Fix cache dir resolving on Windows

  From: Orgad Shaneh <orgads@gmail.com>

... when not running from MSYS environment, and HOME is not set.
---
 gdb/common/pathstuff.c | 584 +++++++++++++++++++++--------------------
 1 file changed, 294 insertions(+), 290 deletions(-)
  

Oops! I mixed UNIX/Windows, and that's the result.

Please ignore it. I'll post a new patch soon.

- Orgad


On Fri, Jun 7, 2019 at 9:21 AM <orgads@gmail.com> wrote:
>
> From: Orgad Shaneh <orgads@gmail.com>
>
> ... when not running from MSYS environment, and HOME is not set.
> ---
>  gdb/common/pathstuff.c | 584 +++++++++++++++++++++--------------------
>  1 file changed, 294 insertions(+), 290 deletions(-)
>
> diff --git a/gdb/common/pathstuff.c b/gdb/common/pathstuff.c
> index 2b1669a5b9..33fa5bbb4d 100644
> --- a/gdb/common/pathstuff.c
> +++ b/gdb/common/pathstuff.c
> @@ -1,290 +1,294 @@
> -/* Path manipulation routines for GDB and gdbserver.
> -
> -   Copyright (C) 1986-2019 Free Software Foundation, Inc.
> -
> -   This file is part of GDB.
> -
> -   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/>.  */
> -
> -#include "common-defs.h"
> -#include "pathstuff.h"
> -#include "host-defs.h"
> -#include "filenames.h"
> -#include "gdb_tilde_expand.h"
> -
> -#ifdef USE_WIN32API
> -#include <windows.h>
> -#endif
> -
> -/* See common/pathstuff.h.  */
> -
> -gdb::unique_xmalloc_ptr<char>
> -gdb_realpath (const char *filename)
> -{
> -/* On most hosts, we rely on canonicalize_file_name to compute
> -   the FILENAME's realpath.
> -
> -   But the situation is slightly more complex on Windows, due to some
> -   versions of GCC which were reported to generate paths where
> -   backlashes (the directory separator) were doubled.  For instance:
> -      c:\\some\\double\\slashes\\dir
> -   ... instead of ...
> -      c:\some\double\slashes\dir
> -   Those double-slashes were getting in the way when comparing paths,
> -   for instance when trying to insert a breakpoint as follow:
> -      (gdb) b c:/some/double/slashes/dir/foo.c:4
> -      No source file named c:/some/double/slashes/dir/foo.c:4.
> -      (gdb) b c:\some\double\slashes\dir\foo.c:4
> -      No source file named c:\some\double\slashes\dir\foo.c:4.
> -   To prevent this from happening, we need this function to always
> -   strip those extra backslashes.  While canonicalize_file_name does
> -   perform this simplification, it only works when the path is valid.
> -   Since the simplification would be useful even if the path is not
> -   valid (one can always set a breakpoint on a file, even if the file
> -   does not exist locally), we rely instead on GetFullPathName to
> -   perform the canonicalization.  */
> -
> -#if defined (_WIN32)
> -  {
> -    char buf[MAX_PATH];
> -    DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL);
> -
> -    /* The file system is case-insensitive but case-preserving.
> -       So it is important we do not lowercase the path.  Otherwise,
> -       we might not be able to display the original casing in a given
> -       path.  */
> -    if (len > 0 && len < MAX_PATH)
> -      return gdb::unique_xmalloc_ptr<char> (xstrdup (buf));
> -  }
> -#else
> -  {
> -    char *rp = canonicalize_file_name (filename);
> -
> -    if (rp != NULL)
> -      return gdb::unique_xmalloc_ptr<char> (rp);
> -  }
> -#endif
> -
> -  /* This system is a lost cause, just dup the buffer.  */
> -  return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -gdb::unique_xmalloc_ptr<char>
> -gdb_realpath_keepfile (const char *filename)
> -{
> -  const char *base_name = lbasename (filename);
> -  char *dir_name;
> -  char *result;
> -
> -  /* Extract the basename of filename, and return immediately
> -     a copy of filename if it does not contain any directory prefix.  */
> -  if (base_name == filename)
> -    return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
