From c6945acad7a14b6afb390a4afc1d354ef5413ea6 Mon Sep 17 00:00:00 2001
From: Matthew Maurer <mmaurer@google.com>
Date: Tue, 30 Jul 2024 09:26:24 +0000
Subject: rust: support arrays in target JSON

Some configuration options such as the supported sanitizer list are
arrays. To support using Rust with sanitizers on x86, we must update the
target.json generator to support this case.

The Push trait is removed in favor of the From trait because the Push
trait doesn't work well in the nested case where you are not really
pushing values to a TargetSpec.

Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Tested-by: Gatlin Newhouse <gatlin.newhouse@gmail.com>
Link: https://lore.kernel.org/r/20240730-target-json-arrays-v1-1-2b376fd0ecf4@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
 scripts/generate_rust_target.rs | 82 ++++++++++++++++++++++++++---------------
 1 file changed, 53 insertions(+), 29 deletions(-)

(limited to 'scripts/generate_rust_target.rs')

diff --git a/scripts/generate_rust_target.rs b/scripts/generate_rust_target.rs
index 863720777313..fbf723996d20 100644
--- a/scripts/generate_rust_target.rs
+++ b/scripts/generate_rust_target.rs
@@ -20,12 +20,28 @@ enum Value {
     Boolean(bool),
     Number(i32),
     String(String),
+    Array(Vec<Value>),
     Object(Object),
 }
 
 type Object = Vec<(String, Value)>;
 
-/// Minimal "almost JSON" generator (e.g. no `null`s, no arrays, no escaping),
+fn comma_sep<T>(
+    seq: &[T],
+    formatter: &mut Formatter<'_>,
+    f: impl Fn(&mut Formatter<'_>, &T) -> Result,
+) -> Result {
+    if let [ref rest @ .., ref last] = seq[..] {
+        for v in rest {
+            f(formatter, v)?;
+            formatter.write_str(",")?;
+        }
+        f(formatter, last)?;
+    }
+    Ok(())
+}
+
+/// Minimal "almost JSON" generator (e.g. no `null`s, no escaping),
 /// enough for this purpose.
 impl Display for Value {
     fn fmt(&self, formatter: &mut Formatter<'_>) -> Result {
@@ -33,59 +49,67 @@ impl Display for Value {
             Value::Boolean(boolean) => write!(formatter, "{}", boolean),
             Value::Number(number) => write!(formatter, "{}", number),
             Value::String(string) => write!(formatter, "\"{}\"", string),
+            Value::Array(values) => {
+                formatter.write_str("[")?;
+                comma_sep(&values[..], formatter, |formatter, v| v.fmt(formatter))?;
+                formatter.write_str("]")
+            }
             Value::Object(object) => {
                 formatter.write_str("{")?;
-                if let [ref rest @ .., ref last] = object[..] {
-                    for (key, value) in rest {
-                        write!(formatter, "\"{}\": {},", key, value)?;
-                    }
-                    write!(formatter, "\"{}\": {}", last.0, last.1)?;
-                }
+                comma_sep(&object[..], formatter, |formatter, v| {
+                    write!(formatter, "\"{}\": {}", v.0, v.1)
+                })?;
                 formatter.write_str("}")
             }
         }
     }
 }
 
-struct TargetSpec(Object);
-
-impl TargetSpec {
-    fn new() -> TargetSpec {
-        TargetSpec(Vec::new())
+impl From<bool> for Value {
+    fn from(value: bool) -> Self {
+        Self::Boolean(value)
     }
 }
 
-trait Push<T> {
-    fn push(&mut self, key: &str, value: T);
+impl From<i32> for Value {
+    fn from(value: i32) -> Self {
+        Self::Number(value)
+    }
 }
 
-impl Push<bool> for TargetSpec {
-    fn push(&mut self, key: &str, value: bool) {
-        self.0.push((key.to_string(), Value::Boolean(value)));
+impl From<String> for Value {
+    fn from(value: String) -> Self {
+        Self::String(value)
     }
 }
 
-impl Push<i32> for TargetSpec {
-    fn push(&mut self, key: &str, value: i32) {
-        self.0.push((key.to_string(), Value::Number(value)));
+impl From<&str> for Value {
+    fn from(value: &str) -> Self {
+        Self::String(value.to_string())
     }
 }
 
-impl Push<String> for TargetSpec {
-    fn push(&mut self, key: &str, value: String) {
-        self.0.push((key.to_string(), Value::String(value)));
+impl From<Object> for Value {
+    fn from(object: Object) -> Self {
+        Self::Object(object)
     }
 }
 
-impl Push<&str> for TargetSpec {
-    fn push(&mut self, key: &str, value: &str) {
-        self.push(key, value.to_string());
+impl<T: Into<Value>, const N: usize> From<[T; N]> for Value {
+    fn from(i: [T; N]) -> Self {
+        Self::Array(i.into_iter().map(|v| v.into()).collect())
     }
 }
 
-impl Push<Object> for TargetSpec {
-    fn push(&mut self, key: &str, value: Object) {
-        self.0.push((key.to_string(), Value::Object(value)));
+struct TargetSpec(Object);
+
+impl TargetSpec {
+    fn new() -> TargetSpec {
+        TargetSpec(Vec::new())
+    }
+
+    fn push(&mut self, key: &str, value: impl Into<Value>) {
+        self.0.push((key.to_string(), value.into()));
     }
 }
 
-- 
cgit