[spirv] Fail when unsupported options are used (#4518)

Some DXC options are not supported in combination with the SPIR-V
backend. Rather than silently ignore them, we should emit a clear error
message. This change adds appropriate error messages for a couple
options that have been mentioned in issues #3111 and #4496, but more
should be added in future.

Author: sudonatalie

lib/DxcSupport/HLSLOptions.cpp

@@ -322,14 +322,34 @@ static bool handleVkShiftArgs(const InputArgList &args, OptSpecifier id,
   return true;
 }
 
+// Check if any options that are unsupported with SPIR-V are used.
+static bool hasUnsupportedSpirvOption(const InputArgList &args,
+                                      llvm::raw_ostream &errors) {
+  // Note: The options checked here are non-exhaustive. A thorough audit of
+  // available options and their current compatibility is needed to generate a
+  // complete list.
+  std::vector<OptSpecifier> unsupportedOpts = {OPT_Fd, OPT_Fre,
+                                               OPT_Qstrip_reflect};
+
+  for (const auto &id : unsupportedOpts) {
+    if (Arg *arg = args.getLastArg(id)) {
+      errors << "-" << arg->getOption().getName()
+             << " is not supported with -spirv";
+      return true;
+    }
+  }
+
+  return false;
+}
+
 namespace {
 
 /// Maximum size of OpString instruction minus two operands
 static const uint32_t kDefaultMaximumSourceLength = 0xFFFDu;
 static const uint32_t kTestingMaximumSourceLength = 13u;
 
 }
-#endif
+#endif // ENABLE_SPIRV_CODEGEN
 // SPIRV Change Ends
 
 namespace hlsl {
@@ -1071,6 +1091,11 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
   opts.SpirvOptions.entrypointName =
       Args.getLastArgValue(OPT_fspv_entrypoint_name_EQ);
 
+  // Check for use of options not implemented in the SPIR-V backend.
+  if (Args.hasFlag(OPT_spirv, OPT_INVALID, false) &&
+      hasUnsupportedSpirvOption(Args, errors))
+    return 1;
+
 #else
   if (Args.hasFlag(OPT_spirv, OPT_INVALID, false) ||
       Args.hasFlag(OPT_fvk_invert_y, OPT_INVALID, false) ||

tools/clang/test/CodeGenSPIRV/spirv.opt.fd.hlsl

@@ -0,0 +1,5 @@
+// RUN: %dxc -T ps_6_0 -E main -spirv -Fd file.ext
+
+void main() {}
+
+// CHECK: -Fd is not supported with -spirv

tools/clang/test/CodeGenSPIRV/spirv.opt.fre.hlsl

@@ -0,0 +1,5 @@
+// RUN: %dxc -T ps_6_0 -E main -spirv -Fre file.ext
+
+void main() {}
+
+// CHECK: -Fre is not supported with -spirv

tools/clang/test/CodeGenSPIRV/spirv.opt.qstripreflect.hlsl

@@ -0,0 +1,5 @@
+// RUN: %dxc -T ps_6_0 -E main -spirv -Qstrip_reflect
+
+void main() {}
+
+// CHECK: -Qstrip_reflect is not supported with -spirv

tools/clang/unittests/SPIRV/CodeGenSpirvTest.cpp

@@ -3131,4 +3131,14 @@ TEST_F(FileTest, RenameEntrypoint) { runFileTest("fspv-entrypoint-name.hlsl"); }
 
 TEST_F(FileTest, PrintAll) { runFileTest("fspv-print-all.hlsl"); }
 
+TEST_F(FileTest, SpirvOptFd) {
+  runFileTest("spirv.opt.fd.hlsl", Expect::Failure);
+}
+TEST_F(FileTest, SpirvOptFre) {
+  runFileTest("spirv.opt.fre.hlsl", Expect::Failure);
+}
+TEST_F(FileTest, SpirvOptQStripReflect) {
+  runFileTest("spirv.opt.qstripreflect.hlsl", Expect::Failure);
+}
+
 } // namespace