2 files changed, 58 insertions, 15 deletions

diff --git a/llvm_tools/patch_sync/src/main.rs b/llvm_tools/patch_sync/src/main.rs
index 9616716c..8c1eff1c 100644
--- a/llvm_tools/patch_sync/src/main.rs
+++ b/llvm_tools/patch_sync/src/main.rs
@@ -2,19 +2,28 @@ mod android_utils;
 mod patch_parsing;
 mod version_control;
 
-use anyhow::{Context, Result};
-use patch_parsing::PatchCollection;
 use std::borrow::ToOwned;
-use std::path::PathBuf;
+use std::collections::BTreeSet;
+use std::path::{Path, PathBuf};
+
+use anyhow::{Context, Result};
 use structopt::StructOpt;
 
+use patch_parsing::{filter_patches_by_platform, PatchCollection, PatchDictSchema};
+
 fn main() -> Result<()> {
     match Opt::from_args() {
         Opt::Show {
             cros_checkout_path,
             android_checkout_path,
             sync,
-        } => show_subcmd(cros_checkout_path, android_checkout_path, sync),
+            keep_unmerged,
+        } => show_subcmd(ShowOpt {
+            cros_checkout_path,
+            android_checkout_path,
+            sync,
+            keep_unmerged,
+        }),
         Opt::Transpose {
             cros_checkout_path,
             cros_reviewers,
@@ -44,29 +53,47 @@ fn main() -> Result<()> {
     }
 }
 
-fn show_subcmd(
+struct ShowOpt {
     cros_checkout_path: PathBuf,
     android_checkout_path: PathBuf,
+    keep_unmerged: bool,
     sync: bool,
-) -> Result<()> {
+}
+
+fn show_subcmd(args: ShowOpt) -> Result<()> {
+    let ShowOpt {
+        cros_checkout_path,
+        android_checkout_path,
+        keep_unmerged,
+        sync,
+    } = args;
     let ctx = version_control::RepoSetupContext {
         cros_checkout: cros_checkout_path,
         android_checkout: android_checkout_path,
         sync_before: sync,
     };
     ctx.setup()?;
-    let cros_patches_path = ctx.cros_patches_path();
-    let android_patches_path = ctx.android_patches_path();
-    let cur_cros_collection = PatchCollection::parse_from_file(&cros_patches_path)
-        .context("could not parse cros PATCHES.json")?;
-    let cur_android_collection = PatchCollection::parse_from_file(&android_patches_path)
-        .context("could not parse android PATCHES.json")?;
+    let make_collection = |platform: &str, patches_fp: &Path| -> Result<PatchCollection> {
+        let parsed_collection = PatchCollection::parse_from_file(patches_fp)
+            .with_context(|| format!("could not parse {} PATCHES.json", platform))?;
+        Ok(if keep_unmerged {
+            parsed_collection
+        } else {
+            filter_patches_by_platform(&parsed_collection, platform).map_patches(|p| {
+                PatchDictSchema {
+                    platforms: BTreeSet::from([platform.to_string()]),
+                    ..p.clone()
+                }
+            })
+        })
+    };
+    let cur_cros_collection = make_collection("chromiumos", &ctx.cros_patches_path())?;
+    let cur_android_collection = make_collection("android", &ctx.android_patches_path())?;
     let merged = cur_cros_collection.union(&cur_android_collection)?;
     println!("{}", merged.serialize_patches()?);
     Ok(())
 }
 
-#[allow(dead_code)]
 struct TransposeOpt {
     cros_checkout_path: PathBuf,
     old_cros_ref: String,
@@ -184,6 +211,12 @@ enum Opt {
         cros_checkout_path: PathBuf,
         #[structopt(parse(from_os_str))]
         android_checkout_path: PathBuf,
+
+        /// Keep a patch's platform field even if it's not merged at that platform.
+        #[structopt(long)]
+        keep_unmerged: bool,
+
+        /// Run repo sync before transposing.
         #[structopt(short, long)]
         sync: bool,
     },
diff --git a/llvm_tools/patch_sync/src/patch_parsing.rs b/llvm_tools/patch_sync/src/patch_parsing.rs
index 1da2c2a6..2f0fbc87 100644
--- a/llvm_tools/patch_sync/src/patch_parsing.rs
+++ b/llvm_tools/patch_sync/src/patch_parsing.rs
@@ -242,8 +242,8 @@ pub fn new_patches(
     platform: &str,
 ) -> Result<(PatchCollection, PatchCollection)> {
     let cur_collection = PatchCollection::parse_from_file(patches_path)
-        .with_context(|| format!("parsing {} PATCHES.json", platform))?
-        .filter_patches(|p| p.platforms.contains(platform));
+        .with_context(|| format!("parsing {} PATCHES.json", platform))?;
+    let cur_collection = filter_patches_by_platform(&cur_collection, platform);
     let cur_collection = cur_collection.filter_patches(|p| cur_collection.patch_exists(p));
     let new_patches: PatchCollection = {
         let old_collection = PatchCollection::parse_from_str(
@@ -264,6 +264,16 @@ pub fn new_patches(
     Ok((cur_collection, new_patches))
 }
 
+/// Create a new collection with only the patches that apply to the
+/// given platform.
+///
+/// If there's no platform listed, the patch should still apply if the patch file exists.
+pub fn filter_patches_by_platform(collection: &PatchCollection, platform: &str) -> PatchCollection {
+    collection.filter_patches(|p| {
+        p.platforms.contains(platform) || (p.platforms.is_empty() && collection.patch_exists(p))
+    })
+}
+
 /// Get the hash from the patch file contents.
 ///
 /// Not every patch file actually contains its own hash,