynamic, or we don't
	know.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index cbb8334..5f64ca6 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2019-08-25  Simon Marchi  <simon.marchi@efficios.com>
+
+       * dwarf2read.c (dw2_debug_names_iterator::next): Use enum to
+       represent whether the symbol is static, dynamic, or we don't
+       know.
+
 2019-08-25  Yoshinori Sato <ysato@users.sourceforge.jp>
 
         * gdb/rx-tdep.c (rx_register_names): New.

diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index de9755f..a0b989f 100644 (file)
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -5843,7 +5843,11 @@ dw2_debug_names_iterator::next ()
       return NULL;
     }
   const mapped_debug_names::index_val &indexval = indexval_it->second;
-  gdb::optional<bool> is_static;
+  enum class symbol_linkage {
+    unknown,
+    static_,
+    extern_,
+  } symbol_linkage = symbol_linkage::unknown;
   dwarf2_per_cu_data *per_cu = NULL;
   for (const mapped_debug_names::index_val::attr &attr : indexval.attr_vec)
     {
@@ -5895,12 +5899,12 @@ dw2_debug_names_iterator::next ()
        case DW_IDX_GNU_internal:
          if (!m_map.augmentation_is_gdb)
            break;
-         is_static = true;
+         symbol_linkage = symbol_linkage::static_;
          break;
        case DW_IDX_GNU_external:
          if (!m_map.augmentation_is_gdb)
            break;
-         is_static = false;
+         symbol_linkage = symbol_linkage::extern_;
          break;
        }
     }
@@ -5910,10 +5914,11 @@ dw2_debug_names_iterator::next ()
     goto again;
 
   /* Check static vs global.  */
-  if (is_static.has_value () && m_block_index.has_value ())
+  if (symbol_linkage != symbol_linkage::unknown && m_block_index.has_value ())
     {
        const bool want_static = *m_block_index == STATIC_BLOCK;
-       if (want_static != *is_static)
+       const bool symbol_is_static = symbol_linkage == symbol_linkage::static_;
+       if (want_static != symbol_is_static)
          goto again;
     }