various small tweaks to blink's gperf use

* make gperf.py call generate_gperf() both when it's invoked via
  use_jinja_gperf_template() as well as when it's called directly
  as a standalone script

* make generate_gperf() do massaging of gperf's output to remove
  uses of the `register` keyword (needed to build with -std=c++17)
  and replace `/*FALLTHROUGH*/` with real FALLTHROUGH statements
  (needed for -Wimplicit-fallthrough)

* remove now-unneeded suppressions for -Wdeprecated-register

* remove TODO about removing gperf.py; that's from a time when the
  script was 1 non-comment line long

* bump check_output() requirement in comment to 3.4 (since that added
  the input= parameter)

* add missing dependency on gperf.py to build steps calling it
  through the jinja interface, so that these edges rerun when
  gperf.py gets modified

* add a comment mentioning gperf.py at the start of the generated
  outputs

* make :character_data not call gperf.py since it doesn't use gperf,
  and make it use compiled_action() instead which is made for
  exactly character_data's use case

No intended behavior change.

Bug: 752720,177475
Change-Id: I56372729bb47787e2d41a5dff2f30804574770f0
Reviewed-on: https://chromium-review.googlesource.com/891141
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Darren Shen <shend@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533269}

third_party/WebKit/Source/build/scripts/core/css/parser/templates/AtRuleDescriptors.cpp.tmpl

@@ -14,12 +14,6 @@
 #pragma warning(disable : 4302 4311)
 #endif
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-// TODO(thakis): Remove once we use a gperf that no longer produces "register".
-#pragma clang diagnostic ignored "-Wdeprecated-register"
-#endif
-
 namespace blink {
 
 namespace {
@@ -48,10 +42,6 @@ struct Property;
 {% endfor %}
 %%
 
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-
 const Property* FindDescriptor(const char* str, unsigned int len) {
   return AtRuleDescriptorHash::findDescriptorImpl(str, len);
 }

third_party/WebKit/Source/build/scripts/core/css/templates/CSSValueKeywords.cpp.tmpl

@@ -14,12 +14,6 @@
 #pragma warning(disable : 4302 4311)
 #endif
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-// TODO(thakis): Remove once we use a gperf that no longer produces "register".
-#pragma clang diagnostic ignored "-Wdeprecated-register"
-#endif
-
 namespace blink {
 static const char valueListStringPool[] = {
 {% for keyword in value_keywords %}
@@ -53,10 +47,6 @@ struct Value;
 {% endfor %}
 %%
 
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-
 const Value* FindValue(const char* str, unsigned int len) {
   return CSSValueKeywordsHash::findValueImpl(str, len);
 }

third_party/WebKit/Source/build/scripts/gperf.py

@@ -4,24 +4,18 @@
 
 # Invokes gperf for the GN build.
 # Usage: gperf.py [--developer_dir PATH_TO_XCODE] gperf ...
-# TODO(brettw) this can be removed once the run_executable rules have been
-# checked in for the GN build.
 
 import argparse
 import os
+import re
 import subprocess
 import sys
 import template_expander
 
 
-def generate_gperf(gperf_path, gperf_input, extra_args=None):
-    # FIXME: If we could depend on Python 2.7, we would use
+def generate_gperf(gperf_path, gperf_input, gperf_args):
+    # FIXME: If we could depend on Python 3.4, we would use
     # subprocess.check_output
-    gperf_args = [gperf_path, '--key-positions=*', '-P', '-n']
-    gperf_args.extend(['-m', '50'])  # Pick best of 50 attempts.
-    gperf_args.append('-D')  # Allow duplicate hashes -> More compact code.
-    if extra_args:
-        gperf_args.extend(extra_args)
 
     # If gperf isn't in the path we get an OSError. We don't want to use
     # the normal solution of shell=True (as this has to run on many
@@ -29,11 +23,23 @@ def generate_gperf(gperf_path, gperf_input, extra_args=None):
     # CalledProcessError like subprocess would do when shell=True is set.
     try:
         gperf = subprocess.Popen(
-            gperf_args,
+            [gperf_path] + gperf_args,
             stdin=subprocess.PIPE,
             stdout=subprocess.PIPE,
             universal_newlines=True)
-        return gperf.communicate(gperf_input)[0]
+        gperf_output = gperf.communicate(gperf_input)[0]
+        # Massage gperf output to be more palatable for modern compilers.
+        # TODO(thakis): Upstream these to gperf so we don't need massaging.
+        # `register` is deprecated in C++11 and removed in C++17, so remove
+        # it from gperf's output.
+        # https://savannah.gnu.org/bugs/index.php?53029
+        gperf_output = re.sub(r'\bregister ', '', gperf_output)
+        # -Wimplicit-fallthrough needs an explicit fallthrough statement,
+        # so replace gperf's /*FALLTHROUGH*/ comment with the statement.
+        # https://savannah.gnu.org/bugs/index.php?53028
+        gperf_output = gperf_output.replace('/*FALLTHROUGH*/', '  FALLTHROUGH;')
+        script = 'third_party/WebKit/Source/build/scripts/gperf.py'
+        return '// Generated by %s\n' % script + gperf_output
     except OSError:
         raise subprocess.CalledProcessError(
             127, gperf_args, output='Command not found.')
@@ -48,7 +54,12 @@ def use_jinja_gperf_template(template_path, gperf_extra_args=None):
             gperf_path = parameters['gperf_path']
             gperf_input = template_expander.apply_template(template_path,
                                                            parameters)
-            return generate_gperf(gperf_path, gperf_input, gperf_extra_args)
+            gperf_args = ['--key-positions=*', '-P', '-n']
+            gperf_args.extend(['-m', '50'])  # Pick best of 50 attempts.
+            gperf_args.append('-D')  # Allow duplicate hashes -> More compact code.
+            if gperf_extra_args:
+                gperf_args.extend(gperf_extra_args)
+            return generate_gperf(gperf_path, gperf_input, gperf_args)
         generator_internal.func_name = generator.func_name
         return generator_internal
     return wrapper
@@ -57,11 +68,21 @@ def use_jinja_gperf_template(template_path, gperf_extra_args=None):
 def main():
     parser = argparse.ArgumentParser()
     parser.add_argument("--developer_dir", required=False)
+    parser.add_argument("--output-file")
     args, unknownargs = parser.parse_known_args()
     if args.developer_dir:
         os.environ['DEVELOPER_DIR'] = args.developer_dir
 
