diff options
| -rw-r--r-- | src/deps_log.cc | 41 | ||||
| -rw-r--r-- | src/deps_log_test.cc | 71 |
2 files changed, 103 insertions, 9 deletions
diff --git a/src/deps_log.cc b/src/deps_log.cc index ceb75ce..5e5bba9 100644 --- a/src/deps_log.cc +++ b/src/deps_log.cc @@ -152,15 +152,23 @@ bool DepsLog::Load(const string& path, State* state, string* err) { return true; } + long offset; + bool read_failed = false; for (;;) { + offset = ftell(f); + uint16_t size; - if (fread(&size, 2, 1, f) < 1) + if (fread(&size, 2, 1, f) < 1) { + read_failed = true; break; + } bool is_deps = (size >> 15) != 0; size = size & 0x7FFF; - if (fread(buf, size, 1, f) < 1) + if (fread(buf, size, 1, f) < 1) { + read_failed = true; break; + } if (is_deps) { assert(size % 4 == 0); @@ -195,16 +203,37 @@ bool DepsLog::Load(const string& path, State* state, string* err) { nodes_.push_back(node); } } - if (ferror(f)) { - *err = strerror(ferror(f)); - return false; + + if (read_failed) { + // An error occurred while loading; try to recover by truncating the + // file to the last fully-read record. + if (ferror(f)) { + *err = strerror(ferror(f)); + } else { + *err = "premature end of file"; + } + fclose(f); + + if (truncate(path.c_str(), offset) < 0) { + *err = strerror(errno); + return false; + } + + // The truncate succeeded; we'll just report the load error as a + // warning because the build can proceed. + *err += "; recovering"; + return true; } + fclose(f); + return true; } DepsLog::Deps* DepsLog::GetDeps(Node* node) { - if (node->id() < 0) + // Abort if the node has no id (never referenced in the deps) or if + // there's no deps recorded for the node. + if (node->id() < 0 || node->id() >= deps_.size()) return NULL; return deps_[node->id()]; } diff --git a/src/deps_log_test.cc b/src/deps_log_test.cc index 40539a7..9623d17 100644 --- a/src/deps_log_test.cc +++ b/src/deps_log_test.cc @@ -218,8 +218,7 @@ TEST_F(DepsLogTest, InvalidHeader) { } } -// Simulate what happens if a write gets interrupted and the resulting -// file is truncated. +// Simulate what happens when loading a truncated log file. TEST_F(DepsLogTest, Truncated) { // Create a file with some entries. { @@ -263,7 +262,7 @@ TEST_F(DepsLogTest, Truncated) { break; } - ASSERT_GE(node_count, log.nodes().size()); + ASSERT_GE(node_count, (int)log.nodes().size()); node_count = log.nodes().size(); // Count how many non-NULL deps entries there are. @@ -278,4 +277,70 @@ TEST_F(DepsLogTest, Truncated) { } } +// Run the truncation-recovery logic. +TEST_F(DepsLogTest, TruncatedRecovery) { + // Create a file with some entries. + { + State state; + DepsLog log; + string err; + EXPECT_TRUE(log.OpenForWrite(kTestFilename, &err)); + ASSERT_EQ("", err); + + vector<Node*> deps; + deps.push_back(state.GetNode("foo.h")); + deps.push_back(state.GetNode("bar.h")); + log.RecordDeps(state.GetNode("out.o"), 1, deps); + + deps.clear(); + deps.push_back(state.GetNode("foo.h")); + deps.push_back(state.GetNode("bar2.h")); + log.RecordDeps(state.GetNode("out2.o"), 2, deps); + + log.Close(); + } + + // Shorten the file, corrupting the last record. + struct stat st; + ASSERT_EQ(0, stat(kTestFilename, &st)); + ASSERT_EQ(0, truncate(kTestFilename, st.st_size - 2)); + + // Load the file again, add an entry. + { + State state; + DepsLog log; + string err; + EXPECT_TRUE(log.Load(kTestFilename, &state, &err)); + ASSERT_EQ("premature end of file; recovering", err); + err.clear(); + + // The truncated entry should've been discarded. + EXPECT_EQ(NULL, log.GetDeps(state.GetNode("out2.o"))); + + EXPECT_TRUE(log.OpenForWrite(kTestFilename, &err)); + ASSERT_EQ("", err); + + // Add a new entry. + vector<Node*> deps; + deps.push_back(state.GetNode("foo.h")); + deps.push_back(state.GetNode("bar2.h")); + log.RecordDeps(state.GetNode("out2.o"), 3, deps); + + log.Close(); + } + + // Load the file a third time to verify appending after a mangled + // entry doesn't break things. + { + State state; + DepsLog log; + string err; + EXPECT_TRUE(log.Load(kTestFilename, &state, &err)); + + // The truncated entry should exist. + DepsLog::Deps* deps = log.GetDeps(state.GetNode("out2.o")); + ASSERT_TRUE(deps); + } +} + } // anonymous namespace |