Modify llvm-objdump to display information for common symbols similar to GNU objdump

[colinl]

Summary

Output for GNU objdump:
$ objdump -t test.o

test.o: file format elf32-little

SYMBOL TABLE:
00000000 l df *ABS* 00000000 test.c
00000000 l d .text 00000000 .text
00000000 l d .data 00000000 .data
00000000 l d .bss 00000000 .bss
00000000 l d .comment 00000000 .comment
00000400 O *COM* 00000008 common_symbol

Output for llvm-objdump:
$ ./bin/llvm-objdump.exe -t test.o

test.o: file format ELF32-hexagon

SYMBOL TABLE:
00000000 *UND* 00000000
00000000 l df *ABS* 00000000 test.c
00000000 l d .text 00000000 .text
00000000 l d .data 00000000 .data
00000000 l d .bss 00000000 .bss
00000000 l d .comment 00000000 .comment
00000400 g *COM* 00000008 common_symbol

[• rafael]

There are a few difference left, but this is going on the right direction.

LGTM

test/tools/llvm-objdump/common-symbol-elf.test

4

please add a newline.

[colinl]

Committed r226932

test/tools/llvm-objdump/common-symbol-elf.test

+// RUN: llvm-objdump -t %p/Inputs/common-symbol-elf | FileCheck %s
+
+CHECK: 00000400 g       *COM*  00000008 common_symbol
 No newline at end of file

tools/llvm-objdump/llvm-objdump.cpp

     bool Global = Flags & SymbolRef::SF_Global;
     bool Weak = Flags & SymbolRef::SF_Weak;
     bool Absolute = Flags & SymbolRef::SF_Absolute;
+    bool Common = Flags & SymbolRef::SF_Common;
 
+    if (Common) {
+      uint32_t Alignment;
+      if (error(Symbol.getAlignment(Alignment)))
+        Alignment = 0;
+      Address = Size;
+      Size = Alignment;
+    }
     if (Address == UnknownAddressOrSize)
       Address = 0;
     if (Size == UnknownAddressOrSize)

            << ' ';
     if (Absolute) {
       outs() << "*ABS*";
+    } else if (Common) {
+      outs() << "*COM*";
     } else if (Section == o->section_end()) {
       outs() << "*UND*";
     } else {