Fix pdb-diff test.

A test was checked in on Friday that worked by checking in an
object file and PDB generated locally by MSVC, and then having
the test run lld-link on the object file and diffing LLD's PDB
against the checked in PDB.

This failed because part of the diffing algorithm involves
determining if two modules are the same, and if so drilling into
the module and diffing individual fields of the module.  The
only thing we can use to make this determination though is the
"name" of the module, which is a path to where the module (obj
file) was read from on the machine where it was linked.  This
fails for obvious reasons when comparing a PDB generated on one
machine to a PDB on another machine.

The fix employed here is to add two command line options to the
diff subcommand, which allow the user to specify a "binary root
path".  The bin root path, if specified, is stripped from the
beginning of any embedded PDB paths.  The test is updated to
specify the user's local test output directory for the left
PDB, and is hardcoded to the location where the original PDB
was created for the right PDB.  This way all the equivalence
comparisons should succeed.

llvm-svn: 307555

1 files changed, 187 insertions, 88 deletions

diff --git a/llvm/tools/llvm-pdbutil/Diff.cpp b/llvm/tools/llvm-pdbutil/Diff.cpp
index 9e520470790..75e8f34bda0 100644
--- a/llvm/tools/llvm-pdbutil/Diff.cpp
+++ b/llvm/tools/llvm-pdbutil/Diff.cpp
@@ -23,13 +23,148 @@
 #include "llvm/DebugInfo/PDB/Native/PDBStringTable.h"
 #include "llvm/DebugInfo/PDB/Native/RawConstants.h"
 
+#include "llvm/Support/FileSystem.h"
 #include "llvm/Support/FormatAdapters.h"
 #include "llvm/Support/FormatProviders.h"
 #include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/Path.h"
 
 using namespace llvm;
 using namespace llvm::pdb;
 
