Track backtraces in target dependencies internally

Carry backtraces on target dependency edges to refer to the line in
project code that caused the edge to appear.

1 files changed, 8 insertions, 3 deletions

diff --git a/Source/cmComputeLinkDepends.cxx b/Source/cmComputeLinkDepends.cxx
index e3d53e4..4717cf6 100644
--- a/Source/cmComputeLinkDepends.cxx
+++ b/Source/cmComputeLinkDepends.cxx
@@ -420,7 +420,8 @@ void cmComputeLinkDepends::HandleSharedDependency(SharedDepEntry const& dep)
 
   // This shared library dependency must follow the item that listed
   // it.
-  this->EntryConstraintGraph[dep.DependerIndex].push_back(index);
+  this->EntryConstraintGraph[dep.DependerIndex].emplace_back(
+    index, true, cmListFileBacktrace());
 
   // Target items may have their own dependencies.
   if (entry.Target) {
@@ -523,7 +524,8 @@ void cmComputeLinkDepends::AddLinkEntries(int depender_index,
 
     // The dependee must come after the depender.
     if (depender_index >= 0) {
-      this->EntryConstraintGraph[depender_index].push_back(dependee_index);
+      this->EntryConstraintGraph[depender_index].emplace_back(
+        dependee_index, false, cmListFileBacktrace());
     } else {
       // This is a direct dependency of the target being linked.
       this->OriginalEntries.push_back(dependee_index);
@@ -595,7 +597,10 @@ void cmComputeLinkDepends::InferDependencies()
 
     // Add the inferred dependencies to the graph.
     cmGraphEdgeList& edges = this->EntryConstraintGraph[depender_index];
-    edges.insert(edges.end(), common.begin(), common.end());
+    edges.reserve(edges.size() + common.size());
+    for (auto const& c : common) {
+      edges.emplace_back(c, true, cmListFileBacktrace());
+    }
   }
 }