Index: test/tools/llvm-size/basic.test
===================================================================
--- test/tools/llvm-size/basic.test
+++ test/tools/llvm-size/basic.test
@@ -11,6 +11,8 @@
 #Compilation: clang -c -O0
 RUN: llvm-size -A %p/Inputs/1.o | FileCheck --check-prefix="SYSV" %s
 RUN: llvm-size -B %p/Inputs/1.o | FileCheck --check-prefix="BSD" %s
+RUN: llvm-size -A -common %p/Inputs/1.o | FileCheck --check-prefix="SYSVCOMM" %s
+RUN: llvm-size -B -common %p/Inputs/1.o | FileCheck --check-prefix="BSDCOMM" %s
 
 ENOENT: {{.*}}llvm-size{{(\.EXE|\.exe)?}}: {{.*}}.blah: {{[Nn]}}o such file or directory
 SYSV:    {{[ -\(\)_A-Za-z0-9.\\/:]+}}  :
@@ -26,3 +28,16 @@
 BSD:        text    data     bss     dec     hex filename
 BSD-NEXT:     67      56       0     123      7b {{[ -\(\)_A-Za-z0-9.\\/:]+}}
 
+SYSVCOMM:    {{[ -\(\)_A-Za-z0-9.\\/:]+}}  :
+SYSVCOMM-NEXT:    section             size   addr
+SYSVCOMM-NEXT:    .text                 67      0
+SYSVCOMM-NEXT:    .data                  0      0
+SYSVCOMM-NEXT:    .bss                   0      0
+SYSVCOMM-NEXT:    .comment              46      0
+SYSVCOMM-NEXT:    .note.GNU-stack        0      0
+SYSVCOMM-NEXT:    .eh_frame             56      0
+SYSVCOMM-NEXT:    *COM*                 12      0
+SYSVCOMM-NEXT:    Total                181
+
+BSDCOMM:        text    data     bss     dec     hex filename
+BSDCOMM-NEXT:     67      56      12     135      87 {{[ -\(\)_A-Za-z0-9.\\/:]+}}
Index: tools/llvm-size/llvm-size.cpp
===================================================================
--- tools/llvm-size/llvm-size.cpp
+++ tools/llvm-size/llvm-size.cpp
@@ -58,6 +58,10 @@
 DarwinLongFormat("l", cl::desc("When format is darwin, use long format "
                                "to include addresses and offsets."));
 
+cl::opt<bool>
+ELFCommons("common", cl::desc("Print common symbols in the ELF file. \
+When using Berkely format, this is added to bss."), cl::init(false));
+
 static cl::list<std::string>
 ArchFlags("arch", cl::desc("architecture(s) from a Mach-O file to dump"),
           cl::ZeroOrMore);
@@ -127,6 +131,16 @@
   }
   return true;
 }
+
+/// @brief Returns total size of all ELF common symbols
+static uint64_t getCommonSize(ObjectFile *Obj) {
+  uint64_t total_commons = 0;
+  for (auto &Sym : Obj->symbols())
+    if (Obj->getSymbolFlags(Sym.getRawDataRefImpl()) & SymbolRef::SF_Common)
+      total_commons += Obj->getCommonSymbolSize(Sym.getRawDataRefImpl());
+  return total_commons;
+}
+
 /// @brief Print the size of each Mach-O segment and section in @p MachO.
 ///
 /// This is when used when @c OutputFormat is darwin and produces the same
@@ -350,6 +364,12 @@
       outs() << format(fmt.str().c_str(), namestr.c_str(), size, addr);
     }
 
+    if (ELFCommons) {
+      uint64_t common_size = getCommonSize(Obj);
+      total += common_size;
+      outs() << format(fmt.str().c_str(), std::string("*COM*").c_str(), common_size, static_cast<uint64_t>(0));
+    }
+
     // Print total.
     fmtbuf.clear();
     fmt << "%-" << max_name_len << "s "
@@ -377,6 +397,9 @@
         total_bss += size;
     }
 
+    if (ELFCommons)
+      total_bss += getCommonSize(Obj);
+
     total = total_text + total_data + total_bss;
 
     if (!berkeleyHeaderPrinted) {