From 3d6e609f03c1551e60b235490b8e8e5860d3e40e Mon Sep 17 00:00:00 2001
From: Frederick Mayle <fmayle@google.com>
Date: Wed, 10 May 2023 14:47:25 -0700
Subject: [PATCH] cargo_embargo: dedup output modules

This is needed because of https://crrev.com/c/4517945. The new resolver
causes there to be multiple `rustc` invocations for some libraries. They
are only trivially different though, so dedup'ing the final output is
sufficient for now.

Bug: 280489895
Test: m cargo_embargo && ./android-merge-2-cargo-embargo.sh
Change-Id: If4a36e4f3847d18d03f76bad63bab6c45a9aef97
---
 tools/cargo_embargo/src/bp.rs   | 5 +++--
 tools/cargo_embargo/src/main.rs | 6 ++++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/cargo_embargo/src/bp.rs b/tools/cargo_embargo/src/bp.rs
index 5c661dc27..9364c5bb5 100644
--- a/tools/cargo_embargo/src/bp.rs
+++ b/tools/cargo_embargo/src/bp.rs
@@ -16,13 +16,14 @@ use anyhow::Result;
 use std::collections::BTreeMap;
 
 /// Build module.
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct BpModule {
     module_type: String,
     pub props: BpProperties,
 }
 
 /// Properties of a build module, or of a nested object value.
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub struct BpProperties {
     map: BTreeMap<String, BpValue>,
     /// A raw block of text to append after the last key-value pair, but before the closing brace.
@@ -43,7 +44,7 @@ pub struct BpProperties {
     pub raw_block: Option<String>,
 }
 
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, PartialOrd, Ord)]
 pub enum BpValue {
     Object(BpProperties),
     Bool(bool),
diff --git a/tools/cargo_embargo/src/main.rs b/tools/cargo_embargo/src/main.rs
index dd2caf594..83ee8967c 100644
--- a/tools/cargo_embargo/src/main.rs
+++ b/tools/cargo_embargo/src/main.rs
@@ -373,6 +373,12 @@ fn write_android_bp(
         return Ok(());
     }
 
+    // In some cases there are nearly identical rustc invocations that that get processed into
+    // identical BP modules. So far, dedup'ing them is a good enough fix. At some point we might
+    // need something more complex, maybe like cargo2android's logic for merging crates.
+    modules.sort();
+    modules.dedup();
+
     modules.sort_by_key(|m| m.props.get_string("name").to_string());
     for m in modules {
         m.write(&mut bp_contents)?;