vendor/lld/lld-trunk-r338150

1 files changed, 221 insertions, 83 deletions

diff --git a/ELF/ScriptParser.cpp b/ELF/ScriptParser.cpp
index 4263944981f2..ddb4a49a3e5e 100644
--- a/ELF/ScriptParser.cpp
+++ b/ELF/ScriptParser.cpp
@@ -63,6 +63,7 @@ private:
   void readExtern();
   void readGroup();
   void readInclude();
+  void readInput();
   void readMemory();
   void readOutput();
   void readOutputArch();
@@ -74,12 +75,14 @@ private:
   void readVersion();
   void readVersionScriptCommand();
 
-  SymbolAssignment *readAssignment(StringRef Name);
+  SymbolAssignment *readSymbolAssignment(StringRef Name);
   ByteCommand *readByteCommand(StringRef Tok);
   uint32_t readFill();
   uint32_t parseFill(StringRef Tok);
   void readSectionAddressType(OutputSection *Cmd);
+  OutputSection *readOverlaySectionDescription();
   OutputSection *readOutputSectionDescription(StringRef OutSec);
+  std::vector<BaseCommand *> readOverlay();
   std::vector<StringRef> readOutputSectionPhdrs();
   InputSectionDescription *readInputSectionDescription(StringRef Tok);
   StringMatcher readFilePatterns();
@@ -88,16 +91,16 @@ private:
   unsigned readPhdrType();
   SortSectionPolicy readSortKind();
   SymbolAssignment *readProvideHidden(bool Provide, bool Hidden);
-  SymbolAssignment *readProvideOrAssignment(StringRef Tok);
+  SymbolAssignment *readAssignment(StringRef Tok);
   void readSort();
-  AssertCommand *readAssert();
-  Expr readAssertExpr();
+  Expr readAssert();
   Expr readConstant();
   Expr getPageSize();
 
   uint64_t readMemoryAssignment(StringRef, StringRef, StringRef);
   std::pair<uint32_t, uint32_t> readMemoryAttributes();
 
+  Expr combine(StringRef Op, Expr L, Expr R);
   Expr readExpr();
   Expr readExpr1(Expr Lhs, int MinPrec);
   StringRef readParenLiteral();
@@ -157,17 +160,6 @@ static ExprValue sub(ExprValue A, ExprValue B) {
   return {A.Sec, false, A.getSectionOffset() - B.getValue(), A.Loc};
 }
 
-static ExprValue mul(ExprValue A, ExprValue B) {
-  return A.getValue() * B.getValue();
-}
-
-static ExprValue div(ExprValue A, ExprValue B) {
-  if (uint64_t BV = B.getValue())
-    return A.getValue() / BV;
-  error("division by zero");
-  return 0;
-}
-
 static ExprValue bitAnd(ExprValue A, ExprValue B) {
   moveAbsRight(A, B);
   return {A.Sec, A.ForceAbsolute,
@@ -237,16 +229,16 @@ void ScriptParser::readLinkerScript() {
     if (Tok == ";")
       continue;
 
-    if (Tok == "ASSERT") {
-      Script->SectionCommands.push_back(readAssert());
-    } else if (Tok == "ENTRY") {
+    if (Tok == "ENTRY") {
       readEntry();
     } else if (Tok == "EXTERN") {
       readExtern();
-    } else if (Tok == "GROUP" || Tok == "INPUT") {
+    } else if (Tok == "GROUP") {
       readGroup();
     } else if (Tok == "INCLUDE") {
       readInclude();
+    } else if (Tok == "INPUT") {
+      readInput();
     } else if (Tok == "MEMORY") {
       readMemory();
     } else if (Tok == "OUTPUT") {
@@ -265,7 +257,7 @@ void ScriptParser::readLinkerScript() {
       readSections();
     } else if (Tok == "VERSION") {
       readVersion();
-    } else if (SymbolAssignment *Cmd = readProvideOrAssignment(Tok)) {
+    } else if (SymbolAssignment *Cmd = readAssignment(Tok)) {
       Script->SectionCommands.push_back(Cmd);
     } else {
       setError("unknown directive: " + Tok);
@@ -336,13 +328,12 @@ void ScriptParser::readExtern() {
 }
 
