[Frontend] Forbid IR generation with -check-api-availability-only

Author: xymus

include/swift/AST/DiagnosticsFrontend.def

@@ -136,6 +136,9 @@ ERROR(error_mode_cannot_emit_module_semantic_info,none,
 ERROR(cannot_emit_ir_skipping_function_bodies,none,
       "the -experimental-skip-*-function-bodies* flags do not support "
       "emitting IR", ())
+ERROR(cannot_emit_ir_checking_api_availability_only,none,
+      "the flag -check-api-availability-only does not support "
+      "emitting IR", ())
 
 WARNING(emit_reference_dependencies_without_primary_file,none,
         "ignoring -emit-reference-dependencies (requires -primary-file)", ())

lib/Frontend/ArgsToFrontendOptionsConverter.cpp

@@ -229,13 +229,19 @@ bool ArgsToFrontendOptionsConverter::convert(
   if (checkUnusedSupplementaryOutputPaths())
     return true;
 
-  if (FrontendOptions::doesActionGenerateIR(Opts.RequestedAction) &&
-      (Args.hasArg(OPT_experimental_skip_non_inlinable_function_bodies) ||
-       Args.hasArg(OPT_experimental_skip_all_function_bodies) ||
-       Args.hasArg(
-         OPT_experimental_skip_non_inlinable_function_bodies_without_types))) {
-    Diags.diagnose(SourceLoc(), diag::cannot_emit_ir_skipping_function_bodies);
-    return true;
+  if (FrontendOptions::doesActionGenerateIR(Opts.RequestedAction)) {
+    if (Args.hasArg(OPT_experimental_skip_non_inlinable_function_bodies) ||
+        Args.hasArg(OPT_experimental_skip_all_function_bodies) ||
+        Args.hasArg(
+         OPT_experimental_skip_non_inlinable_function_bodies_without_types)) {
+      Diags.diagnose(SourceLoc(), diag::cannot_emit_ir_skipping_function_bodies);
+      return true;
+    }
+
+    if (Args.hasArg(OPT_check_api_availability_only)) {
+      Diags.diagnose(SourceLoc(), diag::cannot_emit_ir_checking_api_availability_only);
+      return true;
+    }
   }
 
   if (const Arg *A = Args.getLastArg(OPT_module_abi_name))

test/Sema/api-availability-only.swift

@@ -3,6 +3,9 @@
 
 // RUN: %target-typecheck-verify-swift -module-name MyModule -target %target-cpu-apple-macosx10.15 -check-api-availability-only -enable-library-evolution
 
+// RUN: not %target-build-swift -emit-executable %s -g -o %t -emit-module -Xfrontend -check-api-availability-only 2>&1 | %FileCheck %s
+// CHECK: the flag -check-api-availability-only does not support emitting IR
+
 // REQUIRES: OS=macosx
 
 @available(macOS 11.0, *)