[COMMITTED] ada: Pass Error_Node to calls to Error_Msg in lib-load.adb

[COMMITTED] ada: Pass Error_Node to calls to Error_Msg in lib-load.adb

[Marc Poulhiès]

From: Ghjuvan Lacambre <lacambre@adacore.com>

When not passing Error_Node, Error_Msg will treat Current_Node as the
node attached to the message. When this happens in lib-load.adb due to a
file that cannot be loaded, Current_Node might reference a node that
doesn't actually exist. This is a problem when using -gnatdJ and
-fdiagnostics-format, as in this case GNAT will attempt to retrieve
information from the node attached to the message and thus crash when
said node is invalid.

gcc/ada/

	* lib-load.adb (Load_Unit): Pass Error_Node to calls to Error_Msg.

Tested on x86_64-pc-linux-gnu, committed on master.

---
 gcc/ada/lib-load.adb | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/gcc/ada/lib-load.adb b/gcc/ada/lib-load.adb
index d79ee438243..72196b437f5 100644
--- a/gcc/ada/lib-load.adb
+++ b/gcc/ada/lib-load.adb
@@ -645,11 +645,16 @@ package body Lib.Load is
                   if Is_Predefined_File_Name (Fname) then
                      Error_Msg_Unit_1 := Uname_Actual;
                      Error_Msg
-                       ("$$ is not a language defined unit", Load_Msg_Sloc);
+                       ("$$ is not a language defined unit",
+                        Load_Msg_Sloc,
+                        Error_Node);
                   else
                      Error_Msg_File_1 := Fname;
                      Error_Msg_Unit_1 := Uname_Actual;
-                     Error_Msg ("file{ does not contain unit$", Load_Msg_Sloc);
+                     Error_Msg
+                       ("file{ does not contain unit$",
+                        Load_Msg_Sloc,
+                        Error_Node);
                   end if;
 
                   Write_Dependency_Chain;
@@ -697,7 +702,8 @@ package body Lib.Load is
             end if;
 
             if Present (Error_Node) then
-               Error_Msg ("circular unit dependency", Load_Msg_Sloc);
+               Error_Msg
+                 ("circular unit dependency", Load_Msg_Sloc, Error_Node);
                Write_Dependency_Chain;
             else
                Load_Stack.Decrement_Last;
@@ -798,11 +804,14 @@ package body Lib.Load is
             then
                Error_Msg_File_1 := Unit_File_Name (Corr_Body);
                Error_Msg
-                 ("cannot compile subprogram in file {!", Load_Msg_Sloc);
+                 ("cannot compile subprogram in file {!",
+                  Load_Msg_Sloc,
+                  Error_Node);
                Error_Msg_File_1 := Unit_File_Name (Unum);
                Error_Msg
                  ("\incorrect spec in file { must be removed first!",
-                  Load_Msg_Sloc);
+                  Load_Msg_Sloc,
+                  Error_Node);
                Unum := No_Unit;
                goto Done;
             end if;
@@ -879,15 +888,21 @@ package body Lib.Load is
 
                   Error_Msg_Unit_1 := Uname_Actual;
                   Error_Msg -- CODEFIX
-                    ("$$ is not a predefined library unit", Load_Msg_Sloc);
+                    ("$$ is not a predefined library unit",
+                     Load_Msg_Sloc,
+                     Error_Node);
 
                else
                   Error_Msg_File_1 := Fname;
 
                   if Src_Ind = No_Access_To_Source_File then
-                     Error_Msg ("no read access to file{", Load_Msg_Sloc);
+                     Error_Msg
+                       ("no read access to file{",
+                        Load_Msg_Sloc,
+                        Error_Node
+                        );
                   else
-                     Error_Msg ("file{ not found", Load_Msg_Sloc);
+                     Error_Msg ("file{ not found", Load_Msg_Sloc, Error_Node);
                   end if;
                end if;
 
-- 
2.40.0