> -
> -  dir_name = (char *) alloca ((size_t) (base_name - filename + 2));
> -  /* Allocate enough space to store the dir_name + plus one extra
> -     character sometimes needed under Windows (see below), and
> -     then the closing \000 character.  */
> -  strncpy (dir_name, filename, base_name - filename);
> -  dir_name[base_name - filename] = '\000';
> -
> -#ifdef HAVE_DOS_BASED_FILE_SYSTEM
> -  /* We need to be careful when filename is of the form 'd:foo', which
> -     is equivalent of d:./foo, which is totally different from d:/foo.  */
> -  if (strlen (dir_name) == 2 && isalpha (dir_name[0]) && dir_name[1] == ':')
> -    {
> -      dir_name[2] = '.';
> -      dir_name[3] = '\000';
> -    }
> -#endif
> -
> -  /* Canonicalize the directory prefix, and build the resulting
> -     filename.  If the dirname realpath already contains an ending
> -     directory separator, avoid doubling it.  */
> -  gdb::unique_xmalloc_ptr<char> path_storage = gdb_realpath (dir_name);
> -  const char *real_path = path_storage.get ();
> -  if (IS_DIR_SEPARATOR (real_path[strlen (real_path) - 1]))
> -    result = concat (real_path, base_name, (char *) NULL);
> -  else
> -    result = concat (real_path, SLASH_STRING, base_name, (char *) NULL);
> -
> -  return gdb::unique_xmalloc_ptr<char> (result);
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -gdb::unique_xmalloc_ptr<char>
> -gdb_abspath (const char *path)
> -{
> -  gdb_assert (path != NULL && path[0] != '\0');
> -
> -  if (path[0] == '~')
> -    return gdb_tilde_expand_up (path);
> -
> -  if (IS_ABSOLUTE_PATH (path))
> -    return gdb::unique_xmalloc_ptr<char> (xstrdup (path));
> -
> -  /* Beware the // my son, the Emacs barfs, the botch that catch...  */
> -  return gdb::unique_xmalloc_ptr<char>
> -    (concat (current_directory,
> -            IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
> -            ? "" : SLASH_STRING,
> -            path, (char *) NULL));
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -const char *
> -child_path (const char *parent, const char *child)
> -{
> -  /* The child path must start with the parent path.  */
> -  size_t parent_len = strlen (parent);
> -  if (filename_ncmp (parent, child, parent_len) != 0)
> -    return NULL;
> -
> -  /* The parent path must be a directory and the child must contain at
> -     least one component underneath the parent.  */
> -  const char *child_component;
> -  if (IS_DIR_SEPARATOR (parent[parent_len - 1]))
> -    {
> -      /* The parent path ends in a directory separator, so it is a
> -        directory.  The first child component starts after the common
> -        prefix.  */
> -      child_component = child + parent_len;
> -    }
> -  else
> -    {
> -      /* The parent path does not end in a directory separator.  The
> -        first character in the child after the common prefix must be
> -        a directory separator.
> -
> -        Note that CHILD must hold at least parent_len characters for
> -        filename_ncmp to return zero.  If the character at parent_len
> -        is nul due to CHILD containing the same path as PARENT, the
> -        IS_DIR_SEPARATOR check will fail here.  */
> -      if (!IS_DIR_SEPARATOR (child[parent_len]))
> -       return NULL;
> -
> -      /* The first child component starts after the separator after the
> -        common prefix.  */
> -      child_component = child + parent_len + 1;
> -    }
> -
> -  /* The child must contain at least one non-separator character after
> -     the parent.  */
> -  while (*child_component != '\0')
> -    {
> -      if (!IS_DIR_SEPARATOR (*child_component))
> -       return child_component;
> -
> -      child_component++;
> -    }
> -  return NULL;
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -bool
> -contains_dir_separator (const char *path)
> -{
