[PDB] Tweak bad type index error handling

Translate invalid type indices to a sentinel value instead of skipping
the record. Skipping records isn't a good recovery method, because we
can skip a scope open or close record, which will confuse the scope
management code.

We currently have lots of invalid type indices on Microsoft-provided
standard libraries, because the LF_TYPESERVER2 records contain absolute
paths that are only valid on their build servers. Our type server
handlers need to look at other things (GUIDs) to find these type server
PDBs.

llvm-svn: 307726

lld/COFF/PDB.cpp

@@ -125,26 +125,25 @@ static bool remapTypeIndex(TypeIndex &TI, ArrayRef<TypeIndex> TypeIndexMap) {
   return true;
 }
 
-static bool remapTypesInSymbolRecord(ObjectFile *File,
+static void remapTypesInSymbolRecord(ObjectFile *File,
                                      MutableArrayRef<uint8_t> Contents,
                                      ArrayRef<TypeIndex> TypeIndexMap,
                                      ArrayRef<TiReference> TypeRefs) {
   for (const TiReference &Ref : TypeRefs) {
     unsigned ByteSize = Ref.Count * sizeof(TypeIndex);
-    if (Contents.size() < Ref.Offset + ByteSize) {
-      log("ignoring short symbol record");
-      return false;
-    }
+    if (Contents.size() < Ref.Offset + ByteSize)
+      fatal("ignoring short symbol record");
     MutableArrayRef<TypeIndex> TIs(
         reinterpret_cast<TypeIndex *>(Contents.data() + Ref.Offset), Ref.Count);
-    for (TypeIndex &TI : TIs)
+    for (TypeIndex &TI : TIs) {
       if (!remapTypeIndex(TI, TypeIndexMap)) {
+        TI = TypeIndex(SimpleTypeKind::NotTranslated);
         log("ignoring symbol record in " + File->getName() +
             " with bad type index 0x" + utohexstr(TI.getIndex()));
-        return false;
+        continue;
+      }
     }
   }
-  return true;
 }
 
 /// MSVC translates S_PROC_ID_END to S_END.
@@ -265,8 +264,7 @@ static void mergeSymbolRecords(BumpPtrAllocator &Alloc, ObjectFile *File,
     // Re-map all the type index references.
     MutableArrayRef<uint8_t> Contents =
         NewData.drop_front(sizeof(RecordPrefix));
-    if (!remapTypesInSymbolRecord(File, Contents, TypeIndexMap, TypeRefs))
-      continue;
+    remapTypesInSymbolRecord(File, Contents, TypeIndexMap, TypeRefs);
 
     // Fill in "Parent" and "End" fields by maintaining a stack of scopes.
     CVSymbol NewSym(Sym.kind(), NewData);