-    subprocess.check_call(unknownargs)
+    gperf_path, gperf_args = unknownargs[0], unknownargs[1:]
+    infile = None
+    for arg in gperf_args:
+        if os.path.isfile(arg):
+            assert infile is None, 'duplicate inputs? %s, %s' % (infile, arg)
+            infile = arg
+    assert infile is not None, 'no input found'
+
+    open(args.output_file, 'wb').write(
+        generate_gperf(gperf_path, open(infile).read(), gperf_args))
 
 if __name__ == '__main__':
     main()

third_party/WebKit/Source/build/scripts/templates/CSSPropertyNames.cpp.tmpl

@@ -18,12 +18,6 @@
 #pragma warning(disable : 4302 4311)
 #endif
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-// TODO(thakis): Remove once we use a gperf that no longer produces "register".
-#pragma clang diagnostic ignored "-Wdeprecated-register"
-#endif
-
 namespace blink {
 %}
 %struct-type
@@ -43,10 +37,6 @@ struct Property;
 {{property_to_enum_map}}
 %%
 
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-
 const Property* FindProperty(const char* str, unsigned int len) {
   return {{class_name}}Hash::findPropertyImpl(str, len);
 }

third_party/WebKit/Source/core/BUILD.gn

@@ -1098,6 +1098,7 @@ css_properties("make_core_generated_css_shorthand_property_classes") {
 css_properties("make_core_generated_css_property_names") {
   script = "../build/scripts/make_css_property_names.py"
   other_inputs = [
+    "../build/scripts/gperf.py",
     "../build/scripts/templates/CSSPropertyNames.cpp.tmpl",
     "../build/scripts/templates/CSSPropertyNames.h.tmpl",
   ]
@@ -1110,6 +1111,7 @@ css_properties("make_core_generated_css_property_names") {
 code_generator("make_core_generated_atrule_names") {
   script = "../build/scripts/core/css/parser/make_atrule_names.py"
   json_inputs = [ "css/parser/AtRuleNames.json5" ]
+  other_inputs = [ "../build/scripts/gperf.py" ]
   templates = [
     "../build/scripts/core/css/parser/templates/AtRuleDescriptors.cpp.tmpl",
     "../build/scripts/core/css/parser/templates/AtRuleDescriptors.h.tmpl",
@@ -1177,6 +1179,7 @@ code_generator("make_core_generated_css_value_keywords") {
     "css/CSSValueKeywords.json5",
     "css/SVGCSSValueKeywords.json5",
   ]
+  other_inputs = [ "../build/scripts/gperf.py" ]
   templates = [
     "../build/scripts/core/css/templates/CSSValueKeywords.cpp.tmpl",
     "../build/scripts/core/css/templates/CSSValueKeywords.h.tmpl",

third_party/WebKit/Source/platform/BUILD.gn

@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
+import("//build/compiled_action.gni")
 import("//build/config/features.gni")
 import("//build/config/jumbo.gni")
 import("//build/config/ui.gni")
@@ -93,26 +94,12 @@ action("color_data") {
   ]
 }
 
-action("character_data") {
-  script = "../build/scripts/gperf.py"
-  deps = [
-    ":character_data_generator($host_toolchain)",
-  ]
-  output_file = "$blink_platform_output_dir/CharacterPropertyData.cpp"
+compiled_action("character_data") {
+  tool = ":character_data_generator"
   outputs = [
-    output_file,
-  ]
-
-  # Find character_data_generator, which is generated in a different directory
-  # when cross-compile.
-  generator = "./" + rebase_path(
-                  get_label_info(":character_data_generator($host_toolchain)",
-                                 "root_out_dir") + "/character_data_generator",
-                  root_build_dir)
-  args = [
-    generator,
-    rebase_path(output_file, root_build_dir),
+    "$blink_platform_output_dir/CharacterPropertyData.cpp",
   ]
+  args = rebase_path(outputs, root_build_dir)
 }
 
 action("instrumentation_probes") {

third_party/WebKit/Source/platform/ColorData.gperf

@@ -4,12 +4,6 @@
 
 namespace blink {
 
-#if defined(__clang__)
-#pragma clang diagnostic push
-// TODO(thakis): Remove once we use a gperf that no longer produces "register".
-#pragma clang diagnostic ignored "-Wdeprecated-register"
-#endif
-
 %}
 %struct-type
 struct NamedColor;
@@ -176,10 +170,6 @@ yellow, 0xffffff00
 yellowgreen, 0xff9acd32
 %%
 
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-
 const struct NamedColor* FindColor(const char* str, unsigned len) {
   return ColorDataHash::findColorImpl(str, len);
 }