Re: [PATCH] c++: Allow module name to be a single letter on Windows

2022-11-08 Thread Nathan Sidwell via Gcc-patches

On 11/8/22 05:18, Torbjorn SVENSSON wrote:

Hi Nathan,

On 2022-11-08 00:03, Nathan Sidwell wrote:




Yes, something like the above, but I think you're missing "/bob' in the 
DOS_BASED case?  shouldn't that also be a pathname?


if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.']) // ./FOO or /FOO
#if HAVE_DOS_BASED_FILE_SYSTEM
 // DOS-FS IS_ABSOLUTE_PATH thinks 'A:B' is absolute, but we need to 
consider
 // that as a module:partition.
 || (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2])) // A:/FOO
#endif
 || false)
    return 

Does (something like) that work?


I tested it and your solution appears to work.
Are you okay with me pushing that solution or do you want me to send a v2 with 
it first?


I think it needs a better introductory comment than the one I slapped in there. 
More explanation of the drive vs partition distinction.  Something along the 
lines of 'things that clearly start as pathnames are header-names, everything 
else is treated as a (possibly malformed) named module.


Feel free to just go with it, or iterate here

nathan

--
Nathan Sidwell



Re: [PATCH] c++: Allow module name to be a single letter on Windows

2022-11-08 Thread Torbjorn SVENSSON via Gcc-patches

Hi Nathan,

On 2022-11-08 00:03, Nathan Sidwell wrote:

On 11/3/22 11:06, Torbjorn SVENSSON wrote:



On 2022-11-03 15:17, Nathan Sidwell wrote:

On 10/28/22 05:15, Torbjörn SVENSSON wrote:

On Windows, the ':' character is special and when the module name is
a single character, like 'A', then the flatname would be (for
example) 'A:Foo'. On Windows, 'A:Foo' is treated as an absolute
path by the module loader and is likely not found.

Without this patch, the test case pr98944_c.C fails with:

In module imported at 
/src/gcc/testsuite/g++.dg/modules/pr98944_b.C:7:1,
of module A:Foo, imported at 
/src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:

A:Internals: error: header module expected, module 'A:Internals' found
A:Internals: error: failed to read compiled module: Bad file data
A:Internals: note: compiled module file is 'gcm.cache/A-Internals.gcm'
In module imported at 
/src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:8:

A:Foo: error: failed to read compiled module: Bad import dependency
A:Foo: note: compiled module file is 'gcm.cache/A-Foo.gcm'
A:Foo: fatal error: returning to the gate for a mechanical issue
compilation terminated.

include/ChangeLog:

* filenames.h: Added IS_REAL_ABSOLUTE_PATH macro to check if
path is absolute and not semi-absolute on Windows.


Hm, this is unfortunate.  The current IS_ABSOLUTE_PATH, is really 
'not relative to cwd', and even then that's untrue if the drive 
letter there is the drive letter of cwd, right?


It's awkward to have a new macro for just this purpose and the new 
name isn't very indicative of the difference to the current 
IS_ABSOLUTE_PATH.


Would it be better to not deal with drive letters here?  How 
prevalent are they these days in windows?  Would something like


    if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.'])

suffice?


I don't think you can ignore the drive letter part... see below.


#include 
#include "include/filenames.h"
#define TF(x) ((x) ? "true" : "false")
int main(int argc, char *argv[]) {
   const char *test[] = {
   /* absolute */  "c:\\foo", "c:/foo", "/foo", "\\foo",
   /* semi-absolute */ "c:foo",
   /* relative */  "foo", "./foo", ".\\foo",
   };
   for (int i = 0; i < sizeof(test) / sizeof(test[0]); i++) {
 const char *ptr = test[i];
 printf("\nptr: %s\n", ptr);
 printf("  IS_DOS_ABSOLUTE_PATH: %s\n",
    TF(IS_DOS_ABSOLUTE_PATH(ptr)));
 printf("  IS_DOS_REAL_ABSOLUTE_PATH: %s\n",
    TF(IS_DOS_REAL_ABSOLUTE_PATH(ptr)));
 printf("  IS_DIR_SEPARATOR: %s\n",
    TF(IS_DIR_SEPARATOR(ptr[ptr[0] == '.'])));
   }
   return 0;
}


The output is:

ptr: c:\foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: c:/foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: /foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: true

ptr: \foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: c:foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false

ptr: foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false

ptr: ./foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: true

ptr: .\foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false




or, failing that perhaps put some explicit WINDOWS-specific #ifdef'd 
code there?  It's a real corner case.


