Fix a case where the hash should ignore cwd but still includs it through -working-directory.

Author: qiongsiwu

clang/lib/Tooling/DependencyScanning/ModuleDepCollector.cpp

@@ -492,8 +492,11 @@ static std::string getModuleContextHash(const ModuleDeps &MD,
   HashBuilder.add(getClangFullRepositoryVersion());
   HashBuilder.add(serialization::VERSION_MAJOR, serialization::VERSION_MINOR);
   llvm::ErrorOr<std::string> CWD = VFS.getCurrentWorkingDirectory();
+  auto &FSOpts = const_cast<FileSystemOptions &>(CI.getFileSystemOpts());
   if (CWD && !IgnoreCWD)
     HashBuilder.add(*CWD);
+  else
+    FSOpts.WorkingDir.clear();
 
   // Hash the BuildInvocation without any input files.
   SmallString<0> ArgVec;

clang/test/ClangScanDeps/modules-context-hash-cwd.c

@@ -8,16 +8,19 @@
 // RUN: sed -e "s|DIR|%/t|g" %t/cdb1.json.in > %t/cdb1.json
 // RUN: sed -e "s|DIR|%/t|g" %t/cdb3.json.in > %t/cdb3.json
 // RUN: sed -e "s|DIR|%/t|g" %t/cdb4.json.in > %t/cdb4.json
+// RUN: sed -e "s|DIR|%/t|g" %t/cdb5.json.in > %t/cdb5.json
 // RUN: clang-scan-deps -compilation-database %t/cdb0.json -format experimental-full > %t/result0.json
 // RUN: clang-scan-deps -compilation-database %t/cdb1.json -format experimental-full > %t/result1.json
 // It is not a typo to use cdb1.json for result2. We intend to use the same
 // compilation database, but different clang-scan-deps optimize-args options.
 // RUN: clang-scan-deps -compilation-database %t/cdb1.json -format experimental-full -optimize-args=header-search,system-warnings,vfs,canonicalize-macros > %t/result2.json
 // RUN: clang-scan-deps -compilation-database %t/cdb3.json -format experimental-full > %t/result3.json
 // RUN: clang-scan-deps -compilation-database %t/cdb4.json -format experimental-full > %t/result4.json
+// RUN: clang-scan-deps -compilation-database %t/cdb5.json -format experimental-full > %t/result5.json
 // RUN: cat %t/result0.json %t/result1.json | FileCheck %s
 // RUN: cat %t/result0.json %t/result2.json | FileCheck %s -check-prefix=SKIPOPT
 // RUN: cat %t/result3.json %t/result4.json | FileCheck %s -check-prefix=RELPATH
+// RUN: cat %t/result0.json %t/result5.json | FileCheck %s
 
 //--- cdb0.json.in
 [{
@@ -48,6 +51,14 @@
   "command": "clang -c DIR/tu.c -fmodules -fmodules-cache-path=DIR/cache -fprebuilt-module-path=.././module -IDIR/include/ -o DIR/tu.o ",
   "file": "DIR/tu.c"
 }]
+
+//--- cdb5.json.in
+[{
+  "directory": "DIR",
+  "command": "clang -c DIR/tu.c -fmodules -fmodules-cache-path=DIR/cache -IDIR/include/ -Xclang -working-directory=DIR/a/ -o DIR/tu.o",
+  "file": "DIR/tu.c"
+}]
+
 //--- include/module.modulemap
 module mod {
   header "mod.h"
@@ -58,9 +69,9 @@ module mod {
 //--- tu.c
 #include "mod.h"
 
-// Check that result0 and result1 compute the same hash with optimization
-// on. The only difference between result0 and result1 is the compiler's
-// working directory.
+// Check that result0 and result1/result5 compute the same hash with
+// optimization on. The only difference between result0 and result1/result5 is
+// the compiler's working directory.
 // CHECK:     {
 // CHECK-NEXT:  "modules": [
 // CHECK-NEXT:   {