Add command line switch for reporting DWARF warnings.

Change-Id: Ibcf1b0ddb93f1cf6bf12681ed82871328571f2aa
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/5137659
Reviewed-by: Ivan Penkov <ivanpe@chromium.org>

src/common/dwarf_cu_to_module.h

@@ -254,6 +254,63 @@ class DwarfCUToModule: public RootDIEHandler {
     void UncoveredHeading();
   };
 
+  class NullWarningReporter: public WarningReporter {
+   public:
+    NullWarningReporter(const string &filename, uint64_t cu_offset):
+        WarningReporter(filename, cu_offset) { }
+
+    // Set the name of the compilation unit we're processing to NAME.
+    void SetCUName(const string &name) { }
+
+    // Accessor and setter for uncovered_warnings_enabled_.
+    // UncoveredFunction and UncoveredLine only report a problem if that is
+    // true. By default, these warnings are disabled, because those
+    // conditions occur occasionally in healthy code.
+    void set_uncovered_warnings_enabled(bool value) { }
+
+    // A DW_AT_specification in the DIE at OFFSET refers to a DIE we
+    // haven't processed yet, or that wasn't marked as a declaration,
+    // at TARGET.
+    void UnknownSpecification(uint64_t offset, uint64_t target) { }
+
+    // A DW_AT_abstract_origin in the DIE at OFFSET refers to a DIE we
+    // haven't processed yet, or that wasn't marked as inline, at TARGET.
+    void UnknownAbstractOrigin(uint64_t offset, uint64_t target) { }
+
+    // We were unable to find the DWARF section named SECTION_NAME.
+    void MissingSection(const string &section_name) { }
+
+    // The CU's DW_AT_stmt_list offset OFFSET is bogus.
+    void BadLineInfoOffset(uint64_t offset) { }
+
+    // FUNCTION includes code covered by no line number data.
+    void UncoveredFunction(const Module::Function &function) { }
+
+    // Line number NUMBER in LINE_FILE, of length LENGTH, includes code
+    // covered by no function.
+    void UncoveredLine(const Module::Line &line) { }
+
+    // The DW_TAG_subprogram DIE at OFFSET has no name specified directly
+    // in the DIE, nor via a DW_AT_specification or DW_AT_abstract_origin
+    // link.
+    void UnnamedFunction(uint64_t offset) { }
+
+    // __cxa_demangle() failed to demangle INPUT.
+    void DemangleError(const string &input) { }
+
+    // The DW_FORM_ref_addr at OFFSET to TARGET was not handled because
+    // FilePrivate did not retain the inter-CU specification data.
+    void UnhandledInterCUReference(uint64_t offset, uint64_t target) { }
+
+    // The DW_AT_ranges at offset is malformed (truncated or outside of the
+    // .debug_ranges section's bound).
+    void MalformedRangeList(uint64_t offset) { }
+
+    // A DW_AT_ranges attribute was encountered but the no .debug_ranges
+    // section was found.
+    void MissingRanges() { }
+  };
+
   // Create a DWARF debugging info handler for a compilation unit
   // within FILE_CONTEXT. This uses information received from the
   // CompilationUnit DWARF parser to populate

src/common/mac/dump_syms.cc

@@ -265,6 +265,10 @@ SuperFatArch* DumpSymbols::FindBestMatchForArchitecture(
   return nullptr;
 }
 
+void DumpSymbols::SetReportWarnings(bool report_warnings) {
+    report_warnings_ = report_warnings;
+}
+
 string DumpSymbols::Identifier() {
   scoped_ptr<FileID> file_id;
 
