Port cargo from toml-rs to toml_edit

Benefits:
- A TOML 1.0 compliant parser
- Unblock future work
  - Have `cargo init` add the current crate to the workspace, rather
    than error
  - #5586: Upstream `cargo-add`

Cargo.toml

@@ -57,7 +57,7 @@ strip-ansi-escapes = "0.1.0"
 tar = { version = "0.4.36", default-features = false }
 tempfile = "3.0"
 termcolor = "1.1"
-toml = "0.5.7"
+toml_edit =  { version = "0.13", features = ["serde", "easy"] }
 unicode-xid = "0.2.0"
 url = "2.2.2"
 walkdir = "2.2"

benches/capture/Cargo.toml

@@ -9,4 +9,4 @@ description = "Tool for capturing a real-world workspace for benchmarking."
 cargo_metadata = "0.14.0"
 flate2 = { version = "1.0.3", default-features = false, features = ["zlib"] }
 tar = { version = "0.4.35", default-features = false }
-toml = "0.5.8"
+toml_edit =  { version = "0.9.1", features = ["easy"] }

benches/capture/src/main.rs

@@ -8,6 +8,7 @@ use flate2::{Compression, GzBuilder};
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::process::Command;
+use toml_edit::easy as toml;
 
 fn main() {
     let force = std::env::args().any(|arg| arg == "-f");

crates/cargo-test-support/Cargo.toml

@@ -21,7 +21,7 @@ remove_dir_all = "0.5"
 serde_json = "1.0"
 tar = { version = "0.4.18", default-features = false }
 termcolor = "1.1.2"
-toml = "0.5.7"
+toml_edit =  { version = "0.9.1", features = ["serde", "easy"] }
 url = "2.2.2"
 
 [features]

crates/cargo-test-support/src/registry.rs

@@ -709,7 +709,7 @@ impl Package {
         if !self.cargo_features.is_empty() {
             manifest.push_str(&format!(
                 "cargo-features = {}\n\n",
-                toml::to_string(&self.cargo_features).unwrap()
+                toml_edit::ser::to_item(&self.cargo_features).unwrap()
             ));
         }
 

src/cargo/core/manifest.rs

@@ -9,6 +9,7 @@ use anyhow::Context as _;
 use semver::Version;
 use serde::ser;
 use serde::Serialize;
+use toml_edit::easy as toml;
 use url::Url;
 
 use crate::core::compiler::{CompileKind, CrateType};

src/cargo/core/package.rs

@@ -16,6 +16,7 @@ use lazycell::LazyCell;
 use log::{debug, warn};
 use semver::Version;
 use serde::Serialize;
+use toml_edit::easy as toml;
 
 use crate::core::compiler::{CompileKind, RustcTargetData};
 use crate::core::dependency::DepKind;
@@ -199,7 +200,7 @@ impl Package {
             .manifest()
             .original()
             .prepare_for_publish(ws, self.root())?;
-        let toml = toml::to_string(&manifest)?;
+        let toml = toml::to_string_pretty(&manifest)?;
         Ok(format!("{}\n{}", MANIFEST_PREAMBLE, toml))
     }
 

src/cargo/core/workspace.rs

@@ -8,6 +8,7 @@ use anyhow::{bail, Context as _};
 use glob::glob;
 use itertools::Itertools;
 use log::debug;
+use toml_edit::easy as toml;
 use url::Url;
 
 use crate::core::features::Features;

src/cargo/ops/cargo_config.rs

@@ -127,19 +127,24 @@ fn print_toml(config: &Config, opts: &GetOptions<'_>, key: &ConfigKey, cv: &CV)
             config,
             "{} = {}{}",
             key,
-            toml::to_string(&val).unwrap(),
+            toml_edit::Value::from(val),
             origin(def)
         ),
         CV::List(vals, _def) => {
             if opts.show_origin {
                 drop_println!(config, "{} = [", key);
                 for (val, def) in vals {
-                    drop_println!(config, "    {}, # {}", toml::to_string(&val).unwrap(), def);
+                    drop_println!(
+                        config,
+                        "    {}, # {}",
+                        toml_edit::ser::to_item(&val).unwrap(),
+                        def
+                    );
                 }
                 drop_println!(config, "]");
             } else {
-                let vals: Vec<&String> = vals.iter().map(|x| &x.0).collect();
-                drop_println!(config, "{} = {}", key, toml::to_string(&vals).unwrap());
+                let vals: toml_edit::Array = vals.iter().map(|x| &x.0).collect();
+                drop_println!(config, "{} = {}", key, vals);
             }
         }
         CV::Table(table, _def) => {

src/cargo/ops/cargo_new.rs

@@ -12,6 +12,7 @@ use std::io::{BufRead, BufReader, ErrorKind};
 use std::path::{Path, PathBuf};
 use std::process::Command;
 use std::str::{from_utf8, FromStr};
+use toml_edit::easy as toml;
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub enum VersionControl {

