Auto merge of #12298 - weihanglo:config-include-toml, r=epage

Add `.toml` file extension restriction for `-Zconfig-include`

Author: bors

src/cargo/util/config/mod.rs

@@ -1273,6 +1273,16 @@ impl Config {
                 return Ok(Vec::new());
             }
         };
+
+        for (path, abs_path, def) in &includes {
+            if abs_path.extension() != Some(OsStr::new("toml")) {
+                bail!(
+                    "expected a config include path ending with `.toml`, \
+                     but found `{path}` from `{def}`",
+                )
+            }
+        }
+
         Ok(includes)
     }
 

src/doc/src/reference/unstable.md

@@ -452,27 +452,30 @@ cargo check --keep-going -Z unstable-options
 ### config-include
 * Tracking Issue: [#7723](https://github.com/rust-lang/cargo/issues/7723)
 
+This feature requires the `-Zconfig-include` command-line option.
+
 The `include` key in a config file can be used to load another config file. It
-takes a string for a path to another file relative to the config file, or a
-list of strings. It requires the `-Zconfig-include` command-line option.
+takes a string for a path to another file relative to the config file, or an
+array of config file paths. Only path ending with `.toml` is accepted.
 
 ```toml
-# .cargo/config
-include = '../../some-common-config.toml'
-```
-
-The config values are first loaded from the include path, and then the config
-file's own values are merged on top of it.
+# a path ending with `.toml`
+include = "path/to/mordor.toml"
 
-This can be paired with [config-cli](#config-cli) to specify a file to load
-from the command-line. Pass a path to a config file as the argument to
-`--config`:
-
-```console
-cargo +nightly -Zunstable-options -Zconfig-include --config somefile.toml build
+# or an array of paths
+include = ["frodo.toml", "samwise.toml"]
 ```
 
-CLI paths are relative to the current working directory.
+Unlike other config values, the merge behavior of the `include` key is
+different. When a config file contains an `include` key:
+
+1. The config values are first loaded from the `include` path.
+    * If the value of the `include` key is an array of paths, the config values
+      are loaded and merged from left to right for each path.
+    * Recurse this step if the config values from the `include` path also
+      contain an `include` key.
+2. Then, the config file's own values are merged on top of the config
+   from the `include` path.
 
 ### target-applies-to-host
 * Original Pull Request: [#9322](https://github.com/rust-lang/cargo/pull/9322)

tests/testsuite/config_include.rs

@@ -6,9 +6,9 @@ use cargo_test_support::{no_such_file_err_msg, project};
 #[cargo_test]
 fn gated() {
     // Requires -Z flag.
-    write_config("include='other'");
+    write_config("include='other.toml'");
     write_config_at(
-        ".cargo/other",
+        ".cargo/other.toml",
         "
         othervalue = 1
         ",
@@ -25,13 +25,13 @@ fn simple() {
     write_config_at(
         ".cargo/config",
         "
-        include = 'other'
+        include = 'other.toml'
         key1 = 1
         key2 = 2
         ",
     );
     write_config_at(
-        ".cargo/other",
+        ".cargo/other.toml",
         "
         key2 = 3
         key3 = 4
@@ -84,39 +84,63 @@ fn works_with_cli() {
 }
 
 #[cargo_test]
-fn left_to_right() {
-    // How it merges multiple includes.
+fn left_to_right_bottom_to_top() {
+    // How it merges multiple nested includes.
     write_config_at(
         ".cargo/config",
         "
-        include = ['one', 'two']
-        primary = 1
+        include = ['left-middle.toml', 'right-middle.toml']
+        top = 1
+        ",
+    );
+    write_config_at(
+        ".cargo/right-middle.toml",
+        "
+        include = 'right-bottom.toml'
+        top = 0
+        right-middle = 0
         ",
     );
     write_config_at(
-        ".cargo/one",
+        ".cargo/right-bottom.toml",
         "
-        one = 1
-        primary = 2
+        top = -1
+        right-middle = -1
+        right-bottom = -1
         ",
     );
     write_config_at(
-        ".cargo/two",
+        ".cargo/left-middle.toml",
         "
-        two = 2
-        primary = 3
+        include = 'left-bottom.toml'
+        top = -2
+        right-middle = -2
+        right-bottom = -2
+        left-middle = -2
+        ",
+    );
+    write_config_at(
+        ".cargo/left-bottom.toml",
+        "
+        top = -3
+        right-middle = -3
+        right-bottom = -3
+        left-middle = -3
+        left-bottom = -3
         ",
     );
     let config = ConfigBuilder::new().unstable_flag("config-include").build();
-    assert_eq!(config.get::<i32>("primary").unwrap(), 1);
-    assert_eq!(config.get::<i32>("one").unwrap(), 1);
-    assert_eq!(config.get::<i32>("two").unwrap(), 2);
+    assert_eq!(config.get::<i32>("top").unwrap(), 1);
+    assert_eq!(config.get::<i32>("right-middle").unwrap(), 0);
+    assert_eq!(config.get::<i32>("right-bottom").unwrap(), -1);
+    assert_eq!(config.get::<i32>("left-middle").unwrap(), -2);
+    assert_eq!(config.get::<i32>("left-bottom").unwrap(), -3);
 }
 
