[dsymutil] Add -verify option to run DWARF verifier after linking.

This patch adds support for running the DWARF verifier on the linked
debug info files. If the -verify options is specified and verification
fails, dsymutil exists with abort with non-zero exit code. This behavior
is *not* enabled by default.

Differential revision: https://reviews.llvm.org/D40777

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@320033 91177308-0d34-0410-b5e6-96231b3b80d8

test/tools/dsymutil/X86/verify.test

@@ -0,0 +1,8 @@
+# Multiple inputs in flat mode
+RUN: not llvm-dsymutil -verify -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s --check-prefix=QUIET
+RUN: not llvm-dsymutil -verify -verbose -oso-prepend-path=%p/.. %p/../Inputs/basic.macho.x86_64 %p/../Inputs/basic-archive.macho.x86_64 %p/../Inputs/basic-lto.macho.x86_64 %p/../Inputs/basic-lto-dw4.macho.x86_64 -o %t 2>&1 | FileCheck %s --check-prefix=QUIET --check-prefix=VERBOSE
+
+VERBOSE: Verifying DWARF for architecture: x86_64
+VERBOSE: error: DIE has invalid DW_AT_location encoding:
+VERBOSE: error: DIE has invalid DW_AT_location encoding:
+QUIET: error: verification failed

test/tools/dsymutil/cmdline.test

@@ -14,6 +14,7 @@ HELP: -o=<filename>
 HELP: -oso-prepend-path=<path>
 HELP: -symtab
 HELP: -verbose
+HELP: -verify
 HELP: -y
 HELP-NOT: -reverse-iterate
 

tools/dsymutil/dsymutil.cpp

@@ -20,6 +20,10 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
+#include "llvm/DebugInfo/DIContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFContext.h"
+#include "llvm/DebugInfo/DWARF/DWARFVerifier.h"
+#include "llvm/Object/Binary.h"
 #include "llvm/Object/MachO.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
@@ -40,6 +44,7 @@
 using namespace llvm;
 using namespace llvm::cl;
 using namespace llvm::dsymutil;
+using namespace object;
 
 static OptionCategory DsymCategory("Specific Options");
 static opt<bool> Help("h", desc("Alias for -help"), Hidden);
@@ -114,6 +119,9 @@ static opt<bool> InputIsYAMLDebugMap(
     "y", desc("Treat the input file is a YAML debug map rather than a binary."),
     init(false), cat(DsymCategory));
 
+static opt<bool> Verify("verify", desc("Verify the linked DWARF debug info."),
+                        cat(DsymCategory));
+
 static bool createPlistFile(llvm::StringRef Bin, llvm::StringRef BundleRoot) {
   if (NoOutput)
     return true;
@@ -184,6 +192,34 @@ static bool createBundleDir(llvm::StringRef BundleBase) {
   return true;
 }
 
+static bool verify(llvm::StringRef OutputFile, llvm::StringRef Arch) {
+  if (OutputFile == "-") {
+    llvm::errs() << "warning: verification skipped for " << Arch
+                 << "because writing to stdout.\n";
+    return true;
+  }
+
+  Expected<OwningBinary<Binary>> BinOrErr = createBinary(OutputFile);
+  if (!BinOrErr) {
+    errs() << OutputFile << ": " << toString(BinOrErr.takeError());
+    return false;
+  }
+
+  Binary &Binary = *BinOrErr.get().getBinary();
+  if (auto *Obj = dyn_cast<MachOObjectFile>(&Binary)) {
+    raw_ostream &os = Verbose ? errs() : nulls();
+    os << "Verifying DWARF for architecture: " << Arch << "\n";
+    std::unique_ptr<DWARFContext> DICtx = DWARFContext::create(*Obj);
+    DIDumpOptions DumpOpts;
+    bool success = DICtx->verify(os, DumpOpts.noImplicitRecursion());
+    if (!success)
+        errs() << "error: verification failed for " << Arch << '\n';
+    return success;
+  }
+
+  return false;
+}
+
 static std::string getOutputFileName(llvm::StringRef InputFile) {
   if (FlatOut) {
     // If a flat dSYM has been requested, things are pretty simple.
@@ -361,6 +397,7 @@ int main(int argc, char **argv) {
       std::atomic_char AllOK(1);
       auto LinkLambda = [&]() {
         AllOK.fetch_and(linkDwarf(*OS, *Map, Options));
+        OS->flush();
       };
 
       // FIXME: The DwarfLinker can have some very deep recursion that can max
@@ -376,6 +413,10 @@ int main(int argc, char **argv) {
       if (!AllOK)
         return 1;
 
+      if (Verify && !NoOutput &&
+          !verify(OutputFile, Map->getTriple().getArchName()))
+        return 1;
+
       if (NeedsTempFiles)
         TempFiles.emplace_back(Map->getTriple().getArchName().str(),
                                OutputFile);