[PATCH 2/2] Handle Windows drives in auto-load script paths

[Hannes Domani <ssbssa@yahoo.de>]

Fixes this testsuite fail on Windows:
FAIL: gdb.base/auto-load.exp: print $script_loaded

Converts the debugfile path from c:/dir/file to /c/dir/file, so it can be
appended to the auto-load path.

gdb/ChangeLog:

2020-05-29  Hannes Domani  <ssbssa@yahoo.de>

	* auto-load.c (auto_load_objfile_script_1): Convert drive part
	of debugfile path on Windows.

gdb/doc/ChangeLog:

2020-05-29  Hannes Domani  <ssbssa@yahoo.de>

	* gdb.texinfo: Document Windows drive conversion of
	'set auto-load scripts-directory'.
---
v2:
- Document Windows drive conversion of 'set auto-load scripts-directory'.
---
 gdb/auto-load.c     | 7 +++++++
 gdb/doc/gdb.texinfo | 4 ++++
 2 files changed, 11 insertions(+)

diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index 99bd96b971..88221d9f3d 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -784,6 +784,13 @@ auto_load_objfile_script_1 (struct objfile *objfile, const char *realname,
 					  "scripts-directory' path \"%s\".\n"),
 			    auto_load_dir);
 
+      /* Convert Windows debugfile path from c:/dir/file to /c/dir/file.  */
+      if (HAS_DRIVE_SPEC (debugfile))
+	{
+	  debugfile_holder = STRIP_DRIVE_SPEC (debugfile);
+	  filename = std::string("/") + debugfile[0] + debugfile_holder;
+	}
+
       for (const gdb::unique_xmalloc_ptr<char> &dir : vec)
 	{
 	  /* FILENAME is absolute, so we don't need a "/" here.  */
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 292fd4d14e..f31d7013b9 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -27266,6 +27266,10 @@ script in the specified extension language.
 
 If this file does not exist, then @value{GDBN} will look for
 @var{script-name} file in all of the directories as specified below.
+(On MS-Windows/MS-DOS, the drive letter of the executable's leading
+directories is converted to a one-letter subdirectory, i.e.@:
+@file{d:/usr/bin/} is converted to @file{/d/usr/bin/}, because Windows
+filesystems disallow colons in file names.)
 
 Note that loading of these files requires an accordingly configured
 @code{auto-load safe-path} (@pxref{Auto-loading safe path}).
-- 
2.26.2