Rename GN source_prereqs to inputs, enhance "desc"

tools/gn/target_generator.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/target_generator.h"
 
 #include "tools/gn/action_target_generator.h"
 #include "tools/gn/binary_target_generator.h"
 #include "tools/gn/build_settings.h"
 #include "tools/gn/config.h"
@@ skipping 142 matching lines @@
   // If the public headers are defined, don't default to public.
   target_->set_all_headers_public(false);
 
   Target::FileList dest_public;
   if (!ExtractListOfRelativeFiles(scope_->settings()->build_settings(), *value,
                                   scope_->GetSourceDir(), &dest_public, err_))
     return;
   target_->public_headers().swap(dest_public);
 }
 
-void TargetGenerator::FillSourcePrereqs() {
-  const Value* value = scope_->GetValue(variables::kSourcePrereqs, true);
-  if (!value)
+void TargetGenerator::FillInputs() {
+  const Value* value = scope_->GetValue(variables::kInputs, true);
+  if (!value) {
+    // Older versions used "source_prereqs". Allow use of this variable until
+    // all callers are updated.
+    // TODO(brettw) remove this eventually.
+    value = scope_->GetValue("source_prereqs", true);
+
+    if (!value)
+      return;
+  }
+
+  Target::FileList dest_inputs;
+  if (!ExtractListOfRelativeFiles(scope_->settings()->build_settings(), *value,
+                                  scope_->GetSourceDir(), &dest_inputs, err_))
     return;
-
-  Target::FileList dest_reqs;
-  if (!ExtractListOfRelativeFiles(scope_->settings()->build_settings(), *value,
-                                  scope_->GetSourceDir(), &dest_reqs, err_))
-    return;
-  target_->source_prereqs().swap(dest_reqs);
+  target_->inputs().swap(dest_inputs);
 }
 
 void TargetGenerator::FillConfigs() {
   FillGenericConfigs(variables::kConfigs, &target_->configs());
 }
 
 void TargetGenerator::FillDependentConfigs() {
   FillGenericConfigs(variables::kAllDependentConfigs,
                      &target_->all_dependent_configs());
   FillGenericConfigs(variables::kDirectDependentConfigs,
@@ skipping 68 matching lines @@
 
 void TargetGenerator::FillForwardDependentConfigs() {
   const Value* value = scope_->GetValue(
       variables::kForwardDependentConfigsFrom, true);
   if (value) {
     ExtractListOfLabels(*value, scope_->GetSourceDir(),
                         ToolchainLabelForScope(scope_),
                         &target_->forward_dependent_configs(), err_);
   }
 }