 void ScriptParser::readGroup() {
-  expect("(");
-  while (!errorCount() && !consume(")")) {
-    if (consume("AS_NEEDED"))
-      readAsNeeded();
-    else
-      addFile(unquote(next()));
-  }
+  bool Orig = InputFile::IsInGroup;
+  InputFile::IsInGroup = true;
+  readInput();
+  InputFile::IsInGroup = Orig;
+  if (!Orig)
+    ++InputFile::NextGroupId;
 }
 
 void ScriptParser::readInclude() {
@@ -353,7 +344,7 @@ void ScriptParser::readInclude() {
     return;
   }
 
-  if (Optional<std::string> Path = searchLinkerScript(Tok)) {
+  if (Optional<std::string> Path = searchScript(Tok)) {
     if (Optional<MemoryBufferRef> MB = readFile(*Path))
       tokenize(*MB);
     return;
@@ -361,6 +352,16 @@ void ScriptParser::readInclude() {
   setError("cannot find linker script " + Tok);
 }
 
+void ScriptParser::readInput() {
+  expect("(");
+  while (!errorCount() && !consume(")")) {
+    if (consume("AS_NEEDED"))
+      readAsNeeded();
+    else
+      addFile(unquote(next()));
+  }
+}
+
 void ScriptParser::readOutput() {
   // -o <file> takes predecence over OUTPUT(<file>).
   expect("(");
@@ -437,6 +438,49 @@ void ScriptParser::readSearchDir() {
   expect(")");
 }
 
+// This reads an overlay description. Overlays are used to describe output
+// sections that use the same virtual memory range and normally would trigger
+// linker's sections sanity check failures.
+// https://sourceware.org/binutils/docs/ld/Overlay-Description.html#Overlay-Description
+std::vector<BaseCommand *> ScriptParser::readOverlay() {
+  // VA and LMA expressions are optional, though for simplicity of
+  // implementation we assume they are not. That is what OVERLAY was designed
+  // for first of all: to allow sections with overlapping VAs at different LMAs.
+  Expr AddrExpr = readExpr();
+  expect(":");
+  expect("AT");
+  Expr LMAExpr = readParenExpr();
+  expect("{");
+
+  std::vector<BaseCommand *> V;
+  OutputSection *Prev = nullptr;
+  while (!errorCount() && !consume("}")) {
+    // VA is the same for all sections. The LMAs are consecutive in memory
+    // starting from the base load address specified.
+    OutputSection *OS = readOverlaySectionDescription();
+    OS->AddrExpr = AddrExpr;
+    if (Prev)
+      OS->LMAExpr = [=] { return Prev->getLMA() + Prev->Size; };
+    else
+      OS->LMAExpr = LMAExpr;
+    V.push_back(OS);
+    Prev = OS;
+  }
+
+  // According to the specification, at the end of the overlay, the location
+  // counter should be equal to the overlay base address plus size of the
+  // largest section seen in the overlay.
+  // Here we want to create the Dot assignment command to achieve that.
+  Expr MoveDot = [=] {
+    uint64_t Max = 0;
+    for (BaseCommand *Cmd : V)
+      Max = std::max(Max, cast<OutputSection>(Cmd)->Size);
+    return AddrExpr().getValue() + Max;
+  };
+  V.push_back(make<SymbolAssignment>(".", MoveDot, getCurrentLocation()));
+  return V;
+}
+
 void ScriptParser::readSections() {
   Script->HasSectionsCommand = true;
 
