spirv-val: Add an option to use friendly names or not (#4951)

The always-friendly messages make it harder to debug when the
disassembly is later generated without friendly names.

Additionally, the friendly-name-mapper is slow.  Disabling it improves
performance of an ANGLE test that creates numerous shaders by ~5%.

include/spirv-tools/libspirv.h

@@ -670,6 +670,10 @@ SPIRV_TOOLS_EXPORT void spvValidatorOptionsSetSkipBlockLayout(
 SPIRV_TOOLS_EXPORT void spvValidatorOptionsSetAllowLocalSizeId(
     spv_validator_options options, bool val);
 
+// Whether friendly names should be used in validation error messages.
+SPIRV_TOOLS_EXPORT void spvValidatorOptionsSetFriendlyNames(
+    spv_validator_options options, bool val);
+
 // Creates an optimizer options object with default options. Returns a valid
 // options object. The object remains valid until it is passed into
 // |spvOptimizerOptionsDestroy|.

include/spirv-tools/libspirv.hpp

@@ -148,6 +148,11 @@ class ValidatorOptions {
     spvValidatorOptionsSetBeforeHlslLegalization(options_, val);
   }
 
+  // Whether friendly names should be used in validation error messages.
+  void SetFriendlyNames(bool val) {
+    spvValidatorOptionsSetFriendlyNames(options_, val);
+  }
+
  private:
   spv_validator_options options_;
 };

source/spirv_validator_options.cpp

@@ -125,3 +125,8 @@ void spvValidatorOptionsSetAllowLocalSizeId(spv_validator_options options,
                                             bool val) {
   options->allow_localsizeid = val;
 }
+
+void spvValidatorOptionsSetFriendlyNames(spv_validator_options options,
+                                         bool val) {
+  options->use_friendly_names = val;
+}

source/spirv_validator_options.h

@@ -48,7 +48,8 @@ struct spv_validator_options_t {
         workgroup_scalar_block_layout(false),
         skip_block_layout(false),
         allow_localsizeid(false),
-        before_hlsl_legalization(false) {}
+        before_hlsl_legalization(false),
+        use_friendly_names(true) {}
 
   validator_universal_limits_t universal_limits_;
   bool relax_struct_store;
@@ -60,6 +61,7 @@ struct spv_validator_options_t {
   bool skip_block_layout;
   bool allow_localsizeid;
   bool before_hlsl_legalization;
+  bool use_friendly_names;
 };
 
 #endif  // SOURCE_SPIRV_VALIDATOR_OPTIONS_H_

source/val/validation_state.cpp

@@ -208,9 +208,12 @@ ValidationState_t::ValidationState_t(const spv_const_context ctx,
   }
   UpdateFeaturesBasedOnSpirvVersion(&features_, version_);
 
-  friendly_mapper_ = spvtools::MakeUnique<spvtools::FriendlyNameMapper>(
-      context_, words_, num_words_);
-  name_mapper_ = friendly_mapper_->GetNameMapper();
+  name_mapper_ = spvtools::GetTrivialNameMapper();
+  if (options_->use_friendly_names) {
+    friendly_mapper_ = spvtools::MakeUnique<spvtools::FriendlyNameMapper>(
+        context_, words_, num_words_);
+    name_mapper_ = friendly_mapper_->GetNameMapper();
+  }
 }
 
 void ValidationState_t::preallocateStorage() {