Auto merge of #3502 - RalfJung:GetUserProfileDirectoryW, r=RalfJung

windows: basic support for GetUserProfileDirectoryW

Fixes #3499

Cargo.toml

@@ -25,6 +25,7 @@ aes = { version = "0.8.3", features = ["hazmat"] }
 measureme = "11"
 ctrlc = "3.2.5"
 chrono = { version = "0.4.38", default-features = false, features = ["clock"] }
+directories = "5"
 
 # Copied from `compiler/rustc/Cargo.toml`.
 # But only for some targets, it fails for others. Rustc configures this in its CI, but we can't

src/shims/env.rs

@@ -160,10 +160,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         this.assert_target_os("windows", "GetEnvironmentVariableW");
 
         let name_ptr = this.read_pointer(name_op)?;
+        let buf_ptr = this.read_pointer(buf_op)?;
+        let buf_size = this.read_scalar(size_op)?.to_u32()?; // in characters
+
         let name = this.read_os_str_from_wide_str(name_ptr)?;
         Ok(match this.machine.env_vars.map.get(&name) {
             Some(&var_ptr) => {
-                this.set_last_error(Scalar::from_u32(0))?; // make sure this is unambiguously not an error
                 // The offset is used to strip the "{name}=" part of the string.
                 #[rustfmt::skip]
                 let name_offset_bytes = u64::try_from(name.len()).unwrap()
@@ -172,14 +174,13 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let var_ptr = var_ptr.offset(Size::from_bytes(name_offset_bytes), this)?;
                 let var = this.read_os_str_from_wide_str(var_ptr)?;
 
-                let buf_ptr = this.read_pointer(buf_op)?;
-                // `buf_size` represents the size in characters.
-                let buf_size = u64::from(this.read_scalar(size_op)?.to_u32()?);
-                Scalar::from_u32(windows_check_buffer_size(
-                    this.write_os_str_to_wide_str(
-                        &var, buf_ptr, buf_size, /*truncate*/ false,
-                    )?,
-                ))
+                Scalar::from_u32(windows_check_buffer_size(this.write_os_str_to_wide_str(
+                    &var,
+                    buf_ptr,
+                    buf_size.into(),
+                )?))
+                // This can in fact return 0. It is up to the caller to set last_error to 0
+                // beforehand and check it afterwards to exclude that case.
             }
             None => {
                 let envvar_not_found = this.eval_windows("c", "ERROR_ENVVAR_NOT_FOUND");
@@ -375,9 +376,10 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // If we cannot get the current directory, we return 0
         match env::current_dir() {
             Ok(cwd) => {
-                this.set_last_error(Scalar::from_u32(0))?; // make sure this is unambiguously not an error
+                // This can in fact return 0. It is up to the caller to set last_error to 0
+                // beforehand and check it afterwards to exclude that case.
                 return Ok(Scalar::from_u32(windows_check_buffer_size(
-                    this.write_path_to_wide_str(&cwd, buf, size, /*truncate*/ false)?,
+                    this.write_path_to_wide_str(&cwd, buf, size)?,
                 )));
             }
             Err(e) => this.set_last_error_from_io_error(e.kind())?,
@@ -494,9 +496,60 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
     fn GetCurrentProcessId(&mut self) -> InterpResult<'tcx, u32> {
         let this = self.eval_context_mut();
         this.assert_target_os("windows", "GetCurrentProcessId");
-
         this.check_no_isolation("`GetCurrentProcessId`")?;
 
