Handle -G as an alias to -shared

[• espindola]

Summary

bfd handles -G without a value as meaning -shared.

It looks like gold only support -G as an alias to -shared.

The java3d packages uses -G instead of -shared.

This patch changes lld to handle -G as an alias to -shared. This means we would now error on "-G 123". How common is it for programs to use it meaning --gpsize?

[• rafael]

sending email to llvm-commits

[davide]

test/ELF/g-is-shared.s

6

You mean equivalent to -shared ?

[• rafael]

fix comment

[atanasyan]

This patch changes lld to handle -G as an alias to -shared. This means we would now error on "-G 123". How common is it for programs to use it meaning --gpsize?

On MIPS this option is rarely used for regular programs, but in case of Linux kernel build, embedded software etc it is commonly used. So it is better to continue ignore a numeric argument.

ELF/Options.td

 def alias_pie_pic_executable: F<"pic-executable">, Alias<pie>;
 def alias_print_map_M: Flag<["-"], "M">, Alias<print_map>;
 def alias_relocatable_r: Flag<["-"], "r">, Alias<relocatable>;
 def alias_retain_symbols_file: S<"retain-symbols-file">, Alias<retain_symbols_file>;
 def alias_rpath_R: JoinedOrSeparate<["-"], "R">, Alias<rpath>;
 def alias_rpath_rpath: J<"rpath=">, Alias<rpath>;
 def alias_script_T: JoinedOrSeparate<["-"], "T">, Alias<script>;
 def alias_shared_Bshareable: F<"Bshareable">, Alias<shared>;
+def alias_shared_G: F<"G">, Alias<shared>;
 def alias_soname_h: JoinedOrSeparate<["-"], "h">, Alias<soname>;
 def alias_soname_soname: S<"soname">, Alias<soname>;
 def alias_sort_section: J<"sort-section=">, Alias<sort_section>;
 def alias_script: J<"script=">, Alias<script>;
 def alias_strip_all: Flag<["-"], "s">, Alias<strip_all>;
 def alias_strip_debug_S: Flag<["-"], "S">, Alias<strip_debug>;
 def alias_Tbss: J<"Tbss=">, Alias<Tbss>;
 def alias_Tdata: J<"Tdata=">, Alias<Tdata>;

 def rpath_link: S<"rpath-link">;
 def rpath_link_eq: J<"rpath-link=">;
 def sort_common: F<"sort-common">;
 def stats: F<"stats">;
 def warn_execstack: F<"warn-execstack">;
 def warn_shared_textrel: F<"warn-shared-textrel">;
 def EB : F<"EB">;
 def EL : F<"EL">;
-def G: JoinedOrSeparate<["-"], "G">;
 def Qy : F<"Qy">;
 
 // Aliases for ignored options
 def alias_version_script_version_script: J<"version-script=">,
   Alias<version_script>;
 
 // LTO-related options.
 def lto_aa_pipeline: J<"lto-aa-pipeline=">,

test/ELF/g-is-shared.s

+# REQUIRES: x86
+
+# RUN: llvm-mc -filetype=obj -triple=x86_64-pc-linux %s -o %t.o
+
+# The -G option without any value is equivalent to -shared.
+# RUN: ld.lld -G %t.o -o %t.so
+# RUN: llvm-readobj -file-headers %t.so | FileCheck %s
+# CHECK: Type: SharedObject