Make $nu constant (#10160)

Cargo.lock

@@ -2836,7 +2836,6 @@ dependencies = [
  "nu-path",
  "nu-protocol",
  "nu-utils",
- "sysinfo",
 ]
 
 [[package]]
@@ -2932,6 +2931,8 @@ dependencies = [
  "indexmap 2.0.0",
  "lru",
  "miette",
+ "nu-path",
+ "nu-system",
  "nu-test-support",
  "nu-utils",
  "num-format",
@@ -2967,6 +2968,7 @@ dependencies = [
  "ntapi",
  "once_cell",
  "procfs",
+ "sysinfo",
  "winapi",
 ]
 

crates/nu-cli/src/repl.rs

@@ -16,8 +16,9 @@ use nu_parser::{lex, parse, trim_quotes_str};
 use nu_protocol::{
     config::NuCursorShape,
     engine::{EngineState, Stack, StateWorkingSet},
+    eval_const::create_nu_constant,
     report_error, report_error_new, HistoryFileFormat, PipelineData, ShellError, Span, Spanned,
-    Value,
+    Value, NU_VARIABLE_ID,
 };
 use nu_utils::utils::perf;
 use reedline::{
@@ -164,6 +165,10 @@ pub fn evaluate_repl(
 
     engine_state.set_startup_time(entire_start_time.elapsed().as_nanos() as i64);
 
+    // Regenerate the $nu constant to contain the startup time and any other potential updates
+    let nu_const = create_nu_constant(engine_state, Span::unknown())?;
+    engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
     if load_std_lib.is_none() && engine_state.get_config().show_banner {
         eval_source(
             engine_state,

crates/nu-cli/tests/support/completions_helpers.rs

@@ -4,7 +4,8 @@ use nu_engine::eval_block;
 use nu_parser::parse;
 use nu_protocol::{
     engine::{EngineState, Stack, StateWorkingSet},
-    PipelineData, ShellError, Span, Value,
+    eval_const::create_nu_constant,
+    PipelineData, ShellError, Span, Value, NU_VARIABLE_ID,
 };
 use nu_test_support::fs;
 use reedline::Suggestion;
@@ -28,6 +29,11 @@ pub fn new_engine() -> (PathBuf, String, EngineState, Stack) {
     // Create a new engine with default context
     let mut engine_state = create_default_context();
 
+    // Add $nu
+    let nu_const =
+        create_nu_constant(&engine_state, Span::test_data()).expect("Failed creating $nu");
+    engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
     // New stack
     let mut stack = Stack::new();
 

crates/nu-engine/Cargo.toml

@@ -16,7 +16,5 @@ nu-path = { path = "../nu-path", version = "0.84.1" }
 nu-glob = { path = "../nu-glob", version = "0.84.1" }
 nu-utils = { path = "../nu-utils", version = "0.84.1" }
 
-sysinfo = "0.29"
-
 [features]
 plugin = []

crates/nu-engine/src/eval.rs

@@ -10,9 +10,8 @@ use nu_protocol::{
     PipelineMetadata, Range, Record, ShellError, Span, Spanned, Unit, Value, VarId,
     ENV_VARIABLE_ID,
 };
+use std::collections::HashMap;
 use std::time::Instant;
-use std::{collections::HashMap, path::PathBuf};
-use sysinfo::SystemExt;
 
 pub fn eval_operator(op: &Expression) -> Result<Operator, ShellError> {
     match op {
@@ -1226,183 +1225,6 @@ pub fn eval_subexpression(
     Ok(input)
 }
 
