Reapply "Remove unassigned event log tags feature"

.logtags files are a mapping of an integer -> name. However, there
is an unused feature where you could put a '?' instead of an integer,
and then the build system would assign a number to it, taking care
to avoid all other already-assigned numbers across the source tree.

This feature makes it hard to support some things we're working towards,
like incremental soong and treble common system images, so remove it.

Also modernize the python scripts a little.

The additions since the revert are the cleanups from aosp/3403019, and
removing a missed reference to all-event-log-tags.txt in java.mk.

This reverts commit 07a79235798c369752b3f003be7326e219f992b8.

Bug: 382515940
Test: m event-log-tags on an internal product
Change-Id: I8f8674e65482816e56d44c5e8ae81d2230575cc6

8 files changed, 53 insertions, 186 deletions

diff --git a/core/Makefile b/core/Makefile
index 9728b52936..e106dadda2 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -970,27 +970,12 @@ systemimage:
 
 # -----------------------------------------------------------------
 
-.PHONY: event-log-tags
-
-# Produce an event logs tag file for everything we know about, in order
-# to properly allocate numbers.  Then produce a file that's filtered
-# for what's going to be installed.
-
-all_event_log_tags_file := $(TARGET_OUT_COMMON_INTERMEDIATES)/all-event-log-tags.txt
-
 event_log_tags_file := $(TARGET_OUT)/etc/event-log-tags
 
 # Include tags from all packages that we know about
 all_event_log_tags_src := \
     $(sort $(foreach m, $(ALL_MODULES), $(ALL_MODULES.$(m).EVENT_LOG_TAGS)))
 
-$(all_event_log_tags_file): PRIVATE_SRC_FILES := $(all_event_log_tags_src)
-$(all_event_log_tags_file): $(all_event_log_tags_src) $(MERGETAGS) build/make/tools/event_log_tags.py
-	$(hide) mkdir -p $(dir $@)
-	$(hide) $(MERGETAGS) -o $@ $(PRIVATE_SRC_FILES)
-
-$(call declare-0p-target,$(all_event_log_tags_file))
-
 # Include tags from all packages included in this product, plus all
 # tags that are part of the system (ie, not in a vendor/ or device/
 # directory).
@@ -1002,13 +987,13 @@ event_log_tags_src := \
       $(filter-out vendor/% device/% out/%,$(all_event_log_tags_src)))
 
 $(event_log_tags_file): PRIVATE_SRC_FILES := $(event_log_tags_src)
-$(event_log_tags_file): PRIVATE_MERGED_FILE := $(all_event_log_tags_file)
-$(event_log_tags_file): $(event_log_tags_src) $(all_event_log_tags_file) $(MERGETAGS) build/make/tools/event_log_tags.py
+$(event_log_tags_file): $(event_log_tags_src) $(MERGETAGS)
 	$(hide) mkdir -p $(dir $@)
-	$(hide) $(MERGETAGS) -o $@ -m $(PRIVATE_MERGED_FILE) $(PRIVATE_SRC_FILES)
+	$(hide) $(MERGETAGS) -o $@ $(PRIVATE_SRC_FILES)
 
 $(eval $(call declare-0p-target,$(event_log_tags_file)))
 
+.PHONY: event-log-tags
 event-log-tags: $(event_log_tags_file)
 
 ALL_DEFAULT_INSTALLED_MODULES += $(event_log_tags_file)
diff --git a/core/config.mk b/core/config.mk
index d62b86dda5..20ebeeb08d 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -730,8 +730,8 @@ SYMBOLS_MAP := $(HOST_OUT_EXECUTABLES)/symbols_map
 PROGUARD_HOME := external/proguard
 PROGUARD := $(PROGUARD_HOME)/bin/proguard.sh
 PROGUARD_DEPS := $(PROGUARD) $(PROGUARD_HOME)/lib/proguard.jar
-JAVATAGS := build/make/tools/java-event-log-tags.py
-MERGETAGS := build/make/tools/merge-event-log-tags.py
+JAVATAGS := $(HOST_OUT_EXECUTABLES)/java-event-log-tags
+MERGETAGS := $(HOST_OUT_EXECUTABLES)/merge-event-log-tags
 APPEND2SIMG := $(HOST_OUT_EXECUTABLES)/append2simg
 VERITY_SIGNER := $(HOST_OUT_EXECUTABLES)/verity_signer
 BUILD_VERITY_METADATA := $(HOST_OUT_EXECUTABLES)/build_verity_metadata
diff --git a/core/definitions.mk b/core/definitions.mk
index adb35e07ca..1ab6388838 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1555,7 +1555,7 @@ endef
 define transform-logtags-to-java
 @mkdir -p $(dir $@)
 @echo "logtags: $@ <= $<"
-$(hide) $(JAVATAGS) -o $@ $< $(PRIVATE_MERGED_TAG)
+$(hide) $(JAVATAGS) -o $@ $<
 endef
 
