[target-spec] actually deserialize target_family and target_endian co…

…rrectly

Oof, this is a pretty bad bug -- we weren't deserializing these correctly.

Add some spot checks, some snapshot tests, and remove some old `rustc_version`
code.

target-spec-miette/tests/snapshot/custom-invalid/input/invalid-endian.json

@@ -0,0 +1,36 @@
+{
+    "arch": "powerpc64",
+    "abi-return-struct-as-int": true,
+    "cpu": "ppc64",
+    "crt-objects-fallback": "false",
+    "crt-static-respected": true,
+    "data-layout": "E-m:e-Fn32-i64:64-n32:64",
+    "default-dwarf-version": 2,
+    "dynamic-linking": true,
+    "has-rpath": true,
+    "has-thread-local": true,
+    "is-builtin": true,
+    "linker-flavor": "gnu-cc",
+    "llvm-target": "powerpc64-unknown-freebsd",
+    "max-atomic-width": 64,
+    "metadata": {
+        "description": "PPC64 FreeBSD (ELFv1 and ELFv2)",
+        "host_tools": true,
+        "std": true,
+        "tier": 3
+    },
+    "os": "freebsd",
+    "position-independent-executables": true,
+    "pre-link-args": {
+        "gnu-cc": ["-m64"],
+        "gnu-lld-cc": ["-m64"]
+    },
+    "relro-level": "full",
+    "stack-probes": {
+        "kind": "inline"
+    },
+    "target-endian": "middle",
+    "target-family": ["unix"],
+    "target-mcount": "_mcount",
+    "target-pointer-width": "64"
+}

target-spec-miette/tests/snapshot/custom-invalid/input/invalid-family.json

@@ -0,0 +1,36 @@
+{
+    "arch": "powerpc64",
+    "abi-return-struct-as-int": true,
+    "cpu": "ppc64",
+    "crt-objects-fallback": "false",
+    "crt-static-respected": true,
+    "data-layout": "E-m:e-Fn32-i64:64-n32:64",
+    "default-dwarf-version": 2,
+    "dynamic-linking": true,
+    "has-rpath": true,
+    "has-thread-local": true,
+    "is-builtin": true,
+    "linker-flavor": "gnu-cc",
+    "llvm-target": "powerpc64-unknown-freebsd",
+    "max-atomic-width": 64,
+    "metadata": {
+        "description": "PPC64 FreeBSD (ELFv1 and ELFv2)",
+        "host_tools": true,
+        "std": true,
+        "tier": 3
+    },
+    "os": "freebsd",
+    "position-independent-executables": true,
+    "pre-link-args": {
+        "gnu-cc": ["-m64"],
+        "gnu-lld-cc": ["-m64"]
+    },
+    "relro-level": "full",
+    "stack-probes": {
+        "kind": "inline"
+    },
+    "target-endian": "big",
+    "target-family": "none",
+    "target-mcount": "_mcount",
+    "target-pointer-width": "64"
+}

target-spec-miette/tests/snapshot/custom-invalid/output/invalid-endian.json-display.snap

@@ -0,0 +1,15 @@
+---
+source: target-spec-miette/tests/snapshot/custom.rs
+expression: "format!(\"{:?}\", miette::Report::new_boxed(diagnostic))"
+snapshot_kind: text
+---
+  × error deserializing custom target JSON for `my-target`
+  ╰─▶ unknown variant `middle`, expected `little` or `big` at line 32 column
+      29
+    ╭─[32:29]
+ 31 │     },
+ 32 │     "target-endian": "middle",
+    ·                             ▲
+    ·                             ╰── unknown variant `middle`, expected `little` or `big`
+ 33 │     "target-family": ["unix"],
+    ╰────

target-spec-miette/tests/snapshot/custom-invalid/output/invalid-family.json-display.snap

@@ -0,0 +1,14 @@
+---
+source: target-spec-miette/tests/snapshot/custom.rs
+expression: "format!(\"{:?}\", miette::Report::new_boxed(diagnostic))"
+snapshot_kind: text
+---
+  × error deserializing custom target JSON for `my-target`
+  ╰─▶ invalid type: string "none", expected a sequence at line 33 column 27
+    ╭─[33:27]
+ 32 │     "target-endian": "big",
+ 33 │     "target-family": "none",
+    ·                           ▲
+    ·                           ╰── invalid type: string "none", expected a sequence
+ 34 │     "target-mcount": "_mcount",
+    ╰────

target-spec/Cargo.toml

@@ -29,7 +29,6 @@ unicode-ident = "1.0.14"
 guppy-workspace-hack.workspace = true
 
