Make failing stat() calls abort the build.

Fixes #830, fixes #904.

In practice, this either happens with 64-bit inodes and a 32-bit
userspace when building without -D_FILE_OFFSET_BITS=64 in CFLAGS, or
when a filename is longer than the system file length limit.

Since DiskInterface::Stat() returns -1 on error, and Node used -1 on
"stat state unknown", not aborting the build lead to ninja stat()ing the
same file over and over again, until it finally ran out of stack. That's
now fixed.

* Change RecomputeOutputsDirty() to return success instead of dirty
  state (like RecomputeDirty()) and return the dirty state in a bool
  outparam
* Node::Stat()s old return value wasn't used anywhere, change the
  function to return success instead and add an |err| outparam
* Node::StatIfNecessary()'s old return value was used only in one place.
  Change that place to explicitly check status_known() and make
  StatIfNecessary() return success and add an |err| outparam
* Plan::CleanNode() can now fail, make it return bool and add an |err|
  outparam

1 files changed, 10 insertions, 10 deletions

diff --git a/src/graph.h b/src/graph.h
index 9eafc05..9526712 100644
--- a/src/graph.h
+++ b/src/graph.h
@@ -41,15 +41,14 @@ struct Node {
         in_edge_(NULL),
         id_(-1) {}
 
-  /// Return true if the file exists (mtime_ got a value).
-  bool Stat(DiskInterface* disk_interface);
+  /// Return false on error.
+  bool Stat(DiskInterface* disk_interface, string* err);
 
-  /// Return true if we needed to stat.
-  bool StatIfNecessary(DiskInterface* disk_interface) {
+  /// Return false on error.
+  bool StatIfNecessary(DiskInterface* disk_interface, string* err) {
     if (status_known())
-      return false;
-    Stat(disk_interface);
-    return true;
+      return true;
+    return Stat(disk_interface, err);
   }
 
   /// Mark as not-yet-stat()ed and not dirty.
@@ -236,9 +235,10 @@ struct DependencyScan {
   /// Returns false on failure.
   bool RecomputeDirty(Edge* edge, string* err);
 
-  /// Recompute whether any output of the edge is dirty.
-  /// Returns true if so.
-  bool RecomputeOutputsDirty(Edge* edge, Node* most_recent_input);
+  /// Recompute whether any output of the edge is dirty, if so sets |*dirty|.
+  /// Returns false on failure.
+  bool RecomputeOutputsDirty(Edge* edge, Node* most_recent_input,
+                             bool* dirty, string* err);
 
   BuildLog* build_log() const {
     return build_log_;