Would you rather have something like this in module.cc?

if (ptr[0] == '.')
   {
 if IS_DIR_SEPARATOR (ptr[1]))
   return get_module (build_string (strlen (ptr), ptr));
   }
else
   {
#if HAVE_DOS_BASED_FILE_SYSTEM
 if (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2]))
#else
 if (IS_ABSOLUTE_PATH (ptr))
#endif
   return get_module (build_string (strlen (ptr), ptr));
   }


Yes, something like the above, but I think you're missing "/bob' in the 
DOS_BASED case?  shouldn't that also be a pathname?


if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.']) // ./FOO or /FOO
#if HAVE_DOS_BASED_FILE_SYSTEM
     // DOS-FS IS_ABSOLUTE_PATH thinks 'A:B' is absolute, but we need to 
consider

     // that as a module:partition.
     || (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2])) // A:/FOO
#endif
     || false)
    return 

Does (something like) that work?


I tested it and your solution appears to work.
Are you okay with me pushing that solution or do you want me to send a 
v2 with it first?


Kind regards,
Torbjörn



nathan




Let me know what you prefer.

Kind regards,
Torbjörn



nathan



gcc/cp/ChangeLog:

* module.cc: Use IS_REAL_ABSOLUTE_PATH macro.

Co-Authored-By: Yvan ROUX 
Signed-off-by: Torbjörn SVENSSON 
---
  gcc/cp/module.cc    | 2 +-
  include/filenames.h | 4 
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 

Re: [PATCH] c++: Allow module name to be a single letter on Windows

2022-11-07 Thread Nathan Sidwell via Gcc-patches

On 11/3/22 11:06, Torbjorn SVENSSON wrote:



On 2022-11-03 15:17, Nathan Sidwell wrote:

On 10/28/22 05:15, Torbjörn SVENSSON wrote:

On Windows, the ':' character is special and when the module name is
a single character, like 'A', then the flatname would be (for
example) 'A:Foo'. On Windows, 'A:Foo' is treated as an absolute
path by the module loader and is likely not found.

Without this patch, the test case pr98944_c.C fails with:

In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_b.C:7:1,
of module A:Foo, imported at /src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:
A:Internals: error: header module expected, module 'A:Internals' found
A:Internals: error: failed to read compiled module: Bad file data
A:Internals: note: compiled module file is 'gcm.cache/A-Internals.gcm'
In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:8:
A:Foo: error: failed to read compiled module: Bad import dependency
A:Foo: note: compiled module file is 'gcm.cache/A-Foo.gcm'
A:Foo: fatal error: returning to the gate for a mechanical issue
compilation terminated.

include/ChangeLog:

* filenames.h: Added IS_REAL_ABSOLUTE_PATH macro to check if
path is absolute and not semi-absolute on Windows.


Hm, this is unfortunate.  The current IS_ABSOLUTE_PATH, is really 'not 
relative to cwd', and even then that's untrue if the drive letter there is the 
drive letter of cwd, right?


It's awkward to have a new macro for just this purpose and the new name isn't 
very indicative of the difference to the current IS_ABSOLUTE_PATH.


Would it be better to not deal with drive letters here?  How prevalent are 
they these days in windows?  Would something like


    if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.'])

suffice?


I don't think you can ignore the drive letter part... see below.


#include 
#include "include/filenames.h"
#define TF(x) ((x) ? "true" : "false")
int main(int argc, char *argv[]) {
   const char *test[] = {
   /* absolute */  "c:\\foo", "c:/foo", "/foo", "\\foo",
   /* semi-absolute */ "c:foo",
   /* relative */  "foo", "./foo", ".\\foo",
   };
   for (int i = 0; i < sizeof(test) / sizeof(test[0]); i++) {
     const char *ptr = test[i];
     printf("\nptr: %s\n", ptr);
     printf("  IS_DOS_ABSOLUTE_PATH: %s\n",
    TF(IS_DOS_ABSOLUTE_PATH(ptr)));
     printf("  IS_DOS_REAL_ABSOLUTE_PATH: %s\n",
    TF(IS_DOS_REAL_ABSOLUTE_PATH(ptr)));
     printf("  IS_DIR_SEPARATOR: %s\n",
    TF(IS_DIR_SEPARATOR(ptr[ptr[0] == '.'])));
   }
   return 0;
}


The output is:

ptr: c:\foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: c:/foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: /foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: true

ptr: \foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: true
   IS_DIR_SEPARATOR: false

ptr: c:foo
   IS_DOS_ABSOLUTE_PATH: true
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false

ptr: foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false

ptr: ./foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: true

ptr: .\foo
   IS_DOS_ABSOLUTE_PATH: false
   IS_DOS_REAL_ABSOLUTE_PATH: false
   IS_DIR_SEPARATOR: false




or, failing that perhaps put some explicit WINDOWS-specific #ifdef'd code 
there?  It's a real corner case.


