Add support for unbuffered and zero sized Guile ports.

gdb/ChangeLog

	* NEWS: Mention support for unbuffered Guile memory ports.
	* scm-ports.c (ioscm_memory_port): Update comments on end, size.
	(ioscm_lseek_address): Improve overflow calculation.
	(gdbscm_memory_port_fill_input): Add assert.
	(gdbscm_memory_port_write): Handle unbuffered ports.
	Handle large writes identical to Guile's fport_write.
	(gdbscm_memory_port_seek): Fix seeking past end check.
	(gdbscm_memory_port_close): Handle closing unbuffered port.
	(ioscm_parse_mode_bits): Recognize "0" for unbuffered ports.
	(ioscm_init_memory_port): Handle unbuffered ports.
	(ioscm_reinit_memory_port): Ditto.
	(ioscm_init_memory_port): Update size calculation.
	(gdbscm_open_memory): Support zero sized ports.

gdb/testsuite/ChangeLog

	* gdb.guile/scm-ports.c: New file.
	* gdb.guile/scm-ports.exp: Add memory port tests.

gdb/doc/ChangeLog

	* guile.texi (Memory Ports in Guile): Document support for unbuffered
	memory ports.

2 files changed, 155 insertions, 3 deletions

diff --git a/gdb/testsuite/gdb.guile/scm-ports.c b/gdb/testsuite/gdb.guile/scm-ports.c
new file mode 100644
index 0000000..b92fefb
--- /dev/null
+++ b/gdb/testsuite/gdb.guile/scm-ports.c
@@ -0,0 +1,22 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2015 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see  <http://www.gnu.org/licenses/>.  */
+
+int
+main (void)
+{
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.guile/scm-ports.exp b/gdb/testsuite/gdb.guile/scm-ports.exp
index 099f5e6..420f183 100644
--- a/gdb/testsuite/gdb.guile/scm-ports.exp
+++ b/gdb/testsuite/gdb.guile/scm-ports.exp
@@ -18,20 +18,150 @@
 
 load_lib gdb-guile.exp
 
-# Start with a fresh gdb.
-gdb_exit
-gdb_start
+standard_testfile
+
+if { [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile}] } {
+    return
+}
 
 # Skip all tests if Guile scripting is not enabled.
 if { [skip_guile_tests] } { continue }
 
+if ![gdb_guile_runto_main] {
+   return
+}
+
 gdb_reinitialize_dir $srcdir/$subdir
 
