From 3e808976278b52d0fae64d3232e4bff35a3f5bb2 Mon Sep 17 00:00:00 2001
From: Rui Ueyama <ruiu@google.com>
Date: Sun, 28 Feb 2016 05:09:11 +0000
Subject: [PATCH] ELF: Remove OutSection class and use a map instead.

It is easier to handle section filler data separately rather than
merging with section names.

llvm-svn: 262175
---
 lld/ELF/LinkerScript.cpp | 30 ++++++++++++++----------------
 lld/ELF/LinkerScript.h   | 13 +++++--------
 2 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/lld/ELF/LinkerScript.cpp b/lld/ELF/LinkerScript.cpp
index 0bdf401e09f8..b4580b5fe7c6 100644
--- a/lld/ELF/LinkerScript.cpp
+++ b/lld/ELF/LinkerScript.cpp
@@ -55,21 +55,20 @@ template <class ELFT> bool LinkerScript::shouldKeep(InputSectionBase<ELFT> *S) {
 }
 
 ArrayRef<uint8_t> LinkerScript::getFiller(StringRef Name) {
-  for (OutSection &C : OutSections)
-    if (C.Name == Name)
-      return C.Filler;
-  return {};
+  auto I = Filler.find(Name);
+  if (I == Filler.end())
+    return {};
+  return I->second;
 }
 
 // A compartor to sort output sections. Returns -1 or 1 if both
 // A and B are mentioned in linker scripts. Otherwise, returns 0
 // to use the default rule which is implemented in Writer.cpp.
 int LinkerScript::compareSections(StringRef A, StringRef B) {
-  auto Begin = OutSections.begin();
-  auto End = OutSections.end();
-  auto I = std::find_if(Begin, End, [&](OutSection &C) { return C.Name == A; });
-  auto J = std::find_if(Begin, End, [&](OutSection &C) { return C.Name == B; });
-  if (I == End || J == End)
+  auto E = SectionOrder.end();
+  auto I = std::find(SectionOrder.begin(), E, A);
+  auto J = std::find(SectionOrder.begin(), E, B);
+  if (I == E || J == E)
     return 0;
   return I < J ? -1 : 1;
 }
@@ -429,18 +428,18 @@ std::vector<uint8_t> ScriptParser::parseHex(StringRef S) {
 }
 
 void ScriptParser::readOutputSectionDescription() {
-  OutSection OutSec;
-  OutSec.Name = next();
+  StringRef OutSec = next();
+  Script->SectionOrder.push_back(OutSec);
   expect(":");
   expect("{");
   while (!Error && !skip("}")) {
     StringRef Tok = next();
     if (Tok == "*") {
-      readSectionPatterns(OutSec.Name, false);
+      readSectionPatterns(OutSec, false);
     } else if (Tok == "KEEP") {
       expect("(");
       next(); // Skip *
-      readSectionPatterns(OutSec.Name, true);
+      readSectionPatterns(OutSec, true);
       expect(")");
     } else {
       setError("Unknown command " + Tok);
@@ -452,11 +451,10 @@ void ScriptParser::readOutputSectionDescription() {
       setError("Filler should be a HEX value");
       return;
     }
-    Tok = Tok.substr(3); // Skip '=0x'
-    OutSec.Filler = parseHex(Tok);
+    Tok = Tok.substr(3);
+    Script->Filler[OutSec] = parseHex(Tok);
     next();
   }
-  Script->OutSections.push_back(OutSec);
 }
 
 static bool isUnderSysroot(StringRef Path) {
diff --git a/lld/ELF/LinkerScript.h b/lld/ELF/LinkerScript.h
index 7517838c8864..e4a7a900bfd1 100644
--- a/lld/ELF/LinkerScript.h
+++ b/lld/ELF/LinkerScript.h
@@ -40,11 +40,6 @@ private:
   StringRef SectionPattern;
 };
 
-struct OutSection {
-  StringRef Name;
-  std::vector<uint8_t> Filler;
-};
-
 // This is a runner of the linker script.
 class LinkerScript {
   friend class ScriptParser;
@@ -66,9 +61,11 @@ private:
   // SECTIONS commands.
   std::vector<SectionRule> Sections;
 
-  // Output sections information.
-  // They are sorted by the order of the container.
-  std::vector<OutSection> OutSections;
+  // Output sections are sorted by this order.
+  std::vector<StringRef> SectionOrder;
+
+  // Section fill attribute for each section.
+  llvm::StringMap<std::vector<uint8_t>> Filler;
 
   llvm::BumpPtrAllocator Alloc;
 };