Add CMD support (#1523)

## Sumamry

This PR adds the `activation.bat`, `deactivation.bat` and `pyenv.bat`
files to add support for using uv from CMD.

This PR further fixes an issue with our trampoline implementation where
calling an executable like `black` failed:

```
(venv) C:\Users\Micha\astral\test>where black
C:\Users\Micha\astral\test\.venv\Scripts\black.exe

(venv) C:\Users\Micha\astral\test>black
C:\Users\Micha\AppData\Local\Programs\Python\Python312\python.exe: can't open file 'C:\\Users\\Micha\\astral\\test\\black': [Errno 2] No such file or directory
```

The issue was that CMD doesn't extend `black` to its full path before
passing it to the trampoline and our trampoline generated the command
`<python> black` instead of `<python> .venv/Scripts/black`, and Python
can't find `black` in the project directory.

This PR fixes this by using the full executable name (that we already
parsed out to discover the Python version). This adds one complication,
we need to preserve the arguments without repeating the executable name
that is the first argument.
One option is to use
[`CommandLineToArgvW`](https://learn.microsoft.com/de-de/windows/win32/api/shellapi/nf-shellapi-commandlinetoargvw)
and then serialize the arguments 1.. to a string again. I decided
against that. Win32 API calls are easy to get wrong. That's why I
implemented the parsing rules specified in
[`CommandLineToArgvW`](https://learn.microsoft.com/de-de/windows/win32/api/shellapi/nf-shellapi-commandlinetoargvw)
to skip the first argument.

Fixes https://github.com/astral-sh/uv/issues/1471

## Test Plan


bdb537b6-97c8-4f7e-bb4a-3a614eb5e0f6

Powershell continues to work


6c806477-a7c6-4047-9ffc-5ed91c6f1c84

I haven't been able to test the aarch binaries.

crates/gourgeist/src/activator/.gitattributes

@@ -0,0 +1 @@
+*.bat text eol=crlf

crates/gourgeist/src/activator/activate.bat

@@ -0,0 +1,59 @@
+@REM Copyright (c) 2020-202x The virtualenv developers
+@REM
+@REM Permission is hereby granted, free of charge, to any person obtaining
+@REM a copy of this software and associated documentation files (the
+@REM "Software"), to deal in the Software without restriction, including
+@REM without limitation the rights to use, copy, modify, merge, publish,
+@REM distribute, sublicense, and/or sell copies of the Software, and to
+@REM permit persons to whom the Software is furnished to do so, subject to
+@REM the following conditions:
+@REM
+@REM The above copyright notice and this permission notice shall be
+@REM included in all copies or substantial portions of the Software.
+@REM
+@REM THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+@REM EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+@REM MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+@REM NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+@REM LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+@REM OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+@REM WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+@set "VIRTUAL_ENV={{ VIRTUAL_ENV_DIR }}"
+
+@set "VIRTUAL_ENV_PROMPT=venv"
+@if NOT DEFINED VIRTUAL_ENV_PROMPT (
+    @for %%d in ("%VIRTUAL_ENV%") do @set "VIRTUAL_ENV_PROMPT=%%~nxd"
+)
+
+@if defined _OLD_VIRTUAL_PROMPT (
+    @set "PROMPT=%_OLD_VIRTUAL_PROMPT%"
+) else (
+    @if not defined PROMPT (
+        @set "PROMPT=$P$G"
+    )
+    @if not defined VIRTUAL_ENV_DISABLE_PROMPT (
+        @set "_OLD_VIRTUAL_PROMPT=%PROMPT%"
+    )
+)
+@if not defined VIRTUAL_ENV_DISABLE_PROMPT (
+    @set "PROMPT=(%VIRTUAL_ENV_PROMPT%) %PROMPT%"
+)
+
+@REM Don't use () to avoid problems with them in %PATH%
+@if defined _OLD_VIRTUAL_PYTHONHOME @goto ENDIFVHOME
+    @set "_OLD_VIRTUAL_PYTHONHOME=%PYTHONHOME%"
+:ENDIFVHOME
+
+@set PYTHONHOME=
+
+@REM if defined _OLD_VIRTUAL_PATH (
+@if not defined _OLD_VIRTUAL_PATH @goto ENDIFVPATH1
+    @set "PATH=%_OLD_VIRTUAL_PATH%"
+:ENDIFVPATH1
+@REM ) else (
+@if defined _OLD_VIRTUAL_PATH @goto ENDIFVPATH2
+    @set "_OLD_VIRTUAL_PATH=%PATH%"
+:ENDIFVPATH2
+
+@set "PATH=%VIRTUAL_ENV%\{{ BIN_NAME }};%PATH%"

