ELF2: Add -soname option.

llvm-svn: 249058

lld/ELF/Config.h

@@ -21,6 +21,7 @@ struct Configuration {
   llvm::StringRef DynamicLinker;
   llvm::StringRef Entry;
   llvm::StringRef OutputFile = "a.out";
+  llvm::StringRef SoName;
   llvm::StringRef Sysroot;
   std::string RPath;
   std::vector<llvm::StringRef> InputSearchPaths;

lld/ELF/Driver.cpp

@@ -117,6 +117,9 @@ void LinkerDriver::link(ArrayRef<const char *> ArgsArr) {
   if (auto *Arg = Args.getLastArg(OPT_entry))
     Config->Entry = Arg->getValue();
 
+  if (auto *Arg = Args.getLastArg(OPT_soname))
+    Config->SoName = Arg->getValue();
+
   Config->AllowMultipleDefinition = Args.hasArg(OPT_allow_multiple_definition);
   Config->DiscardAll = Args.hasArg(OPT_discard_all);
   Config->DiscardLocals = Args.hasArg(OPT_discard_locals);

lld/ELF/Options.td

@@ -52,6 +52,9 @@ def rpath : Separate<["-"], "rpath">,
 def shared : Flag<["-"], "shared">,
   HelpText<"Build a shared object">;
 
+def soname : Joined<["-"], "soname=">,
+  HelpText<"Set DT_SONAME">;
+
 def sysroot : Joined<["--"], "sysroot=">,
   HelpText<"Set the system root">;
 
@@ -69,6 +72,7 @@ def alias_discard_all: Flag<["-"], "x">, Alias<discard_all>;
 def alias_discard_locals: Flag<["-"], "X">, Alias<discard_locals>;
 def alias_entry : Separate<["-"], "e">, Alias<entry>;
 def alias_l : Joined<["--"], "library=">, Alias<l>;
+def alias_soname : Separate<["-"], "h">, Alias<soname>;
 
 // Options listed below are silently ignored now.
 def as_needed : Flag<["--"], "as-needed">;

lld/ELF/OutputSections.cpp

@@ -198,10 +198,14 @@ template <class ELFT> void DynamicSection<ELFT>::finalize() {
   ++NumEntries; // DT_STRSZ
   ++NumEntries; // DT_HASH
 
-  StringRef RPath = Config->RPath;
-  if (!RPath.empty()) {
+  if (!Config->RPath.empty()) {
     ++NumEntries; // DT_RUNPATH
-    DynStrSec.add(RPath);
+    DynStrSec.add(Config->RPath);
+  }
+
+  if (!Config->SoName.empty()) {
+    ++NumEntries; // DT_SONAME
+    DynStrSec.add(Config->SoName);
   }
 
   const std::vector<std::unique_ptr<SharedFileBase>> &SharedFiles =
@@ -255,10 +259,15 @@ template <class ELFT> void DynamicSection<ELFT>::writeTo(uint8_t *Buf) {
   P->d_un.d_ptr = HashSec.getVA();
   ++P;
 
-  StringRef RPath = Config->RPath;
-  if (!RPath.empty()) {
+  if (!Config->RPath.empty()) {
     P->d_tag = DT_RUNPATH;
-    P->d_un.d_val = DynStrSec.getFileOff(RPath);
+    P->d_un.d_val = DynStrSec.getFileOff(Config->RPath);
+    ++P;
+  }
+
+  if (!Config->SoName.empty()) {
+    P->d_tag = DT_SONAME;
+    P->d_un.d_val = DynStrSec.getFileOff(Config->SoName);
     ++P;
   }
 

lld/test/elf2/soname2.s

@@ -0,0 +1,8 @@
+// RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+// RUN: lld -flavor gnu2 %t.o -shared -soname=foo.so -o %t
+// RUN: llvm-readobj --dynamic-table %t | FileCheck %s
+
+// CHECK: 0x000000000000000E SONAME  LibrarySoname (foo.so)
+
+.global _start
+_start: