[ELF] - Change -t implementation to print which archive members are u…

…sed.

Previously each archive file was reported no matter were it's member used or not,
like:
lib/libLLVMSupport.a

Now lld prints line for each used internal file, like:
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/StringSaver.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/Host.cpp.o)
lib/libLLVMSupport.a(lib/Support/CMakeFiles/LLVMSupport.dir/ConvertUTF.c.o)

That should be consistent with what gold do.

This fixes PR27243.

Differential revision: http://reviews.llvm.org/D19011

llvm-svn: 266220

lld/ELF/Driver.cpp

@@ -98,7 +98,7 @@ LinkerDriver::getArchiveMembers(MemoryBufferRef MB) {
 // Newly created memory buffers are owned by this driver.
 void LinkerDriver::addFile(StringRef Path) {
   using namespace llvm::sys::fs;
-  if (Config->Verbose || Config->Trace)
+  if (Config->Verbose)
     llvm::outs() << Path << "\n";
   auto MBOrErr = MemoryBuffer::getFile(Path);
   if (!MBOrErr) {

lld/ELF/SymbolTable.cpp

@@ -45,6 +45,15 @@ template <class ELFT> static bool isCompatible(InputFile *FileP) {
   return false;
 }
 
+// Returns "(internal)", "foo.a(bar.o)" or "baz.o".
+static std::string getFilename(InputFile *F) {
+  if (!F)
+    return "(internal)";
+  if (!F->ArchiveName.empty())
+    return (F->ArchiveName + "(" + F->getName() + ")").str();
+  return F->getName();
+}
+
 // Add symbols in File to the symbol table.
 template <class ELFT>
 void SymbolTable<ELFT>::addFile(std::unique_ptr<InputFile> File) {
@@ -61,6 +70,18 @@ void SymbolTable<ELFT>::addFile(std::unique_ptr<InputFile> File) {
     return;
   }
 
+  // Lazy object file
+  if (auto *F = dyn_cast<LazyObjectFile>(FileP)) {
+    LazyObjectFiles.emplace_back(cast<LazyObjectFile>(File.release()));
+    F->parse();
+    for (Lazy &Sym : F->getLazySymbols())
+      addLazy(&Sym);
+    return;
+  }
+
+  if (Config->Trace)
+    llvm::outs() << getFilename(FileP) << "\n";
+
   // .so file
   if (auto *F = dyn_cast<SharedFile<ELFT>>(FileP)) {
     // DSOs are uniquified not by filename but by soname.
@@ -85,15 +106,6 @@ void SymbolTable<ELFT>::addFile(std::unique_ptr<InputFile> File) {
     return;
   }
 
-  // Lazy object file
-  if (auto *F = dyn_cast<LazyObjectFile>(FileP)) {
-    LazyObjectFiles.emplace_back(cast<LazyObjectFile>(File.release()));
-    F->parse();
-    for (Lazy &Sym : F->getLazySymbols())
-      addLazy(&Sym);
-    return;
-  }
-
   // Regular object file
   auto *F = cast<ObjectFile<ELFT>>(FileP);
   ObjectFiles.emplace_back(cast<ObjectFile<ELFT>>(File.release()));
@@ -206,15 +218,6 @@ template <class ELFT> InputFile *SymbolTable<ELFT>::findFile(SymbolBody *B) {
   return nullptr;
 }
 
-// Returns "(internal)", "foo.a(bar.o)" or "baz.o".
-static std::string getFilename(InputFile *F) {
-  if (!F)
-    return "(internal)";
-  if (!F->ArchiveName.empty())
-    return (F->ArchiveName + "(" + F->getName() + ")").str();
-  return F->getName();
-}
-
 // Construct a string in the form of "Sym in File1 and File2".
 // Used to construct an error message.
 template <class ELFT>

lld/test/ELF/Inputs/trace-ar1.s

@@ -0,0 +1,2 @@
+.globl _used
+_used:

lld/test/ELF/Inputs/trace-ar2.s

@@ -0,0 +1,2 @@
+.globl _notused
+_notused:

lld/test/ELF/trace-ar.s

@@ -0,0 +1,21 @@
+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.foo.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/trace-ar1.s -o %t.obj1.o
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/trace-ar2.s -o %t.obj2.o
+# RUN: llvm-ar rcs %t.boo.a %t.obj1.o %t.obj2.o
+
+## Check how -t works with achieves
+# RUN: ld.lld %t.foo.o %t.boo.a -o %t.out -t 2>&1 | FileCheck %s
+# CHECK:      {{.*}}.foo.o
+# CHECK-NEXT: {{.*}}.boo.a({{.*}}.obj1.o)
+# CHECK-NOT:  {{.*}}.boo.a({{.*}}.obj2.o)
+
+## Test output with --start-lib
+# RUN: ld.lld %t.foo.o --start-lib %t.obj1.o %t.obj2.o -o %t.out -t 2>&1 | FileCheck --check-prefix=STARTLIB %s
+# STARTLIB:      {{.*}}.foo.o
+# STARTLIB-NEXT: {{.*}}.obj1.o
+# STARTLIB-NOT:  {{.*}}.obj2.o
+
+.globl _start, _used
+_start:
+ call _used