[RISCV] Pass -u to linker correctly.

[kito-cheng]

Summary

-u is a linker option used to pretend a symbol is undefined,
this option are common used for forcing archive member extraction.

This option should pass to ld, and many other toolchain in Clang
like tools::gnutools has pass that too.

[MaskRay]

-u is a linker option used to pretend a symbol is undefined, this option are common used for force pull-in weak symbol.

for forcing archive member extraction.

weak symbols are somewhat orthogonal.

clang/test/Driver/riscv-args.c

4

Just place all linker options on one run line.

It decreases the number of RUN lines and additionally checks the order (though usually unimportant).

[kito-cheng]

Address @MaskRay's comment

[MaskRay]

clang/test/Driver/riscv-args.c

4

The test hasn't been updated?

[kito-cheng]

clang/test/Driver/riscv-args.c

4

Oh, I only update the testcase I added.

[kito-cheng]

Update testcase.

[MaskRay]

clang/test/Driver/riscv-args.c

4

You can place all link options on the same RUN line.

This additionally checks the order.

[kito-cheng]

Changes:

• Add 2 testcases

[MaskRay]

The update was not what I expected. I said that there should be just one RUN line and you can place -T, -u, --defsym and all other linker options on that line.

This additionally allows us to get a sense of the order.

Each new RUN line consumes some resources on testing machines.

[kito-cheng]

Changes:

• Update testcase again.

clang/lib/Driver/ToolChains/RISCVToolchain.cpp

void RISCV::Linker::ConstructJob(Compilation &C, const JobAction &JA,
   if (WantCRTs) {
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath("crt0.o")));
     CmdArgs.push_back(Args.MakeArgString(ToolChain.GetFilePath(crtbegin)));
   }
 
   AddLinkerInputs(ToolChain, Inputs, Args, CmdArgs, JA);
 
   Args.AddAllArgs(CmdArgs, options::OPT_L);
+  Args.AddAllArgs(CmdArgs, options::OPT_u);
   ToolChain.AddFilePathLibArgs(Args, CmdArgs);
   Args.AddAllArgs(CmdArgs,
                   {options::OPT_T_Group, options::OPT_e, options::OPT_s,
                    options::OPT_t, options::OPT_Z_Flag, options::OPT_r});
 
   // TODO: add C++ includes and libs if compiling C++.
 
   if (!Args.hasArg(options::OPT_nostdlib) &&

clang/test/Driver/riscv-args.c

 // Check the arguments are correctly passed
 
 // Make sure -T is the last with gcc-toolchain option
-// RUN: %clang -### -target riscv32 \
-// RUN:   --gcc-toolchain= -Xlinker --defsym=FOO=10 -T a.lds %s 2>&1 \
+// RUN: %clang -### -target riscv32 --gcc-toolchain= -Xlinker --defsym=FOO=10 -T a.lds -u foo %s 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-LD %s
-// CHECK-LD: {{.*}} "--defsym=FOO=10" {{.*}} "-T" "a.lds"
+// CHECK-LD: {{.*}} "--defsym=FOO=10" {{.*}} "-u" "foo" {{.*}} "-T" "a.lds"