[Driver] Properly handle -pie and -nopie on Fuchsia

[phosek]

Summary

Prior to this patch we would ignore -pie and -nopie options but that
could lead to issues when compiling code that uses either of these
flags.

[mcgrathr]

In GCC the spelling is -no-pie. -nopie is not documented as an alias, and I don't think it works.

[MaskRay]

I suspect that OpenBSD uses -nopie, but this is never adopted by other OSes / GCC. And Clang should not add a new alias that has no significant uses.

[phosek]

That alias is already recognized by the GNU driver. I'm sharing the implementation between the two drivers. Would you prefer to reject -nopie when targeting Fuchsia?

[MaskRay]

In D151186#4369181, @phosek wrote:

That alias is already recognized by the GNU driver. I'm sharing the implementation between the two drivers. Would you prefer to reject -nopie when targeting Fuchsia?

Hmm, handling OPT_nopie in clang/lib/Driver/ToolChains/Gnu.cpp looks like a mistake. We should reject it for Gnu.cpp...

[phosek]

In D151186#4369203, @MaskRay wrote:

In D151186#4369181, @phosek wrote:

That alias is already recognized by the GNU driver. I'm sharing the implementation between the two drivers. Would you prefer to reject -nopie when targeting Fuchsia?

Hmm, handling OPT_nopie in clang/lib/Driver/ToolChains/Gnu.cpp looks like a mistake. We should reject it for Gnu.cpp...

I can send a separate change for that.

clang/lib/Driver/ToolChains/CommonArgs.h

 #include "llvm/Option/Arg.h"
 #include "llvm/Option/ArgList.h"
 #include "llvm/Support/CodeGen.h"
 
 namespace clang {
 namespace driver {
 namespace tools {
 
+bool isPIE(const ToolChain &TC, const llvm::opt::ArgList &Args);
+bool isStaticPIE(const ToolChain &TC, const llvm::opt::ArgList &Args);
+bool isStatic(const llvm::opt::ArgList &Args);
+
 void addPathIfExists(const Driver &D, const Twine &Path,
                      ToolChain::path_list &Paths);
 
 void AddLinkerInputs(const ToolChain &TC, const InputInfoList &Inputs,
                      const llvm::opt::ArgList &Args,
                      llvm::opt::ArgStringList &CmdArgs, const JobAction &JA);
 
 void addLinkerCompressDebugSectionsOption(const ToolChain &TC,

clang/lib/Driver/ToolChains/CommonArgs.cpp

auto GPUKind = T.isAMDGCN() ? llvm::AMDGPU::parseArchAMDGCN(Processor)
                               : llvm::AMDGPU::parseArchR600(Processor);
   auto GPUFeatures = T.isAMDGCN() ? llvm::AMDGPU::getArchAttrAMDGCN(GPUKind)
                                   : llvm::AMDGPU::getArchAttrR600(GPUKind);
   if (GPUFeatures & llvm::AMDGPU::FEATURE_WGP)
     return false;
   return TargetFeatureArg.getOption().matches(options::OPT_mno_cumode);
 }
 
+bool tools::isPIE(const ToolChain &TC, const ArgList &Args) {
+  if (Args.hasArg(options::OPT_shared) || Args.hasArg(options::OPT_static) ||
+      Args.hasArg(options::OPT_r) || Args.hasArg(options::OPT_static_pie))
+    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);
+}
+
+bool tools::isStaticPIE(const ToolChain &TC, const ArgList &Args) {
+  bool HasStaticPIE = Args.hasArg(options::OPT_static_pie);
+  // -no-pie is an alias for -nopie. So, handling -nopie takes care of
+  // -no-pie as well.
+  if (HasStaticPIE && Args.hasArg(options::OPT_nopie)) {
+    const Driver &D = TC.getDriver();
+    const llvm::opt::OptTable &Opts = D.getOpts();
+    StringRef StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
+    StringRef NoPIEName = Opts.getOptionName(options::OPT_nopie);
+    D.Diag(diag::err_drv_cannot_mix_options) << StaticPIEName << NoPIEName;
+  }
+  return HasStaticPIE;
+}
+
+bool tools::isStatic(const ArgList &Args) {
+  return Args.hasArg(options::OPT_static) &&
+      !Args.hasArg(options::OPT_static_pie);
+}
+
 void tools::addPathIfExists(const Driver &D, const Twine &Path,
                             ToolChain::path_list &Paths) {
   if (D.getVFS().exists(Path))
     Paths.push_back(Path.str());
 }
 
 void tools::handleTargetFeaturesGroup(const Driver &D,
                                       const llvm::Triple &Triple,

clang/lib/Driver/ToolChains/Fuchsia.cpp

if (llvm::sys::path::filename(Exec).equals_insensitive("ld.lld") ||
     CmdArgs.push_back("-z");
     CmdArgs.push_back("rel");
     CmdArgs.push_back("--pack-dyn-relocs=relr");
   }
 
   if (!D.SysRoot.empty())
     CmdArgs.push_back(Args.MakeArgString("--sysroot=" + D.SysRoot));
 
