add a straightforward deps log test, fix the other one

The first test I wrote was wrong; write a simpler test that exercises
the "no failures" code paths, then fix the second test and the bugs it
exposed.

1 files changed, 17 insertions, 6 deletions

diff --git a/src/build.cc b/src/build.cc
index 5e874df..7de4b16 100644
--- a/src/build.cc
+++ b/src/build.cc
@@ -801,10 +801,12 @@ void Builder::FinishCommand(CommandRunner::Result* result) {
   // can fail, which makes the command fail from a build perspective.
 
   vector<Node*> deps_nodes;
+  TimeStamp deps_mtime = 0;
   string deps_type = edge->GetBinding("deps");
   if (result->success() && !deps_type.empty()) {
     string extract_err;
-    if (!ExtractDeps(result, deps_type, &deps_nodes, &extract_err)) {
+    if (!ExtractDeps(result, deps_type, &deps_nodes, &deps_mtime,
+                     &extract_err)) {
       if (!result->output.empty())
         result->output.append("\n");
       result->output.append(extract_err);
@@ -875,10 +877,12 @@ void Builder::FinishCommand(CommandRunner::Result* result) {
   if (!deps_type.empty()) {
     assert(edge->outputs_.size() == 1 && "should have been rejected by parser");
     Node* out = edge->outputs_[0];
-    TimeStamp mtime = disk_interface_->Stat(out->path());
-    // XXX we could reuse the restat logic to avoid a second stat,
-    // but in practice we only care about the single output.
-    scan_.deps_log()->RecordDeps(out, mtime, deps_nodes);
+    if (!deps_mtime) {
+      // On Windows there's no separate file to compare against; just reuse
+      // the output's mtime.
+      deps_mtime = disk_interface_->Stat(out->path());
+    }
+    scan_.deps_log()->RecordDeps(out, deps_mtime, deps_nodes);
   }
 
 }
@@ -886,6 +890,7 @@ void Builder::FinishCommand(CommandRunner::Result* result) {
 bool Builder::ExtractDeps(CommandRunner::Result* result,
                           const string& deps_type,
                           vector<Node*>* deps_nodes,
+                          TimeStamp* deps_mtime,
                           string* err) {
 #ifdef _WIN32
   if (deps_type == "msvc") {
@@ -900,7 +905,13 @@ bool Builder::ExtractDeps(CommandRunner::Result* result,
   if (deps_type == "gcc") {
     string depfile = result->edge->GetBinding("depfile");
     if (depfile.empty()) {
-      *err = string("edge with deps=gcc but no depfile makes no sense\n");
+      *err = string("edge with deps=gcc but no depfile makes no sense");
+      return false;
+    }
+
+    *deps_mtime = disk_interface_->Stat(depfile);
+    if (*deps_mtime <= 0) {
+      *err = string("unable to read depfile");
       return false;
     }