Index: clang/lib/Driver/ToolChains/Clang.cpp
===================================================================
--- clang/lib/Driver/ToolChains/Clang.cpp
+++ clang/lib/Driver/ToolChains/Clang.cpp
@@ -4921,6 +4921,12 @@
   if (D.CCGenDiagnostics)
     CmdArgs.push_back("-disable-pragma-debug-crash");
 
+  if (RawTriple.isOSAIX())
+    if (Arg *A = Args.getLastArg(options::OPT_G)) {
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << A->getSpelling() << RawTriple.str();
+    }
+
   bool UseSeparateSections = isUseSeparateSections(Triple);
 
   if (Args.hasFlag(options::OPT_ffunction_sections,
Index: clang/test/Driver/aix-err-options.c
===================================================================
--- /dev/null
+++ clang/test/Driver/aix-err-options.c
@@ -0,0 +1,7 @@
+// RUN: %clang -target powerpc32-ibm-aix-xcoff -### -S -emit-llvm -G 0 2>&1 %s | \
+// RUN:   FileCheck -check-prefix=CHECK32 %s
+// RUN: %clang -target powerpc64-ibm-aix-xcoff -### -S -emit-llvm -G 0 2>&1 %s | \
+// RUN:   FileCheck -check-prefix=CHECK64 %s
+
+// CHECK32: error: unsupported option '-G' for target 'powerpc32-ibm-aix-xcoff'
+// CHECK64: error: unsupported option '-G' for target 'powerpc64-ibm-aix-xcoff'
Index: llvm/CMakeLists.txt
===================================================================
--- llvm/CMakeLists.txt
+++ llvm/CMakeLists.txt
@@ -930,7 +930,7 @@
 
   # Modules should be built with -G, so we can use runtime linking with
   # plugins.
-  string(APPEND CMAKE_MODULE_LINKER_FLAGS " -G")
+  string(APPEND CMAKE_MODULE_LINKER_FLAGS " -Wl,-G")
 
   # Also set the correct flags for building shared libraries.
   string(APPEND CMAKE_SHARED_LINKER_FLAGS " -shared")