@@ -446,26 +490,48 @@ void ScriptParser::readSections() {
   Config->SingleRoRx = true;
 
   expect("{");
+  std::vector<BaseCommand *> V;
   while (!errorCount() && !consume("}")) {
     StringRef Tok = next();
-    BaseCommand *Cmd = readProvideOrAssignment(Tok);
-    if (!Cmd) {
-      if (Tok == "ASSERT")
-        Cmd = readAssert();
-      else
-        Cmd = readOutputSectionDescription(Tok);
+    if (Tok == "OVERLAY") {
+      for (BaseCommand *Cmd : readOverlay())
+        V.push_back(Cmd);
+      continue;
     }
-    Script->SectionCommands.push_back(Cmd);
+
+    if (BaseCommand *Cmd = readAssignment(Tok))
+      V.push_back(Cmd);
+    else
+      V.push_back(readOutputSectionDescription(Tok));
+  }
+
+  if (!atEOF() && consume("INSERT")) {
+    std::vector<BaseCommand *> *Dest = nullptr;
+    if (consume("AFTER"))
+      Dest = &Script->InsertAfterCommands[next()];
+    else if (consume("BEFORE"))
+      Dest = &Script->InsertBeforeCommands[next()];
+    else
+      setError("expected AFTER/BEFORE, but got '" + next() + "'");
+    if (Dest)
+      Dest->insert(Dest->end(), V.begin(), V.end());
+    return;
   }
+
+  Script->SectionCommands.insert(Script->SectionCommands.end(), V.begin(),
+                                 V.end());
 }
 
 static int precedence(StringRef Op) {
   return StringSwitch<int>(Op)
-      .Cases("*", "/", 5)
-      .Cases("+", "-", 4)
-      .Cases("<<", ">>", 3)
-      .Cases("<", "<=", ">", ">=", "==", "!=", 2)
-      .Cases("&", "|", 1)
+      .Cases("*", "/", "%", 8)
+      .Cases("+", "-", 7)
+      .Cases("<<", ">>", 6)
+      .Cases("<", "<=", ">", ">=", "==", "!=", 5)
+      .Case("&", 4)
+      .Case("|", 3)
+      .Case("&&", 2)
+      .Case("||", 1)
       .Default(-1);
 }
 
@@ -588,11 +654,7 @@ void ScriptParser::readSort() {
   expect(")");
 }
 
-AssertCommand *ScriptParser::readAssert() {
-  return make<AssertCommand>(readAssertExpr());
-}
-
-Expr ScriptParser::readAssertExpr() {
+Expr ScriptParser::readAssert() {
   expect("(");
   Expr E = readExpr();
   expect(",");
@@ -617,12 +679,14 @@ uint32_t ScriptParser::readFill() {
   return V;
 }
 
-// Reads an expression and/or the special directive "(NOLOAD)" for an
-// output section definition.
+// Reads an expression and/or the special directive for an output
+// section definition. Directive is one of following: "(NOLOAD)",
+// "(COPY)", "(INFO)" or "(OVERLAY)".
 //
 // An output section name can be followed by an address expression
-// and/or by "(NOLOAD)". This grammar is not LL(1) because "(" can be
-// interpreted as either the beginning of some expression or "(NOLOAD)".
+// and/or directive. This grammar is not LL(1) because "(" can be
+// interpreted as either the beginning of some expression or beginning
+// of directive.
 //
 // https://sourceware.org/binutils/docs/ld/Output-Section-Address.html
 // https://sourceware.org/binutils/docs/ld/Output-Section-Type.html
@@ -633,6 +697,11 @@ void ScriptParser::readSectionAddressType(OutputSection *Cmd) {
       Cmd->Noload = true;
       return;
     }
+    if (consume("COPY") || consume("INFO") || consume("OVERLAY")) {
+      expect(")");
+      Cmd->NonAlloc = true;
+      return;
+    }
     Cmd->AddrExpr = readExpr();
     expect(")");
   } else {
@@ -657,10 +726,23 @@ static Expr checkAlignment(Expr E, std::string &Loc) {
   };
 }
 
