[AIX] Pass the -b option to linker on AIX (with fix to build break)

[anjankgk]

Summary

This patch will re-enable the patch posted under https://reviews.llvm.org/D106688 originally which was reverted due to buildbreak that was caused by mismatched diagnostic message arguments.

[ZarkoCA]

Thanks for the quick turn around and fix @anjankgk, LGTM.

clang/include/clang/Driver/Options.td

 def arch__errors__fatal : Flag<["-"], "arch_errors_fatal">;
 def arch : Separate<["-"], "arch">, Flags<[NoXarchOption]>;
 def arch__only : Separate<["-"], "arch_only">;
 def a : Joined<["-"], "a">;
 def autocomplete : Joined<["--"], "autocomplete=">;
 def bind__at__load : Flag<["-"], "bind_at_load">;
 def bundle__loader : Separate<["-"], "bundle_loader">;
 def bundle : Flag<["-"], "bundle">;
-def b : JoinedOrSeparate<["-"], "b">, Flags<[Unsupported]>;
+def b : JoinedOrSeparate<["-"], "b">, Flags<[LinkerInput, RenderAsInput]>,
+  HelpText<"Pass -b <arg> to the linker on AIX (only).">, MetaVarName<"<arg>">,
+  Group<Link_Group>;
 def cl_opt_disable : Flag<["-"], "cl-opt-disable">, Group<opencl_Group>, Flags<[CC1Option]>,
   HelpText<"OpenCL only. This option disables all optimizations. By default optimizations are enabled.">;
 def cl_strict_aliasing : Flag<["-"], "cl-strict-aliasing">, Group<opencl_Group>, Flags<[CC1Option]>,
   HelpText<"OpenCL only. This option is added for compatibility with OpenCL 1.0.">;
 def cl_single_precision_constant : Flag<["-"], "cl-single-precision-constant">, Group<opencl_Group>, Flags<[CC1Option]>,
   HelpText<"OpenCL only. Treat double precision floating-point constant as single precision constant.">,
   MarshallingInfoFlag<LangOpts<"SinglePrecisionConstants">>;
 def cl_finite_math_only : Flag<["-"], "cl-finite-math-only">, Group<opencl_Group>, Flags<[CC1Option]>,

clang/lib/Driver/ToolChains/CommonArgs.cpp

for (const auto &II : Inputs) {
     if (II.isFilename()) {
       CmdArgs.push_back(II.getFilename());
       continue;
     }
 
     // Otherwise, this is a linker input argument.
     const Arg &A = II.getInputArg();
 
+    if (A.getOption().matches(options::OPT_b)) {
+      const llvm::Triple &T = TC.getTriple();
+      if (!T.isOSAIX()) {
+        TC.getDriver().Diag(diag::err_drv_unsupported_opt_for_target)
+          << A.getSpelling() << T.str();
+      }
+      // Pass -b prefix for AIX linker.
+      A.claim();
+      A.render(Args, CmdArgs);
+    }
     // Handle reserved library options.
     if (A.getOption().matches(options::OPT_Z_reserved_lib_stdcxx))
       TC.AddCXXStdlibLibArgs(Args, CmdArgs);
     else if (A.getOption().matches(options::OPT_Z_reserved_lib_cckext))
       TC.AddCCKextLibArgs(Args, CmdArgs);
     else if (A.getOption().matches(options::OPT_z)) {
       // Pass -z prefix for gcc linker compatibility.
       A.claim();

clang/test/Driver/Xlinker-args.c

 // Check that we extract --no-demangle from '-Xlinker' and '-Wl,', since that
 // was a collect2 argument.
 
 // RUN: %clang -target i386-apple-darwin9 -### \
 // RUN:   -Xlinker one -Xlinker --no-demangle \
 // RUN:   -Wl,two,--no-demangle,three -Xlinker four -z five -r %s 2> %t
 // RUN: FileCheck -check-prefix=DARWIN < %t %s
 
 /// -T is reordered to the last to make sure -L takes precedence.
 // RUN: %clang -target x86_64-pc-linux-gnu -### \
 // RUN:   -e _start -T a.lds -Xlinker one -Xlinker --no-demangle \
 // RUN:   -Wl,two,--no-demangle,three -Xlinker four -z five -r %s 2> %t
 // RUN: FileCheck -check-prefix=LINUX < %t %s
-//
+
+// RUN: %clang -target powerpc-unknown-aix -### \
+// RUN:   -b one %s 2> %t
+// RUN: FileCheck -check-prefix=AIX < %t %s
+
+// RUN: %clang -target powerpc-unknown-linux -### \
+// RUN:   -b one %s 2> %t
+// RUN: FileCheck -check-prefix=NOT-AIX < %t %s
+
 // DARWIN-NOT: --no-demangle
 // DARWIN: "one" "two" "three" "four" "-z" "five" "-r"
 // LINUX: "--no-demangle" "-e" "_start" "one" "two" "three" "four" "-z" "five" "-r" {{.*}} "-T" "a.lds"
+// AIX: "-b" "one" 
+// NOT-AIX: error: unsupported option '-b' for target 'powerpc-unknown-linux'
 
 // Check that we forward '-Xlinker' and '-Wl,' on Windows.
 // RUN: %clang -target i686-pc-win32 -fuse-ld=link -### \
 // RUN:   -Xlinker one -Wl,two %s 2>&1 | \
 // RUN:   FileCheck -check-prefix=WIN %s
 // WIN: link.exe
 // WIN: "one"
 // WIN: "two"