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

[Chen Zheng via llvm-commits]

================
@@ -30,10 +32,131 @@ 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) {}
+  void printPrivateHeaders() override;
+  void printFileHeader();
+  void printAuxiliaryHeader(){};
+  void printLoaderSectionHeader();
+  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();
+  printAuxiliaryHeader();
+  printLoaderSectionHeader();
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chenzheng1030 wrote:

hmm, do we have other way to dump the other info for AIX loader section?
```
The loader section consists of the following parts:

    Header fields
    Symbol table
    Relocation table
    Import file ID strings
    Symbol name string table
```

See https://www.ibm.com/docs/en/aix/7.1?topic=formats-xcoff-object-file-format#XCOFF__vra3i31ejbau__title__1

`Auxiliary Header`(optional header?) is not part of the loader section

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