lld/test/COFF/pdb-invalid-func-type.yaml

@@ -0,0 +1,146 @@
+# This test has an S_GPROC32_ID symbol with an invalid type index. Make sure we
+# keep the record, or we'll have unbalanced scopes, which is bad. This situation
+# can arise when we can't find the type server PDB.
+
+# RUN: yaml2obj %s -o %t.obj
+# RUN: lld-link %t.obj -out:%t.exe -debug -pdb:%t.pdb -nodefaultlib -entry:main
+# RUN: llvm-pdbutil dump -symbols %t.pdb | FileCheck %s
+
+# CHECK: Mod 0000 | `{{.*}}pdb-invalid-func-type.yaml.tmp.obj`:
+# CHECK:      4 | S_GPROC32_ID [size = 44] `main`
+# CHECK:          parent = 0, end = 80, addr = 0000:0000, code size = 3
+# CHECK:     48 | S_FRAMEPROC [size = 32]
+# CHECK:     80 | S_END [size = 4]
+
+--- !COFF
+header:
+  Machine:         IMAGE_FILE_MACHINE_AMD64
+  Characteristics: [  ]
+sections:
+  - Name:            '.debug$S'
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    Subsections:
+      - !Symbols
+        Records:
+          - Kind:            S_GPROC32_ID
+            ProcSym:
+              CodeSize:        3
+              DbgStart:        0
+              DbgEnd:          2
+              # Corrupt function type!
+              FunctionType:    4101
+              Flags:           [  ]
+              DisplayName:     main
+          - Kind:            S_FRAMEPROC
+            FrameProcSym:
+              TotalFrameBytes: 0
+              PaddingFrameBytes: 0
+              OffsetToPadding: 0
+              BytesOfCalleeSavedRegisters: 0
+              OffsetOfExceptionHandler: 0
+              SectionIdOfExceptionHandler: 0
+              Flags:           [ AsynchronousExceptionHandling, OptimizedForSpeed ]
+          - Kind:            S_PROC_ID_END
+            ScopeEndSym:
+      - !Lines
+        CodeSize:        3
+        Flags:           [  ]
+        RelocOffset:     0
+        RelocSegment:    0
+        Blocks:
+          - FileName:        'c:\src\llvm-project\build\t.c'
+            Lines:
+              - Offset:          0
+                LineStart:       1
+                IsStatement:     true
+                EndDelta:        0
+            Columns:
+      - !FileChecksums
+        Checksums:
+          - FileName:        'c:\src\llvm-project\build\t.c'
+            Kind:            MD5
+            Checksum:        270A878DCC1B845655B162F56C4F5020
+      - !StringTable
+        Strings:
+          - 'c:\src\llvm-project\build\t.c'
+    Relocations:
+      - VirtualAddress:  152
+        SymbolName:      main
+        Type:            IMAGE_REL_AMD64_SECREL
+      - VirtualAddress:  156
+        SymbolName:      main
+        Type:            IMAGE_REL_AMD64_SECTION
+      - VirtualAddress:  208
+        SymbolName:      main
+        Type:            IMAGE_REL_AMD64_SECREL
+      - VirtualAddress:  212
+        SymbolName:      main
+        Type:            IMAGE_REL_AMD64_SECTION
+  - Name:            '.debug$T'
+    Characteristics: [ IMAGE_SCN_CNT_INITIALIZED_DATA, IMAGE_SCN_MEM_DISCARDABLE, IMAGE_SCN_MEM_READ ]
+    Alignment:       1
+    Types:
+      - Kind:            LF_ARGLIST
+        ArgList:
+          ArgIndices:      [ 0 ]
+      - Kind:            LF_PROCEDURE
+        Procedure:
+          ReturnType:      116
+          CallConv:        NearC
+          Options:         [ None ]
+          ParameterCount:  0
+          ArgumentList:    4096
+      - Kind:            LF_FUNC_ID
+        FuncId:
+          ParentScope:     0
+          FunctionType:    4097
+          Name:            main
+  - Name:            '.text$mn'
+    Characteristics: [ IMAGE_SCN_CNT_CODE, IMAGE_SCN_MEM_EXECUTE, IMAGE_SCN_MEM_READ ]
+    Alignment:       16
+    SectionData:     33C0C3
+symbols:
+  - Name:            '.debug$S'
+    Value:           0
+    SectionNumber:   1
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          328
+      NumberOfRelocations: 4
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            '.debug$T'
+    Value:           0
+    SectionNumber:   2
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          564
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        0
+      Number:          0
+  - Name:            '.text$mn'
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_NULL
+    StorageClass:    IMAGE_SYM_CLASS_STATIC
+    SectionDefinition:
+      Length:          3
+      NumberOfRelocations: 0
+      NumberOfLinenumbers: 0
+      CheckSum:        4021952397
+      Number:          0
+  - Name:            main
+    Value:           0
+    SectionNumber:   3
+    SimpleType:      IMAGE_SYM_TYPE_NULL
+    ComplexType:     IMAGE_SYM_DTYPE_FUNCTION
+    StorageClass:    IMAGE_SYM_CLASS_EXTERNAL
+...