@@ -524,10 +528,17 @@ void DumpSymbols::ReadDwarf(google_breakpad::Module* module,
   for (uint64_t offset = 0; offset < debug_info_length;) {
     // Make a handler for the root DIE that populates MODULE with the
     // debug info.
-    DwarfCUToModule::WarningReporter reporter(selected_object_name_,
+    DwarfCUToModule::WarningReporter *reporter = nullptr;
-                                              offset);
+    if (report_warnings_) {
+        reporter = new DwarfCUToModule::WarningReporter(
+            selected_object_name_, offset);
+    } else {
+        reporter = new DwarfCUToModule::NullWarningReporter(
+            selected_object_name_, offset);
+    }
     DwarfCUToModule root_handler(&file_context, &line_to_module,
-                                 &ranges_handler, &reporter, handle_inline);
+                                 &ranges_handler, reporter,
+                                 handle_inline);
     // Make a Dwarf2Handler that drives our DIEHandler.
     DIEDispatcher die_dispatcher(&root_handler);
     // Make a DWARF parser for the compilation unit at OFFSET.
@@ -543,6 +554,7 @@ void DumpSymbols::ReadDwarf(google_breakpad::Module* module,
       StartProcessSplitDwarf(&dwarf_reader, module, endianness,
                              handle_inter_cu_refs, handle_inline);
     }
+    delete reporter;
   }
 }
 

src/common/mac/dump_syms.h

@@ -71,7 +71,8 @@ class DumpSymbols {
         selected_object_name_(),
         enable_multiple_(enable_multiple),
         module_name_(module_name),
-        prefer_extern_name_(prefer_extern_name) {}
+        prefer_extern_name_(prefer_extern_name),
+        report_warnings_(true) {}
   ~DumpSymbols() = default;
 
   // Prepare to read debugging information from |filename|. |filename| may be
@@ -103,6 +104,9 @@ class DumpSymbols {
   // architecture matches that of this dumper program.
   bool SetArchitecture(const ArchInfo& info);
 
+  // Set whether or not to report DWARF warnings
+  void SetReportWarnings(bool report_warnings);
+
   // Return a pointer to an array of SuperFatArch structures describing the
   // object files contained in this dumper's file. Set *|count| to the number
   // of elements in the array. The returned array is owned by this DumpSymbols
@@ -224,6 +228,9 @@ class DumpSymbols {
   // (which are placed in the Extern), not in the DWARF symbols (which are
   // placed in the Function).
   bool prefer_extern_name_;
+
+  // Whether or not to report warnings
+  bool report_warnings_;
 };
 
 }  // namespace google_breakpad

src/tools/mac/dump_syms/dump_syms_tool.cc

@@ -77,6 +77,7 @@ struct Options {
   bool enable_multiple;
   string module_name;
   bool prefer_extern_name;
+  bool report_warnings;
 };
 
 static bool StackFrameEntryComparator(const Module::StackFrameEntry* a,
@@ -169,6 +170,8 @@ static bool Start(const Options& options) {
   const string& primary_file =
     split_module ? options.dsymPath : options.srcPath;
 
+  dump_symbols.SetReportWarnings(options.report_warnings);
+
   if (!dump_symbols.Read(primary_file))
     return false;
 
@@ -250,6 +253,7 @@ static void Usage(int argc, const char *argv[]) {
           "[-n MODULE] [-x] <Mach-o file>\n",
           argv[0]);
   fprintf(stderr, "\t-i: Output module header information only.\n");
+  fprintf(stderr, "\t-w: Output warning information.\n");
   fprintf(stderr, "\t-a: Architecture type [default: native, or whatever is\n");
   fprintf(stderr, "\t    in the file, if it contains only one architecture]\n");
   fprintf(stderr, "\t-g: Debug symbol file (dSYM) to dump in addition to the "
@@ -275,11 +279,14 @@ static void SetupOptions(int argc, const char *argv[], Options *options) {
   extern int optind;
   signed char ch;
 
-  while ((ch = getopt(argc, (char* const*)argv, "ia:g:crdm?hn:x")) != -1) {
+  while ((ch = getopt(argc, (char* const*)argv, "iwa:g:crdm?hn:x")) != -1) {
     switch (ch) {
       case 'i':
         options->header_only = true;
         break;
+      case 'w':
+        options->report_warnings = true;
+        break;
       case 'a': {
         std::optional<ArchInfo> arch_info = GetArchInfoFromName(optarg);
         if (!arch_info) {