Index: ELF/LinkerScript.h
===================================================================
--- ELF/LinkerScript.h
+++ ELF/LinkerScript.h
@@ -15,6 +15,7 @@
 #include "Writer.h"
 #include "lld/Core/LLVM.h"
 #include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -127,6 +128,7 @@
   uint32_t Filler = 0;
   ConstraintKind Constraint = ConstraintKind::NoConstraint;
   std::string Location;
+  std::string MemoryRegionName;
 };
 
 // This struct represents one section match pattern in SECTIONS() command.
@@ -187,6 +189,17 @@
   Expr LMAExpr;
 };
 
+struct MemoryRegion {
+  MemoryRegion() : Name(""), Origin(0), Length(0), Index(0) {}
+  MemoryRegion(StringRef N, uint64_t O, uint64_t L)
+      : Name(N), Origin(O), Length(L), Index(O) {}
+
+  std::string Name;
+  uint64_t Origin;
+  uint64_t Length;
+  uint64_t Index;
+};
+
 class LinkerScriptBase {
 protected:
   ~LinkerScriptBase() = default;
@@ -215,6 +228,8 @@
   // List of section patterns specified with KEEP commands. They will
   // be kept even if they are unused and --gc-sections is specified.
   std::vector<InputSectionDescription *> KeptSections;
+
+  llvm::DenseMap<llvm::StringRef, MemoryRegion> MemoryRegions;
 };
 
 extern ScriptConfiguration *ScriptConfig;
@@ -276,6 +291,7 @@
   uintX_t Dot;
   uintX_t LMAOffset = 0;
   OutputSectionBase *CurOutSec = nullptr;
+  MemoryRegion *CurMemRegion = nullptr;
   uintX_t ThreadBssOffset = 0;
   void switchTo(OutputSectionBase *Sec);
   void flush();
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -409,6 +409,18 @@
   // .foo { *(.aaa) a = SIZEOF(.foo); *(.bbb) }
   CurOutSec->Size = Pos - CurOutSec->Addr;
 
+  if (CurMemRegion) {
+    CurMemRegion->Index += CurOutSec->Size;
+    uint64_t CurSize = CurMemRegion->Index - CurMemRegion->Origin;
+    if (CurSize > CurMemRegion->Length) {
+      uint64_t OverflowAmt = CurSize - CurMemRegion->Length;
+      error("a.out section `" + CurOutSec->Name + "' will not fit in region `" +
+            CurMemRegion->Name + "'");
+      error("region `" + CurMemRegion->Name + "' overflowed by " +
+            Twine(OverflowAmt) + " bytes");
+    }
+  }
+
   if (IsTbss)
     ThreadBssOffset = Pos - Dot;
   else
@@ -720,9 +732,19 @@
     }
 
     auto *Cmd = cast<OutputSectionCommand>(Base.get());
-    if (Cmd->AddrExpr)
+    if (Cmd->AddrExpr) {
       Dot = Cmd->AddrExpr(Dot);
+    } else if (!Cmd->MemoryRegionName.empty()) {
+      auto It = Opt.MemoryRegions.find(Cmd->MemoryRegionName);
+      if (It != Opt.MemoryRegions.end()) {
+        CurMemRegion = &It->second;
+        Dot = CurMemRegion->Index;
+      } else {
+        warn("memory region `" + Cmd->MemoryRegionName + "' not declared");
+      }
+    }
     assignOffsets(Cmd);
+    CurMemRegion = nullptr;
   }
 
   uintX_t MinVA = std::numeric_limits<uintX_t>::max();
@@ -976,6 +998,7 @@
   void readExtern();
   void readGroup();
   void readInclude();
+  void readMemory();
   void readOutput();
   void readOutputArch();
   void readOutputFormat();
@@ -1073,6 +1096,8 @@
       readGroup();
     } else if (Tok == "INCLUDE") {
       readInclude();
+    } else if (Tok == "MEMORY") {
+      readMemory();
     } else if (Tok == "OUTPUT") {
       readOutput();
     } else if (Tok == "OUTPUT_ARCH") {
@@ -1464,6 +1489,10 @@
       setError("unknown command " + Tok);
     }
   }
+
+  if (consume(">"))
+    Cmd->MemoryRegionName = next();
+
   Cmd->Phdrs = readOutputSectionPhdrs();
 
   if (consume("="))
@@ -1948,6 +1977,45 @@
   return Ret;
 }
 
+void ScriptParser::readMemory() {
+  // As specified in:
+  // https://sourceware.org/binutils/docs/ld/MEMORY.html#MEMORY
+
+  expect("{");
+  while (!Error && !consume("}")) {
+    StringRef Name = next();
+    if (consume("(")) {
+      StringRef AttrStr = next();
+      expect(")");
+    }
+    expect(":");
+
+    // `ORIGIN = <num>`.
+    if (!(consume("ORIGIN") || consume("org") || consume("o")))
+      setError("expected one of: ORIGIN, org, or o");
+    expect("=");
+    uint64_t Origin;
+    // TODO: Fully support constant expressions.
+    StringRef Tok = next();
+    if (!readInteger(Tok, Origin))
+      setError("nonconstant expression for origin");
+
+    expect(",");
+
+    // `LENGTH = <num>`.
+    if (!(consume("LENGTH") || consume("len") || consume("l")))
+      setError("expected one of: LENGTH, len, or l");
+    expect("=");
+    uint64_t Length;
+    Tok = next();
+    // TODO: Fully support constant expressions.
+    if (!readInteger(Tok, Length))
+      setError("nonconstant expression for length");
+
+    Opt.MemoryRegions[Name] = MemoryRegion(Name, Origin, Length);
+  }
+}
+
 void elf::readLinkerScript(MemoryBufferRef MB) {
   ScriptParser(MB).readLinkerScript();
 }