patch_sync: Add patch_parsing module

At present, the patch_sync code does nothing as the base version
only sets up the code for future reviews.

This adds in the ability to parse the PATCHES.json files, check
the differences across past versions, and transpose those patches
to another repo.

This parsing assumes the PATCHES.json now use the uniform schema,
which the AOSP currently does, but CrOS may not by the time this
commit lands.

BUG=b:209493133
TEST=cargo build
TEST=cargo test

Change-Id: I8de01eae3d9555dbb000378516a5bf38e29fea8e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/3339405
Reviewed-by: George Burgess <gbiv@chromium.org>
Tested-by: Jordan Abrahams <ajordanr@google.com>
Commit-Queue: Jordan Abrahams <ajordanr@google.com>

1 files changed, 41 insertions, 10 deletions

diff --git a/llvm_tools/patch_sync/src/main.rs b/llvm_tools/patch_sync/src/main.rs
index 8eedaaa8..514f054f 100644
--- a/llvm_tools/patch_sync/src/main.rs
+++ b/llvm_tools/patch_sync/src/main.rs
@@ -1,3 +1,4 @@
+mod patch_parsing;
 mod version_control;
 
 use anyhow::{Context, Result};
@@ -45,13 +46,43 @@ fn transpose_subcmd(args: TransposeOpt) -> Result<()> {
         sync_before: false,
     };
     ctx.setup()?;
-    let _cros_patches_path = ctx.cros_patches_path();
-    let _android_patches_path = ctx.android_patches_path();
+    let cros_patches_path = ctx.cros_patches_path();
+    let android_patches_path = ctx.android_patches_path();
+
+    // Chromium OS Patches ----------------------------------------------------
+    let mut cur_cros_collection =
+        patch_parsing::PatchCollection::parse_from_file(&cros_patches_path)
+            .context("parsing cros PATCHES.json")?;
+    let new_cros_patches: patch_parsing::PatchCollection = {
+        let cros_old_patches_json = ctx.old_cros_patch_contents(&args.old_cros_ref)?;
+        let old_cros_collection = patch_parsing::PatchCollection::parse_from_str(
+            cros_patches_path.parent().unwrap().to_path_buf(),
+            &cros_old_patches_json,
+        )?;
+        cur_cros_collection.subtract(&old_cros_collection)?
+    };
+
+    // Android Patches -------------------------------------------------------
+    let mut cur_android_collection =
+        patch_parsing::PatchCollection::parse_from_file(&android_patches_path)
+            .context("parsing android PATCHES.json")?;
+    let new_android_patches: patch_parsing::PatchCollection = {
+        let android_old_patches_json = ctx.old_android_patch_contents(&args.old_android_ref)?;
+        let old_android_collection = patch_parsing::PatchCollection::parse_from_str(
+            android_patches_path.parent().unwrap().to_path_buf(),
+            &android_old_patches_json,
+        )?;
+        cur_android_collection.subtract(&old_android_collection)?
+    };
+
+    // Transpose Patches -----------------------------------------------------
+    new_cros_patches.transpose_write(&mut cur_cros_collection)?;
+    new_android_patches.transpose_write(&mut cur_android_collection)?;
 
     if !args.no_commit {
         return Ok(());
     }
-    // Commit and upload for review.
+    // Commit and upload for review ------------------------------------------
     ctx.cros_repo_upload()
         .context("uploading chromiumos changes")?;
     ctx.android_repo_upload()
@@ -73,34 +104,34 @@ enum Opt {
     /// Transpose patches from two PATCHES.json files
     /// to each other.
     Transpose {
-        #[structopt(long = "cros-checkout", parse(from_os_str))]
         /// Path to the ChromiumOS source repo checkout.
+        #[structopt(long = "cros-checkout", parse(from_os_str))]
         cros_checkout_path: PathBuf,
 
-        #[structopt(long = "overlay-base-ref")]
         /// Git ref (e.g. hash) for the ChromiumOS overlay to use as the base.
+        #[structopt(long = "overlay-base-ref")]
         old_cros_ref: String,
 
-        #[structopt(long = "aosp-checkout", parse(from_os_str))]
         /// Path to the Android Open Source Project source repo checkout.
+        #[structopt(long = "aosp-checkout", parse(from_os_str))]
         android_checkout_path: PathBuf,
 
-        #[structopt(long = "aosp-base-ref")]
         /// Git ref (e.g. hash) for the llvm_android repo to use as the base.
+        #[structopt(long = "aosp-base-ref")]
         old_android_ref: String,
 
-        #[structopt(short, long)]
         /// Print information to stdout
+        #[structopt(short, long)]
         verbose: bool,
 
-        #[structopt(long)]
         /// Do not change any files. Useful in combination with `--verbose`
         /// Implies `--no-commit` and `--no-upload`.
+        #[structopt(long)]
         dry_run: bool,
 
-        #[structopt(long)]
         /// Do not commit any changes made.
         /// Implies `--no-upload`.
+        #[structopt(long)]
         no_commit: bool,
     },
 }