-pub fn eval_nu_variable(engine_state: &EngineState, span: Span) -> Result<Value, ShellError> {
-    fn canonicalize_path(engine_state: &EngineState, path: &PathBuf) -> PathBuf {
-        let cwd = engine_state.current_work_dir();
-
-        if path.exists() {
-            match nu_path::canonicalize_with(path, cwd) {
-                Ok(canon_path) => canon_path,
-                Err(_) => path.clone(),
-            }
-        } else {
-            path.clone()
-        }
-    }
-
-    let mut record = Record::new();
-
-    record.push(
-        "default-config-dir",
-        if let Some(mut path) = nu_path::config_dir() {
-            path.push("nushell");
-            Value::string(path.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not get config directory".into()),
-                span,
-            )
-        },
-    );
-
-    record.push(
-        "config-path",
-        if let Some(path) = engine_state.get_config_path("config-path") {
-            let canon_config_path = canonicalize_path(engine_state, path);
-            Value::string(canon_config_path.to_string_lossy(), span)
-        } else if let Some(mut path) = nu_path::config_dir() {
-            path.push("nushell");
-            path.push("config.nu");
-            Value::string(path.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not get config directory".into()),
-                span,
-            )
-        },
-    );
-
-    record.push(
-        "env-path",
-        if let Some(path) = engine_state.get_config_path("env-path") {
-            let canon_env_path = canonicalize_path(engine_state, path);
-            Value::string(canon_env_path.to_string_lossy(), span)
-        } else if let Some(mut path) = nu_path::config_dir() {
-            path.push("nushell");
-            path.push("env.nu");
-            Value::string(path.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not find environment path".into()),
-                span,
-            )
-        },
-    );
-
-    record.push(
-        "history-path",
-        if let Some(mut path) = nu_path::config_dir() {
-            path.push("nushell");
-            match engine_state.config.history_file_format {
-                nu_protocol::HistoryFileFormat::Sqlite => {
-                    path.push("history.sqlite3");
-                }
-                nu_protocol::HistoryFileFormat::PlainText => {
-                    path.push("history.txt");
-                }
-            }
-            let canon_hist_path = canonicalize_path(engine_state, &path);
-            Value::string(canon_hist_path.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not find history path".into()),
-                span,
-            )
-        },
-    );
-
-    record.push(
-        "loginshell-path",
-        if let Some(mut path) = nu_path::config_dir() {
-            path.push("nushell");
-            path.push("login.nu");
-            let canon_login_path = canonicalize_path(engine_state, &path);
-            Value::string(canon_login_path.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not find login shell path".into()),
-                span,
-            )
-        },
-    );
-
-    #[cfg(feature = "plugin")]
-    {
-        record.push(
-            "plugin-path",
-            if let Some(path) = &engine_state.plugin_signatures {
-                let canon_plugin_path = canonicalize_path(engine_state, path);
-                Value::string(canon_plugin_path.to_string_lossy(), span)
-            } else {
-                Value::error(
-                    ShellError::IOError("Could not get plugin signature location".into()),
-                    span,
-                )
-            },
-        );
-    }
-
-    record.push(
-        "home-path",
-        if let Some(path) = nu_path::home_dir() {
-            let canon_home_path = canonicalize_path(engine_state, &path);
-            Value::string(canon_home_path.to_string_lossy(), span)
-        } else {
-            Value::error(ShellError::IOError("Could not get home path".into()), span)
-        },
-    );
-
-    record.push("temp-path", {
-        let canon_temp_path = canonicalize_path(engine_state, &std::env::temp_dir());
-        Value::string(canon_temp_path.to_string_lossy(), span)
-    });
-
-    record.push("pid", Value::int(std::process::id().into(), span));
-
-    record.push("os-info", {
-        let sys = sysinfo::System::new();
-        let ver = match sys.kernel_version() {
-            Some(v) => v,
-            None => "unknown".into(),
-        };
-        Value::record(
-            record! {
-                "name" => Value::string(std::env::consts::OS, span),
-                "arch" => Value::string(std::env::consts::ARCH, span),
-                "family" => Value::string(std::env::consts::FAMILY, span),
-                "kernel_version" => Value::string(ver, span),
-            },
-            span,
-        )
-    });
-
-    record.push(
-        "startup-time",
-        Value::duration(engine_state.get_startup_time(), span),
-    );
-
-    record.push(
-        "is-interactive",
-        Value::bool(engine_state.is_interactive, span),
-    );
-
-    record.push("is-login", Value::bool(engine_state.is_login, span));
-
-    record.push(
-        "current-exe",
-        if let Ok(current_exe) = std::env::current_exe() {
-            Value::string(current_exe.to_string_lossy(), span)
-        } else {
-            Value::error(
-                ShellError::IOError("Could not get current executable path".to_string()),
-                span,
-            )
-        },
-    );
-
-    Ok(Value::record(record, span))
-}
-
 pub fn eval_variable(
     engine_state: &EngineState,
     stack: &Stack,
@@ -1411,7 +1233,14 @@ pub fn eval_variable(
 ) -> Result<Value, ShellError> {
     match var_id {
         // $nu
-        nu_protocol::NU_VARIABLE_ID => eval_nu_variable(engine_state, span),
+        nu_protocol::NU_VARIABLE_ID => {
+            if let Some(val) = engine_state.get_constant(var_id) {
+                Ok(val.clone())
+            } else {
+                Err(ShellError::VariableNotFoundAtRuntime { span })
+            }
+        }
+        // $env
         ENV_VARIABLE_ID => {
             let env_vars = stack.get_env_vars(engine_state);
             let env_columns = env_vars.keys();

