[AIX][Clang] Respect -r when invoking the linker

[francii]

Summary

On AIX, libraries are still being linked when -r is passed to the driver. This patch corrects this error.

[francii]

Move comment

[francii]

Move -r check in CommonArgs.cpp

[w2yehia]

testcase?

clang/lib/Driver/ToolChains/AIX.cpp

236

nit: can we avoid the code duplication here? We can use a goto or add options::OPT_r checking below.
./lib/Driver/ToolChains/Gnu.cpp can be used as a reference.

[francii]

In D145899#4190055, @w2yehia wrote:

testcase?

This patch is still WIP while I verify the libraries that we intend not to add. But I will add a test case once I've done so :)

[francii]

Update check in AIX.cpp, add test case

[francii]

Update test case

[w2yehia]

LGTM. Would be nice to get @daltenty 's approval too.

clang/test/Driver/aix-ld.c

1094

is there a way to check that -l<anything> is not present?
I'm thinking it's more future-proof ((1) detects if new libraries get added and (2) avoids having to update the testcase).. not sure what the disadvantages of adding the wildcard is.

[francii]

Wildcard check for -l.

[francii]

Rebase

[francii]

Add missing bracket

[francii]

Add missing bracket

[daltenty]

clang/lib/Driver/ToolChains/AIX.cpp

237

This mostly looks good, but I'm not sure other toolchains omit use specified L options. I think we shouldn't either.

clang/lib/Driver/ToolChains/CommonArgs.cpp

1696

I think this is redundant, we guard out this whole function call in the block above.

[francii]

Allow user-specified -L and -l options

[daltenty]

LGTM, with a small nit about the test that should be addressed before committing

clang/test/Driver/aix-ld.c

1085

nit: add the user -L option to the test to reflect the changes above

[francii]

Update test case

clang/lib/Driver/ToolChains/AIX.cpp

if (Arg *A = Args.getLastArgNoClaim(options::OPT_p, options::OPT_pg)) {
         return IsArch32Bit ? "gcrt0.o" : "gcrt0_64.o";
       // Enable profiling when "-p" is specified.
       return IsArch32Bit ? "mcrt0.o" : "mcrt0_64.o";
     }
     return IsArch32Bit ? "crt0.o" : "crt0_64.o";
   };
 
   if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nostartfiles,
-                   options::OPT_shared)) {
+                   options::OPT_shared, options::OPT_r)) {
     CmdArgs.push_back(
         Args.MakeArgString(ToolChain.GetFilePath(getCrt0Basename())));
 
     CmdArgs.push_back(Args.MakeArgString(
         ToolChain.GetFilePath(IsArch32Bit ? "crti.o" : "crti_64.o")));
   }
 
   // Collect all static constructor and destructor functions in both C and CXX
auto ExpCommand = std::make_unique<Command>(
         JA, *this, ResponseFileSupport::None(), CreateExportListExec,
         CreateExportCmdArgs, Inputs, Output);
     ExpCommand->setRedirectFiles(
         {std::nullopt, std::string(ExportList), std::nullopt});
     C.addCommand(std::move(ExpCommand));
     CmdArgs.push_back(Args.MakeArgString(llvm::Twine("-bE:") + ExportList));
   }
 
+  if (!Args.hasArg(options::OPT_r)) {
     // Add directory to library search path.
     Args.AddAllArgs(CmdArgs, options::OPT_L);
     ToolChain.AddFilePathLibArgs(Args, CmdArgs);
     ToolChain.addProfileRTLibs(Args, CmdArgs);
 
     if (getToolChain().ShouldLinkCXXStdlib(Args))
       getToolChain().AddCXXStdlibLibArgs(Args, CmdArgs);
 
     if (!Args.hasArg(options::OPT_nostdlib, options::OPT_nodefaultlibs)) {
       AddRunTimeLibs(ToolChain, D, CmdArgs, Args);
 
       // Add OpenMP runtime if -fopenmp is specified.
       if (Args.hasFlag(options::OPT_fopenmp, options::OPT_fopenmp_EQ,
                        options::OPT_fno_openmp, false)) {
         switch (ToolChain.getDriver().getOpenMPRuntime(Args)) {
         case Driver::OMPRT_OMP:
           CmdArgs.push_back("-lomp");
           break;
         case Driver::OMPRT_IOMP5:
           CmdArgs.push_back("-liomp5");
           break;
         case Driver::OMPRT_GOMP:
           CmdArgs.push_back("-lgomp");
           break;
         case Driver::OMPRT_Unknown:
           // Already diagnosed.
           break;
         }
       }
 
