[binutils-gdb] gas: improve interaction between read_a_source_file() and s_linefile()

[binutils-gdb] gas: improve interaction between read_a_source_file() and s_linefile()

[Jan Beulich]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=7545aa2dd2eb85a852f978dc0d93b3deb6f52536

commit 7545aa2dd2eb85a852f978dc0d93b3deb6f52536
Author: Jan Beulich <jbeulich@suse.com>
Date:   Tue Feb 14 08:34:03 2023 +0100

    gas: improve interaction between read_a_source_file() and s_linefile()
    
    read_a_source_file() would bump line numbers only when seeing a newline,
    whereas is_end_of_line[] indicates further end-of-line characters, in
    particular the nul character. s_linefile() attempts to compensate for
    the bump, but was too aggressive with this so far: It should only adjust
    when a newline ends the line. To facilitate such a check, the check for
    nothing else on the line needs to move ahead, which luckily is easily
    possible: The relevant two conditions match, and the function can
    simply return from the body of that earlier instance of the conditional.
    
    The more strict treatment in s_linefile() then requires an adjustment
    to buffer_and_nest()'s invocation of the function: The line terminator
    now needs to be a newline, not nul.

Diff:
---
 gas/macro.c |  2 +-
 gas/read.c  | 14 +++++++++-----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/gas/macro.c b/gas/macro.c
index 763bafbdc3d..f9f2d63e9f7 100644
--- a/gas/macro.c
+++ b/gas/macro.c
@@ -265,7 +265,7 @@ buffer_and_nest (const char *from, const char *to, sb *ptr,
 	    {
 	      char saved_eol_char = ptr->ptr[ptr->len];
 
-	      ptr->ptr[ptr->len] = '\0';
+	      ptr->ptr[ptr->len] = '\n';
 	      temp_ilp (ptr->ptr + i + 8);
 	      s_linefile (0);
 	      restore_ilp ();
diff --git a/gas/read.c b/gas/read.c
index 9f6a7007ebf..f1099cba1a3 100644
--- a/gas/read.c
+++ b/gas/read.c
@@ -2049,18 +2049,22 @@ s_linefile (int ignore ATTRIBUTE_UNUSED)
 
       if (file || flags)
 	{
-	  linenum--;
+	  demand_empty_rest_of_line ();
+
+	  /* read_a_source_file() will bump the line number only if the line
+	     is terminated by '\n'.  */
+	  if (input_line_pointer[-1] == '\n')
+	    linenum--;
+
 	  new_logical_line_flags (file, linenum, flags);
 #ifdef LISTING
 	  if (listing)
 	    listing_source_line (linenum);
 #endif
+	  return;
 	}
     }
-  if (file || flags)
-    demand_empty_rest_of_line ();
-  else
-    ignore_rest_of_line ();
+  ignore_rest_of_line ();
 }
 
 /* Handle the .end pseudo-op.  Actually, the real work is done in