 
diff --git a/core/java.mk b/core/java.mk
index 5fbc916859..41a1b1ba84 100644
--- a/core/java.mk
+++ b/core/java.mk
@@ -140,8 +140,7 @@ ifneq ($(strip $(logtags_sources)),)
 logtags_java_sources := $(patsubst %.logtags,%.java,$(addprefix $(intermediates.COMMON)/logtags/, $(logtags_sources)))
 logtags_sources := $(addprefix $(LOCAL_PATH)/, $(logtags_sources))
 
-$(logtags_java_sources): PRIVATE_MERGED_TAG := $(TARGET_OUT_COMMON_INTERMEDIATES)/all-event-log-tags.txt
-$(logtags_java_sources): $(intermediates.COMMON)/logtags/%.java: $(LOCAL_PATH)/%.logtags $(TARGET_OUT_COMMON_INTERMEDIATES)/all-event-log-tags.txt $(JAVATAGS) build/make/tools/event_log_tags.py
+$(logtags_java_sources): $(intermediates.COMMON)/logtags/%.java: $(LOCAL_PATH)/%.logtags $(JAVATAGS)
 	$(transform-logtags-to-java)
 
 else
diff --git a/tools/Android.bp b/tools/Android.bp
index 59831a61ec..243cb5647b 100644
--- a/tools/Android.bp
+++ b/tools/Android.bp
@@ -123,3 +123,11 @@ python_binary_host {
         "merge-event-log-tags.py",
     ],
 }
+
+python_binary_host {
+    name: "java-event-log-tags",
+    srcs: [
+        "event_log_tags.py",
+        "java-event-log-tags.py",
+    ],
+}
diff --git a/tools/event_log_tags.py b/tools/event_log_tags.py
index a6ae9f193e..e859b6b3b1 100644
--- a/tools/event_log_tags.py
+++ b/tools/event_log_tags.py
@@ -14,21 +14,21 @@
 
 """A module for reading and parsing event-log-tags files."""
 
+import dataclasses
 import re
 import sys
+from typing import Optional
 
-class Tag(object):
-  __slots__ = ["tagnum", "tagname", "description", "filename", "linenum"]
-
-  def __init__(self, tagnum, tagname, description, filename, linenum):
-    self.tagnum = tagnum
-    self.tagname = tagname
-    self.description = description
-    self.filename = filename
-    self.linenum = linenum
+@dataclasses.dataclass
+class Tag:
+  tagnum: int
+  tagname: str
+  description: Optional[str]
+  filename: str
+  linenum: int
 
 
-class TagFile(object):
+class TagFile:
   """Read an input event-log-tags file."""
   def AddError(self, msg, linenum=None):
     if linenum is None:
@@ -76,14 +76,11 @@ class TagFile(object):
           self.options[parts[1]] = parts[2:]
           continue
 
-        if parts[0] == "?":
-          tag = None
-        else:
-          try:
-            tag = int(parts[0])
-          except ValueError:
-            self.AddError("\"%s\" isn't an integer tag or '?'" % (parts[0],))
-            continue
+        try:
+          tag = int(parts[0])
+        except ValueError:
+          self.AddError("\"%s\" isn't an integer tag" % (parts[0],))
+          continue
 
         tagname = parts[1]
         if len(parts) == 3:
@@ -128,8 +125,8 @@ def WriteOutput(output_file, data):
       out = sys.stdout
       output_file = "<stdout>"
     else:
-      out = open(output_file, "wb")
-    out.write(str.encode(data))
+      out = open(output_file, "w")
+    out.write(data)
     out.close()
   except (IOError, OSError) as e:
     print("failed to write %s: %s" % (output_file, e), file=sys.stderr)
diff --git a/tools/java-event-log-tags.py b/tools/java-event-log-tags.py
index bbd65fa4bf..e3dc07e4ab 100755
--- a/tools/java-event-log-tags.py
+++ b/tools/java-event-log-tags.py
@@ -15,16 +15,12 @@
 # limitations under the License.
 
