[clang][cas] Fix replay with include-tree relative paths

The include-tree embeds the relative path, not the path including the
working directory, which may differ from the original invocation.
Input paths should remain relative while only making output paths
absolute based on the working directory.

Fixes a crash when emitting diagnostics in a relative path during
libclang replay.

rdar://116013181

Author: benlangmuir

clang/include/clang/Frontend/CompileJobCache.h

@@ -82,7 +82,7 @@ class CompileJobCache {
   bool finishComputedResult(CompilerInstance &Clang, bool Success);
 
   static llvm::Expected<std::optional<int>> replayCachedResult(
-      std::shared_ptr<CompilerInvocation> Invok,
+      std::shared_ptr<CompilerInvocation> Invok, StringRef WorkingDir,
       const llvm::cas::CASID &CacheKey,
       cas::CompileJobCacheResult &CachedResult, SmallVectorImpl<char> &DiagText,
       bool WriteOutputAsCASID = false, bool UseCASBackend = false,

clang/lib/Frontend/CompileJobCache.cpp

@@ -21,6 +21,7 @@
 #include "llvm/MCCAS/MCCASObjectV1.h"
 #include "llvm/RemoteCachingService/Client.h"
 #include "llvm/Support/FileOutputBuffer.h"
+#include "llvm/Support/Path.h"
 #include "llvm/Support/PrefixMapper.h"
 #include "llvm/Support/Process.h"
 #include "llvm/Support/ScopedDurationTimer.h"
@@ -36,8 +37,9 @@ class CompileJobCache::CachingOutputs {
 public:
   using OutputKind = clang::cas::CompileJobCacheResult::OutputKind;
 
-  CachingOutputs(CompilerInstance &Clang, llvm::PrefixMapper Mapper,
-                 bool WriteOutputAsCASID, bool UseCASBackend);
+  CachingOutputs(CompilerInstance &Clang, StringRef Workingdir,
+                 llvm::PrefixMapper Mapper, bool WriteOutputAsCASID,
+                 bool UseCASBackend);
   virtual ~CachingOutputs() = default;
 
   /// \returns true if result was found and replayed, false otherwise.
@@ -78,12 +80,13 @@ namespace {
 /// \p llvm::cas::ActionCache.
 class ObjectStoreCachingOutputs : public CompileJobCache::CachingOutputs {
 public:
-  ObjectStoreCachingOutputs(CompilerInstance &Clang, llvm::PrefixMapper Mapper,
-                            bool WriteOutputAsCASID, bool UseCASBackend,
+  ObjectStoreCachingOutputs(CompilerInstance &Clang, StringRef WorkingDir,
+                            llvm::PrefixMapper Mapper, bool WriteOutputAsCASID,
+                            bool UseCASBackend,
                             std::optional<llvm::cas::CASID> &MCOutputID,
                             std::shared_ptr<llvm::cas::ObjectStore> DB,
                             std::shared_ptr<llvm::cas::ActionCache> Cache)
-      : CachingOutputs(Clang, std::move(Mapper), WriteOutputAsCASID,
+      : CachingOutputs(Clang, WorkingDir, std::move(Mapper), WriteOutputAsCASID,
                        UseCASBackend),
         ComputedJobNeedsReplay(WriteOutputAsCASID || UseCASBackend),
         MCOutputID(MCOutputID), CAS(std::move(DB)), Cache(std::move(Cache)) {
@@ -178,9 +181,10 @@ class CollectingOutputBackend : public llvm::vfs::ProxyOutputBackend {
 /// and \p llvm::cas::KeyValueDBClient.
 class RemoteCachingOutputs : public CompileJobCache::CachingOutputs {
 public:
-  RemoteCachingOutputs(CompilerInstance &Clang, llvm::PrefixMapper Mapper,
+  RemoteCachingOutputs(CompilerInstance &Clang, StringRef WorkingDir,
+                       llvm::PrefixMapper Mapper,
                        llvm::cas::remote::ClientServices Clients)
-      : CachingOutputs(Clang, std::move(Mapper),
+      : CachingOutputs(Clang, WorkingDir, std::move(Mapper),
                        /*WriteOutputAsCASID*/ false,
                        /*UseCASBackend*/ false) {
     RemoteKVClient = std::move(Clients.KVDB);
@@ -232,13 +236,23 @@ CompileJobCache::CachingOutputs::getPathForOutputKind(OutputKind Kind) {
   }
 }
 
