Index: ELF/LinkerScript.h
===================================================================
--- ELF/LinkerScript.h
+++ ELF/LinkerScript.h
@@ -106,6 +106,12 @@
 
   // Holds file name and line number for error reporting.
   std::string Location;
+
+  // Keeps string representing the expression. Used when printing map file.
+  StringRef StringView;
+
+  unsigned Offset;
+  unsigned Size;
 };
 
 // Linker scripts allow additional constraints to be put on ouput sections.
@@ -183,6 +189,9 @@
 
   static bool classof(const BaseCommand *C) { return C->Kind == ByteKind; }
 
+  // Keeps string representing the expression. Used when printing map file.
+  StringRef StringView;
+
   Expr Expression;
   unsigned Offset;
   unsigned Size;
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -731,7 +731,9 @@
   for (BaseCommand *Base : Sec->SectionCommands) {
     // This handles the assignments to symbol or to the dot.
     if (auto *Cmd = dyn_cast<SymbolAssignment>(Base)) {
+      Cmd->Offset = Dot - Ctx->OutSec->Addr;
       assignSymbol(Cmd, true);
+      Cmd->Size = Dot - Ctx->OutSec->Addr - Cmd->Offset;
       continue;
     }
 
Index: ELF/MapFile.cpp
===================================================================
--- ELF/MapFile.cpp
+++ ELF/MapFile.cpp
@@ -137,11 +137,29 @@
     OS << OSec->Name << '\n';
 
     // Dump symbols for each input section.
-    for (InputSection *IS : getInputSections(OSec)) {
-      writeHeader(OS, OSec->Addr + IS->OutSecOff, IS->getSize(), IS->Alignment);
-      OS << indent(1) << toString(IS) << '\n';
-      for (Symbol *Sym : SectionSyms[IS])
-        OS << SymStr[Sym] << '\n';
+    for (BaseCommand *Base : OSec->SectionCommands) {
+      if (auto *ISD = dyn_cast<InputSectionDescription>(Base)) {
+        for (InputSection *IS : ISD->Sections) {
+          writeHeader(OS, OSec->Addr + IS->OutSecOff, IS->getSize(),
+                      IS->Alignment);
+          OS << indent(1) << toString(IS) << '\n';
+          for (Symbol *Sym : SectionSyms[IS])
+            OS << SymStr[Sym] << '\n';
+        }
+        continue;
+      }
+
+      if (auto *Cmd = dyn_cast<ByteCommand>(Base)) {
+        writeHeader(OS, OSec->Addr + Cmd->Offset, Cmd->Size, Cmd->Size);
+        OS << indent(1) << Cmd->StringView << '\n';
+        continue;
+      }
+
+      if (auto *Cmd = dyn_cast<SymbolAssignment>(Base)) {
+        writeHeader(OS, OSec->Addr + Cmd->Offset, Cmd->Size, 1);
+        OS << indent(1) << Cmd->StringView << '\n';
+        continue;
+      }
     }
   }
 }
Index: ELF/ScriptParser.cpp
===================================================================
--- ELF/ScriptParser.cpp
+++ ELF/ScriptParser.cpp
@@ -114,6 +114,9 @@
   std::pair<std::vector<SymbolVersion>, std::vector<SymbolVersion>>
   readSymbols();
 
+  // Concatenates tokens in a [StartTok, EndTok] into string with Prefix.
+  StringRef buildStringView(StringRef Prefix, size_t StartTok, size_t EndTok);
+
   // True if a script being read is in a subdirectory specified by -sysroot.
   bool IsUnderSysroot;
 
@@ -773,7 +776,15 @@
   return Cmd;
 }
 
+StringRef ScriptParser::buildStringView(StringRef Prefix, size_t StartTok, size_t EndTok) {
+  std::string S = Prefix;
+  for (size_t I = StartTok; I <= EndTok; ++I)
+    S += (" " + Tokens[I]).str();
+  return Saver.save(S);
+}
+
 SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
+  size_t OldPos = Pos;
   StringRef Op = next();
   assert(Op == "=" || Op == "+=");
   Expr E = readExpr();
@@ -781,7 +792,10 @@
     std::string Loc = getCurrentLocation();
     E = [=] { return add(Script->getSymbolValue(Name, Loc), E()); };
   }
-  return make<SymbolAssignment>(Name, E, getCurrentLocation());
+
+  SymbolAssignment *Ret = make<SymbolAssignment>(Name, E, getCurrentLocation());
+  Ret->StringView = buildStringView(Name, OldPos, Pos - 1);
+  return Ret;
 }
 
 // This is an operator-precedence parser to parse a linker
@@ -935,7 +949,11 @@
                  .Default(-1);
   if (Size == -1)
     return nullptr;
-  return make<ByteCommand>(readParenExpr(), Size);
+
+  size_t OldPos = Pos;
+  ByteCommand* Ret = make<ByteCommand>(readParenExpr(), Size);
+  Ret->StringView = buildStringView(Tok, OldPos, Pos - 1);
+  return Ret;
 }
 
 StringRef ScriptParser::readParenLiteral() {
Index: test/ELF/linkerscript/map-file.test
===================================================================
--- test/ELF/linkerscript/map-file.test
+++ test/ELF/linkerscript/map-file.test
@@ -0,0 +1,38 @@
+# REQUIRES: x86
+
+# RUN: echo ".section .foo.1,\"a\"" > %t.s
+# RUN: echo ".quad 1" >> %t.s
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %t.s -o %t.o
+
+# RUN: ld.lld -o %t %t.o -Map=%t.map --script %s
+# RUN: FileCheck -strict-whitespace %s < %t.map
+
+SECTIONS {
+  . = 0x1000;
+  .foo : {
+    BYTE(0x11)
+    SHORT(0x1122)
+    LONG(0x11223344)
+    QUAD(0x1122334455667788)
+    . += 0x1000;
+    *(.foo.1)
+    . += 0x123 *
+         (1 + 1);
+    foo = .;
+    bar = 0x42 - 0x26;
+  }
+}
+
+# CHECK:      Address          Size             Align Out     In      Symbol
+# CHECK-NEXT: 0000000000001000 000000000000125d     1 .foo
+# CHECK-NEXT: 0000000000001000 0000000000000001     1         BYTE ( 0x11 )
+# CHECK-NEXT: 0000000000001001 0000000000000002     2         SHORT ( 0x1122 )
+# CHECK-NEXT: 0000000000001003 0000000000000004     4         LONG ( 0x11223344 )
+# CHECK-NEXT: 0000000000001007 0000000000000008     8         QUAD ( 0x1122334455667788 )
+# CHECK-NEXT: 000000000000100f 0000000000001000     1         . += 0x1000
+# CHECK-NEXT: 000000000000200f 0000000000000008     1         {{.*}}{{/|\\}}map-file.test.tmp.o:(.foo.1)
+# CHECK-NEXT: 0000000000002017 0000000000000246     1         . += 0x123 * ( 1 + 1 )
+# CHECK-NEXT: 000000000000225d 0000000000000000     1         foo = .
+# CHECK-NEXT: 000000000000225d 0000000000000000     1         bar = 0x42 - 0x26
+# CHECK-NEXT: 0000000000002260 0000000000000000     4 .text
+# CHECK-NEXT: 0000000000002260 0000000000000000     4         {{.*}}{{/|\\}}map-file.test.tmp.o:(.text)