 """
-Usage: java-event-log-tags.py [-o output_file] <input_file> <merged_tags_file>
-
 Generate a java class containing constants for each of the event log
 tags in the given input file.
-
--h to display this usage message and exit.
 """
 
 from io import StringIO
-import getopt
+import argparse
 import os
 import os.path
 import re
@@ -32,57 +28,14 @@ import sys
 
 import event_log_tags
 
-output_file = None
-
-try:
-  opts, args = getopt.getopt(sys.argv[1:], "ho:")
-except getopt.GetoptError as err:
-  print(str(err))
-  print(__doc__)
-  sys.exit(2)
-
-for o, a in opts:
-  if o == "-h":
-    print(__doc__)
-    sys.exit(2)
-  elif o == "-o":
-    output_file = a
-  else:
-    print("unhandled option %s" % (o,), file=sys.stderr)
-    sys.exit(1)
-
-if len(args) != 1 and len(args) != 2:
-  print("need one or two input files, not %d" % (len(args),))
-  print(__doc__)
-  sys.exit(1)
+parser = argparse.ArgumentParser(description=__doc__)
+parser.add_argument('-o', dest='output_file')
+parser.add_argument('file')
+args = parser.parse_args()
 
-fn = args[0]
+fn = args.file
 tagfile = event_log_tags.TagFile(fn)
 
-if len(args) > 1:
-  # Load the merged tag file (which should have numbers assigned for all
-  # tags.  Use the numbers from the merged file to fill in any missing
-  # numbers from the input file.
-  merged_fn = args[1]
-  merged_tagfile = event_log_tags.TagFile(merged_fn)
-  merged_by_name = dict([(t.tagname, t) for t in merged_tagfile.tags])
-  for t in tagfile.tags:
-    if t.tagnum is None:
-      if t.tagname in merged_by_name:
-        t.tagnum = merged_by_name[t.tagname].tagnum
-      else:
-        # We're building something that's not being included in the
-        # product, so its tags don't appear in the merged file.  Assign
-        # them all an arbitrary number so we can emit the java and
-        # compile the (unused) package.
-        t.tagnum = 999999
-else:
-  # Not using the merged tag file, so all tags must have manually assigned
-  # numbers
-  for t in tagfile.tags:
-    if t.tagnum is None:
-      tagfilef.AddError("tag \"%s\" has no number" % (tagname,), tag.linenum)
-
 if "java_package" not in tagfile.options:
   tagfile.AddError("java_package option not specified", linenum=0)
 
@@ -141,11 +94,11 @@ javaTypes = ["ERROR", "int", "long", "String", "Object[]", "float"]
 for t in tagfile.tags:
   methodName = javaName("write_" + t.tagname)
   if t.description:
-    args = [arg.strip("() ").split("|") for arg in t.description.split(",")]
+    fn_args = [arg.strip("() ").split("|") for arg in t.description.split(",")]
   else:
-    args = []
-  argTypesNames = ", ".join([javaTypes[int(arg[1])] + " " + javaName(arg[0]) for arg in args])
-  argNames = "".join([", " + javaName(arg[0]) for arg in args])
+    fn_args = []
+  argTypesNames = ", ".join([javaTypes[int(arg[1])] + " " + javaName(arg[0]) for arg in fn_args])
+  argNames = "".join([", " + javaName(arg[0]) for arg in fn_args])
   buffer.write("\n  public static void %s(%s) {" % (methodName, argTypesNames))
   buffer.write("\n    android.util.EventLog.writeEvent(%s%s);" % (t.tagname.upper(), argNames))
   buffer.write("\n  }\n")
@@ -153,8 +106,8 @@ for t in tagfile.tags:
 
 buffer.write("}\n");
 
-output_dir = os.path.dirname(output_file)
+output_dir = os.path.dirname(args.output_file)
 if not os.path.exists(output_dir):
   os.makedirs(output_dir)
 
-event_log_tags.WriteOutput(output_file, buffer)
+event_log_tags.WriteOutput(args.output_file, buffer)
diff --git a/tools/merge-event-log-tags.py b/tools/merge-event-log-tags.py
index 292604c469..5730c11c43 100755
--- a/tools/merge-event-log-tags.py
+++ b/tools/merge-event-log-tags.py
@@ -15,22 +15,13 @@
 # limitations under the License.
 
