[Driver] Also respect SysRoot for the system library paths on DragonFly (#66056)

Author: brad0

clang/lib/Driver/ToolChains/DragonFly.cpp

@@ -123,7 +123,9 @@ void dragonfly::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
                    options::OPT_r)) {
-    CmdArgs.push_back("-L/usr/lib/gcc80");
+    SmallString<128> Dir(D.SysRoot);
+    llvm::sys::path::append(Dir, "/usr/lib/gcc80");
+    CmdArgs.push_back(Args.MakeArgString("-L" + Dir));
 
     if (!Args.hasArg(options::OPT_static)) {
       CmdArgs.push_back("-rpath");
@@ -192,8 +194,8 @@ DragonFly::DragonFly(const Driver &D, const llvm::Triple &Triple,
     getProgramPaths().push_back(getDriver().Dir);
 
   getFilePaths().push_back(getDriver().Dir + "/../lib");
-  getFilePaths().push_back("/usr/lib");
-  getFilePaths().push_back("/usr/lib/gcc80");
+  getFilePaths().push_back(concat(getDriver().SysRoot, "/usr/lib"));
+  getFilePaths().push_back(concat(getDriver().SysRoot, "/usr/lib/gcc80"));
 }
 
 void DragonFly::AddClangSystemIncludeArgs(

clang/test/Driver/Inputs/basic_dragonfly_tree/usr/lib/crt1.o

@@ -4,6 +4,21 @@
 // CHECK: "-cc1" "-triple" "x86_64-pc-dragonfly"
 // CHECK: ld{{.*}}" "--eh-frame-hdr" "-dynamic-linker" "/usr/libexec/ld-elf.so.{{.*}}" "--hash-style=gnu" "--enable-new-dtags" "-o" "a.out" "{{.*}}crt1.o" "{{.*}}crti.o" "{{.*}}crtbegin.o" "{{.*}}.o" "-L{{.*}}gcc{{.*}}" "-rpath" "{{.*}}gcc{{.*}}" "-lc" "-lgcc" "{{.*}}crtend.o" "{{.*}}crtn.o"
 
+// Check x86_64-unknown-dragonfly, X86_64
+// RUN: %clang -### %s 2>&1 --target=x86_64-unknown-dragonfly \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/basic_dragonfly_tree \
+// RUN:   | FileCheck --check-prefix=CHECK-LD-X86_64 %s
+// CHECK-LD-X86_64: "-cc1" "-triple" "x86_64-unknown-dragonfly"
+// CHECK-LD-X86_64-SAME: "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-LD-X86_64: "{{.*}}ld{{(.exe)?}}"
+// CHECK-LD-X86_64-SAME: "[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}crt1.o"
+// CHECK-LD-X86_64-SAME: "[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}crti.o"
+// CHECK-LD-X86_64-SAME: "[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}gcc80{{/|\\\\}}crtbegin.o"
+// CHECK-LD-X86_64-SAME: "-L[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}gcc80" "-rpath" "/usr/lib/gcc80" "-lc" "-lgcc" "--as-needed" "-lgcc_pic" "--no-as-needed"
+// CHECK-LD-X86_64-SAME: "[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}gcc80{{/|\\\\}}crtend.o"
+// CHECK-LD-X86_64-SAME: "[[SYSROOT]]{{/|\\\\}}usr{{/|\\\\}}lib{{/|\\\\}}crtn.o"
+
 // -r suppresses -dynamic-linker, default -l and crt*.o like -nostdlib.
 // RUN: %clang -### %s --target=x86_64-pc-dragonfly -r \
 // RUN:   2>&1 | FileCheck %s --check-prefix=RELOCATABLE