Merge pull request #8073 from The-OpenROAD-Project-staging/secure-fix-find-instances-matching

dbSta: Enabled multi-level hierarchical path search for get_cells/get_pins/get_nets

Author: maliberty

src/dbSta/BUILD

@@ -35,6 +35,7 @@ cc_library(
         "//src/sta:opensta_lib",
         "//src/utl",
         "@boost.json",
+        "@spdlog",
         "@tk_tcl//:tcl",
     ],
 )

src/dbSta/src/dbSdcNetwork.cc

@@ -3,8 +3,11 @@
 
 #include "dbSdcNetwork.hh"
 
+#include <spdlog/fmt/fmt.h>
+
 #include <memory>
 #include <string>
+#include <string_view>
 
 #include "sta/ParseBus.hh"
 #include "sta/PatternMatch.hh"
@@ -62,14 +65,47 @@ InstanceSeq dbSdcNetwork::findInstancesMatching(
 void dbSdcNetwork::findInstancesMatching1(const PatternMatch* pattern,
                                           InstanceSeq& insts) const
 {
-  std::unique_ptr<InstanceChildIterator> child_iter{
-      childIterator(topInstance())};
-  while (child_iter->hasNext()) {
-    Instance* child = child_iter->next();
-    if (pattern->match(staToSdc(name(child)))) {
-      insts.push_back(child);
+  // A recursive lambda to traverse the design hierarchy with a depth-first
+  // search (DFS).
+  // It builds the hierarchical path incrementally using fmt::memory_buffer to
+  // avoid expensive std::string allocations and copies at each step.
+  std::function<void(Instance*, fmt::memory_buffer&)> dfs_search
+      = [&, this](Instance* instance, fmt::memory_buffer& path_buffer) -> void {
+    // Iterate over the children of the current instance.
+    std::unique_ptr<InstanceChildIterator> child_iter{childIterator(instance)};
+    while (child_iter->hasNext()) {
+      Instance* child = child_iter->next();
+
+      // Save the current size of the buffer to restore it later.
+      const size_t original_size = path_buffer.size();
+
+      // Build the child's full path name incrementally.
+      if (original_size > 0) {
+        path_buffer.push_back(pathDivider());
+      }
+      path_buffer.append(std::string_view(name(child)));
+
+      // Check if the child instance name matches the pattern.
+      // Add a null terminator for C-style string compatibility.
+      path_buffer.push_back('\0');
+      if (pattern->match(staToSdc(path_buffer.data()))) {
+        insts.push_back(child);
+      }
+      path_buffer.resize(path_buffer.size() - 1);  // Remove the null terminator
+
+      // Recurse into the child's hierarchy if it's not a leaf.
+      if (!isLeaf(child)) {
+        dfs_search(child, path_buffer);
+      }
+
+      // Restore the buffer to its original state for the next sibling.
+      path_buffer.resize(original_size);
     }
-  }
+  };
+
+  // Start the search from the top-level instance.
+  fmt::memory_buffer path_buffer;
+  dfs_search(topInstance(), path_buffer);
 }
 
 NetSeq dbSdcNetwork::findNetsMatching(const Instance*,

src/dbSta/test/BUILD

@@ -14,6 +14,7 @@ COMPULSORY_TESTS = [
     "hier2",
     "hierclock",
     "hierwrite",
+    "hier_deep",
     "make_port",
     "network_edit1",
     "power1",
@@ -117,6 +118,7 @@ filegroup(
         "hier2_out.vok",
         "hierclock_gate.v",
         "hierclock_out.vok",
+        "hier_deep.v",
         "liberty1.lef",
         "liberty1.lib",
         "pad.lef",

src/dbSta/test/CMakeLists.txt

@@ -12,6 +12,7 @@ or_integration_tests(
     hier2
     hierclock
     hierwrite
+    hier_deep
     make_port
     network_edit1
     power1

src/dbSta/test/hier_deep.ok

@@ -0,0 +1,44 @@
+[INFO ODB-0227] LEF file: example1.lef, created 2 layers, 6 library cells
+[WARNING ORD-0011] Hierarchical flow (-hier) is currently in development and may cause multiple issues. Do not use in production environments.
+cmd: get_cells level1_inst
+count: 1
+level1_inst
+----------------------
+cmd: get_cells level1_inst/level2_inst
+count: 1
+level1_inst/level2_inst
+----------------------
+cmd: get_cells level1_inst/level2_inst/leaf_inst
+count: 1
+level1_inst/level2_inst/leaf_inst
+----------------------
+cmd: get_cells level1_inst/level2_inst/leaf_inst/inverter
+count: 1
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------
+cmd: get_cells level1_*
+count: 4
+level1_inst
+level1_inst/level2_inst
+level1_inst/level2_inst/leaf_inst
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------
+cmd: get_cells *level2*
+count: 3
+level1_inst/level2_inst
+level1_inst/level2_inst/leaf_inst
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------
+cmd: get_cells *leaf*
+count: 2
+level1_inst/level2_inst/leaf_inst
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------
+cmd: get_cells *inv*
+count: 1
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------
+cmd: get_cells */level2*inv*
+count: 1
+level1_inst/level2_inst/leaf_inst/inverter
+----------------------

src/dbSta/test/hier_deep.tcl

@@ -0,0 +1,26 @@
+source "helpers.tcl"
+read_lef example1.lef
+read_liberty example1_typ.lib
+read_verilog hier_deep.v
+link_design top -hier
+
+proc test_get_cells { pattern } {
+  set cells [get_cells $pattern]
+  puts "cmd: get_cells $pattern"
+  puts "count: [llength $cells]"
+  foreach cell $cells {
+    puts [get_full_name $cell]
+  }
+  puts "----------------------"
+}
+
+test_get_cells "level1_inst"
+test_get_cells "level1_inst/level2_inst"
+test_get_cells "level1_inst/level2_inst/leaf_inst"
+test_get_cells "level1_inst/level2_inst/leaf_inst/inverter"
+
+test_get_cells "level1_*"
+test_get_cells "*level2*"
+test_get_cells "*leaf*"
+test_get_cells "*inv*"
+test_get_cells "*/level2*inv*"

src/dbSta/test/hier_deep.v

@@ -0,0 +1,28 @@
+/*
+ lef: example1.lef
+ lib: example1_typ.lib
+ */
+
+module leaf (a, z);
+  input a;
+  output z;
+  INV_X1 inverter (.A(a), .ZN(z));
+endmodule
+
+module level2 (in, out);
+  input in;
+  output out;
+  leaf leaf_inst (.a(in), .z(out));
+endmodule
+
+module level1 (in, out);
+  input in;
+  output out;
+  level2 level2_inst (.in(in), .out(out));
+endmodule
+
+module top (a, b);
+  input a;
+  output b;
+  level1 level1_inst (.in(a), .out(b));
+endmodule