Re-enable "[gold-plugin] Disable name for values other than GlobalValue"

This restores r266871 with a fix for gold tests relying on the value
names, when using a release compiler, by adding a way to disable the
default discarding. Update affected tests to use the new mechanism so
that value names are preserved as expected, regardless of how the
compiler was built.

llvm-svn: 266881

llvm/test/tools/gold/X86/comdat.ll

@@ -1,6 +1,7 @@
 ; RUN: llvm-as %s -o %t.o
 ; RUN: llvm-as %p/Inputs/comdat.ll -o %t2.o
 ; RUN: %gold -shared -o %t3.o -plugin %llvmshlibdir/LLVMgold.so %t.o %t2.o \
+; RUN:  -plugin-opt=no-discard-value-names \
 ; RUN:  -plugin-opt=emit-llvm
 ; RUN: llvm-dis %t3.o -o - | FileCheck %s
 

llvm/test/tools/gold/X86/strip_names.ll

@@ -0,0 +1,36 @@
+; RUN: llvm-as %s -o %t.o
+
+; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
+; RUN:    --plugin-opt=emit-llvm \
+; RUN:    --plugin-opt=no-discard-value-names \
+; RUN:    -shared %t.o -o %t2.o
+; RUN: llvm-dis %t2.o -o - | FileCheck %s
+
+; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
+; RUN:    --plugin-opt=emit-llvm \
+; RUN:    --plugin-opt=discard-value-names \
+; RUN:    -shared %t.o -o %t2.o
+; RUN: llvm-dis %t2.o -o - | FileCheck ---check-prefix=NONAME %s
+
+; CHECK: @GlobalValueName
+; CHECK: @foo(i32 %in)
+; CHECK: somelabel:
+; CHECK:  %GV = load i32, i32* @GlobalValueName
+; CHECK:  %add = add i32 %in, %GV
+; CHECK:  ret i32 %add
+
+; NONAME: @GlobalValueName
+; NONAME: @foo(i32)
+; NONAME-NOT: somelabel:
+; NONAME:  %2 = load i32, i32* @GlobalValueName
+; NONAME:  %3 = add i32 %0, %2
+; NONAME:  ret i32 %3
+
+@GlobalValueName = global i32 0
+
+define i32 @foo(i32 %in) {
+somelabel:
+  %GV = load i32, i32* @GlobalValueName
+  %add = add i32 %in, %GV
+  ret i32 %add
+}

llvm/test/tools/gold/X86/type-merge2.ll

@@ -2,6 +2,7 @@
 ; RUN: llvm-as %p/Inputs/type-merge2.ll -o %t2.o
 ; RUN: %gold -plugin %llvmshlibdir/LLVMgold.so \
 ; RUN:    --plugin-opt=emit-llvm \
+; RUN:    --plugin-opt=no-discard-value-names \
 ; RUN:    -shared %t.o %t2.o -o %t3.o
 ; RUN: llvm-dis %t3.o -o - | FileCheck %s
 

llvm/tools/gold/gold-plugin.cpp

@@ -166,8 +166,10 @@ namespace options {
   static unsigned Parallelism = 0;
 #ifdef NDEBUG
   static bool DisableVerify = true;
+  static bool DiscardValueNames = true;
 #else
   static bool DisableVerify = false;
+  static bool DiscardValueNames = false;
 #endif
   static std::string obj_path;
   static std::string extra_library_path;
@@ -224,6 +226,10 @@ namespace options {
         message(LDPL_FATAL, "Invalid parallelism level: %s", opt_ + 5);
     } else if (opt == "disable-verify") {
       DisableVerify = true;
+    } else if (opt == "discard-value-names") {
+      DiscardValueNames = true;
+    } else if (opt == "no-discard-value-names") {
+      DiscardValueNames = false;
     } else {
       // Save this option to pass to the code generator.
       // ParseCommandLineOptions() expects argv[0] to be program name. Lazily
@@ -1113,6 +1119,7 @@ static void thinLTOBackendTask(claimed_file &F, const void *View,
                                raw_fd_ostream *OS, unsigned TaskID) {
   // Need to use a separate context for each task
   LLVMContext Context;
+  Context.setDiscardValueNames(options::DiscardValueNames);
   Context.enableDebugTypeODRUniquing(); // Merge debug info types.
   Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true);
 
@@ -1235,6 +1242,7 @@ static ld_plugin_status allSymbolsReadHook(raw_fd_ostream *ApiFile) {
   }
 
   LLVMContext Context;
+  Context.setDiscardValueNames(options::DiscardValueNames);
   Context.enableDebugTypeODRUniquing(); // Merge debug info types.
   Context.setDiagnosticHandler(diagnosticHandlerForContext, nullptr, true);