[Driver] Add PIE support on Solaris

[ro]

Summary

clang currently lacks PIE support on Solaris. This patch fixes this, linking with crtbeginS.o and crtendS.o for -pie and -shared.

Tested on amd64-pc-solaris2.11, sparcv9-sun-solaris2.11, and x86_64-pc-linux-gnu.

[MaskRay]

clang/lib/Driver/ToolChains/Solaris.cpp

67

On Linux, clang -r -static also disable the linker option -pie.
-static-pie is handled as a special case which also disables the regular -pie code path.

clang/test/Driver/solaris-ld.c

110

The convention is to put 2>&1 at the end of the command, aka before |

[MaskRay]

I'll submit a follow-up patch to make use of crtbeginS.o and crtendS.o shortly.

I think this patch should make this change, so that the change is correct on itself.

[ro]

In D158206#4596471, @MaskRay wrote:

I'll submit a follow-up patch to make use of crtbeginS.o and crtendS.o shortly.

I think this patch should make this change, so that the change is correct on itself.

Ok, done. I'll update with the merge patch once another round of testing has finished.

clang/lib/Driver/ToolChains/Solaris.cpp

67

I've taken Gnu.cpp (getPIE), removing the -static-pie handling.

Solaris supports neither -static (no libc.a etc. since Solaris 10) nor -static-pie. Given that gcc silently ignores that, I'm doing the same.

clang/test/Driver/solaris-ld.c

110

I've changed just the newly added tests. There are a few others, but I've left the as is for now to avoid cluttering the patch with unrelated changes.

[ro]

• Merged D158207.
• Incorporate review comments.

[MaskRay]

clang/lib/Driver/ToolChains/Solaris.cpp

136

Q: Interesting. If -shared used crtbegin.o before, how did it work?

On Linux, using GCC crtbegin.o (compiled with -fno-PIC or similar non-PIC option) will cause:

ld.lld: error: relocation R_X86_64_32S cannot be used against local symbol; recompile with -fPIC
>>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
>>> referenced by crtstuff.c
>>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0x7)

ld.lld: error: relocation R_X86_64_32 cannot be used against symbol '_ITM_deregisterTMCloneTable'; recompile with -fPIC
>>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
>>> referenced by crtstuff.c
>>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0xE)

ld.lld: error: relocation R_X86_64_32 cannot be used against local symbol; recompile with -fPIC
>>> defined in /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o
>>> referenced by crtstuff.c
>>>               /usr/lib/gcc/x86_64-linux-gnu/12/crtbegin.o:(.text+0x18)

clang/test/Driver/solaris-ld.c

110

Ultra nit: you may pack --target=sparc-sun-solaris2.11 on the first line to make the commands compacter, like %clang --target=sparc-sun-solaris2.11 -### %s below.

112

Ultra nit: you may pack --target=sparc-sun-solaris2.11 on the first line to make the commands compacter, like %clang --target=sparc-sun-solaris2.11 -### %s below.

FYI: I think --gcc-toolchain="" is to support GCC_INSTALL_PREFIX. I propose that we deprecate the CMake variable to make test maintaining easier: D158218.

[ro]

clang/lib/Driver/ToolChains/Solaris.cpp

136

When the Solaris crts were reworked for Solaris 11.4 back in 2015, the were intentionally built as PIC to avoid issues just like that.

clang/test/Driver/solaris-ld.c

110

Good point, done.

clang/lib/Driver/ToolChains/Solaris.cpp

void solaris::Assembler::ConstructJob(Compilation &C, const JobAction &JA,
   for (const auto &II : Inputs)
     CmdArgs.push_back(II.getFilename());
 
   const char *Exec = Args.MakeArgString(getToolChain().GetProgramPath("as"));
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
                                          Exec, CmdArgs, Inputs, Output));
 }
 
+static bool getPIE(const ArgList &Args, const ToolChain &TC) {
+  if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_static) ||
+      Args.hasArg(options::OPT_r))
+    return false;
+
+  Arg *A = Args.getLastArg(options::OPT_pie, options::OPT_no_pie,
+                           options::OPT_nopie);
+  if (!A)
+    return TC.isPIEDefault(Args);
+  return A->getOption().matches(options::OPT_pie);
+}
+
 void solaris::Linker::ConstructJob(Compilation &C, const JobAction &JA,
                                    const InputInfo &Output,
                                    const InputInfoList &Inputs,
                                    const ArgList &Args,
                                    const char *LinkingOutput) const {
+  const bool IsPIE = getPIE(Args, getToolChain());
   ArgStringList CmdArgs;
 
   // Demangle C++ names in errors
   CmdArgs.push_back("-C");
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_shared)) {
     CmdArgs.push_back("-e");
     CmdArgs.push_back("_start");
   }
 