-static std::string fixupRelativePath(const std::string &Path, FileManager &FM) {
+static std::string fixupRelativePath(const std::string &Path, FileManager &FM,
+                                     StringRef WorkingDir) {
+  if (llvm::sys::path::is_absolute(Path) || Path.empty() || Path == "-")
+    return Path;
+
+  // Apply -working-dir compiler option.
   // FIXME: this needs to stay in sync with createOutputFileImpl. Ideally, clang
   // would create output files by their "kind" rather than by path.
-  if (!Path.empty() && Path != "-" && !llvm::sys::path::is_absolute(Path)) {
-    SmallString<128> PathStorage(Path);
-    if (FM.FixupRelativePath(PathStorage))
-      return std::string(PathStorage);
+  SmallString<128> PathStorage(Path);
+  if (FM.FixupRelativePath(PathStorage))
+    return std::string(PathStorage);
+
+  // Apply "normal" working directory.
+  if (!WorkingDir.empty()) {
+    SmallString<128> Tmp(Path);
+    llvm::sys::fs::make_absolute(WorkingDir, Tmp);
+    return std::string(Tmp);
   }
   return Path;
 }
@@ -311,17 +325,18 @@ std::optional<int> CompileJobCache::initialize(CompilerInstance &Clang) {
            "combination of options not rejected earlier?");
     assert(!UseCASBackend && "combination of options not rejected earlier?");
     CacheBackend = std::make_unique<RemoteCachingOutputs>(
-        Clang, std::move(PrefixMapper), std::move(*Clients));
+        Clang, /*WorkingDir=*/"", std::move(PrefixMapper), std::move(*Clients));
   } else {
     CacheBackend = std::make_unique<ObjectStoreCachingOutputs>(
-        Clang, std::move(PrefixMapper), CacheOpts.WriteOutputAsCASID,
-        UseCASBackend, MCOutputID, CAS, Cache);
+        Clang, /*WorkingDir=*/"", std::move(PrefixMapper),
+        CacheOpts.WriteOutputAsCASID, UseCASBackend, MCOutputID, CAS, Cache);
   }
 
   return std::nullopt;
 }
 
 CompileJobCache::CachingOutputs::CachingOutputs(CompilerInstance &Clang,
+                                                StringRef WorkingDir,
                                                 llvm::PrefixMapper Mapper,
                                                 bool WriteOutputAsCASID,
                                                 bool UseCASBackend)
@@ -332,9 +347,9 @@ CompileJobCache::CachingOutputs::CachingOutputs(CompilerInstance &Clang,
   if (!Clang.hasFileManager())
     Clang.createFileManager();
   FileManager &FM = Clang.getFileManager();
-  OutputFile = fixupRelativePath(FrontendOpts.OutputFile, FM);
-  DependenciesFile =
-      fixupRelativePath(Invocation.getDependencyOutputOpts().OutputFile, FM);
+  OutputFile = fixupRelativePath(FrontendOpts.OutputFile, FM, WorkingDir);
+  DependenciesFile = fixupRelativePath(
+      Invocation.getDependencyOutputOpts().OutputFile, FM, WorkingDir);
   DiagProcessor = std::make_unique<clang::cas::CachingDiagnosticsProcessor>(
       PrefixMapper, FM);
 }
@@ -524,10 +539,10 @@ bool CompileJobCache::finishComputedResult(CompilerInstance &Clang,
 }
 
