[ELF] - handle of command line options incompatible with -r

[grimar]

Summary

I would like to prepare a serie of patches to improve -r support.
This one handles the all incompatible command line options.

[ruiu]

LGTM

ELF/Driver.cpp

144

I'd use early return here.

if (Config->Relocatable)
  return;
if (Config->Shared)
  ....

test/ELF/relocatable-errors.s

1–2

Please add this to driver.test instead of to a new file.

[grimar]

ELF/Driver.cpp

144

Done.

test/ELF/relocatable-errors.s

1–2

Done.

ELF/Driver.cpp

static void checkOptions(opt::InputArgList &Args) {
   // The MIPS ABI as of 2016 does not support the GNU-style symbol lookup
   // table which is a relatively new feature.
   if (Config->EMachine == EM_MIPS && Config->GnuHash)
     error("The .gnu.hash section is not compatible with the MIPS target.");
 
   if (Config->EMachine == EM_AMDGPU && !Config->Entry.empty())
     error("-e option is not valid for AMDGPU.");
 
-  if (Config->Relocatable && Config->Shared)
+  if (Config->Relocatable) {
+    if (Config->Shared)
       error("-r and -shared may not be used together");
+    if (Config->GcSections)
+      error("-r and --gc-sections may not be used together");
+    if (Config->ICF)
+      error("-r and --icf may not be used together");
+  }
 }
 
 static StringRef
 getString(opt::InputArgList &Args, unsigned Key, StringRef Default = "") {
   if (auto *Arg = Args.getLastArg(Key))
     return Arg->getValue();
   return Default;
 }

test/ELF/relocatable-errors.s

+# REQUIRES: x86
+# RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t1.o
+
+## Attempt to link DSO with -r
+# RUN: ld.lld -shared %t1.o -o %t.so
+# RUN: not ld.lld -r %t.so %t1.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR %s
+# ERR: Attempted static link of dynamic object
+
+## Attempt to use -r and -shared together
+# RUN: not ld.lld -r -shared %t1.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR2 %s
+# ERR2: -r and -shared may not be used together
+
+## Attempt to use -r and --gc-sections together
+# RUN: not ld.lld -r --gc-sections %t1.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR3 %s
+# ERR3: -r and --gc-sections may not be used together
+
+## Attempt to use -r and --icf together
+# RUN: not ld.lld -r --icf=all %t1.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR4 %s
+# ERR4: -r and --icf may not be used together
+
+.text
+.globl main
+.type main,@function
+main:
+

test/ELF/relocatable.s

 # RUN: ld.lld --relocatable %t1.o %t2.o %t3.o -o %t
 # RUN: llvm-readobj -file-headers -sections -program-headers -symbols -r %t | FileCheck %s
 # RUN: llvm-objdump -s -d %t | FileCheck -check-prefix=CHECKTEXT %s
 
 ## Verify that we can use our relocation output as input to produce executable
 # RUN: ld.lld -e main %t -o %texec
 # RUN: llvm-readobj -file-headers %texec | FileCheck -check-prefix=CHECKEXE %s
 
-## Attempt to link DSO with -r
-# RUN: ld.lld -shared %t1.o -o %t.so
-# RUN: not ld.lld -r %t.so %t2.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR %s
-# ERR: Attempted static link of dynamic object
-
-## Attempt to use -r and shared together
-# RUN: not ld.lld -r -shared %t2.o -o %tfail 2>&1 | FileCheck -check-prefix=ERR2 %s
-# ERR2: -r and -shared may not be used together
-
 # CHECK:       ElfHeader {
 # CHECK-NEXT:  Ident {
 # CHECK-NEXT:    Magic: (7F 45 4C 46)
 # CHECK-NEXT:    Class: 64-bit
 # CHECK-NEXT:    DataEncoding: LittleEndian
 # CHECK-NEXT:    FileVersion: 1
 # CHECK-NEXT:    OS/ABI: SystemV
 # CHECK-NEXT:    ABIVersion: 0