src/cargo/ops/cargo_output_metadata.rs

@@ -10,6 +10,7 @@ use cargo_platform::Platform;
 use serde::Serialize;
 use std::collections::BTreeMap;
 use std::path::PathBuf;
+use toml_edit::easy as toml;
 
 const VERSION: u32 = 1;
 

src/cargo/ops/common_for_install_and_uninstall.rs

@@ -7,6 +7,7 @@ use std::rc::Rc;
 
 use anyhow::{bail, format_err, Context as _};
 use serde::{Deserialize, Serialize};
+use toml_edit::easy as toml;
 
 use crate::core::compiler::Freshness;
 use crate::core::{Dependency, FeatureValue, Package, PackageId, Source, SourceId};

src/cargo/ops/lockfile.rs

@@ -6,6 +6,7 @@ use crate::util::toml as cargo_toml;
 use crate::util::Filesystem;
 
 use anyhow::Context as _;
+use toml_edit::easy as toml;
 
 pub fn load_pkg_lockfile(ws: &Workspace<'_>) -> CargoResult<Option<Resolve>> {
     if !ws.root().join("Cargo.lock").exists() {
@@ -100,7 +101,7 @@ fn resolve_to_string_orig(
 }
 
 fn serialize_resolve(resolve: &Resolve, orig: Option<&str>) -> String {
-    let toml = toml::Value::try_from(resolve).unwrap();
+    let toml = toml_edit::ser::to_item(resolve).unwrap();
 
     let mut out = String::new();
 
@@ -139,7 +140,7 @@ fn serialize_resolve(resolve: &Resolve, orig: Option<&str>) -> String {
 
     let deps = toml["package"].as_array().unwrap();
     for dep in deps {
-        let dep = dep.as_table().unwrap();
+        let dep = dep.as_inline_table().unwrap();
 
         out.push_str("[[package]]\n");
         emit_package(dep, &mut out);
@@ -149,14 +150,23 @@ fn serialize_resolve(resolve: &Resolve, orig: Option<&str>) -> String {
         let list = patch["unused"].as_array().unwrap();
         for entry in list {
             out.push_str("[[patch.unused]]\n");
-            emit_package(entry.as_table().unwrap(), &mut out);
+            emit_package(entry.as_inline_table().unwrap(), &mut out);
             out.push('\n');
         }
     }
 
     if let Some(meta) = toml.get("metadata") {
-        out.push_str("[metadata]\n");
-        out.push_str(&meta.to_string());
+        // 1. We need to ensure we print the entire tree, not just the direct members of `metadata`
+        //    (which `toml_edit::Table::to_string` only shows)
+        // 2. We need to ensure all children tables have `metadata.` prefix
+        let meta_table = meta
+            .clone()
+            .into_table()
+            .expect("validation ensures this is a table");
+        let mut meta_doc = toml_edit::Document::new();
+        meta_doc["metadata"] = toml_edit::Item::Table(meta_table);
+
+        out.push_str(&meta_doc.to_string());
     }
 
     // Historical versions of Cargo in the old format accidentally left trailing
@@ -190,7 +200,7 @@ fn are_equal_lockfiles(orig: &str, current: &str, ws: &Workspace<'_>) -> bool {
     orig.lines().eq(current.lines())
 }
 
-fn emit_package(dep: &toml::value::Table, out: &mut String) {
+fn emit_package(dep: &toml_edit::InlineTable, out: &mut String) {
     out.push_str(&format!("name = {}\n", &dep["name"]));
     out.push_str(&format!("version = {}\n", &dep["version"]));
 

src/cargo/ops/vendor.rs

@@ -12,6 +12,7 @@ use std::collections::{BTreeMap, BTreeSet, HashMap};
 use std::fs::{self, File, OpenOptions};
 use std::io::{Read, Write};
 use std::path::{Path, PathBuf};
+use toml_edit::easy as toml;
 
 pub struct VendorOptions<'a> {
     pub no_delete: bool,

src/cargo/util/config/key.rs

@@ -111,6 +111,6 @@ fn escape_key_part<'a>(part: &'a str) -> Cow<'a, str> {
         Cow::Borrowed(part)
     } else {
         // This is a bit messy, but toml doesn't expose a function to do this.
-        Cow::Owned(toml::to_string(&toml::Value::String(part.to_string())).unwrap())
+        Cow::Owned(toml_edit::Value::from(part).to_string())
     }
 }

src/cargo/util/config/mod.rs

@@ -79,6 +79,7 @@ use cargo_util::paths;
 use curl::easy::Easy;
 use lazycell::LazyCell;
 use serde::Deserialize;
+use toml_edit::easy as toml;
 use url::Url;
 
 mod de;

src/cargo/util/config/target.rs

@@ -4,6 +4,7 @@ use crate::util::CargoResult;
 use serde::Deserialize;
 use std::collections::{BTreeMap, HashMap};
 use std::path::PathBuf;
+use toml_edit::easy as toml;
 