 #[cargo_test]
 fn missing_file() {
     // Error when there's a missing file.
-    write_config("include='missing'");
+    write_config("include='missing.toml'");
     let config = ConfigBuilder::new()
         .unstable_flag("config-include")
         .build_err();
@@ -127,10 +151,10 @@ fn missing_file() {
 could not load Cargo configuration
 
 Caused by:
-  failed to load config include `missing` from `[..]/.cargo/config`
+  failed to load config include `missing.toml` from `[..]/.cargo/config`
 
 Caused by:
-  failed to read configuration file `[..]/.cargo/missing`
+  failed to read configuration file `[..]/.cargo/missing.toml`
 
 Caused by:
   {}",
@@ -139,12 +163,30 @@ Caused by:
     );
 }
 
+#[cargo_test]
+fn wrong_file_extension() {
+    // Error when it doesn't end with `.toml`.
+    write_config("include='config.png'");
+    let config = ConfigBuilder::new()
+        .unstable_flag("config-include")
+        .build_err();
+    assert_error(
+        config.unwrap_err(),
+        "\
+could not load Cargo configuration
+
+Caused by:
+  expected a config include path ending with `.toml`, but found `config.png` from `[..]/.cargo/config`
+",
+    );
+}
+
 #[cargo_test]
 fn cycle() {
     // Detects a cycle.
-    write_config_at(".cargo/config", "include='one'");
-    write_config_at(".cargo/one", "include='two'");
-    write_config_at(".cargo/two", "include='config'");
+    write_config_at(".cargo/config.toml", "include='one.toml'");
+    write_config_at(".cargo/one.toml", "include='two.toml'");
+    write_config_at(".cargo/two.toml", "include='config.toml'");
     let config = ConfigBuilder::new()
         .unstable_flag("config-include")
         .build_err();
@@ -154,16 +196,16 @@ fn cycle() {
 could not load Cargo configuration
 
 Caused by:
-  failed to load config include `one` from `[..]/.cargo/config`
+  failed to load config include `one.toml` from `[..]/.cargo/config.toml`
 
 Caused by:
-  failed to load config include `two` from `[..]/.cargo/one`
+  failed to load config include `two.toml` from `[..]/.cargo/one.toml`
 
 Caused by:
-  failed to load config include `config` from `[..]/.cargo/two`
+  failed to load config include `config.toml` from `[..]/.cargo/two.toml`
 
 Caused by:
-  config `include` cycle detected with path `[..]/.cargo/config`",
+  config `include` cycle detected with path `[..]/.cargo/config.toml`",
     );
 }
 
@@ -178,10 +220,10 @@ fn cli_include() {
         bar = 2
         ",
     );
-    write_config_at(".cargo/config-foo", "foo = 2");
+    write_config_at(".cargo/config-foo.toml", "foo = 2");
     let config = ConfigBuilder::new()
         .unstable_flag("config-include")
-        .config_arg("include='.cargo/config-foo'")
+        .config_arg("include='.cargo/config-foo.toml'")
         .build();
     assert_eq!(config.get::<i32>("foo").unwrap(), 2);
     assert_eq!(config.get::<i32>("bar").unwrap(), 2);
@@ -209,7 +251,7 @@ fn cli_include_failed() {
     // Error message when CLI include fails to load.
     let config = ConfigBuilder::new()
         .unstable_flag("config-include")
-        .config_arg("include='foobar'")
+        .config_arg("include='foobar.toml'")
         .build_err();
     assert_error(
         config.unwrap_err(),
@@ -218,10 +260,10 @@ fn cli_include_failed() {
 failed to load --config include
 
 Caused by:
-  failed to load config include `foobar` from `--config cli option`
+  failed to load config include `foobar.toml` from `--config cli option`
 
 Caused by:
-  failed to read configuration file `[..]/foobar`
+  failed to read configuration file `[..]/foobar.toml`
 
 Caused by:
   {}",
@@ -235,14 +277,14 @@ fn cli_merge_failed() {
     // Error message when CLI include merge fails.
     write_config("foo = ['a']");
     write_config_at(
-        ".cargo/other",
+        ".cargo/other.toml",
         "
         foo = 'b'
         ",
     );
     let config = ConfigBuilder::new()
         .unstable_flag("config-include")
-        .config_arg("include='.cargo/other'")
+        .config_arg("include='.cargo/other.toml'")
         .build_err();
     // Maybe this error message should mention it was from an include file?
     assert_error(
@@ -251,7 +293,7 @@ fn cli_merge_failed() {
 failed to merge --config key `foo` into `[..]/.cargo/config`
 
 Caused by:
-  failed to merge config value from `[..]/.cargo/other` into `[..]/.cargo/config`: \
+  failed to merge config value from `[..]/.cargo/other.toml` into `[..]/.cargo/config`: \
   expected array, but found string",
     );
 }