[lld] r275159 - [ELF] - Add Id field to Version struct.

[George Rimar via llvm-commits]

Author: grimar
Date: Tue Jul 12 02:44:40 2016
New Revision: 275159

URL: http://llvm.org/viewvc/llvm-project?rev=275159&view=rev
Log:
[ELF] - Add Id field to Version struct.

That helps to avoid expressions like I + 2 in code
that assigns version number to symbols.

Change was suggested by Rui Ueyama.

Differential revision: http://reviews.llvm.org/D22086

Modified:
    lld/trunk/ELF/Config.h
    lld/trunk/ELF/SymbolListFile.cpp
    lld/trunk/ELF/SymbolListFile.h
    lld/trunk/ELF/SymbolTable.cpp

Modified: lld/trunk/ELF/Config.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/Config.h?rev=275159&r1=275158&r2=275159&view=diff
==============================================================================
--- lld/trunk/ELF/Config.h (original)
+++ lld/trunk/ELF/Config.h Tue Jul 12 02:44:40 2016
@@ -38,8 +38,9 @@ enum class UnresolvedPolicy { NoUndef, E
 // This struct contains symbols version definition that
 // can be found in version script if it is used for link.
 struct Version {
-  Version(llvm::StringRef Name) : Name(Name) {}
+  Version(llvm::StringRef Name, size_t Id) : Name(Name), Id(Id) {}
   llvm::StringRef Name;
+  size_t Id;
   std::vector<llvm::StringRef> Globals;
   size_t NameOff; // Offset in string table.
 };

Modified: lld/trunk/ELF/SymbolListFile.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolListFile.cpp?rev=275159&r1=275158&r2=275159&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolListFile.cpp (original)
+++ lld/trunk/ELF/SymbolListFile.cpp Tue Jul 12 02:44:40 2016
@@ -82,9 +82,17 @@ private:
   void parseVersionSymbols(StringRef Version);
 };
 
+size_t elf::defineSymbolVersion(StringRef Version) {
+  // Identifiers start at 2 because 0 and 1 are reserved
+  // for VER_NDX_LOCAL and VER_NDX_GLOBAL constants.
+  size_t VersionId = Config->SymbolVersions.size() + 2;
+  Config->SymbolVersions.push_back(elf::Version(Version, VersionId));
+  return VersionId;
+}
+
 void VersionScriptParser::parseVersion(StringRef Version) {
   expect("{");
-  Config->SymbolVersions.push_back(elf::Version(Version));
+  defineSymbolVersion(Version);
   if (peek() == "global:") {
     next();
     parseVersionSymbols(Version);

Modified: lld/trunk/ELF/SymbolListFile.h
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolListFile.h?rev=275159&r1=275158&r2=275159&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolListFile.h (original)
+++ lld/trunk/ELF/SymbolListFile.h Tue Jul 12 02:44:40 2016
@@ -16,6 +16,8 @@
 namespace lld {
 namespace elf {
 
+size_t defineSymbolVersion(StringRef Version);
+
 void parseDynamicList(MemoryBufferRef MB);
 void parseVersionScript(MemoryBufferRef MB);
 

Modified: lld/trunk/ELF/SymbolTable.cpp
URL: http://llvm.org/viewvc/llvm-project/lld/trunk/ELF/SymbolTable.cpp?rev=275159&r1=275158&r2=275159&view=diff
==============================================================================
--- lld/trunk/ELF/SymbolTable.cpp (original)
+++ lld/trunk/ELF/SymbolTable.cpp Tue Jul 12 02:44:40 2016
@@ -19,6 +19,7 @@
 #include "Error.h"
 #include "LinkerScript.h"
 #include "Strings.h"
+#include "SymbolListFile.h"
 #include "Symbols.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/Support/StringSaver.h"
@@ -180,20 +181,18 @@ static uint16_t getVersionId(Symbol *Sym
   if (Default)
     Version = Version.drop_front();
 
-  size_t I = 2;
-  for (elf::Version &V : Config->SymbolVersions) {
+  for (elf::Version &V : Config->SymbolVersions)
     if (V.Name == Version)
-      return Default ? I : (I | VERSYM_HIDDEN);
-    ++I;
-  }
+      return Default ? V.Id : (V.Id | VERSYM_HIDDEN);
+
 
   // If we are not building shared and version script
   // is not specified, then it is not a error, it is
   // in common not to use script for linking executables.
   // In this case we just create new version.
   if (!Config->Shared && !Config->HasVersionScript) {
-    Config->SymbolVersions.push_back(elf::Version(Version));
-    return Default ? I : (I | VERSYM_HIDDEN);
+    size_t Id = defineSymbolVersion(Version);
+    return Default ? Id : (Id | VERSYM_HIDDEN);
   }
 
   error("symbol " + Name + " has undefined version " + Version);
@@ -608,7 +607,7 @@ template <class ELFT> void SymbolTable<E
       if (B->symbol()->VersionId != VER_NDX_GLOBAL &&
           B->symbol()->VersionId != VER_NDX_LOCAL)
         warning("duplicate symbol " + Name + " in version script");
-      B->symbol()->VersionId = I + 2;
+      B->symbol()->VersionId = V.Id;
     }
   }
 
@@ -621,7 +620,7 @@ template <class ELFT> void SymbolTable<E
       for (SymbolBody *B : findAll(Name))
         if (B->symbol()->VersionId == VER_NDX_GLOBAL ||
             B->symbol()->VersionId == VER_NDX_LOCAL)
-          B->symbol()->VersionId = I + 2;
+          B->symbol()->VersionId = V.Id;
     }
   }
 }