[llvm-readelf] - Change letters used for SHF_ARM_PURECODE and SHF_X86_64_LARGE flags.

GNU uses `l` for SHF_X86_64_LARGE and `y` for SHF_ARM_PURECODE.
Lets follow.

To do this I had to refactor and refine how we print the help flags description.
It was too generic and inconsistent with GNU readelf.

Differential revision: https://reviews.llvm.org/D71464

1 files changed, 27 insertions, 10 deletions

diff --git a/llvm/tools/llvm-readobj/ELFDumper.cpp b/llvm/tools/llvm-readobj/ELFDumper.cpp
index 7d648da41ea..a786dac546e 100644
--- a/llvm/tools/llvm-readobj/ELFDumper.cpp
+++ b/llvm/tools/llvm-readobj/ELFDumper.cpp
@@ -1474,7 +1474,7 @@ static const EnumEntry<unsigned> ElfX86_64SectionFlags[] = {
   LLVM_READOBJ_ENUM_ENT(ELF, SHF_X86_64_LARGE)
 };
 
-static std::string getGNUFlags(uint64_t Flags) {
+static std::string getGNUFlags(unsigned EMachine, uint64_t Flags) {
   // Here we are trying to build the flags string in the same way as GNU does.
   // It is not that straightforward. Imagine we have sh_flags == 0x90000000.
   // SHF_EXCLUDE ("E") has a value of 0x80000000 and SHF_MASKPROC is 0xf0000000.
@@ -1500,7 +1500,11 @@ static std::string getGNUFlags(uint64_t Flags) {
 
     // If we did not find a matching regular flag, then we deal with an OS
     // specific flag, processor specific flag or an unknown flag.
-    if (Flag & ELF::SHF_MASKOS) {
+    if (EMachine == EM_X86_64 && Flag == SHF_X86_64_LARGE) {
+      Str += 'l';
+    } else if (EMachine == EM_ARM && Flag == SHF_ARM_PURECODE) {
+      Str += 'y';
+    } else if (Flag & ELF::SHF_MASKOS) {
       HasOSFlag = true;
       Flags &= ~ELF::SHF_MASKOS;
     } else if (Flag & ELF::SHF_MASKPROC) {
@@ -3513,6 +3517,25 @@ static std::string getSectionTypeString(unsigned Arch, unsigned Type) {
   return "";
 }
 
+static void printSectionDescription(formatted_raw_ostream &OS,
+                                    unsigned EMachine) {
+  OS << "Key to Flags:\n";
+  OS << "  W (write), A (alloc), X (execute), M (merge), S (strings), I "
+        "(info),\n";
+  OS << "  L (link order), O (extra OS processing required), G (group), T "
+        "(TLS),\n";
+  OS << "  C (compressed), x (unknown), o (OS specific), E (exclude),\n";
+
+  if (EMachine == EM_X86_64)
+    OS << "  l (large), ";
+  else if (EMachine == EM_ARM)
+    OS << "  y (purecode), ";
+  else
+    OS << "  ";
+
+  OS << "p (processor specific)\n";
+}
+
 template <class ELFT>
 void GNUStyle<ELFT>::printSectionHeaders(const ELFO *Obj) {
   unsigned Bias = ELFT::Is64Bits ? 0 : 8;
@@ -3543,7 +3566,7 @@ void GNUStyle<ELFT>::printSectionHeaders(const ELFO *Obj) {
     Fields[4].Str = to_string(format_hex_no_prefix(Sec.sh_offset, 6));
     Fields[5].Str = to_string(format_hex_no_prefix(Sec.sh_size, 6));
     Fields[6].Str = to_string(format_hex_no_prefix(Sec.sh_entsize, 2));
-    Fields[7].Str = getGNUFlags(Sec.sh_flags);
+    Fields[7].Str = getGNUFlags(Obj->getHeader()->e_machine, Sec.sh_flags);
     Fields[8].Str = to_string(Sec.sh_link);
     Fields[9].Str = to_string(Sec.sh_info);
     Fields[10].Str = to_string(Sec.sh_addralign);
@@ -3563,13 +3586,7 @@ void GNUStyle<ELFT>::printSectionHeaders(const ELFO *Obj) {
     OS << "\n";
     ++SectionIndex;
   }
-  OS << "Key to Flags:\n"
-     << "  W (write), A (alloc), X (execute), M (merge), S (strings), l "
-        "(large)\n"
-     << "  I (info), L (link order), G (group), T (TLS), E (exclude),\
- x (unknown)\n"
-     << "  O (extra OS processing required) o (OS specific),\
- p (processor specific)\n";
+  printSectionDescription(OS, Obj->getHeader()->e_machine);
 }
 
 template <class ELFT>