[VFS] Add 'ignore-non-existent-contents' field to YAML files

Add 'ignore-non-existent-contents' to tell the VFS whether an invalid path
obtained via 'external-contents' should cause iteration on the VFS to stop.

If 'true', the VFS should ignore the entry and continue with the next. Allows
YAML files to be shared across multiple compiler invocations regardless of
prior existent paths in 'external-contents'. This global value is overridable
on a per-file basis.

This adds the parsing and write test part, but use by VFS comes next.

Differential Revision: https://reviews.llvm.org/D23422

rdar://problem/27531549

llvm-svn: 278456

diff --git a/clang/include/clang/Basic/VirtualFileSystem.h b/clang/include/clang/Basic/VirtualFileSystem.h
index 6ac0812..e977aa6 100644 (file)
--- a/clang/include/clang/Basic/VirtualFileSystem.h
+++ b/clang/include/clang/Basic/VirtualFileSystem.h
@@ -340,6 +340,7 @@ class YAMLVFSWriter {
   Optional<bool> IsCaseSensitive;
   Optional<bool> IsOverlayRelative;
   Optional<bool> UseExternalNames;
+  Optional<bool> IgnoreNonExistentContents;
   std::string OverlayDir;
 
 public:
@@ -351,6 +352,9 @@ public:
   void setUseExternalNames(bool UseExtNames) {
     UseExternalNames = UseExtNames;
   }
+  void setIgnoreNonExistentContents(bool IgnoreContents) {
+    IgnoreNonExistentContents = IgnoreContents;
+  }
   void setOverlayDir(StringRef OverlayDirectory) {
     IsOverlayRelative = true;
     OverlayDir.assign(OverlayDirectory.str());

diff --git a/clang/lib/Basic/VirtualFileSystem.cpp b/clang/lib/Basic/VirtualFileSystem.cpp
index 8ace2b3..62a386b 100644 (file)
--- a/clang/lib/Basic/VirtualFileSystem.cpp
+++ b/clang/lib/Basic/VirtualFileSystem.cpp
@@ -801,6 +801,7 @@ public:
 ///   'case-sensitive': <boolean, default=true>
 ///   'use-external-names': <boolean, default=true>
 ///   'overlay-relative': <boolean, default=false>
+///   'ignore-non-existent-contents': <boolean, default=true>
 ///
 /// Virtual directories are represented as
 /// \verbatim
@@ -860,6 +861,14 @@ class RedirectingFileSystem : public vfs::FileSystem {
   /// \brief Whether to use to use the value of 'external-contents' for the
   /// names of files.  This global value is overridable on a per-file basis.
   bool UseExternalNames = true;
+
+  /// \brief Whether an invalid path obtained via 'external-contents' should
+  /// cause iteration on the VFS to stop. If 'true', the VFS should ignore
+  /// the entry and continue with the next. Allows YAML files to be shared
+  /// across multiple compiler invocations regardless of prior existent
+  /// paths in 'external-contents'. This global value is overridable on a
+  /// per-file basis.
+  bool IgnoreNonExistentContents = true;
   /// @}
 
   /// Virtual file paths and external files could be canonicalized without "..",
@@ -937,6 +946,10 @@ public:
     return ExternalContentsPrefixDir;
   }
 
+  bool ignoreNonExistentContents() const {
+    return IgnoreNonExistentContents;
+  }
+
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
 LLVM_DUMP_METHOD void dump() const {
     for (const std::unique_ptr<Entry> &Root : Roots)
@@ -1301,6 +1314,7 @@ public:
       KeyStatusPair("case-sensitive", false),
       KeyStatusPair("use-external-names", false),
       KeyStatusPair("overlay-relative", false),
+      KeyStatusPair("ignore-non-existent-contents", false),
       KeyStatusPair("roots", true),
     };
 
@@ -1359,6 +1373,9 @@ public:
       } else if (Key == "use-external-names") {
         if (!parseScalarBool(I->getValue(), FS->UseExternalNames))
           return false;
+      } else if (Key == "ignore-non-existent-contents") {
+        if (!parseScalarBool(I->getValue(), FS->IgnoreNonExistentContents))
+          return false;
       } else {
         llvm_unreachable("key missing from Keys");
       }
@@ -1619,7 +1636,7 @@ public:
   JSONWriter(llvm::raw_ostream &OS) : OS(OS) {}
   void write(ArrayRef<YAMLVFSEntry> Entries, Optional<bool> UseExternalNames,
              Optional<bool> IsCaseSensitive, Optional<bool> IsOverlayRelative,
-             StringRef OverlayDir);
+             Optional<bool> IgnoreNonExistentContents, StringRef OverlayDir);
 };
 }
 