 /// Config definition of a `[target.'cfg(…)']` table.
 ///

src/cargo/util/toml/mod.rs

@@ -13,6 +13,7 @@ use semver::{self, VersionReq};
 use serde::de;
 use serde::ser;
 use serde::{Deserialize, Serialize};
+use toml_edit::easy as toml;
 use url::Url;
 
 use crate::core::compiler::{CompileKind, CompileTarget};
@@ -77,16 +78,21 @@ pub fn read_manifest_from_str(
         let pretty_filename = manifest_file
             .strip_prefix(config.cwd())
             .unwrap_or(manifest_file);
-        parse(contents, pretty_filename, config)?
+        parse_document(contents, pretty_filename, config)?
     };
 
     // Provide a helpful error message for a common user error.
     if let Some(package) = toml.get("package").or_else(|| toml.get("project")) {
         if let Some(feats) = package.get("cargo-features") {
+            let mut feats = feats.clone();
+            if let Some(value) = feats.as_value_mut() {
+                // Only keep formatting inside of the `[]` and not formatting around it
+                value.decor_mut().clear();
+            }
             bail!(
                 "cargo-features = {} was found in the wrong location: it \
                  should be set at the top of Cargo.toml before any tables",
-                toml::to_string(feats).unwrap()
+                feats.to_string()
             );
         }
     }
@@ -164,6 +170,16 @@ pub fn parse(toml: &str, _file: &Path, _config: &Config) -> CargoResult<toml::Va
         .map_err(|e| anyhow::Error::from(e).context("could not parse input as TOML"))
 }
 
+pub fn parse_document(
+    toml: &str,
+    _file: &Path,
+    _config: &Config,
+) -> CargoResult<toml_edit::Document> {
+    // At the moment, no compatibility checks are needed.
+    toml.parse()
+        .map_err(|e| anyhow::Error::from(e).context("could not parse input as TOML"))
+}
+
 type TomlLibTarget = TomlTarget;
 type TomlBinTarget = TomlTarget;
 type TomlExampleTarget = TomlTarget;

tests/testsuite/bad_config.rs

@@ -196,7 +196,12 @@ Caused by:
   could not parse input as TOML
 
 Caused by:
-  expected an equals, found eof at line 1 column 2
+  TOML parse error at line 1, column 2
+    |
+  1 | 4
+    |  ^
+  Unexpected end of input
+  Expected `.` or `=`
 ",
         )
         .run();
@@ -442,7 +447,13 @@ Caused by:
   could not parse input as TOML
 
 Caused by:
-  expected a table key, found a newline at line 8 column 27
+  TOML parse error at line 8, column 27
+    |
+  8 |                 native = {
+    |                           ^
+  Unexpected `
+  `
+  Expected key
 ",
         )
         .run();
@@ -781,7 +792,26 @@ fn invalid_toml_historically_allowed_fails() {
 
     p.cargo("build")
         .with_status(101)
-        .with_stderr_contains("  expected newline, found an identifier at line 1 column 7")
+        .with_stderr(
+            "\
+error: could not load Cargo configuration
+
+Caused by:
+  could not parse TOML configuration in `[..]`
+
+Caused by:
+  could not parse input as TOML
+
+Caused by:
+  TOML parse error at line 1, column 7
+    |
+  1 | [bar] baz = 2
+    |       ^
+  Unexpected `b`
+  Expected newline or end of input
+  While parsing a Table Header
+",
+        )
         .run();
 }
 

tests/testsuite/build.rs

@@ -198,7 +198,12 @@ Caused by:
   could not parse input as TOML
 
 Caused by:
-  invalid TOML value, did you mean to use a quoted string? at line 3 column 23
+  TOML parse error at line 3, column 23
+    |
+  3 |                 foo = bar
+    |                       ^
+  Unexpected `b`
+  Expected quoted string
 ",
         )
         .run();
@@ -218,7 +223,12 @@ Caused by:
   could not parse input as TOML
 
 Caused by:
-  invalid TOML value, did you mean to use a quoted string? at line 1 column 5
+  TOML parse error at line 1, column 5
+    |
+  1 | a = bar
+    |     ^
+  Unexpected `b`
+  Expected quoted string
 ",
         )
         .run();
@@ -2740,7 +2750,12 @@ Caused by:
   could not parse input as TOML
 
 Caused by:
-  expected an equals, found an identifier at line 1 column 6
+  TOML parse error at line 1, column 6
+    |
+  1 | this is not valid toml
+    |      ^
+  Unexpected `i`
+  Expected `.` or `=`
 ",
         )
         .run();