       // Support POSIX threads if "-pthreads" or "-pthread" is present.
       if (Args.hasArg(options::OPT_pthreads, options::OPT_pthread))
         CmdArgs.push_back("-lpthreads");
 
       if (D.CCCIsCXX())
         CmdArgs.push_back("-lm");
 
       CmdArgs.push_back("-lc");
 
       if (Args.hasArgNoClaim(options::OPT_p, options::OPT_pg)) {
         CmdArgs.push_back(Args.MakeArgString((llvm::Twine("-L") + D.SysRoot) +
                                              "/lib/profiled"));
         CmdArgs.push_back(Args.MakeArgString((llvm::Twine("-L") + D.SysRoot) +
                                              "/usr/lib/profiled"));
       }
     }
 
     const char *Exec = Args.MakeArgString(ToolChain.GetLinkerPath());
-  C.addCommand(std::make_unique<Command>(JA, *this, ResponseFileSupport::None(),
-                                         Exec, CmdArgs, Inputs, Output));
+    C.addCommand(std::make_unique<Command>(
+        JA, *this, ResponseFileSupport::None(), Exec, CmdArgs, Inputs, Output));
   }
 
 /// AIX - AIX tool chain which can call as(1) and ld(1) directly.
 AIX::AIX(const Driver &D, const llvm::Triple &Triple, const ArgList &Args)
     : ToolChain(D, Triple, Args) {
   getProgramPaths().push_back(getDriver().getInstalledDir());
   if (getDriver().getInstalledDir() != getDriver().Dir)
     getProgramPaths().push_back(getDriver().Dir);
 

clang/lib/Driver/ToolChains/CommonArgs.cpp

case ToolChain::UNW_Libgcc: {
     if (LGT == LibGccType::StaticLibGcc)
       CmdArgs.push_back("-lgcc_eh");
     else
       CmdArgs.push_back("-lgcc_s");
     break;
   }
   case ToolChain::UNW_CompilerRT:
     if (TC.getTriple().isOSAIX()) {
+      if (Args.hasArg(options::OPT_r))
+        break;
       // AIX only has libunwind as a shared library. So do not pass
       // anything in if -static is specified.
       if (LGT != LibGccType::StaticLibGcc)
         CmdArgs.push_back("-lunwind");
     } else if (LGT == LibGccType::StaticLibGcc) {
       CmdArgs.push_back("-l:libunwind.a");
     } else if (LGT == LibGccType::SharedLibGcc) {
       if (TC.getTriple().isOSCygMing())

clang/test/Driver/aix-ld.c

 
 // Check powerpc-ibm-aix7.1.0.0, 32-bit. -fopenmp=libfoo results an error.
 // RUN: %clang %s 2>&1 -### \
 // RUN:        --target=powerpc-ibm-aix7.1.0.0 \
 // RUN:        --sysroot %S/Inputs/aix_ppc_tree \
 // RUN:        -fopenmp=libfoo \
 // RUN:   | FileCheck --check-prefixes=CHECK-FOPENMP-FOO %s
 // CHECK-FOPENMP-FOO: error: unsupported argument 'libfoo' to option '-fopenmp='
+
+// Check powerpc-ibm-aix7.1.0.0. -r does not link object files or libraries
+// RUN: %clang %s 2>&1 -### \
+// RUN:        --target=powerpc-ibm-aix7.1.0.0 \
+// RUN:        --sysroot %S/Inputs/aix_ppc_tree \
+// RUN:        --unwindlib=libunwind \
+// RUN:        -r \
+// RUN:   | FileCheck --check-prefixes=CHECK-RELOCATABLE %s
+
+// CHECK-RELOCATABLE:     "-cc1" "-triple" "powerpc-ibm-aix7.1.0.0"
+// CHECK-RELOCATABLE:     "-isysroot" "[[SYSROOT:[^"]+]]"
+// CHECK-RELOCATABLE:     "-r"
+// CHECK-RELOCATABLE-NOT:     "[[SYSROOT]]/usr/lib{{/|\\\\}}crt0.o"
+// CHECK-RELOCATABLE-NOT:     "[[SYSROOT]]/usr/lib{{/|\\\\}}crti.o"
+// CHECK-RELOCATABLE-NOT:     "-l{{.*}}"