 gdb_install_guile_utils
 gdb_install_guile_module
 
+gdb_scm_test_silent_cmd "guile (use-modules (rnrs io ports) (rnrs bytevectors))" \
+    "import (rnrs io ports) (rnrs bytevectors)"
+
 gdb_test "guile (print (stdio-port? 42))" "= #f"
 gdb_test "guile (print (stdio-port? (%make-void-port \"r\")))" "= #f"
 gdb_test "guile (print (stdio-port? (input-port)))" "= #t"
 gdb_test "guile (print (stdio-port? (output-port)))" "= #t"
 gdb_test "guile (print (stdio-port? (error-port)))" "= #t"
+
+# Test memory port open/close.
+
+proc test_port { mode } {
+    with_test_prefix "basic $mode tests" {
+	gdb_test_no_output "guile (define my-port (open-memory #:mode \"$mode\"))" \
+	    "create memory port"
+	gdb_test "guile (print (memory-port? my-port))" "= #t"
+	switch -glob $mode {
+	    "r+*" {
+		gdb_test "guile (print (input-port? my-port))" "= #t"
+		gdb_test "guile (print (output-port? my-port))" "= #t"
+	    }
+	    "r*" {
+		gdb_test "guile (print (input-port? my-port))" "= #t"
+		gdb_test "guile (print (output-port? my-port))" "= #f"
+	    }
+	    "w*" {
+		gdb_test "guile (print (input-port? my-port))" "= #f"
+		gdb_test "guile (print (output-port? my-port))" "= #t"
+	    }
+	    default {
+		error "bad test mode"
+	    }
+	}
+	gdb_test "guile (print (port-closed? my-port))" "= #f" \
+	    "test port-closed? before it's closed"
+	gdb_test "guile (print (close-port my-port))" "= #t"
+	gdb_test "guile (print (port-closed? my-port))" "= #t" \
+	    "test port-closed? after it's closed"
+    }
+}
+
+set port_variations { r w r+ rb wb r+b r0 w0 r+0 }
+foreach variation $port_variations {
+    test_port $variation
+}
+
+# Test read/write of memory ports.
+
+proc test_mem_port_rw { kind } {
+    if { "$kind" == "buffered" } {
+	set buffered 1
+    } else {
+	set buffered 0
+    }
+    with_test_prefix $kind {
+	if $buffered {
+	    set mode "r+"
+	} else {
+	    set mode "r+0"
+	}
+	gdb_test_no_output "guile (define rw-mem-port (open-memory #:mode \"$mode\"))" \
+	    "create r/w memory port"
+	gdb_test "guile (print rw-mem-port)" \
+	    "#<input-output: gdb:memory-port 0x0-0xf+>"
+	gdb_test_no_output "guile (define sp-reg (parse-and-eval \"\$sp\"))" \
+	    "get sp reg"
+	# Note: Only use $sp_reg for gdb_test result matching, don't use it in
+	# gdb commands.  Otherwise transcript.N becomes unusable.
+	set sp_reg [get_integer_valueof "\$sp" 0]
+	gdb_test_no_output "guile (define byte-at-sp (parse-and-eval \"*(char*) \$sp\"))" \
+	    "save current value at sp"
+	# Pass the result of parse-and-eval through value-fetch-lazy!,
+	# otherwise the value gets left as a lazy reference to memory, which
+	# when re-evaluated after we flush the write will yield the newly
+	# written value.  PR 18175
+	gdb_test_no_output "guile (value-fetch-lazy! byte-at-sp)" \
+	    "un-lazyify byte-at-sp"
+	gdb_test "guile (print (seek rw-mem-port (value->integer sp-reg) SEEK_SET))" \
+	    "= $sp_reg" \
+	    "seek to \$sp"
+	gdb_test_no_output "guile (define old-value (value->integer byte-at-sp))" \
+	    "define old-value"
+	gdb_test_no_output "guile (define new-value (logxor old-value 1))" \
+	    "define new-value"
+	gdb_test "guile (print (put-bytevector rw-mem-port (make-bytevector 1 new-value)))" \
+	    "= #<unspecified>"
+	if $buffered {
+	    # Value shouldn't be in memory yet.
+	    gdb_test "guile (print (value=? (parse-and-eval \"*(char*) \$sp\") byte-at-sp))" \
+		"= #t" \
+		"test byte at sp, before flush"
+	    gdb_test_no_output "guile (force-output rw-mem-port)" \
+		"flush port"
+	}
+	# Value should be in memory now.
+	gdb_test "guile (print (value=? (parse-and-eval \"*(char*) \$sp\") byte-at-sp))" \
+	    "= #f" \
+	    "test byte at sp, after flush"
+	# Restore the value for cleanliness sake, and to verify close-port
+	# flushes the buffer.
+	gdb_test "guile (print (seek rw-mem-port (value->integer sp-reg) SEEK_SET))" \
+	    "= $sp_reg" \
+	    "seek to \$sp for restore"
+	gdb_test "guile (print (put-bytevector rw-mem-port (make-bytevector 1 old-value)))" \
+	    "= #<unspecified>"
+	gdb_test "guile (print (close-port rw-mem-port))" \
+	    "= #t"
+	gdb_test "guile (print (value=? (parse-and-eval \"*(char*) \$sp\") byte-at-sp))" \
+	    "= #t" \
+	    "test byte at sp, after close"
+    }
+}
+
+test_mem_port_rw buffered
+test_mem_port_rw unbuffered
+
+# Test zero-length memory ports.
+
+gdb_test_no_output "guile (define zero-mem-port (open-memory #:start 0 #:size 0 #:mode \"r+\"))" \
+    "create zero length memory port"
+gdb_test "guile (print (read-char zero-mem-port))" \
+    "= #<eof>"
+gdb_test "guile (print (write-char #\\a zero-mem-port))" \
+    "ERROR: .*Out of range: writing beyond end of memory range.*Error while executing Scheme code."
+gdb_test "guile (print (get-bytevector-n zero-mem-port 0))" \
+    "= #vu8\\(\\)"
+gdb_test "guile (print (put-bytevector zero-mem-port (make-bytevector 0)))" \
+    "= #<unspecified>"
+gdb_test "guile (print (close-port zero-mem-port))" "= #t"