         Ok(std::process::id())
     }
+
+    #[allow(non_snake_case)]
+    fn GetUserProfileDirectoryW(
+        &mut self,
+        token: &OpTy<'tcx, Provenance>, // HANDLE
+        buf: &OpTy<'tcx, Provenance>,   // LPWSTR
+        size: &OpTy<'tcx, Provenance>,  // LPDWORD
+    ) -> InterpResult<'tcx, Scalar<Provenance>> // returns BOOL
+    {
+        let this = self.eval_context_mut();
+        this.assert_target_os("windows", "GetUserProfileDirectoryW");
+        this.check_no_isolation("`GetUserProfileDirectoryW`")?;
+
+        let token = this.read_target_isize(token)?;
+        let buf = this.read_pointer(buf)?;
+        let size = this.deref_pointer(size)?;
+
+        if token != -4 {
+            throw_unsup_format!(
+                "GetUserProfileDirectoryW: only CURRENT_PROCESS_TOKEN is supported"
+            );
+        }
+
+        // See <https://learn.microsoft.com/en-us/windows/win32/api/userenv/nf-userenv-getuserprofiledirectoryw> for docs.
+        Ok(match directories::UserDirs::new() {
+            Some(dirs) => {
+                let home = dirs.home_dir();
+                let size_avail = if this.ptr_is_null(size.ptr())? {
+                    0 // if the buf pointer is null, we can't write to it; `size` will be updated to the required length
+                } else {
+                    this.read_scalar(&size)?.to_u32()?
+                };
+                // Of course we cannot use `windows_check_buffer_size` here since this uses
+                // a different method for dealing with a too-small buffer than the other functions...
+                let (success, len) = this.write_path_to_wide_str(home, buf, size_avail.into())?;
+                // The Windows docs just say that this is written on failure. But std
+                // seems to rely on it always being written.
+                this.write_scalar(Scalar::from_u32(len.try_into().unwrap()), &size)?;
+                if success {
+                    Scalar::from_i32(1) // return TRUE
+                } else {
+                    this.set_last_error(this.eval_windows("c", "ERROR_INSUFFICIENT_BUFFER"))?;
+                    Scalar::from_i32(0) // return FALSE
+                }
+            }
+            None => {
+                // We have to pick some error code.
+                this.set_last_error(this.eval_windows("c", "ERROR_BAD_USER_PROFILE"))?;
+                Scalar::from_i32(0) // return FALSE
+            }
+        })
+    }
 }

src/shims/os_str.rs

@@ -72,11 +72,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         u16vec_to_osstring(u16_vec)
     }
 
-    /// Helper function to write an OsStr as a null-terminated sequence of bytes, which is what
-    /// the Unix APIs usually handle. This function returns `Ok((false, length))` without trying
-    /// to write if `size` is not large enough to fit the contents of `os_string` plus a null
-    /// terminator. It returns `Ok((true, length))` if the writing process was successful. The
-    /// string length returned does include the null terminator.
+    /// Helper function to write an OsStr as a null-terminated sequence of bytes, which is what the
+    /// Unix APIs usually handle. Returns `(success, full_len)`, where length includes the null
+    /// terminator. On failure, nothing is written.
     fn write_os_str_to_c_str(
         &mut self,
         os_str: &OsStr,
@@ -87,19 +85,9 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         self.eval_context_mut().write_c_str(bytes, ptr, size)
     }
 
-    /// Helper function to write an OsStr as a 0x0000-terminated u16-sequence, which is what the
-    /// Windows APIs usually handle.
-    ///
-    /// If `truncate == false` (the usual mode of operation), this function returns `Ok((false,
-    /// length))` without trying to write if `size` is not large enough to fit the contents of
-    /// `os_string` plus a null terminator. It returns `Ok((true, length))` if the writing process
-    /// was successful. The string length returned does include the null terminator. Length is
-    /// measured in units of `u16.`
-    ///
-    /// If `truncate == true`, then in case `size` is not large enough it *will* write the first
-    /// `size.saturating_sub(1)` many items, followed by a null terminator (if `size > 0`).
-    /// The return value is still `(false, length)` in that case.
-    fn write_os_str_to_wide_str(
+    /// Internal helper to share code between `write_os_str_to_wide_str` and
+    /// `write_os_str_to_wide_str_truncated`.
+    fn write_os_str_to_wide_str_helper(
         &mut self,
         os_str: &OsStr,
         ptr: Pointer<Option<Provenance>>,
@@ -133,6 +121,29 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         Ok((written, size_needed))
     }
 