+namespace {
+// Compare and format two stream numbers.  Stream numbers are considered
+// identical if they contain the same value, equivalent if they are both
+// the invalid stream or neither is the invalid stream, and different if
+// one is the invalid stream and another isn't.
+struct StreamNumberProvider {
+  static DiffResult compare(uint16_t L, uint16_t R) {
+    if (L == R)
+      return DiffResult::IDENTICAL;
+    bool LP = L != kInvalidStreamIndex;
+    bool RP = R != kInvalidStreamIndex;
+    if (LP != RP)
+      return DiffResult::DIFFERENT;
+    return DiffResult::EQUIVALENT;
+  }
+
+  static std::string format(uint16_t SN, bool Right) {
+    if (SN == kInvalidStreamIndex)
+      return "(not present)";
+    return formatv("{0}", SN).str();
+  }
+};
+
+// Compares and formats two module indices.  Modis are considered identical
+// if they are identical, equivalent if they either both contain a value or
+// both don't contain a value, and different if one contains a value and the
+// other doesn't.
+struct ModiProvider {
+  DiffResult compare(Optional<uint32_t> L, Optional<uint32_t> R) {
+    if (L == R)
+      return DiffResult::IDENTICAL;
+    if (L.hasValue() != R.hasValue())
+      return DiffResult::DIFFERENT;
+    return DiffResult::EQUIVALENT;
+  }
+
+  std::string format(Optional<uint32_t> Modi, bool Right) {
+    if (!Modi.hasValue())
+      return "(not present)";
+    return formatv("{0}", *Modi).str();
+  }
+};
+
+// Compares and formats two paths embedded in the PDB, ignoring the beginning
+// of the path if the user specified it as a "root path" on the command line.
+struct BinaryPathProvider {
+  explicit BinaryPathProvider(uint32_t MaxLen) : MaxLen(MaxLen) {}
+
+  DiffResult compare(StringRef L, StringRef R) {
+    if (L == R)
+      return DiffResult::IDENTICAL;
+
+    SmallString<64> LN = removeRoot(L, false);
+    SmallString<64> RN = removeRoot(R, true);
+
+    return (LN.equals_lower(RN)) ? DiffResult::EQUIVALENT
+                                 : DiffResult::DIFFERENT;
+  }
+
+  std::string format(StringRef S, bool Right) {
+    if (S.empty())
+      return "(empty)";
+
+    SmallString<64> Native = removeRoot(S, Right);
+    return truncateStringFront(Native.str(), MaxLen);
+  }
+
+  SmallString<64> removeRoot(StringRef Path, bool IsRight) const {
+    SmallString<64> Native(Path);
+    SmallString<64> Root =
+        IsRight ? opts::diff::RightRoot : opts::diff::LeftRoot;
+    // pdb paths always use windows syntax, convert slashes to backslashes.
+    sys::path::native(Root, sys::path::Style::windows);
+    if (sys::path::has_stem(Root, sys::path::Style::windows))
+      sys::path::append(Root,
+                        sys::path::get_separator(sys::path::Style::windows));
+
+    sys::path::replace_path_prefix(Native, Root, "");
+    return Native;
+  }
+  uint32_t MaxLen;
+};
+
+// Compare and format two stream purposes.  For general streams, this just
+// compares the description.  For module streams it uses the path comparison
+// algorithm taking into consideration the binary root, described above.
+// Formatting stream purposes just prints the stream purpose, except for
+// module streams and named streams, where it prefixes the name / module
+// with an identifier.  Example:
+//
+//   Named Stream "\names"
+//   Module Stream "foo.obj"
+//
+// If a named stream is too long to fit in a column, it is truncated at the
+// end, and if a module is too long to fit in a column, it is truncated at the
+// beginning.  Example:
+//
+//  Named Stream "\Really Long Str..."
+//  Module Stream "...puts\foo.obj"
+//
+struct StreamPurposeProvider {
+  explicit StreamPurposeProvider(uint32_t MaxLen) : MaxLen(MaxLen) {}
+
+  DiffResult compare(const std::pair<StreamPurpose, std::string> &L,
+                     const std::pair<StreamPurpose, std::string> &R) {
+    if (L.first != R.first)
+      return DiffResult::DIFFERENT;
+    if (L.first == StreamPurpose::ModuleStream) {
+      BinaryPathProvider PathProvider(MaxLen);
+      return PathProvider.compare(L.second, R.second);
+    }
+    return (L.second == R.second) ? DiffResult::IDENTICAL
+                                  : DiffResult::DIFFERENT;
+  }
+
+  std::string format(const std::pair<StreamPurpose, std::string> &P,
+                     bool Right) {
+    if (P.first == StreamPurpose::Other)
+      return truncateStringBack(P.second, MaxLen);
+    if (P.first == StreamPurpose::NamedStream)
+      return truncateQuotedNameBack("Named Stream", P.second, MaxLen);
+
+    assert(P.first == StreamPurpose::ModuleStream);
+    uint32_t ExtraChars = strlen("Module \"\"");
+    BinaryPathProvider PathProvider(MaxLen - ExtraChars);
+    std::string Result = PathProvider.format(P.second, Right);
+    return formatv("Module \"{0}\"", Result);
+  }
+
+  uint32_t MaxLen;
+};
+}
+
 namespace llvm {
 template <> struct format_provider<PdbRaw_FeatureSig> {
   static void format(const PdbRaw_FeatureSig &Sig, raw_ostream &Stream,
@@ -100,19 +235,12 @@ Error DiffStyle::dump() {
   return Error::success();
 }
 
-static std::string shortFilePath(StringRef Path, uint32_t Width) {
-  if (Path.size() <= Width)
-    return Path;
-  Path = Path.take_back(Width - 3);
-  return std::string("...") + Path.str();
-}
-
 Error DiffStyle::diffSuperBlock() {
   DiffPrinter D(2, "MSF Super Block", 16, 20, opts::diff::PrintResultColumn,
                 opts::diff::PrintValueColumns, outs());
   D.printExplicit("File", DiffResult::UNSPECIFIED,
-                  shortFilePath(File1.getFilePath(), 18),
-                  shortFilePath(File2.getFilePath(), 18));
+                  truncateStringFront(File1.getFilePath(), 18),
+                  truncateStringFront(File2.getFilePath(), 18));
   D.print("Block Size", File1.getBlockSize(), File2.getBlockSize());
   D.print("Block Count", File1.getBlockCount(), File2.getBlockCount());
   D.print("Unknown 1", File1.getUnknown1(), File2.getUnknown1());
@@ -125,13 +253,13 @@ Error DiffStyle::diffStreamDirectory() {
   DiffPrinter D(2, "Stream Directory", 30, 20, opts::diff::PrintResultColumn,
                 opts::diff::PrintValueColumns, outs());
   D.printExplicit("File", DiffResult::UNSPECIFIED,
-                  shortFilePath(File1.getFilePath(), 18),
-                  shortFilePath(File2.getFilePath(), 18));
+                  truncateStringFront(File1.getFilePath(), 18),
+                  truncateStringFront(File2.getFilePath(), 18));
 