crates/nu-protocol/Cargo.toml

@@ -14,6 +14,8 @@ bench = false
 
 [dependencies]
 nu-utils = { path = "../nu-utils", version = "0.84.1" }
+nu-path = { path = "../nu-path", version = "0.84.1" }
+nu-system = { path = "../nu-system", version = "0.84.1" }
 
 byte-unit = "4.0"
 chrono = { version = "0.4", features = [ "serde", "std", "unstable-locales" ], default-features = false }

crates/nu-protocol/src/engine/engine_state.rs

@@ -748,6 +748,15 @@ impl EngineState {
             .expect("internal error: missing variable")
     }
 
+    pub fn get_constant(&self, var_id: VarId) -> Option<&Value> {
+        let var = self.get_var(var_id);
+        var.const_val.as_ref()
+    }
+
+    pub fn set_variable_const_val(&mut self, var_id: VarId, val: Value) {
+        self.vars[var_id].const_val = Some(val);
+    }
+
     #[allow(clippy::borrowed_box)]
     pub fn get_decl(&self, decl_id: DeclId) -> &Box<dyn Command> {
         self.decls

crates/nu-protocol/src/eval_const.rs

@@ -1,8 +1,183 @@
 use crate::{
     ast::{Block, Call, Expr, Expression, PipelineElement},
-    engine::StateWorkingSet,
-    PipelineData, Record, ShellError, Span, Value,
+    engine::{EngineState, StateWorkingSet},
+    record, HistoryFileFormat, PipelineData, Record, ShellError, Span, Value,
 };
+use nu_system::os_info::{get_kernel_version, get_os_arch, get_os_family, get_os_name};
+use std::path::PathBuf;
+
+pub fn create_nu_constant(engine_state: &EngineState, span: Span) -> Result<Value, ShellError> {
+    fn canonicalize_path(engine_state: &EngineState, path: &PathBuf) -> PathBuf {
+        let cwd = engine_state.current_work_dir();
+
+        if path.exists() {
+            match nu_path::canonicalize_with(path, cwd) {
+                Ok(canon_path) => canon_path,
+                Err(_) => path.clone(),
+            }
+        } else {
+            path.clone()
+        }
+    }
+
+    let mut record = Record::new();
+
+    record.push(
+        "default-config-dir",
+        if let Some(mut path) = nu_path::config_dir() {
+            path.push("nushell");
+            Value::string(path.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not get config directory".into()),
+                span,
+            )
+        },
+    );
+
+    record.push(
+        "config-path",
+        if let Some(path) = engine_state.get_config_path("config-path") {
+            let canon_config_path = canonicalize_path(engine_state, path);
+            Value::string(canon_config_path.to_string_lossy(), span)
+        } else if let Some(mut path) = nu_path::config_dir() {
+            path.push("nushell");
+            path.push("config.nu");
+            Value::string(path.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not get config directory".into()),
+                span,
+            )
+        },
+    );
+
+    record.push(
+        "env-path",
+        if let Some(path) = engine_state.get_config_path("env-path") {
+            let canon_env_path = canonicalize_path(engine_state, path);
+            Value::string(canon_env_path.to_string_lossy(), span)
+        } else if let Some(mut path) = nu_path::config_dir() {
+            path.push("nushell");
+            path.push("env.nu");
+            Value::string(path.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not find environment path".into()),
+                span,
+            )
+        },
+    );
+
+    record.push(
+        "history-path",
+        if let Some(mut path) = nu_path::config_dir() {
+            path.push("nushell");
+            match engine_state.config.history_file_format {
+                HistoryFileFormat::Sqlite => {
+                    path.push("history.sqlite3");
+                }
+                HistoryFileFormat::PlainText => {
+                    path.push("history.txt");
+                }
+            }
+            let canon_hist_path = canonicalize_path(engine_state, &path);
+            Value::string(canon_hist_path.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not find history path".into()),
+                span,
+            )
+        },
+    );
+
+    record.push(
+        "loginshell-path",