 """
-Usage: merge-event-log-tags.py [-o output_file] [input_files...]
-
 Merge together zero or more event-logs-tags files to produce a single
 output file, stripped of comments.  Checks that no tag numbers conflict
 and fails if they do.
-
--h to display this usage message and exit.
 """
 
 from io import StringIO
-import getopt
-try:
-  import hashlib
-except ImportError:
-  import md5 as hashlib
-import struct
+import argparse
 import sys
 
 import event_log_tags
@@ -38,32 +29,10 @@ import event_log_tags
 errors = []
 warnings = []
 
-output_file = None
-pre_merged_file = None
-
-# Tags with a tag number of ? are assigned a tag in the range
-# [ASSIGN_START, ASSIGN_LIMIT).
-ASSIGN_START = 900000
-ASSIGN_LIMIT = 1000000
-
-try:
-  opts, args = getopt.getopt(sys.argv[1:], "ho:m:")
-except getopt.GetoptError as err:
-  print(str(err))
-  print(__doc__)
-  sys.exit(2)
-
-for o, a in opts:
-  if o == "-h":
-    print(__doc__)
-    sys.exit(2)
-  elif o == "-o":
-    output_file = a
-  elif o == "-m":
-    pre_merged_file = a
-  else:
-    print("unhandled option %s" % (o,), file=sys.stderr)
-    sys.exit(1)
+parser = argparse.ArgumentParser(description=__doc__)
+parser.add_argument('-o', dest='output_file')
+parser.add_argument('files', nargs='*')
+args = parser.parse_args()
 
 # Restrictions on tags:
 #
@@ -77,12 +46,7 @@ for o, a in opts:
 by_tagname = {}
 by_tagnum = {}
 
-pre_merged_tags = {}
-if pre_merged_file:
-  for t in event_log_tags.TagFile(pre_merged_file).tags:
-    pre_merged_tags[t.tagname] = t
-
-for fn in args:
+for fn in args.files:
   tagfile = event_log_tags.TagFile(fn)
 
   for t in tagfile.tags:
@@ -93,12 +57,6 @@ for fn in args:
     if t.tagname in by_tagname:
       orig = by_tagname[t.tagname]
 
-      # Allow an explicit tag number to define an implicit tag number
-      if orig.tagnum is None:
-        orig.tagnum = t.tagnum
-      elif t.tagnum is None:
-        t.tagnum = orig.tagnum
-
       if (t.tagnum == orig.tagnum and
           t.description == orig.description):
         # if the name and description are identical, issue a warning
@@ -114,7 +72,7 @@ for fn in args:
             linenum=t.linenum)
       continue
 
-    if t.tagnum is not None and t.tagnum in by_tagnum:
+    if t.tagnum in by_tagnum:
       orig = by_tagnum[t.tagnum]
 
       if t.tagname != orig.tagname:
@@ -125,8 +83,7 @@ for fn in args:
         continue
 
     by_tagname[t.tagname] = t
-    if t.tagnum is not None:
-      by_tagnum[t.tagnum] = t
+    by_tagnum[t.tagnum] = t
 
   errors.extend(tagfile.errors)
   warnings.extend(tagfile.warnings)
@@ -140,38 +97,6 @@ if warnings:
   for fn, ln, msg in warnings:
     print("%s:%d: warning: %s" % (fn, ln, msg), file=sys.stderr)
 
-# Python's hash function (a) isn't great and (b) varies between
-# versions of python.  Using md5 is overkill here but is the same from
-# platform to platform and speed shouldn't matter in practice.
-def hashname(str):
-  d = hashlib.md5(str).digest()[:4]
-  return struct.unpack("!I", d)[0]
-
-# Assign a tag number to all the entries that say they want one
-# assigned.  We do this based on a hash of the tag name so that the
-# numbers should stay relatively stable as tags are added.
-
-# If we were provided pre-merged tags (w/ the -m option), then don't
-# ever try to allocate one, just fail if we don't have a number
-
-for name, t in sorted(by_tagname.items()):
-  if t.tagnum is None:
-    if pre_merged_tags:
-      try:
-        t.tagnum = pre_merged_tags[t.tagname]
-      except KeyError:
-        print("Error: Tag number not defined for tag `%s'. Have you done a full build?" % t.tagname,
-              file=sys.stderr)
-        sys.exit(1)
-    else:
-      while True:
-        x = (hashname(name) % (ASSIGN_LIMIT - ASSIGN_START - 1)) + ASSIGN_START
-        if x not in by_tagnum:
-          t.tagnum = x
-          by_tagnum[x] = t
-          break
-        name = "_" + name
-
 # by_tagnum should be complete now; we've assigned numbers to all tags.
 
 buffer = StringIO()
@@ -181,4 +106,4 @@ for n, t in sorted(by_tagnum.items()):
   else:
     buffer.write("%d %s\n" % (t.tagnum, t.tagname))
 
-event_log_tags.WriteOutput(output_file, buffer)
+event_log_tags.WriteOutput(args.output_file, buffer)