[ELF] [HEXAGON] Let input determine ELF header e_flags

[sidneym]

Summary

Use the input file list to determine e_flags.

[ruiu]

ELF/Arch/Hexagon.cpp

59

I don't think you need to define this function -- you can just inline.

73

Target is a bit weird name. Maybe just Ret.

[sidneym]

Update following Rui's suggestions.

[ruiu]

Can you add a test?

[sidneym]

Add testcase

[ruiu]

LGTM

test/ELF/hexagon-eflag.s

5

Remove an extraneous space.

6

Ditto

9

FileCheck doesn't distinguish 2 or more spaces from a single space, so please remove extraneous spaces between "Flags:" and 0x62.

ELF/Arch/Hexagon.cpp

Hexagon::Hexagon() {
   PltEntrySize = 16;
   PltHeaderSize = 32;
 
   // Hexagon Linux uses 64K pages by default.
   DefaultMaxPageSize = 0x10000;
   NoneRel = R_HEX_NONE;
 }
 
-// Support V60 only at the moment.
-uint32_t Hexagon::calcEFlags() const { return 0x60; }
+uint32_t Hexagon::calcEFlags() const {
+  assert(!ObjectFiles.empty());
+
+  // The architecture revision must always be equal to or greater than
+  // greatest revision in the list of inputs.
+  uint32_t Ret = 0;
+  for (InputFile *F : ObjectFiles) {
+    uint32_t EFlags = cast<ObjFile<ELF32LE>>(F)->getObj().getHeader()->e_flags;
+    if (EFlags > Ret)
+      Ret = EFlags;
+  }
+  return Ret;
+}
 
 static uint32_t applyMask(uint32_t Mask, uint32_t Data) {
   uint32_t Result = 0;
   size_t Off = 0;
 
   for (size_t Bit = 0; Bit != 32; ++Bit) {
     uint32_t ValBit = (Data >> Off) & 1;
     uint32_t MaskBit = (Mask >> Bit) & 1;
     if (MaskBit) {
       Result |= (ValBit << Bit);
       ++Off;

test/ELF/hexagon-eflag.s

+# REQUIRES: hexagon
+# RUN: llvm-mc -filetype=obj -mv62 -triple=hexagon-unknown-elf %s -o %t
+# RUN: llvm-mc -filetype=obj -mv60 -triple=hexagon-unknown-elf %S/Inputs/hexagon.s -o %t2
+# RUN: ld.lld %t2 %t  -o %t3
+# RUN: llvm-readelf -h  %t3 | FileCheck %s
+# Verify that the largest arch in the input list is selected.
+# CHECK: Flags: 0x62