gdbserver: handle newlines in inferior arguments

Similarly to how single quotes were mishandled, which was fixed two
commits ago, this commit fixes handling of newlines in arguments
passed to gdbserver.

We already had a test that covered this, gdb.base/args.exp, which,
when run with the native-extended-gdbserver board contained several
KFAIL covering this situation.

In this commit I remove the unnecessary, attempt to quote incoming
newlines within arguments, and do some minimal cleanup of the related
code.  There is additional cleanup that can be done, but I'm leaving
that for the next commit.

Then I've removed the KFAIL from the test case, and performed some
minimal cleanup there too.

After this commit the gdb.base/args.exp is 100% passing with the
native-extended-gdbserver board file.

During review I was pointed to this older series:

  https://inbox.sourceware.org/gdb-patches/20211022071933.3478427-1-m.weghorn@posteo.de/

which also includes this fix as part of a larger set of changes.  I'm
giving a Co-Authored-By credit to the author of that original series.
I believe this smaller fix brings some benefits on its own, though the
original series does offer additional improvements.  Once this is
merged I'll take a look at rebasing and resubmitting the original series.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=27989

Co-Authored-By: Michael Weghorn <m.weghorn@posteo.de>
Approved-By: Tom Tromey <tom@tromey.com>

2 files changed, 5 insertions, 32 deletions

diff --git a/gdb/testsuite/gdb.base/args.exp b/gdb/testsuite/gdb.base/args.exp
index 092b44b..0e2dc8b 100644
--- a/gdb/testsuite/gdb.base/args.exp
+++ b/gdb/testsuite/gdb.base/args.exp
@@ -30,10 +30,10 @@ if {[build_executable $testfile.exp $testfile \
     return -1
 }
 
-# If SINGLE_QUOTES_NEWLINE_KFAIL true, arguments made of exactly '' or a
-# newline character will fail, so kfail those tests.
+# NAME is the name to use for the tests and ARGLIST is the list of
+# expected arguments.
 
-proc args_test { name arglist {single_quotes_newline_kfail false}} {
+proc args_test { name arglist } {
     global srcdir
     global subdir
     global testfile
@@ -51,10 +51,6 @@ proc args_test { name arglist {single_quotes_newline_kfail false}} {
 
     set i 1
     foreach arg $arglist {
-	if { $single_quotes_newline_kfail
-	     && ($arg == {''} || $arg == {\\n}) } {
-	    setup_kfail "gdb/27989" "*-*-*"
-	}
 	gdb_test "print argv\[$i\]" "\\\$$decimal = $hex \"$arg\"" \
 	    "argv\[$i\] for $name"
 	set i [expr $i + 1]
@@ -68,12 +64,6 @@ proc args_test { name arglist {single_quotes_newline_kfail false}} {
 save_vars { GDBFLAGS } {
     set old_gdbflags $GDBFLAGS
 
-    # Single quotes and newlines are not well handled by the extended-remote
-    # target:  https://sourceware.org/bugzilla/show_bug.cgi?id=27989
-    set single_quotes_newline_kfail \
-	[expr { [target_info exists gdb_protocol] \
-	        && [target_info gdb_protocol] == "extended-remote" }]
-
     set GDBFLAGS "$old_gdbflags --args $binfile 1 3"
     args_test basic {{1} {3}}
 
@@ -102,8 +92,8 @@ save_vars { GDBFLAGS } {
     # try with arguments containing literal newlines.
 
     set GDBFLAGS "$old_gdbflags --args $binfile 1 {\n} 3"
-    args_test "one newline" {{1} {\\n} {3}} $single_quotes_newline_kfail
+    args_test "one newline" {{1} {\\n} {3}}
 
     set GDBFLAGS "$old_gdbflags --args $binfile 1 {\n} {\n} 3"
-    args_test "two newlines" {{1} {\\n} {\\n} {3}} $single_quotes_newline_kfail
+    args_test "two newlines" {{1} {\\n} {\\n} {3}}
 }
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index d78eb5a..84b8712 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -2997,34 +2997,17 @@ handle_v_run (char *own_buf)
 	  /* These are pointers used to navigate the strings above.  */
 	  char *tmp_arg = arg;
 	  char *tmp_full_arg = full_arg;
-	  int need_quote = 0;
 
 	  hex2bin (p, (gdb_byte *) arg, len);
 	  arg[len] = '\0';
 
 	  while (*tmp_arg != '\0')
 	    {
-	      switch (*tmp_arg)
-		{
-		case '\n':
-		  /* Quote \n.  */
-		  *tmp_full_arg = '\'';
-		  ++tmp_full_arg;
-		  need_quote = 1;
-		  break;
-
-		default:
-		  break;
-		}
-
 	      *tmp_full_arg = *tmp_arg;
 	      ++tmp_full_arg;
 	      ++tmp_arg;
 	    }
 
-	  if (need_quote)
-	    *tmp_full_arg++ = '\'';
-
 	  /* Finish FULL_ARG and push it into the vector containing
 	     the argv.  */
 	  *tmp_full_arg = '\0';