[PATCH] D21607: [ELF] - Proccess 'extern' keyword in version scripts.

[George Rimar via llvm-commits]

grimar created this revision.
grimar added reviewers: rafael, ruiu.
grimar added subscribers: llvm-commits, grimar.
Herald added a subscriber: emaste.

During investigation about FreeBsd scripts I found that few of them uses
'extern' keyword. This patch just reads all globals inside as regular ones.

Note: I downloaded FreeBsd sources and tried to link with every *.map file in batch mode,
some of them are not script files, so I had to skip them manually.
Seems that this one in combination with D21556 allows to parse all available 
FreeBsd version scripts.

http://reviews.llvm.org/D21607

Files:
  ELF/SymbolListFile.cpp
  test/ELF/version-script-err.s
  test/ELF/version-script-extern.s

Index: test/ELF/version-script-extern.s
===================================================================
--- test/ELF/version-script-extern.s
+++ test/ELF/version-script-extern.s
@@ -0,0 +1,34 @@
+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
+
+# RUN: echo "VERSION_1.0{      \
+# RUN:  extern "C++" {         \
+# RUN:    foo;                 \
+# RUN:    "bar";               \
+# RUN:  };                     \
+# RUN: }; " > %t1.script
+# RUN: ld.lld --version-script %t1.script -shared %t.o -o %t.so
+# RUN: llvm-readobj -dyn-symbols %t.so | FileCheck %s
+
+# CHECK: DynamicSymbols [
+# CHECK:   Symbol {
+# CHECK:     Name: bar@@VERSION_1.0
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: foo@@VERSION_1.0
+# CHECK:   }
+# CHECK:   Symbol {
+# CHECK:     Name: zed@
+
+.global foo
+.type foo, @function
+foo:
+
+.global bar
+.type bar, @function
+bar:
+
+.global zed
+.type zed, @function
+zed:
Index: test/ELF/version-script-err.s
===================================================================
--- test/ELF/version-script-err.s
+++ test/ELF/version-script-err.s
@@ -8,3 +8,8 @@
 // RUN: not ld.lld --version-script %terr1.script -shared %t.o -o %t.so 2>&1 | \
 // RUN:   FileCheck -check-prefix=ERR1 %s
 // ERR1: unclosed quote
+
+// RUN: echo "VERSION { extern "C--" {}; }; " > %terr2.script
+// RUN: not ld.lld --version-script %terr2.script -shared %t.o -o %t.so 2>&1 | \
+// RUN:   FileCheck -check-prefix=ERR2 %s
+// ERR2: unsupported language C-- in extern scope
Index: ELF/SymbolListFile.cpp
===================================================================
--- ELF/SymbolListFile.cpp
+++ ELF/SymbolListFile.cpp
@@ -80,6 +80,7 @@
   void parseVersion(StringRef Version);
   void parseLocal();
   void parseVersionSymbols(StringRef Version);
+  void parseExtern(StringRef Version);
 };
 
 void VersionScriptParser::parseVersion(StringRef Version) {
@@ -104,6 +105,19 @@
   Config->VersionScriptGlobalByDefault = false;
 }
 
+void VersionScriptParser::parseExtern(StringRef Version) {
+  expect("extern");
+  StringRef Lang = next();
+  if (Lang != "C" && Lang != "C++") {
+    setError("unsupported language " + Lang + " in extern scope");
+    return;
+  }
+  expect("{");
+  parseVersionSymbols(Version);
+  expect("}");
+  expect(";");
+}
+
 void VersionScriptParser::parseVersionSymbols(StringRef Version) {
   std::vector<StringRef> *Globals;
   if (Version.empty()) {
@@ -117,6 +131,10 @@
     StringRef Cur = peek();
     if (Cur == "}" || Cur == "local:" || Error)
       return;
+    if (Cur == "extern") {
+      parseExtern(Version);
+      continue;
+    }
     next();
     Globals->push_back(Cur);
     expect(";");


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