+        if let Some(mut path) = nu_path::config_dir() {
+            path.push("nushell");
+            path.push("login.nu");
+            let canon_login_path = canonicalize_path(engine_state, &path);
+            Value::string(canon_login_path.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not find login shell path".into()),
+                span,
+            )
+        },
+    );
+
+    #[cfg(feature = "plugin")]
+    {
+        record.push(
+            "plugin-path",
+            if let Some(path) = &engine_state.plugin_signatures {
+                let canon_plugin_path = canonicalize_path(engine_state, path);
+                Value::string(canon_plugin_path.to_string_lossy(), span)
+            } else {
+                Value::error(
+                    ShellError::IOError("Could not get plugin signature location".into()),
+                    span,
+                )
+            },
+        );
+    }
+
+    record.push(
+        "home-path",
+        if let Some(path) = nu_path::home_dir() {
+            let canon_home_path = canonicalize_path(engine_state, &path);
+            Value::string(canon_home_path.to_string_lossy(), span)
+        } else {
+            Value::error(ShellError::IOError("Could not get home path".into()), span)
+        },
+    );
+
+    record.push("temp-path", {
+        let canon_temp_path = canonicalize_path(engine_state, &std::env::temp_dir());
+        Value::string(canon_temp_path.to_string_lossy(), span)
+    });
+
+    record.push("pid", Value::int(std::process::id().into(), span));
+
+    record.push("os-info", {
+        let ver = get_kernel_version();
+        Value::record(
+            record! {
+                "name" => Value::string(get_os_name(), span),
+                "arch" => Value::string(get_os_arch(), span),
+                "family" => Value::string(get_os_family(), span),
+                "kernel_version" => Value::string(ver, span),
+            },
+            span,
+        )
+    });
+
+    record.push(
+        "startup-time",
+        Value::duration(engine_state.get_startup_time(), span),
+    );
+
+    record.push(
+        "is-interactive",
+        Value::bool(engine_state.is_interactive, span),
+    );
+
+    record.push("is-login", Value::bool(engine_state.is_login, span));
+
+    record.push(
+        "current-exe",
+        if let Ok(current_exe) = std::env::current_exe() {
+            Value::string(current_exe.to_string_lossy(), span)
+        } else {
+            Value::error(
+                ShellError::IOError("Could not get current executable path".to_string()),
+                span,
+            )
+        },
+    );
+
+    Ok(Value::record(record, span))
+}
 
 fn eval_const_call(
     working_set: &StateWorkingSet,

crates/nu-system/Cargo.toml

@@ -15,6 +15,7 @@ bench = false
 [dependencies]
 libc = "0.2"
 log = "0.4"
+sysinfo = "0.29"
 
 [target.'cfg(target_family = "unix")'.dependencies]
 nix = { version = "0.26", default-features = false, features = ["fs", "term", "process", "signal"] }
@@ -32,31 +33,31 @@ ntapi = "0.4"
 once_cell = "1.18"
 winapi = { version = "0.3", features = [
     "tlhelp32",
-    "fileapi",
-    "handleapi",
-    "ifdef",
-    "ioapiset",
-    "minwindef",
-    "pdh",
-    "psapi",
-    "synchapi",
-    "sysinfoapi",
-    "winbase",
-    "winerror",
-    "winioctl",
-    "winnt",
-    "oleauto",
-    "wbemcli",
-    "rpcdce",
-    "combaseapi",
-    "objidl",
-    "powerbase",
-    "netioapi",
-    "lmcons",
-    "lmaccess",
-    "lmapibuf",
-    "memoryapi",
-    "shellapi",
-    "std",
-    "securitybaseapi",
-] }
+        "fileapi",
+        "handleapi",
+        "ifdef",
+        "ioapiset",
+        "minwindef",
+        "pdh",
+        "psapi",
+        "synchapi",
+        "sysinfoapi",
+        "winbase",
+        "winerror",
+        "winioctl",
+        "winnt",
+        "oleauto",
+        "wbemcli",
+        "rpcdce",
+        "combaseapi",
+        "objidl",
+        "powerbase",
+        "netioapi",
+        "lmcons",
+        "lmaccess",
+        "lmapibuf",
+        "memoryapi",
+        "shellapi",
+        "std",
+        "securitybaseapi",
+        ] }

