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, 2 insertions, 1 deletions

diff --git a/src/build.h b/src/build.h
index eb3636a..5d5db80 100644
--- a/src/build.h
+++ b/src/build.h
@@ -61,7 +61,8 @@ struct Plan {
   void EdgeFinished(Edge* edge);
 
   /// Clean the given node during the build.
-  void CleanNode(DependencyScan* scan, Node* node);
+  /// Return false on error.
+  bool CleanNode(DependencyScan* scan, Node* node, string* err);
 
   /// Number of edges with commands to run.
   int command_edge_count() const { return command_edges_; }