[Driver][SYCL] Improve -lname static linking with shared objects (#5790)

By default, the expectation for linking is dynamic.  Abide by these
rules when processing library files for fat static archives.

For example:  clang++ -fsycl -lname

This should only attempt to unbundle libname.a when there is no libname.so
found.  Exception being when we are forcing static linking with options
such as -static and -Wl,-Bstatic.

Author: mdtoguchi

clang/lib/Driver/Driver.cpp

@@ -3013,10 +3013,19 @@ getLinkerArgs(Compilation &C, DerivedArgList &Args, bool IncludeObj = false) {
   // TODO: The static archive processing for SYCL is done in a different
   // manner than the OpenMP processing.  We should try and refactor this
   // to use the OpenMP flow (adding -l<name> to the llvm-link step)
-  auto resolveStaticLib = [&](StringRef LibName) -> bool {
+  auto resolveStaticLib = [&](StringRef LibName, bool IsStatic) -> bool {
     if (!LibName.startswith("-l"))
       return false;
     for (auto LPath : LibPaths) {
+      if (!IsStatic) {
+        // Current linking state is dynamic.  We will first check for the
+        // shared object and not pull in the static library if it is found.
+        SmallString<128> SoLibName(LPath);
+        llvm::sys::path::append(SoLibName,
+                                Twine("lib" + LibName.substr(2) + ".so").str());
+        if (llvm::sys::fs::exists(SoLibName))
+          return false;
+      }
       SmallString<128> FullName(LPath);
       llvm::sys::path::append(FullName,
                               Twine("lib" + LibName.substr(2) + ".a").str());
@@ -3029,6 +3038,7 @@ getLinkerArgs(Compilation &C, DerivedArgList &Args, bool IncludeObj = false) {
   };
   for (const auto *A : Args) {
     std::string FileName = A->getAsString(Args);
+    static bool IsLinkStateStatic(Args.hasArg(options::OPT_static));
     auto addLibArg = [&](StringRef LibName) -> bool {
       if (isStaticArchiveFile(LibName) ||
           (IncludeObj && isObjectFile(LibName.str()))) {
@@ -3088,7 +3098,20 @@ getLinkerArgs(Compilation &C, DerivedArgList &Args, bool IncludeObj = false) {
             LibArgs.push_back(Args.MakeArgString(V));
             return;
           }
-          resolveStaticLib(V);
+          if (optionMatches("-Bstatic", V.str()) ||
+              optionMatches("-dn", V.str()) ||
+              optionMatches("-non_shared", V.str()) ||
+              optionMatches("-static", V.str())) {
+            IsLinkStateStatic = true;
+            return;
+          }
+          if (optionMatches("-Bdynamic", V.str()) ||
+              optionMatches("-dy", V.str()) ||
+              optionMatches("-call_shared", V.str())) {
+            IsLinkStateStatic = false;
+            return;
+          }
+          resolveStaticLib(V, IsLinkStateStatic);
         };
         if (Value[0] == '@') {
           // Found a response file, we want to expand contents to try and
@@ -3128,7 +3151,7 @@ getLinkerArgs(Compilation &C, DerivedArgList &Args, bool IncludeObj = false) {
       continue;
     }
     if (A->getOption().matches(options::OPT_l))
-      resolveStaticLib(A->getAsString(Args));
+      resolveStaticLib(A->getAsString(Args), IsLinkStateStatic);
   }
   return LibArgs;
 }

clang/test/Driver/sycl-offload-static-lib-2.cpp

@@ -35,8 +35,14 @@
 // STATIC_LIB: ld{{.*}} "{{.*}}_lib.{{(a|lo)}}" "[[HOSTOBJ]]"
 
 // Test using -l<name> style for passing libraries.
+// RUN: mkdir -p %t_dir
+// RUN: touch %t_dir/liblin64.so
 // RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -L%S/Inputs/SYCL -llin64 -### %t_obj.o 2>&1 \
 // RUN:   | FileCheck %s -check-prefixes=STATIC_L_LIB,STATIC_L_LIB_DEF -DBUNDLE_TRIPLE=sycl-spir64-unknown-unknown
+// RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -static -L%t_dir -L%S/Inputs/SYCL -llin64 -### %t_obj.o 2>&1 \
+// RUN:   | FileCheck %s -check-prefixes=STATIC_L_LIB,STATIC_L_LIB_DEF -DBUNDLE_TRIPLE=sycl-spir64-unknown-unknown
+// RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -Xlinker -Bstatic -L%t_dir -L%S/Inputs/SYCL -llin64 -### %t_obj.o 2>&1 \
+// RUN:   | FileCheck %s -check-prefixes=STATIC_L_LIB,STATIC_L_LIB_DEF -DBUNDLE_TRIPLE=sycl-spir64-unknown-unknown
 // RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -fsycl-targets=nvptx64-nvidia-cuda -L%S/Inputs/SYCL -llin64 -### %t_obj.o 2>&1 \
 // RUN:   | FileCheck %s -check-prefixes=STATIC_L_LIB,STATIC_L_LIB_NVPTX -DBUNDLE_TRIPLE=sycl-nvptx64-nvidia-cuda-sm_50
 // STATIC_L_LIB: clang-offload-bundler{{.*}} "-type=o" "-targets={{.*}},[[BUNDLE_TRIPLE]]" "-inputs=[[INPUTO:.+\.o]]" "-outputs=[[HOSTOBJ:.+\.o]],{{.+\.o}}"
@@ -49,6 +55,9 @@
 // STATIC_L_LIB: ld{{.*}} "-llin64" "[[HOSTOBJ]]"
 
 // non-fat libraries should not trigger the unbundling step.
+// presence of shared object should not trigger unbundling step.
+// RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -L%t_dir -L%S/Inputs/SYCL -llin64 -### 2>&1 \
+// RUN:   | FileCheck %s -check-prefixes=NO_STATIC_UNBUNDLE
 // RUN: %clangxx -target x86_64-unknown-linux-gnu -fsycl -lc -lm -ldl -### 2>&1 \
 // RUN:   | FileCheck %s -check-prefixes=NO_STATIC_UNBUNDLE
 // NO_STATIC_UNBUNDLE-NOT: clang-offload-bundler{{.*}} "-type=aoo" {{.*}} "-inputs={{.*}}lib{{.*}}.a"