Merge commit 'f682bc0c3807' from swift/release/5.9 into stable/20221013

Author: git apple-llvm automerger

llvm/test/tools/dsymutil/ARM/static-archive-collision.test

@@ -0,0 +1,26 @@
+$ cat f.c
+int f() {
+  volatile int i;
+  return i;
+}
+$ cat g.c
+int g() {
+  volatile int i;
+  return i;
+}
+$ cat main.c
+int f();
+int g();
+
+int main() {
+  return f() + g();
+}
+$ clang -g f.c -c -o f/foo.o
+$ clang -g g.c -c -o g/foo.o
+$ libtool -static f/foo.o g/foo.o -o foo.a
+$ clang main.o foo.a -o main.out
+
+RUN: dsymutil -oso-prepend-path %p/../Inputs %p/../Inputs/private/tmp/collision/main.out --dump-debug-map 2>&1 | FileCheck %s
+CHECK: skipping debug map object with duplicate name and timestamp: {{.*}} /private/tmp/collision/foo.a(foo.o)
+CHECK-NOT: could not find object file symbol for symbol _g
+CHECK-NOT: could not find object file symbol for symbol _f

llvm/test/tools/dsymutil/Inputs/private/tmp/collision/foo.a

@@ -9,9 +9,10 @@
 #include "BinaryHolder.h"
 #include "DebugMap.h"
 #include "MachOUtils.h"
-#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/Object/MachO.h"
+#include "llvm/Support/Chrono.h"
 #include "llvm/Support/Path.h"
 #include "llvm/Support/WithColor.h"
 #include "llvm/Support/raw_ostream.h"
@@ -31,7 +32,7 @@ class MachODebugMapParser {
       : BinaryPath(std::string(BinaryPath)), Archs(Archs.begin(), Archs.end()),
         PathPrefix(std::string(PathPrefix)),
         PaperTrailWarnings(PaperTrailWarnings), BinHolder(VFS, Verbose),
-        CurrentDebugMapObject(nullptr) {}
+        CurrentDebugMapObject(nullptr), SkipDebugMapObject(false) {}
 
   /// Parses and returns the DebugMaps of the input binary. The binary contains
   /// multiple maps in case it is a universal binary.
@@ -42,6 +43,8 @@ class MachODebugMapParser {
   /// Walk the symbol table and dump it.
   bool dumpStab();
 
+  using OSO = std::pair<llvm::StringRef, uint64_t>;
+
 private:
   std::string BinaryPath;
   SmallVector<StringRef, 1> Archs;
@@ -70,12 +73,18 @@ class MachODebugMapParser {
   /// Element of the debug map corresponding to the current object file.
   DebugMapObject *CurrentDebugMapObject;
 
+  /// Whether we need to skip the current debug map object.
+  bool SkipDebugMapObject;
+
   /// Holds function info while function scope processing.
   const char *CurrentFunctionName;
   uint64_t CurrentFunctionAddress;
 
   std::unique_ptr<DebugMap> parseOneBinary(const MachOObjectFile &MainBinary,
                                            StringRef BinaryPath);
+  void handleStabDebugMap(
+      const MachOObjectFile &MainBinary,
+      std::function<void(uint32_t, uint8_t, uint8_t, uint16_t, uint64_t)> F);
 
   void
   switchToNewDebugMapObject(StringRef Filename,
@@ -85,13 +94,21 @@ class MachODebugMapParser {
   std::vector<StringRef> getMainBinarySymbolNames(uint64_t Value);
   void loadMainBinarySymbols(const MachOObjectFile &MainBinary);
   void loadCurrentObjectFileSymbols(const object::MachOObjectFile &Obj);
+
+  void handleStabOSOEntry(uint32_t StringIndex, uint8_t Type,
+                          uint8_t SectionIndex, uint16_t Flags, uint64_t Value,
+                          llvm::DenseSet<OSO> &OSOs,
+                          llvm::SmallSet<OSO, 4> &Duplicates);
   void handleStabSymbolTableEntry(uint32_t StringIndex, uint8_t Type,
                                   uint8_t SectionIndex, uint16_t Flags,
-                                  uint64_t Value);
+                                  uint64_t Value,
+                                  const llvm::SmallSet<OSO, 4> &Duplicates);
 
-  template <typename STEType> void handleStabDebugMapEntry(const STEType &STE) {
-    handleStabSymbolTableEntry(STE.n_strx, STE.n_type, STE.n_sect, STE.n_desc,
-                               STE.n_value);
+  template <typename STEType>
+  void handleStabDebugMapEntry(
+      const STEType &STE,
+      std::function<void(uint32_t, uint8_t, uint8_t, uint16_t, uint64_t)> F) {
+    F(STE.n_strx, STE.n_type, STE.n_sect, STE.n_desc, STE.n_value);
   }
 
   void addCommonSymbols();
@@ -140,6 +157,7 @@ void MachODebugMapParser::resetParserState() {
   CurrentObjectAliasMap.clear();
   SeenAliasValues.clear();
   CurrentDebugMapObject = nullptr;
+  SkipDebugMapObject = false;
 }
 
