[lld] Keep full library path in DT_NEEDED.

Fixes PR32572.

When
    (a) a library has no soname
and (b) library is given on the command line with path (and not through -L/-l flags)
DT_NEEDED entry for such library keeps the path as given.

This behavior is consistent with gold and bfd, and is used in compiler-rt test suite.

This is a second attempt after r300007 got reverted. This time relro-omagic test is
changed in a way to avoid hardcoding the path to the test directory in the objdump'd
binary.

llvm-svn: 300011

lld/ELF/Driver.cpp

@@ -153,7 +153,7 @@ LinkerDriver::getArchiveMembers(MemoryBufferRef MB) {
 
 // Opens and parses a file. Path has to be resolved already.
 // Newly created memory buffers are owned by this driver.
-void LinkerDriver::addFile(StringRef Path) {
+void LinkerDriver::addFile(StringRef Path, bool WithLOption) {
   using namespace sys::fs;
 
   Optional<MemoryBufferRef> Buffer = readFile(Path);
@@ -184,6 +184,11 @@ void LinkerDriver::addFile(StringRef Path) {
       return;
     }
     Files.push_back(createSharedFile(MBRef));
+    // If the library is found at an explicitly given path use the entire path
+    // as he default soname. Such libraries should not require RPATH or
+    // LD_LIBRARY_PATH to run.
+    Files.back()->DefaultSoName =
+        WithLOption ? sys::path::filename(Path) : Path;
     return;
   default:
     if (InLib)
@@ -196,7 +201,7 @@ void LinkerDriver::addFile(StringRef Path) {
 // Add a given library by searching it from input search paths.
 void LinkerDriver::addLibrary(StringRef Name) {
   if (Optional<std::string> Path = searchLibrary(Name))
-    addFile(*Path);
+    addFile(*Path, /*WithLOption=*/true);
   else
     error("unable to find library -l" + Name);
 }
@@ -762,7 +767,7 @@ void LinkerDriver::createFiles(opt::InputArgList &Args) {
       addLibrary(Arg->getValue());
       break;
     case OPT_INPUT:
-      addFile(Arg->getValue());
+      addFile(Arg->getValue(), /*WithLOption=*/false);
       break;
     case OPT_alias_script_T:
     case OPT_script:

lld/ELF/Driver.h

@@ -27,7 +27,7 @@ extern class LinkerDriver *Driver;
 class LinkerDriver {
 public:
   void main(ArrayRef<const char *> Args, bool CanExitEarly);
-  void addFile(StringRef Path);
+  void addFile(StringRef Path, bool WithLOption);
   void addLibrary(StringRef Name);
 
 private:

lld/ELF/InputFiles.cpp

@@ -661,7 +661,7 @@ template <class ELFT> void SharedFile<ELFT>::parseSoName() {
   // DSOs are identified by soname, and they usually contain
   // DT_SONAME tag in their header. But if they are missing,
   // filenames are used as default sonames.
-  SoName = sys::path::filename(this->getName());
+  SoName = this->DefaultSoName;
 
   if (!DynamicSec)
     return;

lld/ELF/InputFiles.h

@@ -93,6 +93,10 @@ public:
   uint16_t EMachine = llvm::ELF::EM_NONE;
   uint8_t OSABI = 0;
 
+  // For SharedKind inputs, the string to use in DT_NEEDED when the library
+  // has no soname.
+  std::string DefaultSoName;
+
   // Cache for toString(). Only toString() should use this member.
   mutable std::string ToStringCache;
 

lld/ELF/ScriptParser.cpp

@@ -243,25 +243,26 @@ void ScriptParser::addFile(StringRef S) {
     SmallString<128> PathData;
     StringRef Path = (Config->Sysroot + S).toStringRef(PathData);
     if (sys::fs::exists(Path)) {
-      Driver->addFile(Saver.save(Path));
+      Driver->addFile(Saver.save(Path), /*WithLOption=*/false);
       return;
     }
   }
 
   if (sys::path::is_absolute(S)) {
-    Driver->addFile(S);
+    Driver->addFile(S, /*WithLOption=*/false);
   } else if (S.startswith("=")) {
     if (Config->Sysroot.empty())
-      Driver->addFile(S.substr(1));
+      Driver->addFile(S.substr(1), /*WithLOption=*/false);
     else
-      Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)));
+      Driver->addFile(Saver.save(Config->Sysroot + "/" + S.substr(1)),
+                      /*WithLOption=*/false);
   } else if (S.startswith("-l")) {
     Driver->addLibrary(S.substr(2));
   } else if (sys::fs::exists(S)) {
-    Driver->addFile(S);
+    Driver->addFile(S, /*WithLOption=*/false);
   } else {
     if (Optional<std::string> Path = findFromSearchPaths(S))
-      Driver->addFile(Saver.save(*Path));
+      Driver->addFile(Saver.save(*Path), /*WithLOption=*/true);
     else
       setError("unable to find " + S);
   }

lld/test/ELF/as-needed-no-reloc.s

@@ -16,7 +16,7 @@
 # CHECK-NEXT: Other: 0
 # CHECK-NEXT: Section: Undefined
 
-# CHECK: NEEDED SharedLibrary (as-needed-no-reloc{{.*}}2.so)
+# CHECK: NEEDED SharedLibrary ({{.*}}as-needed-no-reloc{{.*}}2.so)
 
         .globl _start
 _start:

lld/test/ELF/no-soname.s

@@ -0,0 +1,31 @@
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+// RUN: mkdir -p %T/no-soname
+// RUN: ld.lld %t.o -shared -o %T/no-soname/libfoo.so
+
+// RUN: ld.lld %t.o %T/no-soname/libfoo.so -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s
+
+// CHECK:  0x0000000000000001 NEEDED               SharedLibrary ({{.*}}/no-soname/libfoo.so)
+// CHECK-NOT: NEEDED
+
+// RUN: ld.lld %t.o %T/no-soname/../no-soname/libfoo.so -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s --check-prefix=CHECK2
+
+// CHECK2:  0x0000000000000001 NEEDED               SharedLibrary ({{.*}}/no-soname/../no-soname/libfoo.so)
+// CHECK2-NOT: NEEDED
+
+// RUN: ld.lld %t.o -L%T/no-soname/../no-soname -lfoo -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s --check-prefix=CHECK3
+
+// CHECK3:  0x0000000000000001 NEEDED               SharedLibrary (libfoo.so)
+// CHECK3-NOT: NEEDED
+
+// RUN: ld.lld %t.o -shared -soname libbar.so -o %T/no-soname/libbar.so
+// RUN: ld.lld %t.o %T/no-soname/libbar.so -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s --check-prefix=CHECK4
+
+// CHECK4:  0x0000000000000001 NEEDED               SharedLibrary (libbar.so)
+// CHECK4-NOT: NEEDED
+
+.global _start
+_start:

lld/test/ELF/relro-omagic.s

@@ -1,6 +1,6 @@
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.o
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %p/Inputs/shared.s -o %t2.o
-# RUN: ld.lld -shared %t2.o -o %t2.so
+# RUN: ld.lld -shared %t2.o -o %t2.so -soname relro-omagic.s.tmp2.so
 # RUN: ld.lld -N %t.o %t2.so -o %t
 # RUN: llvm-objdump -section-headers %t | FileCheck --check-prefix=NORELRO %s
 # RUN: llvm-readobj --program-headers %t | FileCheck --check-prefix=NOPHDRS %s