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, 12 insertions, 4 deletions

diff --git a/src/disk_interface_test.cc b/src/disk_interface_test.cc
index 05d509c..658fffd 100644
--- a/src/disk_interface_test.cc
+++ b/src/disk_interface_test.cc
@@ -204,7 +204,9 @@ TEST_F(StatTest, Simple) {
 "build out: cat in\n"));
 
   Node* out = GetNode("out");
-  out->Stat(this);
+  string err;
+  EXPECT_TRUE(out->Stat(this, &err));
+  EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
   scan_.RecomputeDirty(out->in_edge(), NULL);
   ASSERT_EQ(2u, stats_.size());
@@ -218,7 +220,9 @@ TEST_F(StatTest, TwoStep) {
 "build mid: cat in\n"));
 
   Node* out = GetNode("out");
-  out->Stat(this);
+  string err;
+  EXPECT_TRUE(out->Stat(this, &err));
+  EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
   scan_.RecomputeDirty(out->in_edge(), NULL);
   ASSERT_EQ(3u, stats_.size());
@@ -236,7 +240,9 @@ TEST_F(StatTest, Tree) {
 "build mid2: cat in21 in22\n"));
 
   Node* out = GetNode("out");
-  out->Stat(this);
+  string err;
+  EXPECT_TRUE(out->Stat(this, &err));
+  EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
   scan_.RecomputeDirty(out->in_edge(), NULL);
   ASSERT_EQ(1u + 6u, stats_.size());
@@ -255,7 +261,9 @@ TEST_F(StatTest, Middle) {
   mtimes_["out"] = 1;
 
   Node* out = GetNode("out");
-  out->Stat(this);
+  string err;
+  EXPECT_TRUE(out->Stat(this, &err));
+  EXPECT_EQ("", err);
   ASSERT_EQ(1u, stats_.size());
   scan_.RecomputeDirty(out->in_edge(), NULL);
   ASSERT_FALSE(GetNode("in")->dirty());