[gn build] Don't pass -Wl,-z,defs for sanitizer builds

-Wl,-z,defs doesn't work with sanitizers.
See https://clang.llvm.org/docs/AddressSanitizer.html

Reviewed By: thakis

Differential Revision: https://reviews.llvm.org/D110086

llvm/utils/gn/build/BUILD.gn

@@ -370,6 +370,14 @@ config("no_rtti") {
   cflags_objcc = cflags_cc
 }
 
+config("zdefs") {
+  # -Wl,-z,defs doesn't work with sanitizers.
+  # https://clang.llvm.org/docs/AddressSanitizer.html
+  if (current_os != "ios" && current_os != "mac" && current_os != "win" && !(use_asan || use_tsan || use_ubsan)) {
+    ldflags = [ "-Wl,-z,defs" ]
+  }
+}
+
 # To make an archive that can be distributed, you need to remove this config and
 # set complete_static_lib.
 config("thin_archive") {

llvm/utils/gn/build/BUILDCONFIG.gn

@@ -22,7 +22,7 @@ set_defaults("static_library") {
   configs = shared_binary_target_configs
 }
 set_defaults("shared_library") {
-  configs = shared_binary_target_configs
+  configs = shared_binary_target_configs + [ "//llvm/utils/gn/build:zdefs" ]
 }
 set_defaults("source_set") {
   configs = shared_binary_target_configs

llvm/utils/gn/build/toolchain/BUILD.gn

@@ -109,7 +109,7 @@ template("unix_toolchain") {
         command = "$ld -shared {{ldflags}} -o $outfile {{inputs}} {{libs}} {{frameworks}}"
         default_output_extension = ".dylib"
       } else {
-        command = "$ld -shared {{ldflags}} -Wl,-z,defs -Wl,-soname,{{target_output_name}}{{output_extension}} -o $outfile {{inputs}} {{libs}}"
+        command = "$ld -shared {{ldflags}} -Wl,-soname,{{target_output_name}}{{output_extension}} -o $outfile {{inputs}} {{libs}}"
         default_output_extension = ".so"
       }
       description = "SOLINK $outfile"