Index: ELF/LinkerScript.h
===================================================================
--- ELF/LinkerScript.h
+++ ELF/LinkerScript.h
@@ -57,12 +57,17 @@
   int Kind;
 };
 
+enum class SymbolProvision { Create, Provide, ProvideHidden, Ignore };
+
 struct SymbolAssignment : BaseCommand {
-  SymbolAssignment(StringRef Name, std::vector<StringRef> &Expr)
-      : BaseCommand(AssignmentKind), Name(Name), Expr(std::move(Expr)) {}
+  SymbolAssignment(StringRef Name, std::vector<StringRef> &Expr,
+                   SymbolProvision Provision = SymbolProvision::Create)
+      : BaseCommand(AssignmentKind), Name(Name), Expr(std::move(Expr)),
+        Provision(Provision) {}
   static bool classof(const BaseCommand *C);
   StringRef Name;
   std::vector<StringRef> Expr;
+  SymbolProvision Provision;
 };
 
 struct OutputSectionCommand : BaseCommand {
Index: ELF/LinkerScript.cpp
===================================================================
--- ELF/LinkerScript.cpp
+++ ELF/LinkerScript.cpp
@@ -278,10 +278,9 @@
   for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands) {
     if (auto *Cmd = dyn_cast<SymbolAssignment>(Base.get())) {
       uint64_t Val = evalExpr(Cmd->Expr, Dot);
-      if (Cmd->Name == ".") {
-
+      if (Cmd->Name == ".")
         Dot = Val;
-      } else {
+      else if (Cmd->Provision != SymbolProvision::Ignore) {
         auto *D = cast<DefinedRegular<ELFT>>(Symtab<ELFT>::X->find(Cmd->Name));
         D->Value = Val;
       }
@@ -450,8 +449,15 @@
 template <class ELFT> void LinkerScript<ELFT>::addScriptedSymbols() {
   for (const std::unique_ptr<BaseCommand> &Base : Opt.Commands)
     if (auto *Cmd = dyn_cast<SymbolAssignment>(Base.get()))
-      if (Cmd->Name != "." && Symtab<ELFT>::X->find(Cmd->Name) == nullptr)
-        Symtab<ELFT>::X->addAbsolute(Cmd->Name, STV_DEFAULT);
+      if (Cmd->Name != ".") {
+        if (Symtab<ELFT>::X->find(Cmd->Name) == nullptr)
+          Symtab<ELFT>::X->addAbsolute(
+              Cmd->Name, Cmd->Provision == SymbolProvision::ProvideHidden
+                             ? STV_HIDDEN
+                             : STV_DEFAULT);
+        else if (Cmd->Provision != SymbolProvision::Create)
+          Cmd->Provision = SymbolProvision::Ignore;
+      }
 }
 
 template <class ELFT> bool LinkerScript<ELFT>::hasPhdrsCommands() {
@@ -512,7 +518,8 @@
   void readOutputSectionDescription(StringRef OutSec);
   std::vector<StringRef> readOutputSectionPhdrs();
   unsigned readPhdrType();
-  void readSymbolAssignment(StringRef Name);
+  void readProvideBody(SymbolProvision Provision);
+  void readSymbolAssignment(StringRef Name, SymbolProvision Provision);
   std::vector<StringRef> readSectionsCommandExpr();
 
   const static StringMap<Handler> Cmd;
@@ -709,8 +716,12 @@
       continue;
     }
     next();
-    if (peek() == "=")
-      readSymbolAssignment(Tok);
+    if (Tok == "PROVIDE")
+      readProvideBody(SymbolProvision::Provide);
+    else if (Tok == "PROVIDE_HIDDEN")
+      readProvideBody(SymbolProvision::ProvideHidden);
+    else if (peek() == "=")
+      readSymbolAssignment(Tok, SymbolProvision::Create);
     else
       readOutputSectionDescription(Tok);
   }
@@ -766,19 +777,34 @@
   }
 }
 
