[LLD] [MinGW] Implement support for the --image-base option

[rnk]

lgtm

[ruiu]

LGTM

lld/trunk/MinGW/Driver.cpp

bool mingw::link(ArrayRef<const char *> ArgsArr, raw_ostream &Diag) {
   if (auto *A = Args.getLastArg(OPT_subs))
     Add("-subsystem:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_out_implib))
     Add("-implib:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_stack))
     Add("-stack:" + StringRef(A->getValue()));
   if (auto *A = Args.getLastArg(OPT_output_def))
     Add("-output-def:" + StringRef(A->getValue()));
+  if (auto *A = Args.getLastArg(OPT_image_base))
+    Add("-base:" + StringRef(A->getValue()));
 
   if (auto *A = Args.getLastArg(OPT_o))
     Add("-out:" + StringRef(A->getValue()));
   else if (Args.hasArg(OPT_shared))
     Add("-out:a.dll");
   else
     Add("-out:a.exe");
 

lld/trunk/MinGW/Options.td

 include "llvm/Option/OptParser.td"
 
 class F<string name>: Flag<["--", "-"], name>;
 class J<string name>: Joined<["--", "-"], name>;
 class S<string name>: Separate<["--", "-"], name>;
 
 def L: JoinedOrSeparate<["-"], "L">, MetaVarName<"<dir>">,
   HelpText<"Add a directory to the library search path">;
 def dynamicbase: F<"dynamicbase">, HelpText<"Enable ASLR">;
 def entry: S<"entry">, MetaVarName<"<entry>">,
   HelpText<"Name of entry point symbol">;
 def export_all_symbols: F<"export-all-symbols">,
     HelpText<"Export all symbols even if a def file or dllexport attributes are used">;
+def image_base: S<"image-base">, HelpText<"Base address of the program">;
 def l: JoinedOrSeparate<["-"], "l">, MetaVarName<"<libName>">,
   HelpText<"Root name of library to use">;
 def m: JoinedOrSeparate<["-"], "m">, HelpText<"Set target emulation">;
 def no_whole_archive: F<"no-whole-archive">,
     HelpText<"No longer include all object files for following archives">;
 def large_address_aware: Flag<["--"], "large-address-aware">,
     HelpText<"Enable large addresses">;
 def o: JoinedOrSeparate<["-"], "o">, MetaVarName<"<path>">,

lld/trunk/test/MinGW/driver.test

 RUN: ld.lld -### -m i386pep foo.o | FileCheck -check-prefix DEFAULT-DISABLE-FLAGS %s
 DEFAULT-DISABLE-FLAGS: -dynamicbase:no
 
 # The extra '-' in the following check pattern is intentional, to make sure
 # that a check for "-dynamicbase" doesn't match the default "-dynamicbase:no".
 RUN: ld.lld -### -m i386pep foo.o --dynamicbase | FileCheck -check-prefix DYNAMICBASE %s
 RUN: ld.lld -### -m i386pep foo.o -dynamicbase | FileCheck -check-prefix DYNAMICBASE %s
 DYNAMICBASE: -dynamicbase -
+
+RUN: ld.lld -### -m i386pep foo.o --image-base 0x1230000 | FileCheck -check-prefix IMAGE-BASE %s
+RUN: ld.lld -### -m i386pep foo.o -image-base 0x1230000 | FileCheck -check-prefix IMAGE-BASE %s
+IMAGE-BASE: -base:0x1230000