Refactor RecomputeDirty to take a node instead of an edge

All call sites have a node on which they call `in_edge()` to call
RecomputeDirty.  Simplify call sites by taking the node directly and
calling `in_edge()` internally.

5 files changed, 39 insertions, 47 deletions

diff --git a/src/build.cc b/src/build.cc
index 8f4169b..c2a615a 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -640,9 +640,10 @@ Node* Builder::AddTarget(const string& name, string* err) {
 }
 
 bool Builder::AddTarget(Node* node, string* err) {
+  if (!scan_.RecomputeDirty(node, err))
+    return false;
+
   if (Edge* in_edge = node->in_edge()) {
-    if (!scan_.RecomputeDirty(in_edge, err))
-      return false;
     if (in_edge->outputs_ready())
       return true;  // Nothing to do.
   }
diff --git a/src/disk_interface_test.cc b/src/disk_interface_test.cc
index 7187bdf..d7fb8f8 100644
--- a/src/disk_interface_test.cc
+++ b/src/disk_interface_test.cc
@@ -245,7 +245,7 @@ TEST_F(StatTest, Simple) {
   EXPECT_TRUE(out->Stat(this, &err));
   EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
-  scan_.RecomputeDirty(out->in_edge(), NULL);
+  scan_.RecomputeDirty(out, NULL);
   ASSERT_EQ(2u, stats_.size());
   ASSERT_EQ("out", stats_[0]);
   ASSERT_EQ("in",  stats_[1]);
@@ -261,7 +261,7 @@ TEST_F(StatTest, TwoStep) {
   EXPECT_TRUE(out->Stat(this, &err));
   EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
-  scan_.RecomputeDirty(out->in_edge(), NULL);
+  scan_.RecomputeDirty(out, NULL);
   ASSERT_EQ(3u, stats_.size());
   ASSERT_EQ("out", stats_[0]);
   ASSERT_TRUE(GetNode("out")->dirty());
@@ -281,7 +281,7 @@ TEST_F(StatTest, Tree) {
   EXPECT_TRUE(out->Stat(this, &err));
   EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
-  scan_.RecomputeDirty(out->in_edge(), NULL);
+  scan_.RecomputeDirty(out, NULL);
   ASSERT_EQ(1u + 6u, stats_.size());
   ASSERT_EQ("mid1", stats_[1]);
   ASSERT_TRUE(GetNode("mid1")->dirty());
@@ -302,7 +302,7 @@ TEST_F(StatTest, Middle) {
   EXPECT_TRUE(out->Stat(this, &err));
   EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
-  scan_.RecomputeDirty(out->in_edge(), NULL);
+  scan_.RecomputeDirty(out, NULL);
   ASSERT_FALSE(GetNode("in")->dirty());
   ASSERT_TRUE(GetNode("mid")->dirty());
   ASSERT_TRUE(GetNode("out")->dirty());
diff --git a/src/graph.cc b/src/graph.cc
index c90aaad..c34fab8 100644
--- a/src/graph.cc
+++ b/src/graph.cc
@@ -31,7 +31,16 @@ bool Node::Stat(DiskInterface* disk_interface, string* err) {
   return (mtime_ = disk_interface->Stat(path_, err)) != -1;
 }
 
-bool DependencyScan::RecomputeDirty(Edge* edge, string* err) {
+bool DependencyScan::RecomputeDirty(Node* node, string* err) {
+  Edge* edge = node->in_edge();
+  if (!edge) {
+    // This node has no in-edge; it is dirty if it is missing.
+    if (!node->exists())
+      EXPLAIN("%s has no in-edge and is missing", node->path().c_str());
+    node->set_dirty(!node->exists());
+    return true;
+  }
+
   bool dirty = false;
   edge->outputs_ready_ = true;
   edge->deps_missing_ = false;
@@ -66,15 +75,8 @@ bool DependencyScan::RecomputeDirty(Edge* edge, string* err) {
     if (!(*i)->status_known()) {
       if (!(*i)->StatIfNecessary(disk_interface_, err))
         return false;
-      if (Edge* in_edge = (*i)->in_edge()) {
-        if (!RecomputeDirty(in_edge, err))
-          return false;
-      } else {
-        // This input has no in-edge; it is dirty if it is missing.
-        if (!(*i)->exists())
-          EXPLAIN("%s has no in-edge and is missing", (*i)->path().c_str());
-        (*i)->set_dirty(!(*i)->exists());
-      }
+      if (!RecomputeDirty(*i, err))
+        return false;
     }
 
     // If an input is not ready, neither are our outputs.
diff --git a/src/graph.h b/src/graph.h
index ec24293..9e82ca2 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -246,11 +246,12 @@ struct DependencyScan {
         disk_interface_(disk_interface),
         dep_loader_(state, deps_log, disk_interface) {}
 
+  /// Update the |dirty_| state of the given node by inspecting its input edge.
   /// Examine inputs, outputs, and command lines to judge whether an edge
   /// needs to be re-run, and update outputs_ready_ and each outputs' |dirty_|
   /// state accordingly.
   /// Returns false on failure.
-  bool RecomputeDirty(Edge* edge, string* err);
+  bool RecomputeDirty(Node* node, string* err);
 
   /// Recompute whether any output of the edge is dirty, if so sets |*dirty|.
   /// Returns false on failure.
diff --git a/src/graph_test.cc b/src/graph_test.cc
index be08b19..87f3430 100644
--- a/src/graph_test.cc
+++ b/src/graph_test.cc
@@ -30,9 +30,8 @@ TEST_F(GraphTest, MissingImplicit) {
   fs_.Create("in", "");
   fs_.Create("out", "");
 