+OutputSection *ScriptParser::readOverlaySectionDescription() {
+  OutputSection *Cmd =
+      Script->createOutputSection(next(), getCurrentLocation());
+  Cmd->InOverlay = true;
+  expect("{");
+  while (!errorCount() && !consume("}"))
+    Cmd->SectionCommands.push_back(readInputSectionRules(next()));
+  Cmd->Phdrs = readOutputSectionPhdrs();
+  return Cmd;
+}
+
 OutputSection *ScriptParser::readOutputSectionDescription(StringRef OutSec) {
   OutputSection *Cmd =
       Script->createOutputSection(OutSec, getCurrentLocation());
 
+  size_t SymbolsReferenced = Script->ReferencedSymbols.size();
+
   if (peek() != ":")
     readSectionAddressType(Cmd);
   expect(":");
@@ -684,13 +766,10 @@ OutputSection *ScriptParser::readOutputSectionDescription(StringRef OutSec) {
     StringRef Tok = next();
     if (Tok == ";") {
       // Empty commands are allowed. Do nothing here.
-    } else if (SymbolAssignment *Assign = readProvideOrAssignment(Tok)) {
+    } else if (SymbolAssignment *Assign = readAssignment(Tok)) {
       Cmd->SectionCommands.push_back(Assign);
     } else if (ByteCommand *Data = readByteCommand(Tok)) {
       Cmd->SectionCommands.push_back(Data);
-    } else if (Tok == "ASSERT") {
-      Cmd->SectionCommands.push_back(readAssert());
-      expect(";");
     } else if (Tok == "CONSTRUCTORS") {
       // CONSTRUCTORS is a keyword to make the linker recognize C++ ctors/dtors
       // by name. This is for very old file formats such as ECOFF/XCOFF.
@@ -709,6 +788,14 @@ OutputSection *ScriptParser::readOutputSectionDescription(StringRef OutSec) {
   if (consume(">"))
     Cmd->MemoryRegionName = next();
 
+  if (consume("AT")) {
+    expect(">");
+    Cmd->LMARegionName = next();
+  }
+
+  if (Cmd->LMAExpr && !Cmd->LMARegionName.empty())
+    error("section can't have both LMA and a load region");
+
   Cmd->Phdrs = readOutputSectionPhdrs();
 
   if (consume("="))
@@ -719,6 +806,8 @@ OutputSection *ScriptParser::readOutputSectionDescription(StringRef OutSec) {
   // Consume optional comma following output section command.
   consume(",");
 
+  if (Script->ReferencedSymbols.size() > SymbolsReferenced)
+    Cmd->ExpressionsUseSymbols = true;
   return Cmd;
 }
 
@@ -741,30 +830,39 @@ uint32_t ScriptParser::parseFill(StringRef Tok) {
 
 SymbolAssignment *ScriptParser::readProvideHidden(bool Provide, bool Hidden) {
   expect("(");
-  SymbolAssignment *Cmd = readAssignment(next());
+  SymbolAssignment *Cmd = readSymbolAssignment(next());
   Cmd->Provide = Provide;
   Cmd->Hidden = Hidden;
   expect(")");
-  expect(";");
   return Cmd;
 }
 
-SymbolAssignment *ScriptParser::readProvideOrAssignment(StringRef Tok) {
+SymbolAssignment *ScriptParser::readAssignment(StringRef Tok) {
+  // Assert expression returns Dot, so this is equal to ".=."
+  if (Tok == "ASSERT")
+    return make<SymbolAssignment>(".", readAssert(), getCurrentLocation());
+
+  size_t OldPos = Pos;
   SymbolAssignment *Cmd = nullptr;
-  if (peek() == "=" || peek() == "+=") {
-    Cmd = readAssignment(Tok);
-    expect(";");
-  } else if (Tok == "PROVIDE") {
+  if (peek() == "=" || peek() == "+=")
+    Cmd = readSymbolAssignment(Tok);
+  else if (Tok == "PROVIDE")
     Cmd = readProvideHidden(true, false);
-  } else if (Tok == "HIDDEN") {
+  else if (Tok == "HIDDEN")
     Cmd = readProvideHidden(false, true);
-  } else if (Tok == "PROVIDE_HIDDEN") {
+  else if (Tok == "PROVIDE_HIDDEN")
     Cmd = readProvideHidden(true, true);
+
+  if (Cmd) {
+    Cmd->CommandString =
+        Tok.str() + " " +
+        llvm::join(Tokens.begin() + OldPos, Tokens.begin() + Pos, " ");
+    expect(";");
   }
   return Cmd;
 }
 