 Expected<std::optional<int>> CompileJobCache::replayCachedResult(
-    std::shared_ptr<CompilerInvocation> Invok, const llvm::cas::CASID &CacheKey,
-    cas::CompileJobCacheResult &CachedResult, SmallVectorImpl<char> &DiagText,
-    bool WriteOutputAsCASID, bool UseCASBackend,
-    std::optional<llvm::cas::CASID> *OutMCOutputID) {
+    std::shared_ptr<CompilerInvocation> Invok, StringRef WorkingDir,
+    const llvm::cas::CASID &CacheKey, cas::CompileJobCacheResult &CachedResult,
+    SmallVectorImpl<char> &DiagText, bool WriteOutputAsCASID,
+    bool UseCASBackend, std::optional<llvm::cas::CASID> *OutMCOutputID) {
   CompilerInstance Clang;
   Clang.setInvocation(std::move(Invok));
   llvm::raw_svector_ostream DiagOS(DiagText);
@@ -556,10 +571,10 @@ Expected<std::optional<int>> CompileJobCache::replayCachedResult(
   assert(!Clang.getDiagnostics().hasErrorOccurred());
 
   std::optional<llvm::cas::CASID> MCOutputID;
-  ObjectStoreCachingOutputs CachingOutputs(Clang, std::move(PrefixMapper),
-                                           WriteOutputAsCASID, UseCASBackend,
-                                           MCOutputID,
-                                           /*CAS*/ nullptr, /*Cache*/ nullptr);
+  ObjectStoreCachingOutputs CachingOutputs(
+      Clang, WorkingDir, std::move(PrefixMapper), WriteOutputAsCASID,
+      UseCASBackend, MCOutputID,
+      /*CAS*/ nullptr, /*Cache*/ nullptr);
   if (OutMCOutputID)
     *OutMCOutputID = std::move(MCOutputID);
 

clang/test/CAS/libclang-replay-job.c

@@ -68,10 +68,11 @@
 // RUN: diff -u %t/t1.d %t/a/b/rel.d
 // FIXME: Get clang's `-working-directory` to affect relative path for serialized diagnostics.
 
+// Use relative path to inputs and outputs.
 //--- cdb.json.template
 [{
   "directory": "DIR",
-  "command": "clang -c DIR/main.c -target x86_64-apple-macos11 -MD -MF t1.d -MT deps -o output1.o",
+  "command": "clang -c main.c -target x86_64-apple-macos11 -MD -MF t1.d -MT deps -o output1.o",
   "file": "DIR/main.c"
 }]
 

clang/tools/libclang/CCAS.cpp

@@ -418,10 +418,7 @@ CXCASReplayResult clang_experimental_cas_replayCompilation(
 
   SmallVector<const char *, 256> Args(argv, argv + argc);
   llvm::BumpPtrAllocator Alloc;
-  bool CLMode = driver::IsClangCL(
-      driver::getDriverMode(argv[0], ArrayRef(Args).slice(1)));
-
-  if (llvm::Error E = driver::expandResponseFiles(Args, CLMode, Alloc)) {
+  if (llvm::Error E = driver::expandResponseFiles(Args, /*CLMode=*/false, Alloc)) {
     Diags.Report(diag::err_drv_expand_response_file)
         << llvm::toString(std::move(E));
     if (OutError)
@@ -438,16 +435,12 @@ CXCASReplayResult clang_experimental_cas_replayCompilation(
     return nullptr;
   }
 
-  StringRef WorkingDir = WorkingDirectory;
-  if (!WorkingDir.empty())
-    Invok->getFileSystemOpts().WorkingDir = WorkingDir;
-
   SmallString<256> DiagText;
   std::optional<int> Ret;
-  if (Error E =
-          CompileJobCache::replayCachedResult(std::move(Invok), WComp.CacheKey,
-                                              WComp.CachedResult, DiagText)
-              .moveInto(Ret)) {
+  if (Error E = CompileJobCache::replayCachedResult(
+                    std::move(Invok), WorkingDirectory, WComp.CacheKey,
+                    WComp.CachedResult, DiagText)
+                    .moveInto(Ret)) {
     if (OutError)
       *OutError = cxerror::create(std::move(E));
     else