 /// Commons symbols won't show up in the symbol map but might need to be
@@ -198,21 +216,60 @@ static std::string getArchName(const object::MachOObjectFile &Obj) {
   return std::string(T.getArchName());
 }
 
+void MachODebugMapParser::handleStabDebugMap(
+    const MachOObjectFile &MainBinary,
+    std::function<void(uint32_t, uint8_t, uint8_t, uint16_t, uint64_t)> F) {
+  for (const SymbolRef &Symbol : MainBinary.symbols()) {
+    const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
+    if (MainBinary.is64Bit())
+      handleStabDebugMapEntry(MainBinary.getSymbol64TableEntry(DRI), F);
+    else
+      handleStabDebugMapEntry(MainBinary.getSymbolTableEntry(DRI), F);
+  }
+}
+
 std::unique_ptr<DebugMap>
 MachODebugMapParser::parseOneBinary(const MachOObjectFile &MainBinary,
                                     StringRef BinaryPath) {
   Result = std::make_unique<DebugMap>(MainBinary.getArchTriple(), BinaryPath,
                                       MainBinary.getUuid());
   loadMainBinarySymbols(MainBinary);
   MainBinaryStrings = MainBinary.getStringTableData();
-  for (const SymbolRef &Symbol : MainBinary.symbols()) {
-    const DataRefImpl &DRI = Symbol.getRawDataRefImpl();
-    if (MainBinary.is64Bit())
-      handleStabDebugMapEntry(MainBinary.getSymbol64TableEntry(DRI));
-    else
-      handleStabDebugMapEntry(MainBinary.getSymbolTableEntry(DRI));
+
+  // Static archives can contain multiple object files with identical names, in
+  // which case the timestamp is used to disambiguate. However, if both are
+  // identical, there's no way to tell them apart. Detect this and skip
+  // duplicate debug map objects.
+  llvm::DenseSet<OSO> OSOs;
+  llvm::SmallSet<OSO, 4> Duplicates;
+
+  // Iterate over all the STABS to find duplicate OSO entries.
+  handleStabDebugMap(MainBinary,
+                     [&](uint32_t StringIndex, uint8_t Type,
+                         uint8_t SectionIndex, uint16_t Flags, uint64_t Value) {
+                       handleStabOSOEntry(StringIndex, Type, SectionIndex,
+                                          Flags, Value, OSOs, Duplicates);
+                     });
+
+  // Print an informative warning with the duplicate object file name and time
+  // stamp.
+  for (const auto &OSO : Duplicates) {
+    std::string Buffer;
+    llvm::raw_string_ostream OS(Buffer);
+    OS << sys::TimePoint<std::chrono::seconds>(sys::toTimePoint(OSO.second));
+    Warning("skipping debug map object with duplicate name and timestamp: " +
+            OS.str() + Twine(" ") + Twine(OSO.first));
   }
 
+  // Build the debug map by iterating over the STABS again but ignore the
+  // duplicate debug objects.
+  handleStabDebugMap(MainBinary, [&](uint32_t StringIndex, uint8_t Type,
+                                     uint8_t SectionIndex, uint16_t Flags,
+                                     uint64_t Value) {
+    handleStabSymbolTableEntry(StringIndex, Type, SectionIndex, Flags, Value,
+                               Duplicates);
+  });
+
   resetParserState();
   return std::move(Result);
 }
@@ -407,20 +464,38 @@ ErrorOr<std::vector<std::unique_ptr<DebugMap>>> MachODebugMapParser::parse() {
   return std::move(Results);
 }
 
+void MachODebugMapParser::handleStabOSOEntry(
+    uint32_t StringIndex, uint8_t Type, uint8_t SectionIndex, uint16_t Flags,
+    uint64_t Value, llvm::DenseSet<OSO> &OSOs,
+    llvm::SmallSet<OSO, 4> &Duplicates) {
+  if (Type != MachO::N_OSO)
+    return;
+
+  OSO O(&MainBinaryStrings.data()[StringIndex], Value);
+  if (!OSOs.insert(O).second)
+    Duplicates.insert(O);
+}
+
 /// Interpret the STAB entries to fill the DebugMap.
-void MachODebugMapParser::handleStabSymbolTableEntry(uint32_t StringIndex,
-                                                     uint8_t Type,
-                                                     uint8_t SectionIndex,
-                                                     uint16_t Flags,
-                                                     uint64_t Value) {
+void MachODebugMapParser::handleStabSymbolTableEntry(
+    uint32_t StringIndex, uint8_t Type, uint8_t SectionIndex, uint16_t Flags,
+    uint64_t Value, const llvm::SmallSet<OSO, 4> &Duplicates) {
   if (!(Type & MachO::N_STAB))
     return;
 
   const char *Name = &MainBinaryStrings.data()[StringIndex];
 
   // An N_OSO entry represents the start of a new object file description.
-  if (Type == MachO::N_OSO)
+  if (Type == MachO::N_OSO) {
+    if (Duplicates.count(OSO(Name, Value))) {
+      SkipDebugMapObject = true;
+      return;
+    }
     return switchToNewDebugMapObject(Name, sys::toTimePoint(Value));
+  }
+
+  if (SkipDebugMapObject)
+    return;
 
   if (Type == MachO::N_AST) {
     SmallString<80> Path(PathPrefix);