crates/gourgeist/src/activator/deactivate.bat

@@ -0,0 +1,39 @@
+@REM Copyright (c) 2020-202x The virtualenv developers
+@REM
+@REM Permission is hereby granted, free of charge, to any person obtaining
+@REM a copy of this software and associated documentation files (the
+@REM "Software"), to deal in the Software without restriction, including
+@REM without limitation the rights to use, copy, modify, merge, publish,
+@REM distribute, sublicense, and/or sell copies of the Software, and to
+@REM permit persons to whom the Software is furnished to do so, subject to
+@REM the following conditions:
+@REM
+@REM The above copyright notice and this permission notice shall be
+@REM included in all copies or substantial portions of the Software.
+@REM
+@REM THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+@REM EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+@REM MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+@REM NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+@REM LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+@REM OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+@REM WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+@set VIRTUAL_ENV=
+@set VIRTUAL_ENV_PROMPT=
+
+@REM Don't use () to avoid problems with them in %PATH%
+@if not defined _OLD_VIRTUAL_PROMPT @goto ENDIFVPROMPT
+    @set "PROMPT=%_OLD_VIRTUAL_PROMPT%"
+    @set _OLD_VIRTUAL_PROMPT=
+:ENDIFVPROMPT
+
+@if not defined _OLD_VIRTUAL_PYTHONHOME @goto ENDIFVHOME
+    @set "PYTHONHOME=%_OLD_VIRTUAL_PYTHONHOME%"
+    @set _OLD_VIRTUAL_PYTHONHOME=
+:ENDIFVHOME
+
+@if not defined _OLD_VIRTUAL_PATH @goto ENDIFVPATH
+    @set "PATH=%_OLD_VIRTUAL_PATH%"
+    @set _OLD_VIRTUAL_PATH=
+:ENDIFVPATH

crates/gourgeist/src/activator/pydoc.bat

@@ -0,0 +1,22 @@
+@REM Copyright (c) 2020-202x The virtualenv developers
+@REM
+@REM Permission is hereby granted, free of charge, to any person obtaining
+@REM a copy of this software and associated documentation files (the
+@REM "Software"), to deal in the Software without restriction, including
+@REM without limitation the rights to use, copy, modify, merge, publish,
+@REM distribute, sublicense, and/or sell copies of the Software, and to
+@REM permit persons to whom the Software is furnished to do so, subject to
+@REM the following conditions:
+@REM
+@REM The above copyright notice and this permission notice shall be
+@REM included in all copies or substantial portions of the Software.
+@REM
+@REM THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+@REM EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+@REM MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+@REM NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+@REM LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+@REM OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+@REM WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+python.exe -m pydoc %*

crates/gourgeist/src/bare.rs

@@ -18,6 +18,9 @@ const ACTIVATE_TEMPLATES: &[(&str, &str)] = &[
     ("activate.fish", include_str!("activator/activate.fish")),
     ("activate.nu", include_str!("activator/activate.nu")),
     ("activate.ps1", include_str!("activator/activate.ps1")),
+    ("activate.bat", include_str!("activator/activate.bat")),
+    ("deactivate.bat", include_str!("activator/deactivate.bat")),
+    ("pydoc.bat", include_str!("activator/pydoc.bat")),
     (
         "activate_this.py",
         include_str!("activator/activate_this.py"),

crates/uv-trampoline/src/bounce.rs

@@ -37,43 +37,64 @@ fn getenv(name: &CStr) -> Option<CString> {
     }
 }
 
-fn make_child_cmdline(is_gui: bool) -> Vec<u8> {
-    unsafe {
-        let python_exe = find_python_exe(is_gui);
+/// Transform `<command> <arguments>` to `python <command> <arguments>`.
+fn make_child_cmdline(is_gui: bool) -> CString {
+    let executable_name: CString = executable_filename();
+    let python_exe = find_python_exe(is_gui, &executable_name);
+    let mut child_cmdline = Vec::<u8>::new();
 