Would you rather have something like this in module.cc?

if (ptr[0] == '.')
   {
     if IS_DIR_SEPARATOR (ptr[1]))
   return get_module (build_string (strlen (ptr), ptr));
   }
else
   {
#if HAVE_DOS_BASED_FILE_SYSTEM
     if (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2]))
#else
     if (IS_ABSOLUTE_PATH (ptr))
#endif
   return get_module (build_string (strlen (ptr), ptr));
   }


Yes, something like the above, but I think you're missing "/bob' in the 
DOS_BASED case?  shouldn't that also be a pathname?


if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.']) // ./FOO or /FOO
#if HAVE_DOS_BASED_FILE_SYSTEM
// DOS-FS IS_ABSOLUTE_PATH thinks 'A:B' is absolute, but we need to consider
// that as a module:partition.
|| (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2])) // A:/FOO
#endif
|| false)
   return 

Does (something like) that work?

nathan




Let me know what you prefer.

Kind regards,
Torbjörn



nathan



gcc/cp/ChangeLog:

* module.cc: Use IS_REAL_ABSOLUTE_PATH macro.

Co-Authored-By: Yvan ROUX 
Signed-off-by: Torbjörn SVENSSON 
---
  gcc/cp/module.cc    | 2 +-
  include/filenames.h | 4 
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 9957df510e6..84680e183b7 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -13958,7 +13958,7 @@ get_module (tree name, module_state *parent, bool 
partition)

  static module_state *
  get_module (const char *ptr)
  {
-  if (ptr[0] 

Re: [PATCH] c++: Allow module name to be a single letter on Windows

2022-11-03 Thread Torbjorn SVENSSON via Gcc-patches




On 2022-11-03 15:17, Nathan Sidwell wrote:

On 10/28/22 05:15, Torbjörn SVENSSON wrote:

On Windows, the ':' character is special and when the module name is
a single character, like 'A', then the flatname would be (for
example) 'A:Foo'. On Windows, 'A:Foo' is treated as an absolute
path by the module loader and is likely not found.

Without this patch, the test case pr98944_c.C fails with:

In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_b.C:7:1,
of module A:Foo, imported at 
/src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:

A:Internals: error: header module expected, module 'A:Internals' found
A:Internals: error: failed to read compiled module: Bad file data
A:Internals: note: compiled module file is 'gcm.cache/A-Internals.gcm'
In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:8:
A:Foo: error: failed to read compiled module: Bad import dependency
A:Foo: note: compiled module file is 'gcm.cache/A-Foo.gcm'
A:Foo: fatal error: returning to the gate for a mechanical issue
compilation terminated.

include/ChangeLog:

* filenames.h: Added IS_REAL_ABSOLUTE_PATH macro to check if
path is absolute and not semi-absolute on Windows.


Hm, this is unfortunate.  The current IS_ABSOLUTE_PATH, is really 'not 
relative to cwd', and even then that's untrue if the drive letter there 
is the drive letter of cwd, right?


It's awkward to have a new macro for just this purpose and the new name 
isn't very indicative of the difference to the current IS_ABSOLUTE_PATH.


Would it be better to not deal with drive letters here?  How prevalent 
are they these days in windows?  Would something like


    if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.'])

suffice?


I don't think you can ignore the drive letter part... see below.


#include 
#include "include/filenames.h"
#define TF(x) ((x) ? "true" : "false")
int main(int argc, char *argv[]) {
  const char *test[] = {
  /* absolute */  "c:\\foo", "c:/foo", "/foo", "\\foo",
  /* semi-absolute */ "c:foo",
  /* relative */  "foo", "./foo", ".\\foo",
  };
  for (int i = 0; i < sizeof(test) / sizeof(test[0]); i++) {
const char *ptr = test[i];
printf("\nptr: %s\n", ptr);
printf("  IS_DOS_ABSOLUTE_PATH: %s\n",
   TF(IS_DOS_ABSOLUTE_PATH(ptr)));
printf("  IS_DOS_REAL_ABSOLUTE_PATH: %s\n",
   TF(IS_DOS_REAL_ABSOLUTE_PATH(ptr)));
printf("  IS_DIR_SEPARATOR: %s\n",
   TF(IS_DIR_SEPARATOR(ptr[ptr[0] == '.'])));
  }
  return 0;
}