-SymbolAssignment *ScriptParser::readAssignment(StringRef Name) {
+SymbolAssignment *ScriptParser::readSymbolAssignment(StringRef Name) {
   StringRef Op = next();
   assert(Op == "=" || Op == "+=");
   Expr E = readExpr();
@@ -787,15 +885,31 @@ Expr ScriptParser::readExpr() {
   return E;
 }
 
-static Expr combine(StringRef Op, Expr L, Expr R) {
+Expr ScriptParser::combine(StringRef Op, Expr L, Expr R) {
   if (Op == "+")
     return [=] { return add(L(), R()); };
   if (Op == "-")
     return [=] { return sub(L(), R()); };
   if (Op == "*")
-    return [=] { return mul(L(), R()); };
-  if (Op == "/")
-    return [=] { return div(L(), R()); };
+    return [=] { return L().getValue() * R().getValue(); };
+  if (Op == "/") {
+    std::string Loc = getCurrentLocation();
+    return [=]() -> uint64_t {
+      if (uint64_t RV = R().getValue())
+        return L().getValue() / RV;
+      error(Loc + ": division by zero");
+      return 0;
+    };
+  }
+  if (Op == "%") {
+    std::string Loc = getCurrentLocation();
+    return [=]() -> uint64_t {
+      if (uint64_t RV = R().getValue())
+        return L().getValue() % RV;
+      error(Loc + ": modulo by zero");
+      return 0;
+    };
+  }
   if (Op == "<<")
     return [=] { return L().getValue() << R().getValue(); };
   if (Op == ">>")
@@ -812,6 +926,10 @@ static Expr combine(StringRef Op, Expr L, Expr R) {
     return [=] { return L().getValue() == R().getValue(); };
   if (Op == "!=")
     return [=] { return L().getValue() != R().getValue(); };
+  if (Op == "||")
+    return [=] { return L().getValue() || R().getValue(); };
+  if (Op == "&&")
+    return [=] { return L().getValue() && R().getValue(); };
   if (Op == "&")
     return [=] { return bitAnd(L(), R()); };
   if (Op == "|")
@@ -865,20 +983,13 @@ Expr ScriptParser::readConstant() {
   if (S == "MAXPAGESIZE")
     return [] { return Config->MaxPageSize; };
   setError("unknown constant: " + S);
-  return {};
+  return [] { return 0; };
 }
 
 // Parses Tok as an integer. It recognizes hexadecimal (prefixed with
 // "0x" or suffixed with "H") and decimal numbers. Decimal numbers may
 // have "K" (Ki) or "M" (Mi) suffixes.
 static Optional<uint64_t> parseInt(StringRef Tok) {
-  // Negative number
-  if (Tok.startswith("-")) {
-    if (Optional<uint64_t> Val = parseInt(Tok.substr(1)))
-      return -*Val;
-    return None;
-  }
-
   // Hexadecimal
   uint64_t Val;
   if (Tok.startswith_lower("0x")) {
@@ -917,12 +1028,21 @@ ByteCommand *ScriptParser::readByteCommand(StringRef Tok) {
                  .Default(-1);
   if (Size == -1)
     return nullptr;
-  return make<ByteCommand>(readParenExpr(), Size);
+
+  size_t OldPos = Pos;
+  Expr E = readParenExpr();
+  std::string CommandString =
+      Tok.str() + " " +
+      llvm::join(Tokens.begin() + OldPos, Tokens.begin() + Pos, " ");
+  return make<ByteCommand>(E, Size, CommandString);
 }
 
