Add --offoading option to llvm-readobj

  Utilize new extensions to LLVM Offloading API to
  handle offloading fatbin Bundles.

  The tool will output a list of available offload bundles
  using URI syntax.

Change-Id: Ib24a722be16f499ffb56bf46e4b82e90d8775040

Author: david-salinas

llvm/docs/CommandGuide/llvm-readobj.rst

@@ -104,6 +104,10 @@ file formats.
  Do not demangle symbol names in the output. This option is only for ELF and
  XCOFF file formats. The option is enabled by default.
 
+.. option:: --offloading
+
+ Display list of HIP Offload bundles using URI syntax.
+
 .. option:: --relocations, --relocs, -r
 
  Display the relocation entries in the file.

llvm/include/llvm/Object/OffloadBundle.h

@@ -161,7 +161,7 @@ struct OffloadBundleURI {
     OffsetStr.getAsInteger(10, O);
     Str = Str.drop_front(OffsetStr.size());
 
-    if (Str.consume_front("&size="))
+    if (!Str.consume_front("&size="))
       return createStringError(object_error::parse_failed,
                                "Reading 'size' in URI");
 

llvm/test/tools/llvm-readobj/ELF/AMDGPU/offloading.test

@@ -16,6 +16,8 @@
 #include "llvm/Object/Archive.h"
 #include "llvm/Object/Decompressor.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/OffloadBinary.h"
+#include "llvm/Object/OffloadBundle.h"
 #include "llvm/Support/Error.h"
 #include "llvm/Support/FormatVariadic.h"
 #include "llvm/Support/ScopedPrinter.h"
@@ -230,4 +232,21 @@ void ObjDumper::printSectionsAsHex(const object::ObjectFile &Obj,
   }
 }
 
+// TODO: add proper error handling.
+void ObjDumper::printOffloading(const object::ObjectFile &Obj) {
+  // we can use an argument to let user select which offloading section they
+  // want to print. but for now, we're hardcoding ELF and "hip_fatbin".
+  assert((Obj.isELF() || Obj.isCOFF()) && "Invalid file type");
+
+  SmallVector<llvm::object::OffloadBundleFatBin> Bundles;
+  if (Error Err = llvm::object::extractOffloadBundleFatBinary(Obj, Bundles))
+    reportWarning(createError("Cannot extract Fatbin Binary from Object."),
+                  Obj.getFileName());
+
+  // Print out all the FatBin Bundles that are contained in this buffer.
+  for (const auto &[Index, Bundle] : llvm::enumerate(Bundles)) {
+    Bundle.printEntriesAsURI();
+  }
+}
+
 } // namespace llvm

llvm/tools/llvm-readobj/ObjDumper.cpp

@@ -16,6 +16,7 @@
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Object/ObjectFile.h"
+#include "llvm/Object/OffloadBinary.h"
 #include "llvm/Support/CommandLine.h"
 
 #include <unordered_set>
@@ -186,6 +187,7 @@ class ObjDumper {
   std::function<Error(const Twine &Msg)> WarningHandler;
   void reportUniqueWarning(Error Err) const;
   void reportUniqueWarning(const Twine &Msg) const;
+  void printOffloading(const object::ObjectFile &Obj);
 
 protected:
   ScopedPrinter &W;

llvm/tools/llvm-readobj/ObjDumper.h

@@ -64,6 +64,9 @@ def notes : FF<"notes", "Display notes">, Group<grp_elf>;
 def program_headers : FF<"program-headers", "Display program headers">, Group<grp_elf>;
 def version_info : FF<"version-info", "Display version sections">, Group<grp_elf>;
 
+def offloading : Flag<["--"], "offloading">,
+  HelpText<"Display the content of the offloading section">;
+
 // Mach-O specific options.
 def grp_mach_o : OptionGroup<"kind">, HelpText<"OPTIONS (Mach-O specific)">;
 def macho_data_in_code : FF<"macho-data-in-code", "Display Data in Code command">, Group<grp_mach_o>;

llvm/tools/llvm-readobj/Opts.td

@@ -138,6 +138,7 @@ static bool Notes;
 static bool ProgramHeaders;
 static bool SectionGroups;
 static bool VersionInfo;
+static bool Offloading;
 
 // Mach-O specific options.
 static bool MachODataInCode;
@@ -288,6 +289,7 @@ static void parseOptions(const opt::InputArgList &Args) {
     }
   }
   opts::VersionInfo = Args.hasArg(OPT_version_info);
+  opts::Offloading = Args.hasArg(OPT_offloading);
 
   // Mach-O specific options.
   opts::MachODataInCode = Args.hasArg(OPT_macho_data_in_code);
@@ -455,6 +457,8 @@ static void dumpObject(ObjectFile &Obj, ScopedPrinter &Writer,
     Dumper->printGnuHashTable();
   if (opts::VersionInfo)
     Dumper->printVersionInfo();
+  if (opts::Offloading)
+    Dumper->printOffloading(Obj);
   if (opts::StringTable)
     Dumper->printStringTable();
   if (Obj.isELF()) {
@@ -699,6 +703,7 @@ int llvm_readobj_main(int argc, char **argv, const llvm::ToolContext &) {
     opts::DynamicTable = true;
     opts::Notes = true;
     opts::VersionInfo = true;
+    opts::Offloading = true;
     opts::UnwindInfo = true;
     opts::SectionGroups = true;
     opts::HashHistogram = true;