> -  for (; *path != '\0'; path++)
> -    {
> -      if (IS_DIR_SEPARATOR (*path))
> -       return true;
> -    }
> -
> -  return false;
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -std::string
> -get_standard_cache_dir ()
> -{
> -#ifdef __APPLE__
> -#define HOME_CACHE_DIR "Library/Caches"
> -#else
> -#define HOME_CACHE_DIR ".cache"
> -#endif
> -
> -#ifndef __APPLE__
> -  const char *xdg_cache_home = getenv ("XDG_CACHE_HOME");
> -  if (xdg_cache_home != NULL)
> -    {
> -      /* Make sure the path is absolute and tilde-expanded.  */
> -      gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (xdg_cache_home));
> -      return string_printf ("%s/gdb", abs.get ());
> -    }
> -#endif
> -
> -  const char *home = getenv ("HOME");
> -  if (home != NULL)
> -    {
> -      /* Make sure the path is absolute and tilde-expanded.  */
> -      gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (home));
> -      return string_printf ("%s/" HOME_CACHE_DIR "/gdb", abs.get ());
> -    }
> -
> -  return {};
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -std::string
> -get_standard_temp_dir ()
> -{
> -#ifdef WIN32
> -  const char *tmp = getenv ("TMP");
> -  if (tmp != nullptr)
> -    return tmp;
> -
> -  tmp = getenv ("TEMP");
> -  if (tmp != nullptr)
> -    return tmp;
> -
> -  error (_("Couldn't find temp dir path, both TMP and TEMP are unset."));
> -
> -#else
> -  const char *tmp = getenv ("TMPDIR");
> -  if (tmp != nullptr)
> -    return tmp;
> -
> -  return "/tmp";
> -#endif
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -const char *
> -get_shell ()
> -{
> -  const char *ret = getenv ("SHELL");
> -  if (ret == NULL)
> -    ret = "/bin/sh";
> -
> -  return ret;
> -}
> -
> -/* See common/pathstuff.h.  */
> -
> -gdb::char_vector
> -make_temp_filename (const std::string &f)
> -{
> -  gdb::char_vector filename_temp (f.length () + 8);
> -  strcpy (filename_temp.data (), f.c_str ());
> -  strcat (filename_temp.data () + f.size (), "-XXXXXX");
> -  return filename_temp;
> -}
> +/* Path manipulation routines for GDB and gdbserver.
> +
> +   Copyright (C) 1986-2019 Free Software Foundation, Inc.
> +
> +   This file is part of GDB.
> +
> +   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/>.  */
> +
> +#include "common-defs.h"
> +#include "pathstuff.h"
> +#include "host-defs.h"
> +#include "filenames.h"
> +#include "gdb_tilde_expand.h"
> +
> +#ifdef USE_WIN32API
> +#include <windows.h>
> +#endif
> +
> +/* See common/pathstuff.h.  */
> +
> +gdb::unique_xmalloc_ptr<char>
> +gdb_realpath (const char *filename)
> +{
> +/* On most hosts, we rely on canonicalize_file_name to compute
> +   the FILENAME's realpath.
> +
> +   But the situation is slightly more complex on Windows, due to some
> +   versions of GCC which were reported to generate paths where
> +   backlashes (the directory separator) were doubled.  For instance:
> +      c:\\some\\double\\slashes\\dir
> +   ... instead of ...
> +      c:\some\double\slashes\dir
> +   Those double-slashes were getting in the way when comparing paths,
> +   for instance when trying to insert a breakpoint as follow:
> +      (gdb) b c:/some/double/slashes/dir/foo.c:4
> +      No source file named c:/some/double/slashes/dir/foo.c:4.
> +      (gdb) b c:\some\double\slashes\dir\foo.c:4
> +      No source file named c:\some\double\slashes\dir\foo.c:4.
> +   To prevent this from happening, we need this function to always
> +   strip those extra backslashes.  While canonicalize_file_name does
> +   perform this simplification, it only works when the path is valid.
> +   Since the simplification would be useful even if the path is not
> +   valid (one can always set a breakpoint on a file, even if the file
> +   does not exist locally), we rely instead on GetFullPathName to
> +   perform the canonicalization.  */
> +
> +#if defined (_WIN32)
