From: Eric Botcazou <ebotcazou@adacore.com>
Date: Tue, 6 Jul 2021 14:47:31 +0000 (+0200)
Subject: [Ada] Small optimization to DWARF 5 mode in System.Dwarf_Line
X-Git-Tag: releases/gcc-11.3.0~848
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a872ad6d709494ff3a8d340a60f466bb0e8154e3;p=thirdparty%2Fgcc.git

[Ada] Small optimization to DWARF 5 mode in System.Dwarf_Line

gcc/ada/

	* libgnat/s-dwalin.adb (To_File_Name): Fetch only the last string
	from the .debug_line_str section.
	(Symbolic_Address.Set_Result): Likewise.
---

diff --git a/gcc/ada/libgnat/s-dwalin.adb b/gcc/ada/libgnat/s-dwalin.adb
index 3fd6d1184e9b..b8e8c112dd7b 100644
--- a/gcc/ada/libgnat/s-dwalin.adb
+++ b/gcc/ada/libgnat/s-dwalin.adb
@@ -957,8 +957,10 @@ package body System.Dwarf_Lines is
 
                      when DW_FORM_line_strp =>
                         Read_Section_Offset (C.Lines, Off, C.Header.Is64);
-                        Seek (C.Line_Str, Off);
-                        Read_C_String (C.Line_Str, Buf);
+                        if J = File then
+                           Seek (C.Line_Str, Off);
+                           Read_C_String (C.Line_Str, Buf);
+                        end if;
 
                      when others =>
                         raise Dwarf_Error with "DWARF form not implemented";
@@ -1674,8 +1676,10 @@ package body System.Dwarf_Lines is
 
                         when DW_FORM_line_strp =>
                            Read_Section_Offset (C.Lines, Off, C.Header.Is64);
-                           Seek (C.Line_Str, Off);
-                           File_Name := Read_C_String (C.Line_Str);
+                           if J = Match.File then
+                              Seek (C.Line_Str, Off);
+                              File_Name := Read_C_String (C.Line_Str);
+                           end if;
 
                         when others =>
                            raise Dwarf_Error with "DWARF form not implemented";
@@ -1718,8 +1722,10 @@ package body System.Dwarf_Lines is
 
                         when DW_FORM_line_strp =>
                            Read_Section_Offset (C.Lines, Off, C.Header.Is64);
-                           Seek (C.Line_Str, Off);
-                           Dir_Name := Read_C_String (C.Line_Str);
+                           if J = Dir_Idx then
+                              Seek (C.Line_Str, Off);
+                              Dir_Name := Read_C_String (C.Line_Str);
+                           end if;
 
                         when others =>
                            raise Dwarf_Error with "DWARF form not implemented";