-        let my_cmdline = CStr::from_ptr(GetCommandLineA() as _);
-        let mut child_cmdline = Vec::<u8>::new();
-        child_cmdline.push(b'"');
-        for byte in python_exe.as_bytes() {
-            if *byte == b'"' {
-                // 3 double quotes: one to end the quoted span, one to become a literal double-quote,
-                // and one to start a new quoted span.
-                child_cmdline.extend(br#"""""#);
-            } else {
-                child_cmdline.push(*byte);
-            }
-        }
-        child_cmdline.extend(br#"" "#);
-        child_cmdline.extend(my_cmdline.to_bytes_with_nul());
-        //eprintln!("new_cmdline: {}", core::str::from_utf8_unchecked(new_cmdline.as_slice()));
-        child_cmdline
-    }
+    push_quoted_path(&python_exe, &mut child_cmdline);
+    child_cmdline.push(b' ');
+
+    // Use the full executable name because CMD only passes the name of the executable (but not the path)
+    // when e.g. invoking `black` instead of `<PATH_TO_VENV>/Scripts/black` and Python then fails
+    // to find the file. Unfortunately, this complicates things because we now need to split the executable
+    // from the arguments string...
+    push_quoted_path(&executable_name, &mut child_cmdline);
+
+    push_arguments(&mut child_cmdline);
+
+    child_cmdline.push(b'\0');
+
+    // Helpful when debugging trampline issues
+    // eprintln!(
+    //     "executable_name: '{}'\nnew_cmdline: {}",
+    //     core::str::from_utf8(executable_name.to_bytes(),
+    //     core::str::from_utf8(child_cmdline.as_slice())
+    // );
+
+    // SAFETY: We push the null termination byte at the end.
+    unsafe { CString::from_vec_with_nul_unchecked(child_cmdline) }
 }
 
-/// The scripts are in the same directory as the Python interpreter, so we can find Python by getting the locations of
-/// the current .exe and replacing the filename with `python[w].exe`.
-fn find_python_exe(is_gui: bool) -> CString {
-    unsafe {
-        // MAX_PATH is a lie, Windows paths can be longer.
-        // https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation
-        // But it's a good first guess, usually paths are short and we should only need a single attempt.
-        let mut buffer: Vec<u8> = vec![0; MAX_PATH as usize];
-        loop {
-            // Call the Windows API function to get the module file name
-            let len = GetModuleFileNameA(0, buffer.as_mut_ptr(), buffer.len() as u32);
+fn push_quoted_path(path: &CStr, command: &mut Vec<u8>) {
+    command.push(b'"');
+    for byte in path.to_bytes() {
+        if *byte == b'"' {
+            // 3 double quotes: one to end the quoted span, one to become a literal double-quote,
+            // and one to start a new quoted span.
+            command.extend(br#"""""#);
+        } else {
+            command.push(*byte);
+        }
+    }
+    command.extend(br#"""#);
+}
 
