Add code to populate the basic block predecessors

Author: VedantParanjape

src/blocks/basic_blocks.cpp

@@ -153,5 +153,12 @@ std::vector<std::shared_ptr<basic_block>> generate_basic_blocks(block::stmt_bloc
         }
     }
 
+    // step 5: populate the predecessors
+    for (auto bb: return_list) {
+        for (auto succ: bb->successor) {
+            succ->predecessor.push_back(bb);
+        }
+    }
+ 
     return return_list;
 }

src/blocks/loop_finder.cpp

@@ -133,7 +133,11 @@ void loop_finder::visit(stmt_block::Ptr a) {
 
 	std::cout << "++++++ basic blocks ++++++ \n";
 	for (auto bb: BBs) {
-		std::cout << bb->name << ":" << "\n";
+		std::cout << bb->name << ":" << "  ; ";
+		for (auto pred: bb->predecessor) {
+			std::cout << pred->name << ", ";
+		}
+		std::cout << "\n";
 		if (bb->branch_expr) {
 			std::cout << "  ";
 			bb->branch_expr->dump(std::cout, 0);