-  Edge* edge = GetNode("out")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out"), &err));
   ASSERT_EQ("", err);
 
   // A missing implicit dep *should* make the output dirty.
@@ -49,9 +48,8 @@ TEST_F(GraphTest, ModifiedImplicit) {
   fs_.Tick();
   fs_.Create("implicit", "");
 
-  Edge* edge = GetNode("out")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out"), &err));
   ASSERT_EQ("", err);
 
   // A modified implicit dep should make the output dirty.
@@ -70,9 +68,8 @@ TEST_F(GraphTest, FunkyMakefilePath) {
   fs_.Tick();
   fs_.Create("implicit.h", "");
 
-  Edge* edge = GetNode("out.o")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
 
   // implicit.h has changed, though our depfile refers to it with a
@@ -94,9 +91,8 @@ TEST_F(GraphTest, ExplicitImplicit) {
   fs_.Tick();
   fs_.Create("data", "");
 
-  Edge* edge = GetNode("out.o")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
 
   // We have both an implicit and an explicit dep on implicit.h.
@@ -123,9 +119,8 @@ TEST_F(GraphTest, ImplicitOutputMissing) {
   fs_.Create("in", "");
   fs_.Create("out", "");
 
-  Edge* edge = GetNode("out")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_TRUE(GetNode("out")->dirty());
@@ -140,9 +135,8 @@ TEST_F(GraphTest, ImplicitOutputOutOfDate) {
   fs_.Create("in", "");
   fs_.Create("out", "");
 
-  Edge* edge = GetNode("out")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_TRUE(GetNode("out")->dirty());
@@ -165,9 +159,8 @@ TEST_F(GraphTest, ImplicitOutputOnlyMissing) {
 "build | out.imp: cat in\n"));
   fs_.Create("in", "");
 
-  Edge* edge = GetNode("out.imp")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.imp"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_TRUE(GetNode("out.imp")->dirty());
@@ -180,9 +173,8 @@ TEST_F(GraphTest, ImplicitOutputOnlyOutOfDate) {
   fs_.Tick();
   fs_.Create("in", "");
 
-  Edge* edge = GetNode("out.imp")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.imp"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_TRUE(GetNode("out.imp")->dirty());
@@ -198,9 +190,8 @@ TEST_F(GraphTest, PathWithCurrentDirectory) {
   fs_.Create("out.o.d", "out.o: foo.cc\n");
   fs_.Create("out.o", "");
 
-  Edge* edge = GetNode("out.o")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_FALSE(GetNode("out.o")->dirty());
@@ -247,9 +238,8 @@ TEST_F(GraphTest, DepfileWithCanonicalizablePath) {
   fs_.Create("out.o.d", "out.o: bar/../foo.cc\n");
   fs_.Create("out.o", "");
 
-  Edge* edge = GetNode("out.o")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
 
   EXPECT_FALSE(GetNode("out.o")->dirty());
@@ -268,15 +258,14 @@ TEST_F(GraphTest, DepfileRemoved) {
   fs_.Create("out.o.d", "out.o: foo.h\n");
   fs_.Create("out.o", "");
 
-  Edge* edge = GetNode("out.o")->in_edge();
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
   EXPECT_FALSE(GetNode("out.o")->dirty());
 
   state_.Reset();
   fs_.RemoveFile("out.o.d");
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("out.o"), &err));
   ASSERT_EQ("", err);
   EXPECT_TRUE(GetNode("out.o")->dirty());
 }
@@ -323,8 +312,7 @@ TEST_F(GraphTest, NestedPhonyPrintsDone) {
 "build n2: phony n1\n"
   );
   string err;
-  Edge* edge = GetNode("n2")->in_edge();
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("n2"), &err));
   ASSERT_EQ("", err);
 
   Plan plan_;
@@ -347,13 +335,13 @@ TEST_F(GraphTest, CycleWithLengthZeroFromDepfile) {
   fs_.Create("dep.d", "a: b\n");
 
   string err;
-  Edge* edge = GetNode("a")->in_edge();
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("a"), &err));
   ASSERT_EQ("", err);
 
   // Despite the depfile causing edge to be a cycle (it has outputs a and b,
   // but the depfile also adds b as an input), the deps should have been loaded
   // only once:
+  Edge* edge = GetNode("a")->in_edge();
   EXPECT_EQ(1, edge->inputs_.size());
   EXPECT_EQ("b", edge->inputs_[0]->path());
 }
@@ -372,13 +360,13 @@ TEST_F(GraphTest, CycleWithLengthOneFromDepfile) {
   fs_.Create("dep.d", "a: c\n");
 
   string err;
-  Edge* edge = GetNode("a")->in_edge();
-  EXPECT_TRUE(scan_.RecomputeDirty(edge, &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("a"), &err));
   ASSERT_EQ("", err);
 
   // Despite the depfile causing edge to be a cycle (|edge| has outputs a and b,
   // but c's in_edge has b as input but the depfile also adds |edge| as
   // output)), the deps should have been loaded only once:
+  Edge* edge = GetNode("a")->in_edge();
   EXPECT_EQ(1, edge->inputs_.size());
   EXPECT_EQ("c", edge->inputs_[0]->path());
 }
@@ -399,7 +387,7 @@ TEST_F(GraphTest, CycleWithLengthOneFromDepfileOneHopAway) {
   fs_.Create("dep.d", "a: c\n");
 
   string err;
-  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("d")->in_edge(), &err));
+  EXPECT_TRUE(scan_.RecomputeDirty(GetNode("d"), &err));
   ASSERT_EQ("", err);
 
   // Despite the depfile causing edge to be a cycle (|edge| has outputs a and b,