-void ScriptParser::readSymbolAssignment(StringRef Name) {
+void ScriptParser::readProvideBody(SymbolProvision Provision) {
+  expect("(");
+  readSymbolAssignment(next(), Provision);
+  expect(")");
+  expect(";");
+}
+
+void ScriptParser::readSymbolAssignment(StringRef Name,
+                                        SymbolProvision Provision) {
   expect("=");
   std::vector<StringRef> Expr = readSectionsCommandExpr();
   if (Expr.empty())
     error("error in symbol assignment expression");
   else
-    Opt.Commands.push_back(llvm::make_unique<SymbolAssignment>(Name, Expr));
+    Opt.Commands.push_back(
+        llvm::make_unique<SymbolAssignment>(Name, Expr, Provision));
 }
 
 std::vector<StringRef> ScriptParser::readSectionsCommandExpr() {
+  int Braces = 0;
   std::vector<StringRef> Expr;
   while (!Error) {
-    StringRef Tok = next();
+    StringRef Tok = peek();
+    Braces += (Tok == "(");
+    Braces -= (Tok == ")");
+    if (Braces < 0)
+      break;
+    next();
     if (Tok == ";")
       break;
     Expr.push_back(Tok);
Index: test/ELF/linkerscript-locationcounter.s
===================================================================
--- test/ELF/linkerscript-locationcounter.s
+++ test/ELF/linkerscript-locationcounter.s
@@ -267,7 +267,7 @@
 # RUN: }" > %t.script
 # RUN: not ld.lld %t --script %t.script -o %t2 2>&1 | \
 # RUN:  FileCheck --check-prefix=BRACKETERR2 %s
-# BRACKETERR2: stray token: )
+# BRACKETERR2: expected, but got *
 
 ## Empty expression.
 # RUN: echo "SECTIONS { \
Index: test/ELF/linkerscript-symbols.s
===================================================================
--- test/ELF/linkerscript-symbols.s
+++ test/ELF/linkerscript-symbols.s
@@ -1,11 +1,43 @@
 # REQUIRES: x86
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t
 
+# Simple symbol assignment. Should raise conflict in case we 
+# have duplicates in any input section, but currently simply
+# replaces the value.
 # RUN: echo "SECTIONS {.text : {*(.text.*)} text_end = .;}" > %t.script
 # RUN: ld.lld -o %t1 --script %t.script %t
-# RUN: llvm-objdump -t %t1 | FileCheck %s
-# CHECK: 0000000000000121         *ABS*    00000000 text_end
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=SIMPLE %s
+# SIMPLE: 0000000000000121         *ABS*    00000000 text_end
+
+# Provide new symbol. The value should be 1, like set in PROVIDE()
+# RUN: echo "SECTIONS { PROVIDE(newsym = 1);}" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=PROVIDE1 %s
+# PROVIDE1: 0000000000000001         *ABS*    00000000 newsym
+
+# Provide new symbol (hidden). The value should be 1
+# RUN: echo "SECTIONS { PROVIDE_HIDDEN(newsym = 1);}" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=HIDDEN1 %s
+# HIDDEN1: 0000000000000001         *ABS*    00000000 .hidden newsym
+
+# Provide existing symbol. The value should be 0, even though we 
+# have value of 1 in PROVIDE()
+# RUN: echo "SECTIONS { PROVIDE(somesym = 1);}" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=PROVIDE2 %s
+# PROVIDE2: 0000000000000000         *ABS*    00000000 somesym
+
+# Provide existing symbol. The value should be 0, even though we 
+# have value of 1 in PROVIDE(). Visibility should not change
+# RUN: echo "SECTIONS { PROVIDE(somesym = 1);}" > %t.script
+# RUN: ld.lld -o %t1 --script %t.script %t
+# RUN: llvm-objdump -t %t1 | FileCheck --check-prefix=HIDDEN2 %s
+# HIDDEN2: 0000000000000000         *ABS*    00000000 somesym
 
 .global _start
 _start:
  nop
+
+.global somesym
+somesym=0