-  SmallVector<std::string, 32> P;
-  SmallVector<std::string, 32> Q;
-  discoverStreamPurposes(File1, P, 28);
-  discoverStreamPurposes(File2, Q, 28);
+  SmallVector<std::pair<StreamPurpose, std::string>, 32> P;
+  SmallVector<std::pair<StreamPurpose, std::string>, 32> Q;
+  discoverStreamPurposes(File1, P);
+  discoverStreamPurposes(File2, Q);
   D.print("Stream Count", File1.getNumStreams(), File2.getNumStreams());
   auto PI = to_vector<32>(enumerate(P));
   auto QI = to_vector<32>(enumerate(Q));
@@ -139,26 +267,31 @@ Error DiffStyle::diffStreamDirectory() {
   // Scan all streams in the left hand side, looking for ones that are also
   // in the right.  Each time we find one, remove it.  When we're done, Q
   // should contain all the streams that are in the right but not in the left.
+  StreamPurposeProvider StreamProvider(28);
   for (const auto &P : PI) {
     typedef decltype(PI) ContainerType;
     typedef typename ContainerType::value_type value_type;
 
-    auto Iter = llvm::find_if(
-        QI, [P](const value_type &V) { return V.value() == P.value(); });
+    auto Iter = llvm::find_if(QI, [P, &StreamProvider](const value_type &V) {
+      DiffResult Result = StreamProvider.compare(P.value(), V.value());
+      return Result == DiffResult::EQUIVALENT ||
+             Result == DiffResult::IDENTICAL;
+    });
 
     if (Iter == QI.end()) {
-      D.printExplicit(P.value(), DiffResult::DIFFERENT, P.index(),
-                      "(not present)");
+      D.printExplicit(StreamProvider.format(P.value(), false),
+                      DiffResult::DIFFERENT, P.index(), "(not present)");
       continue;
     }
 
-    D.print<EquivalentDiffProvider>(P.value(), P.index(), Iter->index());
+    D.print<EquivalentDiffProvider>(StreamProvider.format(P.value(), false),
+                                    P.index(), Iter->index());
     QI.erase(Iter);
   }
 
   for (const auto &Q : QI) {
-    D.printExplicit(Q.value(), DiffResult::DIFFERENT, "(not present)",
-                    Q.index());
+    D.printExplicit(StreamProvider.format(Q.value(), true),
+                    DiffResult::DIFFERENT, "(not present)", Q.index());
   }
 
   return Error::success();
@@ -168,8 +301,8 @@ Error DiffStyle::diffStringTable() {
   DiffPrinter D(2, "String Table", 30, 20, opts::diff::PrintResultColumn,
                 opts::diff::PrintValueColumns, outs());
   D.printExplicit("File", DiffResult::UNSPECIFIED,
-                  shortFilePath(File1.getFilePath(), 18),
-                  shortFilePath(File2.getFilePath(), 18));
+                  truncateStringFront(File1.getFilePath(), 18),
+                  truncateStringFront(File2.getFilePath(), 18));
 
   auto ExpectedST1 = File1.getStringTable();
   auto ExpectedST2 = File2.getStringTable();
@@ -257,8 +390,8 @@ Error DiffStyle::diffInfoStream() {
   DiffPrinter D(2, "PDB Stream", 22, 40, opts::diff::PrintResultColumn,
                 opts::diff::PrintValueColumns, outs());
   D.printExplicit("File", DiffResult::UNSPECIFIED,
-                  shortFilePath(File1.getFilePath(), 38),
-                  shortFilePath(File2.getFilePath(), 38));
+                  truncateStringFront(File1.getFilePath(), 38),
+                  truncateStringFront(File2.getFilePath(), 38));
 
   auto ExpectedInfo1 = File1.getPDBInfoStream();
   auto ExpectedInfo2 = File2.getPDBInfoStream();
@@ -292,53 +425,6 @@ Error DiffStyle::diffInfoStream() {
   return Error::success();
 }
 