The output is:

ptr: c:\foo
  IS_DOS_ABSOLUTE_PATH: true
  IS_DOS_REAL_ABSOLUTE_PATH: true
  IS_DIR_SEPARATOR: false

ptr: c:/foo
  IS_DOS_ABSOLUTE_PATH: true
  IS_DOS_REAL_ABSOLUTE_PATH: true
  IS_DIR_SEPARATOR: false

ptr: /foo
  IS_DOS_ABSOLUTE_PATH: true
  IS_DOS_REAL_ABSOLUTE_PATH: true
  IS_DIR_SEPARATOR: true

ptr: \foo
  IS_DOS_ABSOLUTE_PATH: true
  IS_DOS_REAL_ABSOLUTE_PATH: true
  IS_DIR_SEPARATOR: false

ptr: c:foo
  IS_DOS_ABSOLUTE_PATH: true
  IS_DOS_REAL_ABSOLUTE_PATH: false
  IS_DIR_SEPARATOR: false

ptr: foo
  IS_DOS_ABSOLUTE_PATH: false
  IS_DOS_REAL_ABSOLUTE_PATH: false
  IS_DIR_SEPARATOR: false

ptr: ./foo
  IS_DOS_ABSOLUTE_PATH: false
  IS_DOS_REAL_ABSOLUTE_PATH: false
  IS_DIR_SEPARATOR: true

ptr: .\foo
  IS_DOS_ABSOLUTE_PATH: false
  IS_DOS_REAL_ABSOLUTE_PATH: false
  IS_DIR_SEPARATOR: false




or, failing that perhaps put some explicit WINDOWS-specific #ifdef'd 
code there?  It's a real corner case.


Would you rather have something like this in module.cc?

if (ptr[0] == '.')
  {
if IS_DIR_SEPARATOR (ptr[1]))
  return get_module (build_string (strlen (ptr), ptr));
  }
else
  {
#if HAVE_DOS_BASED_FILE_SYSTEM
if (HAS_DRIVE_SPEC (ptr) && IS_DIR_SEPARATOR (ptr[2]))
#else
if (IS_ABSOLUTE_PATH (ptr))
#endif
  return get_module (build_string (strlen (ptr), ptr));
  }


Let me know what you prefer.

Kind regards,
Torbjörn



nathan



gcc/cp/ChangeLog:

* module.cc: Use IS_REAL_ABSOLUTE_PATH macro.

Co-Authored-By: Yvan ROUX 
Signed-off-by: Torbjörn SVENSSON 
---
  gcc/cp/module.cc    | 2 +-
  include/filenames.h | 4 
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 9957df510e6..84680e183b7 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -13958,7 +13958,7 @@ get_module (tree name, module_state *parent, 
bool partition)

  static module_state *
  get_module (const char *ptr)
  {
-  if (ptr[0] == '.' ? IS_DIR_SEPARATOR (ptr[1]) : IS_ABSOLUTE_PATH 
(ptr))
+  if (ptr[0] == '.' ? IS_DIR_SEPARATOR (ptr[1]) : 
IS_REAL_ABSOLUTE_PATH (ptr))

  /* A header name.  */
  return get_module (build_string (strlen (ptr), ptr));
diff --git a/include/filenames.h b/include/filenames.h
index 6c72c422edd..d04fccfed64 100644
--- a/include/filenames.h
+++ b/include/filenames.h
@@ -43,6 +43,7 @@ extern "C" {
  #  define HAS_DRIVE_SPEC(f) HAS_DOS_DRIVE_SPEC (f)
  #  define IS_DIR_SEPARATOR(c) IS_DOS_DIR_SEPARATOR (c)
  #  define IS_ABSOLUTE_PATH(f) IS_DOS_ABSOLUTE_PATH (f)

Re: [PATCH] c++: Allow module name to be a single letter on Windows

2022-11-03 Thread Nathan Sidwell via Gcc-patches

On 10/28/22 05:15, Torbjörn SVENSSON wrote:

On Windows, the ':' character is special and when the module name is
a single character, like 'A', then the flatname would be (for
example) 'A:Foo'. On Windows, 'A:Foo' is treated as an absolute
path by the module loader and is likely not found.

