Revert "Revert "[Modules] Fallback to building the module if a timeout occurs""
This reverts commit 0e8eae263e113aa995b26602e8cc61a841ff9b9a.
The uncovered bug was fixed in 30015fa6343.
rdar://problem/30413458
diff --git a/include/clang/Basic/DiagnosticCommonKinds.td b/include/clang/Basic/DiagnosticCommonKinds.td
index fe83b85..aeaa824 100644
--- a/include/clang/Basic/DiagnosticCommonKinds.td
+++ b/include/clang/Basic/DiagnosticCommonKinds.td
@@ -90,10 +90,10 @@
"%select{|umbrella }0header '%1' not found">;
def err_module_shadowed : Error<
"import of shadowed module '%0'">;
-def err_module_lock_failure : Error<
- "could not acquire lock file for module '%0': %1">, DefaultFatal;
-def err_module_lock_timeout : Error<
- "timed out waiting to acquire lock file for module '%0'">, DefaultFatal;
+def remark_module_lock_failure : Remark<
+ "could not acquire lock file for module '%0': %1">, InGroup<ModuleBuild>;
+def remark_module_lock_timeout : Remark<
+ "timed out waiting to acquire lock file for module '%0'">, InGroup<ModuleBuild>;
def err_module_cycle : Error<"cyclic dependency in module '%0': %1">,
DefaultFatal;
def err_module_prebuilt : Error<
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 1447471..86db639 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -1201,10 +1201,14 @@
llvm::LockFileManager Locked(ModuleFileName);
switch (Locked) {
case llvm::LockFileManager::LFS_Error:
- Diags.Report(ModuleNameLoc, diag::err_module_lock_failure)
+ // PCMCache takes care of correctness and locks are only necessary for
+ // performance. If there are errors creating the lock, do not use it
+ // and fallback to building the module ourselves.
+ Diags.Report(ModuleNameLoc, diag::remark_module_lock_failure)
<< Module->Name << Locked.getErrorMessage();
- return false;
-
+ // Clear the lock file in case there's some leftover around.
+ Locked.unsafeRemoveLockFile();
+ // FALLTHROUGH
case llvm::LockFileManager::LFS_Owned:
// We're responsible for building the module ourselves.
if (!compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
@@ -1224,11 +1228,14 @@
case llvm::LockFileManager::Res_OwnerDied:
continue; // try again to get the lock.
case llvm::LockFileManager::Res_Timeout:
- Diags.Report(ModuleNameLoc, diag::err_module_lock_timeout)
+ // Since PCMCache takes care of correctness, we try waiting for another
+ // process to complete the build so that this isn't done twice. If we
+ // reach a timeout, it's not a problem, try to build it ourselves then.
+ Diags.Report(ModuleNameLoc, diag::remark_module_lock_timeout)
<< Module->Name;
// Clear the lock file so that future invokations can make progress.
Locked.unsafeRemoveLockFile();
- return false;
+ continue;
}
break;
}
