[llvm-pdbutil] Fix crashes when TypeIndex is simple or doesn't exist in type stream

[zequanwu]

Summary

• Print simple TypeIndex
• Print error message when type doesn't exist.

[rnk]

lgtm

Seems reasonable.

llvm/test/tools/llvm-pdbutil/partial-type-stream.test

 ; RUN: llvm-pdbutil dump -type-index=0x1019 %p/Inputs/ClassLayoutTest.pdb \
 ; RUN:     | FileCheck --check-prefix=NODEPS %s
 ; RUN: llvm-pdbutil dump -type-index=0x1019 -dependents -dont-resolve-forward-refs \
 ; RUN:     %p/Inputs/ClassLayoutTest.pdb | FileCheck --check-prefix=DEPS %s
+; RUN: llvm-pdbutil dump -type-index=0x3,0x30,0x44,0x74 \
+; RUN:     %p/Inputs/ClassLayoutTest.pdb | FileCheck --check-prefix=SIMPLE %s 
 
 
 NODEPS:                          Types (TPI Stream)
 NODEPS-NEXT: ============================================================
 NODEPS-NEXT:   Showing 1 records.
 NODEPS-NEXT:   0x1019 | LF_MFUNCTION [size = 28]
 NODEPS-NEXT:            return type = 0x0003 (void), # args = 0, param list = 0x100E
 NODEPS-NEXT:            class type = 0x1017, this type = 0x1018, this adjust = 0

 DEPS-NEXT:            vtable: <no type>, base list: <no type>, field list: <no type>
 DEPS-NEXT:            options: forward ref | has unique name
 DEPS-NEXT:   0x1018 | LF_POINTER [size = 12]
 DEPS-NEXT:            referent = 0x1017, mode = pointer, opts = const, kind = ptr32
 DEPS-NEXT:   0x1019 | LF_MFUNCTION [size = 28]
 DEPS-NEXT:            return type = 0x0003 (void), # args = 0, param list = 0x100E
 DEPS-NEXT:            class type = 0x1017, this type = 0x1018, this adjust = 0
 DEPS-NEXT:            calling conv = thiscall, options = None
+
+
+SIMPLE:                          Types (TPI Stream)
+SIMPLE-NEXT: ============================================================
+SIMPLE-NEXT:   Showing 4 records.
+SIMPLE-NEXT:   0x0003 (void) | void
+SIMPLE-NEXT:   0x0030 (bool) | bool
+SIMPLE-NEXT:   0x0044 (__float48) | __float48
+SIMPLE-NEXT:   0x0074 (int) | int

llvm/tools/llvm-pdbutil/DumpOutputStyle.cpp

for (auto &Dep : DepSet) {
         Printer.formatLine("An error occurred dumping type record {0}: {1}",
                            Dep.first, toString(std::move(EC)));
     }
   } else {
     Printer.formatLine("Showing {0:N} records.", TiList.size());
 
     for (const auto &I : TiList) {
       TypeIndex TI(I);
-      CVType Type = Types.getType(TI);
-      if (auto EC = codeview::visitTypeRecord(Type, TI, V))
-        Printer.formatLine("An error occurred dumping type record {0}: {1}", TI,
-                           toString(std::move(EC)));
+      if (TI.isSimple()) {
+        Printer.formatLine("{0} | {1}", fmt_align(I, AlignStyle::Right, Width),
+                           Types.getTypeName(TI));
+      } else if (Optional<CVType> Type = Types.tryGetType(TI)) {
+        if (auto EC = codeview::visitTypeRecord(*Type, TI, V))
+          Printer.formatLine("An error occurred dumping type record {0}: {1}",
+                             TI, toString(std::move(EC)));
+      } else {
+        Printer.formatLine("Type {0} doesn't exist in TPI stream", TI);
+      }
     }
   }
 }
 
 Error DumpOutputStyle::dumpTypesFromObjectFile() {
   LazyRandomTypeCollection Types(100);
 
   for (const auto &S : getObj().sections()) {