> +  {
> +    char buf[MAX_PATH];
> +    DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL);
> +
> +    /* The file system is case-insensitive but case-preserving.
> +       So it is important we do not lowercase the path.  Otherwise,
> +       we might not be able to display the original casing in a given
> +       path.  */
> +    if (len > 0 && len < MAX_PATH)
> +      return gdb::unique_xmalloc_ptr<char> (xstrdup (buf));
> +  }
> +#else
> +  {
> +    char *rp = canonicalize_file_name (filename);
> +
> +    if (rp != NULL)
> +      return gdb::unique_xmalloc_ptr<char> (rp);
> +  }
> +#endif
> +
> +  /* This system is a lost cause, just dup the buffer.  */
> +  return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +gdb::unique_xmalloc_ptr<char>
> +gdb_realpath_keepfile (const char *filename)
> +{
> +  const char *base_name = lbasename (filename);
> +  char *dir_name;
> +  char *result;
> +
> +  /* Extract the basename of filename, and return immediately
> +     a copy of filename if it does not contain any directory prefix.  */
> +  if (base_name == filename)
> +    return gdb::unique_xmalloc_ptr<char> (xstrdup (filename));
> +
> +  dir_name = (char *) alloca ((size_t) (base_name - filename + 2));
> +  /* Allocate enough space to store the dir_name + plus one extra
> +     character sometimes needed under Windows (see below), and
> +     then the closing \000 character.  */
> +  strncpy (dir_name, filename, base_name - filename);
> +  dir_name[base_name - filename] = '\000';
> +
> +#ifdef HAVE_DOS_BASED_FILE_SYSTEM
> +  /* We need to be careful when filename is of the form 'd:foo', which
> +     is equivalent of d:./foo, which is totally different from d:/foo.  */
> +  if (strlen (dir_name) == 2 && isalpha (dir_name[0]) && dir_name[1] == ':')
> +    {
> +      dir_name[2] = '.';
> +      dir_name[3] = '\000';
> +    }
> +#endif
> +
> +  /* Canonicalize the directory prefix, and build the resulting
> +     filename.  If the dirname realpath already contains an ending
> +     directory separator, avoid doubling it.  */
> +  gdb::unique_xmalloc_ptr<char> path_storage = gdb_realpath (dir_name);
> +  const char *real_path = path_storage.get ();
> +  if (IS_DIR_SEPARATOR (real_path[strlen (real_path) - 1]))
> +    result = concat (real_path, base_name, (char *) NULL);
> +  else
> +    result = concat (real_path, SLASH_STRING, base_name, (char *) NULL);
> +
> +  return gdb::unique_xmalloc_ptr<char> (result);
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +gdb::unique_xmalloc_ptr<char>
> +gdb_abspath (const char *path)
> +{
> +  gdb_assert (path != NULL && path[0] != '\0');
> +
> +  if (path[0] == '~')
> +    return gdb_tilde_expand_up (path);
> +
> +  if (IS_ABSOLUTE_PATH (path))
> +    return gdb::unique_xmalloc_ptr<char> (xstrdup (path));
> +
> +  /* Beware the // my son, the Emacs barfs, the botch that catch...  */
> +  return gdb::unique_xmalloc_ptr<char>
> +    (concat (current_directory,
> +            IS_DIR_SEPARATOR (current_directory[strlen (current_directory) - 1])
> +            ? "" : SLASH_STRING,
> +            path, (char *) NULL));
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +const char *
> +child_path (const char *parent, const char *child)
> +{
> +  /* The child path must start with the parent path.  */
> +  size_t parent_len = strlen (parent);
> +  if (filename_ncmp (parent, child, parent_len) != 0)
> +    return NULL;
> +
> +  /* The parent path must be a directory and the child must contain at
> +     least one component underneath the parent.  */
> +  const char *child_component;
> +  if (IS_DIR_SEPARATOR (parent[parent_len - 1]))
> +    {
> +      /* The parent path ends in a directory separator, so it is a
> +        directory.  The first child component starts after the common
> +        prefix.  */