 [dev-dependencies]
-rustc_version = "0.4.1"
 test-case = "3.3.1"
 toml = "0.5.11"
 

target-spec/src/custom.rs

@@ -13,6 +13,13 @@ use serde::{Deserialize, Serialize};
 #[derive(Clone, Debug, Deserialize, Serialize, Eq, Hash, Ord, PartialEq, PartialOrd)]
 #[serde(rename_all = "kebab-case")]
 pub(crate) struct TargetDefinition {
+    // TODO: it would be nice to use target-spec-json for this, but that has a
+    // few limitations as of v0.1:
+    //
+    // * target-pointer-width is a string, not an integer.
+    // * Os and Env deserialized to enums, but we would really like them to be strings.
+    //
+    // ---
     arch: String,
     #[serde(rename = "target-pointer-width", with = "target_pointer_width")]
     pointer_width: u8,
@@ -34,9 +41,9 @@ pub(crate) struct TargetDefinition {
     #[serde(default)]
     vendor: Option<String>,
     #[serde(default)]
-    families: Vec<String>,
+    target_family: Vec<String>,
     #[serde(default)]
-    endian: Endian,
+    target_endian: Endian,
     #[serde(default)]
     min_atomic_width: Option<u16>,
     #[serde(default)]
@@ -76,9 +83,9 @@ impl TargetDefinition {
             arch: Arch::new(self.arch),
             env: self.env.map(Env::new),
             vendor: self.vendor.map(Vendor::new),
-            families: Families::new(self.families.into_iter().map(Family::new)),
+            families: Families::new(self.target_family.into_iter().map(Family::new)),
             pointer_width: self.pointer_width,
-            endian: self.endian.to_cfg_expr(),
+            endian: self.target_endian.to_cfg_expr(),
             has_atomics: HasAtomics::new(has_atomics),
             panic: self.panic_strategy.to_cfg_expr(),
         }
@@ -156,13 +163,6 @@ mod tests {
 
     #[test]
     fn test_all_builtin_specs_recognized() {
-        let version = rustc_version::version().expect("rustc_version succeeded");
-        if version.minor < 70 {
-            // all-target-specs-json is only present on Rust 1.70 and above.
-            println!("** skipping, minor version {} < 70", version.minor);
-            return;
-        }
-
         let rustc_bin: String = std::env::var("RUSTC").unwrap_or_else(|_| "rustc".to_owned());
         let output = Command::new(rustc_bin)
             // Used for -Zunstable-options. This is test-only code so it doesn't matter.
@@ -178,12 +178,28 @@ mod tests {
             eprintln!("*** testing {triple}");
             // Just make sure this doesn't panic. (If this becomes fallible in the future, then this
             // shouldn't return an error either.)
-            target_def.clone().into_target_info(triple.into());
+            target_def.clone().into_target_info(triple.clone().into());
             let json =
                 serde_json::to_string(&target_def).expect("target def serialized successfully");
             eprintln!("* minified json: {json}");
             let target_def_2 = serde_json::from_str(&json).expect("target def 2 deserialized");
             assert_eq!(target_def, target_def_2, "matches");
+
+            // Do some spot checks for things like big-endian targets.
+            if triple.contains("powerpc") {
+                assert_eq!(
+                    target_def.target_endian,
+                    Endian::Big,
+                    "powerpc is big-endian"
+                );
+            }
+            if triple.contains("-linux") {
+                assert!(
+                    target_def.target_family.contains(&"unix".to_owned()),
+                    "linux target_family should contain unix (was {:#?})",
+                    target_def.target_family,
+                );
+            }
         }
     }
 }

workspace-hack/Cargo.toml

@@ -33,7 +33,6 @@ petgraph = { version = "0.6.5", default-features = false, features = ["graphmap"
 regex = { version = "1.10.5", default-features = false, features = ["perf", "std"] }
 regex-automata = { version = "0.4.5", default-features = false, features = ["dfa", "hybrid", "meta", "nfa", "perf", "unicode"] }
 regex-syntax = { version = "0.8.2" }
-semver = { version = "1.0.23", features = ["serde"] }
 serde = { version = "1.0.215", features = ["alloc", "derive"] }
 serde_json = { version = "1.0.133", features = ["unbounded_depth"] }
 textwrap = { version = "0.16.0" }