[gccrs COMMIT 3/3] gccrs: Address review feedback for straight-line BIR drop analysis

From: Lishin <[email protected]>

gcc/rust/ChangeLog:

	* checks/errors/borrowck/rust-bir-drop-analysis.cc
	(BasicBlockIdHash): New helper.
	(DropAnalysis::analyze): Use unordered_set for visited block tracking.
	* checks/errors/borrowck/rust-bir-drop-analysis.h: Include rust-bir.h
	directly and remove Function forward declaration.
	* checks/errors/borrowck/rust-bir-place.h
	(IndexVec::IndexVec): Add comment for sized constructor.

Signed-off-by: Lishin <[email protected]>
---
This change was merged into the gccrs repository and is posted here for
upstream visibility and potential drive-by review, as requested by GCC
release managers.
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Commit on github: https://github.com/Rust-GCC/gccrs/commit/7a3c1de74ae6e3cf18b3ccf81f1a9f356f3e5c74

The commit has NOT been mentioned in any issue.

The commit has been mentioned in the following pull-request(s):
 - https://github.com/Rust-GCC/gccrs/pull/4730

 .../errors/borrowck/rust-bir-drop-analysis.cc    | 16 +++++++++++++++-
 .../errors/borrowck/rust-bir-drop-analysis.h     |  3 +--
 gcc/rust/checks/errors/borrowck/rust-bir-place.h |  1 +
 3 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.cc b/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.cc
index c0de04fac..006b07f22 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.cc
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.cc
@@ -19,14 +19,28 @@
 #include "rust-bir-drop-analysis.h"
 #include "rust-bir.h"
 
+#include <unordered_set>
+
 namespace Rust {
 namespace BIR {
 
+namespace {
+
+struct BasicBlockIdHash
+{
+  size_t operator() (BasicBlockId id) const
+  {
+    return std::hash<uint32_t> () (id.value);
+  }
+};
+
+} // namespace
+
 void
 DropAnalysis::analyze (Function &function)
 {
   std::vector<BasicBlockId> block_order;
-  std::set<BasicBlockId> visited;
+  std::unordered_set<BasicBlockId, BasicBlockIdHash> visited;
 
   BasicBlockId current = ENTRY_BASIC_BLOCK;
 
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.h b/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.h
index eb63f1e1e..c6298985a 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-drop-analysis.h
@@ -19,11 +19,10 @@
 #ifndef RUST_BIR_DROP_ANALYSIS_H
 #define RUST_BIR_DROP_ANALYSIS_H
 
+#include "rust-bir.h"
 namespace Rust {
 namespace BIR {
 
-struct Function;
-
 /*
   Classifies scheduled whole-local BIR Drop statements according to
   whether their place is initialized at the drop point.
diff --git a/gcc/rust/checks/errors/borrowck/rust-bir-place.h b/gcc/rust/checks/errors/borrowck/rust-bir-place.h
index d11ded9c9..46b1f5dc8 100644
--- a/gcc/rust/checks/errors/borrowck/rust-bir-place.h
+++ b/gcc/rust/checks/errors/borrowck/rust-bir-place.h
@@ -209,6 +209,7 @@ template <typename I, typename T> class IndexVec
 
 public:
   IndexVec () = default;
+  // Creates `size` elements, instead of only reserving space.
   IndexVec (size_t size) : internal_vector (size) {}
 
   T &at (I pid) { return internal_vector[pid.value]; }
-- 
2.54.0