From 86f255360c4f1741e8c5bef95e6994b81cd8d2e1 Mon Sep 17 00:00:00 2001
From: Groverkss <groverkss@gmail.com>
Date: Sat, 2 Apr 2022 18:14:38 +0530
Subject: [PATCH] [MLIR][Presburger] Make constructors from PresburgerSpace
 explicit

This patch makes constructors of IntegerRelation, IntegerPolyhedron,
PresburgerRelation, PresburgerSet from PresburgerSpace explicit. This
prevents bugs like:

```
void fun(IntegerRelation a, IntegerRelation b) {
  IntegerPolyhedron c = a.intersect(b);
}
```

Here, `a.intersect(b)` will return `IntegerRelation`, which will be implicitly
converted to `PresburgerSpace` and will use the `PresburgerSpace` constructor
for IntegerPolyhedron. Leading to loss of any constraints in the intersection
of `a` and `b`. After this patch, this will give a compile error.

Reviewed By: arjunp

Differential Revision: https://reviews.llvm.org/D122972
---
 mlir/include/mlir/Analysis/Presburger/IntegerRelation.h    | 4 ++--
 mlir/include/mlir/Analysis/Presburger/PresburgerRelation.h | 6 ++++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h b/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
index 47a1ae2ae656..6add6e8aa9b2 100644
--- a/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
+++ b/mlir/include/mlir/Analysis/Presburger/IntegerRelation.h
@@ -66,7 +66,7 @@ public:
   }
 
   /// Constructs a relation with the specified number of dimensions and symbols.
-  IntegerRelation(const PresburgerSpace &space)
+  explicit IntegerRelation(const PresburgerSpace &space)
       : IntegerRelation(/*numReservedInequalities=*/0,
                         /*numReservedEqualities=*/0,
                         /*numReservedCols=*/space.getNumIds() + 1, space) {}
@@ -567,7 +567,7 @@ public:
 
   /// Constructs a relation with the specified number of dimensions and
   /// symbols.
-  IntegerPolyhedron(const PresburgerSpace &space)
+  explicit IntegerPolyhedron(const PresburgerSpace &space)
       : IntegerPolyhedron(/*numReservedInequalities=*/0,
                           /*numReservedEqualities=*/0,
                           /*numReservedCols=*/space.getNumIds() + 1, space) {}
diff --git a/mlir/include/mlir/Analysis/Presburger/PresburgerRelation.h b/mlir/include/mlir/Analysis/Presburger/PresburgerRelation.h
index bc64fbef44db..b0015fd1f03b 100644
--- a/mlir/include/mlir/Analysis/Presburger/PresburgerRelation.h
+++ b/mlir/include/mlir/Analysis/Presburger/PresburgerRelation.h
@@ -116,7 +116,8 @@ public:
 protected:
   /// Construct an empty PresburgerRelation with the specified number of
   /// dimension and symbols.
-  PresburgerRelation(const PresburgerSpace &space) : PresburgerSpace(space) {
+  explicit PresburgerRelation(const PresburgerSpace &space)
+      : PresburgerSpace(space) {
     assert(space.getNumLocalIds() == 0 &&
            "PresburgerRelation cannot have local ids.");
   }
@@ -151,7 +152,8 @@ public:
 protected:
   /// Construct an empty PresburgerRelation with the specified number of
   /// dimension and symbols.
-  PresburgerSet(const PresburgerSpace &space) : PresburgerRelation(space) {
+  explicit PresburgerSet(const PresburgerSpace &space)
+      : PresburgerRelation(space) {
     assert(space.getNumDomainIds() == 0 && "Set type cannot have domain ids.");
     assert(space.getNumLocalIds() == 0 &&
            "PresburgerRelation cannot have local ids.");