-  if (!Args.hasArg(options::OPT_shared) && !Args.hasArg(options::OPT_r))
+  if (isPIE(ToolChain, Args))
     CmdArgs.push_back("-pie");
 
   if (Args.hasArg(options::OPT_rdynamic))
     CmdArgs.push_back("-export-dynamic");
 
   if (Args.hasArg(options::OPT_s))
     CmdArgs.push_back("-s");
 

clang/lib/Driver/ToolChains/Gnu.cpp

case llvm::Triple::ve:
     return "elf64ve";
   case llvm::Triple::csky:
     return "cskyelf_linux";
   default:
     return nullptr;
   }
 }
 
-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) || Args.hasArg(options::OPT_static_pie))
-    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);
-}
-
-static bool getStaticPIE(const ArgList &Args, const ToolChain &TC) {
-  bool HasStaticPIE = Args.hasArg(options::OPT_static_pie);
-  // -no-pie is an alias for -nopie. So, handling -nopie takes care of
-  // -no-pie as well.
-  if (HasStaticPIE && Args.hasArg(options::OPT_nopie)) {
-    const Driver &D = TC.getDriver();
-    const llvm::opt::OptTable &Opts = D.getOpts();
-    StringRef StaticPIEName = Opts.getOptionName(options::OPT_static_pie);
-    StringRef NoPIEName = Opts.getOptionName(options::OPT_nopie);
-    D.Diag(diag::err_drv_cannot_mix_options) << StaticPIEName << NoPIEName;
-  }
-  return HasStaticPIE;
-}
-
-static bool getStatic(const ArgList &Args) {
-  return Args.hasArg(options::OPT_static) &&
-      !Args.hasArg(options::OPT_static_pie);
-}
-
 void tools::gnutools::StaticLibTool::ConstructJob(
     Compilation &C, const JobAction &JA, const InputInfo &Output,
     const InputInfoList &Inputs, const ArgList &Args,
     const char *LinkingOutput) const {
   const Driver &D = getToolChain().getDriver();
 
   // Silence warning for "clang -g foo.o -o foo"
   Args.ClaimAllArgs(options::OPT_g_Group);
void tools::gnutools::Linker::ConstructJob(Compilation &C, const JobAction &JA,
 
   const llvm::Triple &Triple = getToolChain().getEffectiveTriple();
 
   const llvm::Triple::ArchType Arch = ToolChain.getArch();
   const bool isOHOSFamily = ToolChain.getTriple().isOHOSFamily();
   const bool isAndroid = ToolChain.getTriple().isAndroid();
   const bool IsIAMCU = ToolChain.getTriple().isOSIAMCU();
   const bool IsVE = ToolChain.getTriple().isVE();
-  const bool IsPIE = getPIE(Args, ToolChain);
-  const bool IsStaticPIE = getStaticPIE(Args, ToolChain);
-  const bool IsStatic = getStatic(Args);
+  const bool IsPIE = isPIE(ToolChain, Args);
+  const bool IsStaticPIE = isStaticPIE(ToolChain, Args);
+  const bool IsStatic = isStatic(Args);
   const bool HasCRTBeginEndFiles =
       ToolChain.getTriple().hasEnvironment() ||
       (ToolChain.getTriple().getVendor() != llvm::Triple::MipsTechnologies);
 
   ArgStringList CmdArgs;
 
   // Silence warning for "clang -g foo.o -o foo"
   Args.ClaimAllArgs(options::OPT_g_Group);

clang/test/Driver/fuchsia.c

 // CHECK-FP-ALL: "-mframe-pointer=all"
 // CHECK-FP-NONLEAF: "-mframe-pointer=non-leaf"
 // CHECK-FP-NONE: "-mframe-pointer=none"
 
 // RUN: %clang -### %s --target=x86_64-unknown-fuchsia -rtlib=libgcc -fuse-ld=lld 2>&1 \
 // RUN:     | FileCheck %s -check-prefix=CHECK-RTLIB
 // CHECK-RTLIB: error: invalid runtime library name in argument '-rtlib=libgcc'
 
+// RUN: %clang -### %s --target=x86_64-unknown-fuchsia -pie -fuse-ld=lld 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-PIE
+// CHECK-PIE: "-pie"
+
+// RUN: %clang -### %s --target=x86_64-unknown-fuchsia -nopie -fuse-ld=lld 2>&1 \
+// RUN:     | FileCheck %s -check-prefix=CHECK-NOPIE
+// CHECK-NOPIE-NOT: "-pie"
+
 // RUN: %clang -### %s --target=x86_64-unknown-fuchsia -static -fuse-ld=lld 2>&1 \
 // RUN:     | FileCheck %s -check-prefix=CHECK-STATIC
 // CHECK-STATIC: "-Bstatic"
 // CHECK-STATIC: "-Bdynamic"
 // CHECK-STATIC: "-lc"
 
 // RUN: %clang -### %s --target=x86_64-unknown-fuchsia -shared -fuse-ld=lld 2>&1 \
 // RUN:     | FileCheck %s -check-prefix=CHECK-SHARED