+    /// Helper function to write an OsStr as a 0x0000-terminated u16-sequence, which is what the
+    /// Windows APIs usually handle. Returns `(success, full_len)`, where length is measured
+    /// in units of `u16` and includes the null terminator. On failure, nothing is written.
+    fn write_os_str_to_wide_str(
+        &mut self,
+        os_str: &OsStr,
+        ptr: Pointer<Option<Provenance>>,
+        size: u64,
+    ) -> InterpResult<'tcx, (bool, u64)> {
+        self.write_os_str_to_wide_str_helper(os_str, ptr, size, /*truncate*/ false)
+    }
+
+    /// Like `write_os_str_to_wide_str`, but on failure as much as possible is written into
+    /// the buffer (always with a null terminator).
+    fn write_os_str_to_wide_str_truncated(
+        &mut self,
+        os_str: &OsStr,
+        ptr: Pointer<Option<Provenance>>,
+        size: u64,
+    ) -> InterpResult<'tcx, (bool, u64)> {
+        self.write_os_str_to_wide_str_helper(os_str, ptr, size, /*truncate*/ true)
+    }
+
     /// Allocate enough memory to store the given `OsStr` as a null-terminated sequence of bytes.
     fn alloc_os_str_as_c_str(
         &mut self,
@@ -160,9 +171,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         let arg_type = Ty::new_array(this.tcx.tcx, this.tcx.types.u16, size);
         let arg_place = this.allocate(this.layout_of(arg_type).unwrap(), memkind)?;
-        let (written, _) = self
-            .write_os_str_to_wide_str(os_str, arg_place.ptr(), size, /*truncate*/ false)
-            .unwrap();
+        let (written, _) = self.write_os_str_to_wide_str(os_str, arg_place.ptr(), size).unwrap();
         assert!(written);
         Ok(arg_place.ptr())
     }
@@ -217,12 +226,25 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         path: &Path,
         ptr: Pointer<Option<Provenance>>,
         size: u64,
-        truncate: bool,
     ) -> InterpResult<'tcx, (bool, u64)> {
         let this = self.eval_context_mut();
         let os_str =
             this.convert_path(Cow::Borrowed(path.as_os_str()), PathConversion::HostToTarget);
-        this.write_os_str_to_wide_str(&os_str, ptr, size, truncate)
+        this.write_os_str_to_wide_str(&os_str, ptr, size)
+    }
+
+    /// Write a Path to the machine memory (as a null-terminated sequence of `u16`s),
+    /// adjusting path separators if needed.
+    fn write_path_to_wide_str_truncated(
+        &mut self,
+        path: &Path,
+        ptr: Pointer<Option<Provenance>>,
+        size: u64,
+    ) -> InterpResult<'tcx, (bool, u64)> {
+        let this = self.eval_context_mut();
+        let os_str =
+            this.convert_path(Cow::Borrowed(path.as_os_str()), PathConversion::HostToTarget);
+        this.write_os_str_to_wide_str_truncated(&os_str, ptr, size)
     }
 
     /// Allocate enough memory to store a Path as a null-terminated sequence of bytes,

src/shims/unix/linux/mem.rs

@@ -23,7 +23,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // old_address must be a multiple of the page size
         #[allow(clippy::arithmetic_side_effects)] // PAGE_SIZE is nonzero
         if old_address.addr().bytes() % this.machine.page_size != 0 || new_size == 0 {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
 
@@ -37,7 +37,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         if flags & this.eval_libc_i32("MREMAP_MAYMOVE") == 0 {
             // We only support MREMAP_MAYMOVE, so not passing the flag is just a failure
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
 

src/shims/unix/mem.rs

@@ -53,11 +53,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         // First, we do some basic argument validation as required by mmap
         if (flags & (map_private | map_shared)).count_ones() != 1 {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
         if length == 0 {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
 
@@ -77,7 +77,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         //
         // Miri doesn't support MAP_FIXED or any any protections other than PROT_READ|PROT_WRITE.
         if flags & map_fixed != 0 || prot != prot_read | prot_write {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("ENOTSUP")))?;
+            this.set_last_error(this.eval_libc("ENOTSUP"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
 
@@ -96,11 +96,11 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
 
         let align = this.machine.page_align();
         let Some(map_length) = length.checked_next_multiple_of(this.machine.page_size) else {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         };
         if map_length > this.target_usize_max() {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }
 
@@ -131,16 +131,16 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         // as a dealloc.
         #[allow(clippy::arithmetic_side_effects)] // PAGE_SIZE is nonzero
         if addr.addr().bytes() % this.machine.page_size != 0 {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(Scalar::from_i32(-1));
         }
 
         let Some(length) = length.checked_next_multiple_of(this.machine.page_size) else {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(Scalar::from_i32(-1));
         };
         if length > this.target_usize_max() {
-            this.set_last_error(Scalar::from_i32(this.eval_libc_i32("EINVAL")))?;
+            this.set_last_error(this.eval_libc("EINVAL"))?;
             return Ok(this.eval_libc("MAP_FAILED"));
         }