-            // That's the error condition because len doesn't include the trailing null byte
-            if len as usize == buffer.len() {
+/// Returns the full path of the executable.
+/// See https://learn.microsoft.com/en-us/windows/win32/api/libloaderapi/nf-libloaderapi-getmodulefilenamea
+fn executable_filename() -> CString {
+    // MAX_PATH is a lie, Windows paths can be longer.
+    // https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file#maximum-path-length-limitation
+    // But it's a good first guess, usually paths are short and we should only need a single attempt.
+    let mut buffer: Vec<u8> = vec![0; MAX_PATH as usize];
+    loop {
+        // Call the Windows API function to get the module file name
+        let len = unsafe { GetModuleFileNameA(0, buffer.as_mut_ptr(), buffer.len() as u32) };
+
+        // That's the error condition because len doesn't include the trailing null byte
+        if len as usize == buffer.len() {
+            unsafe {
                 let last_error = GetLastError();
                 match last_error {
                     ERROR_INSUFFICIENT_BUFFER => {
@@ -86,30 +107,84 @@ fn find_python_exe(is_gui: bool) -> CString {
                         ExitProcess(1);
                     }
                 }
-            } else {
-                buffer.truncate(len as usize + b"\0".len());
-                break;
+            }
+        } else {
+            buffer.truncate(len as usize + b"\0".len());
+            break;
+        }
+    }
+
+    unsafe { CString::from_vec_with_nul_unchecked(buffer) }
+}
+
+/// The scripts are in the same directory as the Python interpreter, so we can find Python by getting the locations of
+/// the current .exe and replacing the filename with `python[w].exe`.
+fn find_python_exe(is_gui: bool, executable_name: &CStr) -> CString {
+    // Replace the filename (the last segment of the path) with "python.exe"
+    // Assumption: We are not in an encoding where a backslash byte can be part of a larger character.
+    let bytes = executable_name.to_bytes();
+    let Some(last_backslash) = bytes.iter().rposition(|byte| *byte == b'\\') else {
+        eprintln!(
+            "Invalid current exe path (missing backslash): `{}`",
+            &*executable_name.to_string_lossy()
+        );
+        unsafe {
+            ExitProcess(1);
+        }
+    };
+
+    let mut buffer = bytes[..last_backslash + 1].to_vec();
+    buffer.extend_from_slice(if is_gui {
+        b"pythonw.exe"
+    } else {
+        b"python.exe"
+    });
+    buffer.push(b'\0');
+
+    unsafe { CString::from_vec_with_nul_unchecked(buffer) }
+}
+
+fn push_arguments(output: &mut Vec<u8>) {
+    let arguments_as_str = unsafe {
+        // SAFETY: We rely on `GetCommandLineA` to return a valid pointer to a null terminated string.
+        CStr::from_ptr(GetCommandLineA() as _)
+    };
+
+    // Skip over the executable name and then push the rest of the arguments
+    let after_executable = skip_one_argument(arguments_as_str.to_bytes());
+
+    output.extend_from_slice(after_executable)
+}
+
+fn skip_one_argument(arguments: &[u8]) -> &[u8] {
+    let mut quoted = false;
+    let mut offset = 0;
+    let mut bytes_iter = arguments.iter().peekable();
+
+    // Implements https://learn.microsoft.com/en-us/cpp/c-language/parsing-c-command-line-arguments?view=msvc-170
+    while let Some(byte) = bytes_iter.next().copied() {
+        match byte {
+            b'"' => {
+                quoted = !quoted;
+            }
+            b'\\' => {
+                // Skip over escaped quotes or even number of backslashes.
+                if matches!(bytes_iter.peek().copied(), Some(&b'\"' | &b'\\')) {
+                    offset += 1;
+                    bytes_iter.next();
+                }
+            }
+            byte => {
+                if byte.is_ascii_whitespace() && !quoted {
+                    break;
+                }
             }
         }
-        // Replace the filename (the last segment of the path) with "python.exe"
-        // Assumption: We are not in an encoding where a backslash byte can be part of a larger character.
-        let Some(last_backslash) = buffer.iter().rposition(|byte| *byte == b'\\') else {
-            eprintln!(
-                "Invalid current exe path (missing backslash): `{}`",
-                CString::from_vec_with_nul_unchecked(buffer)
-                    .to_string_lossy()
-                    .as_ref()
-            );
-            ExitProcess(1);
-        };
-        buffer.truncate(last_backslash + 1);
-        buffer.extend_from_slice(if is_gui {
-            b"pythonw.exe\0"
-        } else {
-            b"python.exe\0"
-        });
-        CString::from_vec_with_nul_unchecked(buffer)
+
+        offset += 1;
     }
+
+    &arguments[offset..]
 }
 
 fn make_job_object() -> HANDLE {
@@ -137,7 +212,7 @@ fn make_job_object() -> HANDLE {
     }
 }
 
-fn spawn_child(si: &STARTUPINFOA, child_cmdline: &mut [u8]) -> HANDLE {
+fn spawn_child(si: &STARTUPINFOA, child_cmdline: CString) -> HANDLE {
     unsafe {
         if si.dwFlags & STARTF_USESTDHANDLES != 0 {
             // ignore errors from these -- if the handle's not inheritable/not valid, then nothing
@@ -151,7 +226,7 @@ fn spawn_child(si: &STARTUPINFOA, child_cmdline: &mut [u8]) -> HANDLE {
             null(),
             // Why does this have to be mutable? Who knows. But it's not a mistake --
             // MS explicitly documents that this buffer might be mutated by CreateProcess.
-            child_cmdline.as_mut_ptr(),
+            child_cmdline.into_bytes_with_nul().as_mut_ptr(),
             null(),
             null(),
             1,
@@ -236,14 +311,14 @@ fn clear_app_starting_state(child_handle: HANDLE) {
 
 pub fn bounce(is_gui: bool) -> ! {
     unsafe {
-        let mut child_cmdline = make_child_cmdline(is_gui);
-        let job = make_job_object();
+        let child_cmdline = make_child_cmdline(is_gui);
 
         let mut si = MaybeUninit::<STARTUPINFOA>::uninit();
         GetStartupInfoA(si.as_mut_ptr());
         let si = si.assume_init();
 
-        let child_handle = spawn_child(&si, child_cmdline.as_mut_slice());
+        let child_handle = spawn_child(&si, child_cmdline);
+        let job = make_job_object();
         check!(AssignProcessToJobObject(job, child_handle));
 
         // (best effort) Close all the handles that we can