[llvm] [llvm-objdump] Print out xcoff file header for xcoff object file with option private-headers (PR #96350)

[zhijian lin via llvm-commits]

================
@@ -30,10 +32,87 @@ using namespace llvm::support;
 
 namespace {
 class XCOFFDumper : public objdump::Dumper {
+  const XCOFFObjectFile &Obj;
+  unsigned Width;
+
 public:
-  XCOFFDumper(const object::XCOFFObjectFile &O) : Dumper(O) {}
-  void printPrivateHeaders() override {}
+  XCOFFDumper(const object::XCOFFObjectFile &O) : Dumper(O), Obj(O) {}
+
+private:
+  void printPrivateHeaders() override;
+  void printFileHeader();
+  FormattedString formatName(StringRef Name);
+  void printHex(StringRef Name, uint64_t Value);
+  void printNumber(StringRef Name, uint64_t Value);
+  void printStrHex(StringRef Name, StringRef Str, uint64_t Value);
+  void setWidth(unsigned W) { Width = W; };
 };
+
+void XCOFFDumper::printPrivateHeaders() { printFileHeader(); }
+
+FormattedString XCOFFDumper::formatName(StringRef Name) {
+  return FormattedString(Name, Width, FormattedString::JustifyLeft);
+}
+
+void XCOFFDumper::printHex(StringRef Name, uint64_t Value) {
+  outs() << formatName(Name) << format_hex(Value, 0) << "\n";
+}
+
+void XCOFFDumper::printNumber(StringRef Name, uint64_t Value) {
+  outs() << formatName(Name) << format_decimal(Value, 0) << "\n";
+}
+
+void XCOFFDumper::printStrHex(StringRef Name, StringRef Str, uint64_t Value) {
+  outs() << formatName(Name) << Str << " (" << format_decimal(Value, 0)
+         << ")\n";
+}
+
+void XCOFFDumper::printFileHeader() {
+  setWidth(20);
+  outs() << "\n---File Header:\n";
+  printHex("Magic:", Obj.getMagic());
+  printNumber("NumberOfSections:", Obj.getNumberOfSections());
+
+  int32_t Timestamp = Obj.getTimeStamp();
+  if (TimeStamp > 0) {
+    // This handling of the timestamp assumes that the host system's time_t is
+    // compatible with AIX time_t. If a platform is not compatible, the lit
+    // tests will let us know.
+    time_t TimeDate = TimeStamp;
+
+    char FormattedTime[80] = {};
+
+    size_t BytesFormatted = std::strftime(FormattedTime, sizeof(FormattedTime),
+                                          "%F %T", gmtime(&TimeDate));
+    if (BytesFormatted)
+      printStrHex("Timestamp:", FormattedTime, TimeStamp);
+    else
+      printHex("Timestamp:", TimeStamp);
----------------
diggerlin wrote:

I think the std::strftime returning zero only happen when  the size of FormattedTime is less than the size the date/time string in the specific format.  since the size of is large enough to hold the  date/time string, there should not return zero.


https://github.com/llvm/llvm-project/pull/96350