crates/nu-system/src/lib.rs

@@ -3,6 +3,7 @@ mod foreground;
 mod linux;
 #[cfg(target_os = "macos")]
 mod macos;
+pub mod os_info;
 #[cfg(target_os = "windows")]
 mod windows;
 

crates/nu-system/src/os_info.rs

@@ -0,0 +1,21 @@
+use sysinfo::SystemExt;
+
+pub fn get_os_name() -> &'static str {
+    std::env::consts::OS
+}
+
+pub fn get_os_arch() -> &'static str {
+    std::env::consts::ARCH
+}
+
+pub fn get_os_family() -> &'static str {
+    std::env::consts::FAMILY
+}
+
+pub fn get_kernel_version() -> String {
+    let sys = sysinfo::System::new();
+    match sys.kernel_version() {
+        Some(v) => v,
+        None => "unknown".to_string(),
+    }
+}

src/main.rs

@@ -24,8 +24,10 @@ use log::Level;
 use miette::Result;
 use nu_cli::gather_parent_env_vars;
 use nu_cmd_base::util::get_init_cwd;
-use nu_protocol::{engine::EngineState, report_error_new, Value};
-use nu_protocol::{util::BufferedReader, PipelineData, RawStream};
+use nu_protocol::{
+    engine::EngineState, eval_const::create_nu_constant, report_error_new, util::BufferedReader,
+    PipelineData, RawStream, Span, Value, NU_VARIABLE_ID,
+};
 use nu_std::load_standard_library;
 use nu_utils::utils::perf;
 use run::{run_commands, run_file, run_repl};
@@ -274,6 +276,10 @@ fn main() -> Result<()> {
         use_color,
     );
 
+    // Set up the $nu constant before evaluating config files (need to have $nu available in them)
+    let nu_const = create_nu_constant(&engine_state, input.span().unwrap_or_else(Span::unknown))?;
+    engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
     if let Some(commands) = parsed_nu_cli_args.commands.clone() {
         run_commands(
             &mut engine_state,

src/run.rs

@@ -7,7 +7,8 @@ use crate::{
 #[cfg(feature = "plugin")]
 use nu_cli::read_plugin_file;
 use nu_cli::{evaluate_commands, evaluate_file, evaluate_repl};
-use nu_protocol::PipelineData;
+use nu_protocol::eval_const::create_nu_constant;
+use nu_protocol::{PipelineData, Span, NU_VARIABLE_ID};
 use nu_utils::utils::perf;
 
 pub(crate) fn run_commands(
@@ -82,8 +83,14 @@ pub(crate) fn run_commands(
             use_color,
         );
     }
+
     // Before running commands, set up the startup time
     engine_state.set_startup_time(entire_start_time.elapsed().as_nanos() as i64);
+
+    // Regenerate the $nu constant to contain the startup time and any other potential updates
+    let nu_const = create_nu_constant(engine_state, commands.span)?;
+    engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
     let start_time = std::time::Instant::now();
     let ret_val = evaluate_commands(
         commands,
@@ -169,6 +176,10 @@ pub(crate) fn run_file(
         use_color,
     );
 
+    // Regenerate the $nu constant to contain the startup time and any other potential updates
+    let nu_const = create_nu_constant(engine_state, input.span().unwrap_or_else(Span::unknown))?;
+    engine_state.set_variable_const_val(NU_VARIABLE_ID, nu_const);
+
     let start_time = std::time::Instant::now();
     let ret_val = evaluate_file(
         script_name,