> +      child_component = child + parent_len;
> +    }
> +  else
> +    {
> +      /* The parent path does not end in a directory separator.  The
> +        first character in the child after the common prefix must be
> +        a directory separator.
> +
> +        Note that CHILD must hold at least parent_len characters for
> +        filename_ncmp to return zero.  If the character at parent_len
> +        is nul due to CHILD containing the same path as PARENT, the
> +        IS_DIR_SEPARATOR check will fail here.  */
> +      if (!IS_DIR_SEPARATOR (child[parent_len]))
> +       return NULL;
> +
> +      /* The first child component starts after the separator after the
> +        common prefix.  */
> +      child_component = child + parent_len + 1;
> +    }
> +
> +  /* The child must contain at least one non-separator character after
> +     the parent.  */
> +  while (*child_component != '\0')
> +    {
> +      if (!IS_DIR_SEPARATOR (*child_component))
> +       return child_component;
> +
> +      child_component++;
> +    }
> +  return NULL;
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +bool
> +contains_dir_separator (const char *path)
> +{
> +  for (; *path != '\0'; path++)
> +    {
> +      if (IS_DIR_SEPARATOR (*path))
> +       return true;
> +    }
> +
> +  return false;
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +std::string
> +get_standard_cache_dir ()
> +{
> +#ifdef __APPLE__
> +#define HOME_CACHE_DIR "Library/Caches"
> +#else
> +#define HOME_CACHE_DIR ".cache"
> +#endif
> +
> +#ifndef __APPLE__
> +  const char *xdg_cache_home = getenv ("XDG_CACHE_HOME");
> +  if (xdg_cache_home != NULL)
> +    {
> +      /* Make sure the path is absolute and tilde-expanded.  */
> +      gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (xdg_cache_home));
> +      return string_printf ("%s/gdb", abs.get ());
> +    }
> +#endif
> +
> +  const char *home = getenv ("HOME");
> +#ifdef _WIN32
> +  if (home == nullptr)
> +      home = getenv ("APPDATA");
> +#endif
> +  if (home != NULL)
> +    {
> +      /* Make sure the path is absolute and tilde-expanded.  */
> +      gdb::unique_xmalloc_ptr<char> abs (gdb_abspath (home));
> +      return string_printf ("%s/" HOME_CACHE_DIR "/gdb", abs.get ());
> +    }
> +
> +  return {};
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +std::string
> +get_standard_temp_dir ()
> +{
> +#ifdef WIN32
> +  const char *tmp = getenv ("TMP");
> +  if (tmp != nullptr)
> +    return tmp;
> +
> +  tmp = getenv ("TEMP");
> +  if (tmp != nullptr)
> +    return tmp;
> +
> +  error (_("Couldn't find temp dir path, both TMP and TEMP are unset."));
> +
> +#else
> +  const char *tmp = getenv ("TMPDIR");
> +  if (tmp != nullptr)
> +    return tmp;
> +
> +  return "/tmp";
> +#endif
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +const char *
> +get_shell ()
> +{
> +  const char *ret = getenv ("SHELL");
> +  if (ret == NULL)
> +    ret = "/bin/sh";
> +
> +  return ret;
> +}
> +
> +/* See common/pathstuff.h.  */
> +
> +gdb::char_vector
> +make_temp_filename (const std::string &f)
> +{
> +  gdb::char_vector filename_temp (f.length () + 8);
> +  strcpy (filename_temp.data (), f.c_str ());
> +  strcat (filename_temp.data () + f.size (), "-XXXXXX");
> +  return filename_temp;
> +}
> --
> 2.20.1
>
  

> From: orgads@gmail.com
> Cc: Orgad Shaneh <orgads@gmail.com>
> Date: Fri,  7 Jun 2019 09:20:49 +0300
> 
> From: Orgad Shaneh <orgads@gmail.com>
> 
> ... when not running from MSYS environment, and HOME is not set.
> ---
>  gdb/common/pathstuff.c | 584 +++++++++++++++++++++--------------------
>  1 file changed, 294 insertions(+), 290 deletions(-)

Something's wrong with this patch: you delete all the lines and then
add them, plus 4 more.  I suspect some snafu with EOL format, which
caused Git to decide that every line was different.  Please
double-check.

Thanks.