Without this patch, the test case pr98944_c.C fails with:

In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_b.C:7:1,
of module A:Foo, imported at /src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:
A:Internals: error: header module expected, module 'A:Internals' found
A:Internals: error: failed to read compiled module: Bad file data
A:Internals: note: compiled module file is 'gcm.cache/A-Internals.gcm'
In module imported at /src/gcc/testsuite/g++.dg/modules/pr98944_c.C:7:8:
A:Foo: error: failed to read compiled module: Bad import dependency
A:Foo: note: compiled module file is 'gcm.cache/A-Foo.gcm'
A:Foo: fatal error: returning to the gate for a mechanical issue
compilation terminated.

include/ChangeLog:

* filenames.h: Added IS_REAL_ABSOLUTE_PATH macro to check if
path is absolute and not semi-absolute on Windows.


Hm, this is unfortunate.  The current IS_ABSOLUTE_PATH, is really 'not relative 
to cwd', and even then that's untrue if the drive letter there is the drive 
letter of cwd, right?


It's awkward to have a new macro for just this purpose and the new name isn't 
very indicative of the difference to the current IS_ABSOLUTE_PATH.


Would it be better to not deal with drive letters here?  How prevalent are they 
these days in windows?  Would something like


   if (IS_DIR_SEPARATOR (ptr[ptr[0] == '.'])

suffice?

or, failing that perhaps put some explicit WINDOWS-specific #ifdef'd code there? 
 It's a real corner case.


nathan



gcc/cp/ChangeLog:

* module.cc: Use IS_REAL_ABSOLUTE_PATH macro.

Co-Authored-By: Yvan ROUX 
Signed-off-by: Torbjörn SVENSSON 
---
  gcc/cp/module.cc| 2 +-
  include/filenames.h | 4 
  2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/gcc/cp/module.cc b/gcc/cp/module.cc
index 9957df510e6..84680e183b7 100644
--- a/gcc/cp/module.cc
+++ b/gcc/cp/module.cc
@@ -13958,7 +13958,7 @@ get_module (tree name, module_state *parent, bool 
partition)
  static module_state *
  get_module (const char *ptr)
  {
-  if (ptr[0] == '.' ? IS_DIR_SEPARATOR (ptr[1]) : IS_ABSOLUTE_PATH (ptr))
+  if (ptr[0] == '.' ? IS_DIR_SEPARATOR (ptr[1]) : IS_REAL_ABSOLUTE_PATH (ptr))
  /* A header name.  */
  return get_module (build_string (strlen (ptr), ptr));
  
diff --git a/include/filenames.h b/include/filenames.h

index 6c72c422edd..d04fccfed64 100644
--- a/include/filenames.h
+++ b/include/filenames.h
@@ -43,6 +43,7 @@ extern "C" {
  #  define HAS_DRIVE_SPEC(f) HAS_DOS_DRIVE_SPEC (f)
  #  define IS_DIR_SEPARATOR(c) IS_DOS_DIR_SEPARATOR (c)
  #  define IS_ABSOLUTE_PATH(f) IS_DOS_ABSOLUTE_PATH (f)
+#  define IS_REAL_ABSOLUTE_PATH(f) IS_DOS_REAL_ABSOLUTE_PATH (f)
  #else /* not DOSish */
  #  if defined(__APPLE__)
  #ifndef HAVE_CASE_INSENSITIVE_FILE_SYSTEM
@@ -52,6 +53,7 @@ extern "C" {
  #  define HAS_DRIVE_SPEC(f) (0)
  #  define IS_DIR_SEPARATOR(c) IS_UNIX_DIR_SEPARATOR (c)
  #  define IS_ABSOLUTE_PATH(f) IS_UNIX_ABSOLUTE_PATH (f)
+#  define IS_REAL_ABSOLUTE_PATH(f) IS_ABSOLUTE_PATH (f)
  #endif
  
  #define IS_DIR_SEPARATOR_1(dos_based, c)\

@@ -67,6 +69,8 @@ extern "C" {
  
  #define IS_DOS_DIR_SEPARATOR(c) IS_DIR_SEPARATOR_1 (1, c)

  #define IS_DOS_ABSOLUTE_PATH(f) IS_ABSOLUTE_PATH_1 (1, f)
+#define IS_DOS_REAL_ABSOLUTE_PATH(f) \
+  ((f)[0] && (f)[1] == ':' && ((f)[2] == '/' || (f)[2] == '\\'))
  #define HAS_DOS_DRIVE_SPEC(f) HAS_DRIVE_SPEC_1 (1, f)
  
  #define IS_UNIX_DIR_SEPARATOR(c) IS_DIR_SEPARATOR_1 (0, c)


--
Nathan Sidwell