[PATCH] Reimplement dwarf_unit_type_name

[Tom Tromey <tromey@adacore.com>]

I noticed that dwarf_unit_type_name is nearly identical to
get_DW_UT_name from libiberty; but rather than simply replacing it, it
seemed better to have it work like the other DWARF constant
stringification functions -- return a string showing unrecognized
numeric forms rather than nullptr.  (The previous code did include
numeric values for the recognized constants, but this seems to be not
that useful to me.)

gdb/ChangeLog
2021-03-18  Tom Tromey  <tromey@adacore.com>

	* dwarf2/stringify.c (dwarf_unit_type_name): New function.  Use
	get_DW_UT_name.
	* dwarf2/stringify.h (dwarf_unit_type_name): Declare.
	* dwarf2/comp-unit.c (dwarf_unit_type_name): Remove.
---
 gdb/ChangeLog          |  7 +++++++
 gdb/dwarf2/comp-unit.c | 29 +----------------------------
 gdb/dwarf2/stringify.c | 13 +++++++++++++
 gdb/dwarf2/stringify.h |  3 +++
 4 files changed, 24 insertions(+), 28 deletions(-)

diff --git a/gdb/dwarf2/comp-unit.c b/gdb/dwarf2/comp-unit.c
index 72b4e80d808..ce3b55778f4 100644
--- a/gdb/dwarf2/comp-unit.c
+++ b/gdb/dwarf2/comp-unit.c
@@ -29,34 +29,7 @@
 #include "dwarf2/leb.h"
 #include "dwarf2/read.h"
 #include "dwarf2/section.h"
-
-/* Convert a unit type to corresponding DW_UT name.  */
-
-static const char *
-dwarf_unit_type_name (int unit_type)
-{
-  switch (unit_type)
-    {
-      case 0x01:
-	return "DW_UT_compile (0x01)";
-      case 0x02:
-	return "DW_UT_type (0x02)";
-      case 0x03:
-	return "DW_UT_partial (0x03)";
-      case 0x04:
-	return "DW_UT_skeleton (0x04)";
-      case 0x05:
-	return "DW_UT_split_compile (0x05)";
-      case 0x06:
-	return "DW_UT_split_type (0x06)";
-      case 0x80:
-	return "DW_UT_lo_user (0x80)";
-      case 0xff:
-	return "DW_UT_hi_user (0xff)";
-      default:
-	return nullptr;
-    }
-}
+#include "dwarf2/stringify.h"
 
 /* See comp-unit.h.  */
 
diff --git a/gdb/dwarf2/stringify.c b/gdb/dwarf2/stringify.c
index 43e88f9043f..b292f9fccc8 100644
--- a/gdb/dwarf2/stringify.c
+++ b/gdb/dwarf2/stringify.c
@@ -112,3 +112,16 @@ dwarf_type_encoding_name (unsigned enc)
 
   return name;
 }
+
+/* See stringify.h.  */
+
+const char *
+dwarf_unit_type_name (int unit_type)
+{
+  const char *name = get_DW_UT_name (unit_type);
+
+  if (name == nullptr)
+    return dwarf_unknown ("UT", unit_type);
+
+  return name;
+}
diff --git a/gdb/dwarf2/stringify.h b/gdb/dwarf2/stringify.h
index ada4c1e77e7..d2139d91db9 100644
--- a/gdb/dwarf2/stringify.h
+++ b/gdb/dwarf2/stringify.h
@@ -35,4 +35,7 @@ extern const char *dwarf_bool_name (unsigned mybool);
 /* Convert a DWARF type code into its string name.  */
 extern const char *dwarf_type_encoding_name (unsigned enc);
 
+/* Convert a DWARF unit type into is string name.  */
+extern const char *dwarf_unit_type_name (int unit_type);
+
 #endif /* GDB_DWARF2_STRINGIFY_H */
-- 
2.26.2