 StringRef ScriptParser::readParenLiteral() {
   expect("(");
+  bool Orig = InExpr;
+  InExpr = false;
   StringRef Tok = next();
+  InExpr = Orig;
   expect(")");
   return Tok;
 }
@@ -995,7 +1115,7 @@ Expr ScriptParser::readPrimary() {
     };
   }
   if (Tok == "ASSERT")
-    return readAssertExpr();
+    return readAssert();
   if (Tok == "CONSTANT")
     return readConstant();
   if (Tok == "DATA_SEGMENT_ALIGN") {
@@ -1032,8 +1152,10 @@ Expr ScriptParser::readPrimary() {
   }
   if (Tok == "LENGTH") {
     StringRef Name = readParenLiteral();
-    if (Script->MemoryRegions.count(Name) == 0)
+    if (Script->MemoryRegions.count(Name) == 0) {
       setError("memory region not defined: " + Name);
+      return [] { return 0; };
+    }
     return [=] { return Script->MemoryRegions[Name]->Length; };
   }
   if (Tok == "LOADADDR") {
@@ -1044,10 +1166,22 @@ Expr ScriptParser::readPrimary() {
       return Cmd->getLMA();
     };
   }
+  if (Tok == "MAX" || Tok == "MIN") {
+    expect("(");
+    Expr A = readExpr();
+    expect(",");
+    Expr B = readExpr();
+    expect(")");
+    if (Tok == "MIN")
+      return [=] { return std::min(A().getValue(), B().getValue()); };
+    return [=] { return std::max(A().getValue(), B().getValue()); };
+  }
   if (Tok == "ORIGIN") {
     StringRef Name = readParenLiteral();
-    if (Script->MemoryRegions.count(Name) == 0)
+    if (Script->MemoryRegions.count(Name) == 0) {
       setError("memory region not defined: " + Name);
+      return [] { return 0; };
+    }
     return [=] { return Script->MemoryRegions[Name]->Origin; };
   }
   if (Tok == "SEGMENT_START") {
@@ -1229,6 +1363,9 @@ ScriptParser::readSymbols() {
 
 // Reads an "extern C++" directive, e.g.,
 // "extern "C++" { ns::*; "f(int, double)"; };"
+//
+// The last semicolon is optional. E.g. this is OK:
+// "extern "C++" { ns::*; "f(int, double)" };"
 std::vector<SymbolVersion> ScriptParser::readVersionExtern() {
   StringRef Tok = next();
   bool IsCXX = Tok == "\"C++\"";
@@ -1241,6 +1378,8 @@ std::vector<SymbolVersion> ScriptParser::readVersionExtern() {
     StringRef Tok = next();
     bool HasWildcard = !Tok.startswith("\"") && hasWildcard(Tok);
     Ret.push_back({unquote(Tok), IsCXX, HasWildcard});
+    if (consume("}"))
+      return Ret;
     expect(";");
   }
 
@@ -1280,11 +1419,10 @@ void ScriptParser::readMemory() {
     uint64_t Length = readMemoryAssignment("LENGTH", "len", "l");
 
     // Add the memory region to the region map.
-    if (Script->MemoryRegions.count(Name))
+    MemoryRegion *MR =
+        make<MemoryRegion>(Name, Origin, Length, Flags, NegFlags);
+    if (!Script->MemoryRegions.insert({Name, MR}).second)
       setError("region '" + Name + "' already defined");
-    MemoryRegion *MR = make<MemoryRegion>();
-    *MR = {Name, Origin, Length, Flags, NegFlags};
-    Script->MemoryRegions[Name] = MR;
   }
 }