@@ -1675,6 +1692,7 @@ void JSONWriter::write(ArrayRef<YAMLVFSEntry> Entries,
                        Optional<bool> UseExternalNames,
                        Optional<bool> IsCaseSensitive,
                        Optional<bool> IsOverlayRelative,
+                       Optional<bool> IgnoreNonExistentContents,
                        StringRef OverlayDir) {
   using namespace llvm::sys;
 
@@ -1692,6 +1710,9 @@ void JSONWriter::write(ArrayRef<YAMLVFSEntry> Entries,
     OS << "  'overlay-relative': '"
        << (UseOverlayRelative ? "true" : "false") << "',\n";
   }
+  if (IgnoreNonExistentContents.hasValue())
+    OS << "  'ignore-non-existent-contents': '"
+       << (IgnoreNonExistentContents.getValue() ? "true" : "false") << "',\n";
   OS << "  'roots': [\n";
 
   if (!Entries.empty()) {
@@ -1748,7 +1769,8 @@ void YAMLVFSWriter::write(llvm::raw_ostream &OS) {
   });
 
   JSONWriter(OS).write(Mappings, UseExternalNames, IsCaseSensitive,
-                       IsOverlayRelative, OverlayDir);
+                       IsOverlayRelative, IgnoreNonExistentContents,
+                       OverlayDir);
 }
 
 VFSFromYamlDirIterImpl::VFSFromYamlDirIterImpl(

diff --git a/clang/lib/Frontend/ModuleDependencyCollector.cpp b/clang/lib/Frontend/ModuleDependencyCollector.cpp
index 11d36e5..cc655f6 100644 (file)
--- a/clang/lib/Frontend/ModuleDependencyCollector.cpp
+++ b/clang/lib/Frontend/ModuleDependencyCollector.cpp
@@ -134,6 +134,10 @@ void ModuleDependencyCollector::writeFileMap() {
   // allows crash reproducer scripts to work across machines.
   VFSWriter.setOverlayDir(VFSDir);
 
+  // Do not ignore non existent contents otherwise we might skip something
+  // that should have been collected here.
+  VFSWriter.setIgnoreNonExistentContents(false);
+
   // Explicitly set case sensitivity for the YAML writer. For that, find out
   // the sensitivity at the path where the headers all collected to.
   VFSWriter.setCaseSensitivity(isCaseSensitivePath(VFSDir));

diff --git a/clang/test/Modules/crash-vfs-run-reproducer.m b/clang/test/Modules/crash-vfs-run-reproducer.m
index d0eaa93..e9ecb47 100644 (file)
--- a/clang/test/Modules/crash-vfs-run-reproducer.m
+++ b/clang/test/Modules/crash-vfs-run-reproducer.m
@@ -36,6 +36,7 @@
 // CHECKYAML: 'case-sensitive':
 // CHECKYAML-NEXT: 'use-external-names': 'false',
 // CHECKYAML-NEXT: 'overlay-relative': 'true',
+// CHECKYAML-NEXT: 'ignore-non-existent-contents': 'false'
 // CHECKYAML: 'type': 'directory'
 // CHECKYAML: 'name': "/[[PATH:.*]]/Inputs/crash-recovery/usr/include",
 // CHECKYAML-NEXT: 'contents': [

diff --git a/clang/test/VFS/Inputs/vfsoverlay2.yaml b/clang/test/VFS/Inputs/vfsoverlay2.yaml
index ae2a0ce..688ae64 100644 (file)
--- a/clang/test/VFS/Inputs/vfsoverlay2.yaml
+++ b/clang/test/VFS/Inputs/vfsoverlay2.yaml
@@ -1,5 +1,6 @@
 {
   'version': 0,
+  'ignore-non-existent-contents': false,
   'roots': [
     { 'name': 'OUT_DIR', 'type': 'directory',
       'contents': [