1 files changed, 91 insertions, 6 deletions

diff --git a/src/makefile/inference_rules.rs b/src/makefile/inference_rules.rs
index 8d4f3b6..d7db1e6 100644
--- a/src/makefile/inference_rules.rs
+++ b/src/makefile/inference_rules.rs
@@ -1,18 +1,18 @@
-use std::fmt;
+use std::collections::HashMap;
+use std::{fmt, mem};
 
+use super::pattern::r#match;
+use super::{CommandLine, ItemSource, MacroSet};
 use eyre::{eyre, OptionExt, Result};
 use regex::Captures;
 
-use super::command_line::CommandLine;
-use super::pattern::r#match;
-use super::ItemSource;
-
-#[derive(PartialEq, Eq, Clone, Debug)]
+#[derive(Clone, Debug)]
 pub struct InferenceRule {
     pub source: ItemSource,
     pub products: Vec<String>,
     pub prerequisites: Vec<String>,
     pub commands: Vec<CommandLine>,
+    pub macros: MacroSet,
 }
 
 impl InferenceRule {
@@ -22,12 +22,14 @@ impl InferenceRule {
         s1: String,
         s2: String,
         commands: Vec<CommandLine>,
+        macros: MacroSet,
     ) -> Self {
         Self {
             source,
             products: vec![format!("%{}", s1)],
             prerequisites: vec![format!("%{}", s2)],
             commands,
+            macros,
         }
     }
 
@@ -58,6 +60,30 @@ impl InferenceRule {
             .iter()
             .map(move |p| p.replace('%', percent_expansion)))
     }
+
+    fn extend(&mut self, other: Self) {
+        assert_eq!(&self.products, &other.products);
+        match (self.commands.is_empty(), other.commands.is_empty()) {
+            (false, false) => {
+                // both rules have commands, so replace this entirely
+                *self = other;
+            }
+            (true, false) => {
+                // this rule doesn't have commands, but the other one does,
+                // so it's the real one
+                let mut other = other;
+                mem::swap(self, &mut other);
+                self.extend(other);
+            }
+            (false, true) | (true, true) => {
+                // this rule might have commands, but the other one doesn't,
+                // so append non-command stuff
+                // TODO decide something smart about sources
+                self.prerequisites.extend(other.prerequisites);
+                self.macros.extend(other.macros);
+            }
+        }
+    }
 }
 
 impl fmt::Display for InferenceRule {
@@ -75,6 +101,63 @@ impl fmt::Display for InferenceRule {
     }
 }
 
+#[derive(Clone, Default)]
+pub struct InferenceRuleSet {
+    /// Maps from products to a map from prerequisites to rules.
+    data: HashMap<Vec<String>, HashMap<Vec<String>, InferenceRule>>,
+}
+
+impl InferenceRuleSet {
+    pub fn get(&self, products: &[String], prerequisites: &[String]) -> Option<&InferenceRule> {
+        self.data.get(products).and_then(|x| x.get(prerequisites))
+    }
+
+    fn get_mut(
+        &mut self,
+        products: &[String],
+        prerequisites: &[String],
+    ) -> Option<&mut InferenceRule> {
+        self.data
+            .get_mut(products)
+            .and_then(|x| x.get_mut(prerequisites))
+    }
+
+    pub fn put(&mut self, rule: InferenceRule) {
+        if let Some(existing_rule) = self.get_mut(&rule.products, &rule.prerequisites) {
+            existing_rule.extend(rule);
+        } else {
+            self.data
+                .entry(rule.products.clone())
+                .or_default()
+                .insert(rule.prerequisites.clone(), rule);
+        }
+    }
+
+    pub fn len(&self) -> usize {
+        self.data.len()
+    }
+
+    pub fn extend(&mut self, other: Self) {
+        for other in other.data.into_values().flat_map(HashMap::into_values) {
+            self.put(other);
+        }
+    }
+
+    pub fn iter(&self) -> impl Iterator<Item = &InferenceRule> {
+        self.data.values().flat_map(HashMap::values)
+    }
+}
+
+impl From<Vec<InferenceRule>> for InferenceRuleSet {
+    fn from(value: Vec<InferenceRule>) -> Self {
+        let mut result = Self::default();
+        for rule in value {
+            result.put(rule);
+        }
+        result
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::*;
@@ -88,6 +171,7 @@ mod test {
             ".o".to_owned(),
             ".c".to_owned(),
             vec![],
+            MacroSet::new(),
         );
         assert!(rule.matches("foo.o")?);
         assert!(rule.matches("dir/foo.o")?);
@@ -107,6 +191,7 @@ mod test {
                 "goneall.gpg".to_owned(),
             ],
             commands: vec![],
+            macros: MacroSet::new(),
         };
         assert!(rule.matches("licenseListPublisher-2.2.1.jar-valid")?);
         Ok(())