+  if (IsPIE) {
+    CmdArgs.push_back("-z");
+    CmdArgs.push_back("type=pie");
+  }
+
   if (Args.hasArg(options::OPT_static)) {
     CmdArgs.push_back("-Bstatic");
     CmdArgs.push_back("-dn");
   } else {
     CmdArgs.push_back("-Bdynamic");
     if (Args.hasArg(options::OPT_shared)) {
       CmdArgs.push_back("-shared");
     }
if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
     CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath(values_X)));
 
     const char *values_xpg = "values-xpg6.o";
     // Use values-xpg4.o for -std=c90, -std=gnu90, -std=iso9899:199409.
     if (LangStd && LangStd->getLanguage() == Language::C && !LangStd->isC99())
       values_xpg = "values-xpg4.o";
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath(values_xpg)));
-    CmdArgs.push_back(
-        Args.MakeArgString(getToolChain().GetFilePath("crtbegin.o")));
+
+    const char *crtbegin = nullptr;
+    if (Args.hasArg(options::OPT_shared) || IsPIE)
+      crtbegin = "crtbeginS.o";
+    else
+      crtbegin = "crtbegin.o";
+    CmdArgs.push_back(Args.MakeArgString(getToolChain().GetFilePath(crtbegin)));
     // Add crtfastmath.o if available and fast math is enabled.
     getToolChain().addFastMathRuntimeIfAvailable(Args, CmdArgs);
   }
 
   getToolChain().AddFilePathLibArgs(Args, CmdArgs);
 
   Args.AddAllArgs(CmdArgs,
                   {options::OPT_L, options::OPT_T_Group, options::OPT_r});
if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs,
     // Avoid AsanInitInternal cycle, Issue #64126.
     if (getToolChain().getTriple().isX86() && SA.needsSharedRt() &&
         SA.needsAsanRt())
       CmdArgs.push_back("-znow");
   }
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
                    options::OPT_r)) {
+    if (Args.hasArg(options::OPT_shared) || IsPIE)
+      CmdArgs.push_back(
+          Args.MakeArgString(getToolChain().GetFilePath("crtendS.o")));
+    else
       CmdArgs.push_back(
           Args.MakeArgString(getToolChain().GetFilePath("crtend.o")));
     CmdArgs.push_back(
         Args.MakeArgString(getToolChain().GetFilePath("crtn.o")));
   }
 
   getToolChain().addProfileRTLibs(Args, CmdArgs);
 
   const char *Exec = Args.MakeArgString(getToolChain().GetLinkerPath());
   C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),

clang/test/Driver/solaris-ld.c

 // RUN:     --sysroot=%S/Inputs/solaris_sparc_tree \
 // RUN:   | FileCheck --check-prefix=CHECK-SPARC32-SHARED %s
 // CHECK-SPARC32-SHARED: "{{.*}}ld{{(.exe)?}}"
 // CHECK-SPARC32-SHARED-SAME: "-lgcc_s"
 // CHECK-SPARC32-SHARED-SAME: "-lc"
 // CHECK-SPARC32-SHARED-NOT: "-lgcc"
 // CHECK-SPARC32-SHARED-NOT: "-lm"
 
+// Check the right ld flags are present with -pie.
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -pie \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-PIE %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -nopie \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOPIE %s
+
+// Check that -shared/-r/-static disable PIE.
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -shared -pie \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOPIE %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -r -pie \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOPIE %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -static -pie \
+// RUN:     --gcc-toolchain="" \
+// RUN:     --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOPIE %s
+
+// CHECK-PIE: "-z" "type=pie"
+// CHECK-NOPIE-NOT: "-z" "type=pie"
+
 // -r suppresses default -l and crt*.o, values-*.o like -nostdlib.
 // RUN: %clang -### %s --target=sparc-sun-solaris2.11 -r 2>&1 \
 // RUN:   | FileCheck %s --check-prefix=CHECK-RELOCATABLE
 // CHECK-RELOCATABLE:     "-L
 // CHECK-RELOCATABLE:     "-r"
 // CHECK-RELOCATABLE-NOT: "-l
 // CHECK-RELOCATABLE-NOT: /crt{{[^.]+}}.o
 // CHECK-RELOCATABLE-NOT: /values-{{[^.]+}}.o
 
+// Check that crt{begin,end}S.o is linked with -shared/-pie.
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s \
+// RUN:        --gcc-toolchain="" \
+// RUN:        --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOCRTS %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -shared \
+// RUN:        --gcc-toolchain="" \
+// RUN:        --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-CRTS %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -nopie \
+// RUN:        --gcc-toolchain="" \
+// RUN:        --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-NOCRTS %s
+// RUN: %clang --target=sparc-sun-solaris2.11 -### %s -pie \
+// RUN:        --gcc-toolchain="" \
+// RUN:        --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-CRTS %s
+// CHECK-CRTS: crtbeginS.o
+// CHECK-CRTS: crtendS.o
+// CHECK-NOCRTS-NOT: crtbeginS.o
+// CHECK-NOCRTS-NOT: crtendS.o
+
 // Check that crtfastmath.o is linked with -ffast-math.
 
 // Check sparc-sun-solaris2.11, 32bit
 // RUN: %clang --target=sparc-sun-solaris2.11 -### %s \
 // RUN:        --gcc-toolchain="" \
 // RUN:        --sysroot=%S/Inputs/solaris_sparc_tree 2>&1 \
 // RUN:   | FileCheck --check-prefix=CHECK-NOCRTFASTMATH-SPARC32 %s
 // RUN: %clang --target=sparc-sun-solaris2.11 -### %s -ffast-math \