-struct StreamNumberProvider {
-  static DiffResult compare(uint16_t L, uint16_t R) {
-    if (L == R)
-      return DiffResult::IDENTICAL;
-    bool LP = L != kInvalidStreamIndex;
-    bool RP = R != kInvalidStreamIndex;
-    if (LP != RP)
-      return DiffResult::DIFFERENT;
-    return DiffResult::EQUIVALENT;
-  }
-
-  static std::string format(uint16_t SN) {
-    if (SN == kInvalidStreamIndex)
-      return "(not present)";
-    return formatv("{0}", SN).str();
-  }
-};
-
-struct ModiProvider {
-  DiffResult compare(Optional<uint32_t> L, Optional<uint32_t> R) {
-    if (L == R)
-      return DiffResult::IDENTICAL;
-    if (L.hasValue() != R.hasValue())
-      return DiffResult::DIFFERENT;
-    return DiffResult::EQUIVALENT;
-  }
-
-  std::string format(Optional<uint32_t> Modi) {
-    if (!Modi.hasValue())
-      return "(not present)";
-    return formatv("{0}", *Modi).str();
-  }
-};
-
-struct StringProvider {
-  DiffResult compare(StringRef L, StringRef R) {
-    IdenticalDiffProvider I;
-    return I.compare(L, R);
-  }
-
-  std::string format(StringRef S) {
-    if (S.empty())
-      return "(empty)";
-    return S;
-  }
-};
-
 static std::vector<std::pair<uint32_t, DbiModuleDescriptor>>
 getModuleDescriptors(const DbiModuleList &ML) {
   std::vector<std::pair<uint32_t, DbiModuleDescriptor>> List;
@@ -348,16 +434,31 @@ getModuleDescriptors(const DbiModuleList &ML) {
   return List;
 }
 
-static void diffOneModule(
-    DiffPrinter &D, const std::pair<uint32_t, DbiModuleDescriptor> Item,
-    std::vector<std::pair<uint32_t, DbiModuleDescriptor>> &Other, bool Invert) {
-  D.printFullRow(
-      truncateQuotedNameFront("Module", Item.second.getModuleName(), 70));
+static void
+diffOneModule(DiffPrinter &D,
+              const std::pair<uint32_t, DbiModuleDescriptor> Item,
+              std::vector<std::pair<uint32_t, DbiModuleDescriptor>> &Other,
+              bool ItemIsRight) {
+  StreamPurposeProvider HeaderProvider(70);
+  std::pair<StreamPurpose, std::string> Header;
+  Header.first = StreamPurpose::ModuleStream;
+  Header.second = Item.second.getModuleName();
+  D.printFullRow(HeaderProvider.format(Header, ItemIsRight));
 
+  const auto *L = &Item;
+
+  BinaryPathProvider PathProvider(28);
   auto Iter = llvm::find_if(
-      Other, [&Item](const std::pair<uint32_t, DbiModuleDescriptor> &Other) {
-        return Other.second.getModuleName().equals_lower(
-            Item.second.getModuleName());
+      Other, [&Item, &PathProvider, ItemIsRight,
+              L](const std::pair<uint32_t, DbiModuleDescriptor> &Other) {
+        const auto *Left = L;
+        const auto *Right = &Other;
+        if (ItemIsRight)
+          std::swap(Left, Right);
+        DiffResult Result = PathProvider.compare(Left->second.getModuleName(),
+                                                 Right->second.getModuleName());
+        return Result == DiffResult::EQUIVALENT ||
+               Result == DiffResult::IDENTICAL;
       });
   if (Iter == Other.end()) {
     // We didn't find this module at all on the other side.  Just print one row
@@ -367,15 +468,13 @@ static void diffOneModule(
   }
 
   // We did find this module.  Go through and compare each field.
-  const auto *L = &Item;
   const auto *R = &*Iter;
-  if (Invert)
+  if (ItemIsRight)
     std::swap(L, R);
 
   D.print<ModiProvider>("- Modi", L->first, R->first);
-  D.print<StringProvider>("- Obj File Name",
-                          shortFilePath(L->second.getObjFileName(), 28),
-                          shortFilePath(R->second.getObjFileName(), 28));
+  D.print<BinaryPathProvider>("- Obj File Name", L->second.getObjFileName(),
+                              R->second.getObjFileName(), PathProvider);
   D.print<StreamNumberProvider>("- Debug Stream",
                                 L->second.getModuleStreamIndex(),
                                 R->second.getModuleStreamIndex());
@@ -398,8 +497,8 @@ Error DiffStyle::diffDbiStream() {
   DiffPrinter D(2, "DBI Stream", 40, 30, opts::diff::PrintResultColumn,
                 opts::diff::PrintValueColumns, outs());
   D.printExplicit("File", DiffResult::UNSPECIFIED,
-                  shortFilePath(File1.getFilePath(), 28),
-                  shortFilePath(File2.getFilePath(), 28));
+                  truncateStringFront(File1.getFilePath(), 28),
+                  truncateStringFront(File2.getFilePath(), 28));
 
   auto ExpectedDbi1 = File1.getPDBDbiStream();
   auto ExpectedDbi2 = File2.getPDBDbiStream();