diff --git a/core/Makefile b/core/Makefile
index 7b52193..7082f5a 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -1621,10 +1621,9 @@
   $(HOST_LIBRARY_PATH)/libconscrypt_openjdk_jni$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libbrillo$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libbrillo-stream$(HOST_SHLIB_SUFFIX) \
-  $(HOST_LIBRARY_PATH)/libbrillo-http$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libchrome$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libcurl-host$(HOST_SHLIB_SUFFIX) \
-  $(HOST_LIBRARY_PATH)/libevent$(HOST_SHLIB_SUFFIX) \
+  $(HOST_LIBRARY_PATH)/libevent-host$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libprotobuf-cpp-lite$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libssl-host$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libz-host$(HOST_SHLIB_SUFFIX) \
diff --git a/core/binary.mk b/core/binary.mk
index 41520c2..85d084f 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -70,6 +70,9 @@
     $(error $(LOCAL_PATH): LOCAL_SDK_VERSION cannot be used in host module)
   endif
 
+  # Make sure we've built the NDK.
+  my_additional_dependencies += ndk
+
   # mips32r6 is not supported by the NDK. No released NDK contains these
   # libraries, but the r10 in prebuilts/ndk had a local hack to add them :(
   #
@@ -81,9 +84,31 @@
     endif
   endif
 
-  my_ndk_source_root := $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/sources
-  my_ndk_sysroot := $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/platforms/android-$(LOCAL_SDK_VERSION)/arch-$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)
-  my_ndk_sysroot_include := $(my_ndk_sysroot)/usr/include
+  my_arch := $(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)
+  ifneq (,$(filter arm64 mips64 x86_64,$(my_arch)))
+    my_min_sdk_version := 21
+  else
+    my_min_sdk_version := 9
+  endif
+
+  # Historically we've just set up a bunch of symlinks in prebuilts/ndk to map
+  # missing API levels to existing ones where necessary, but we're not doing
+  # that for the generated libraries. Clip the API level to the minimum where
+  # appropriate.
+  my_ndk_api := \
+    $(shell if [ $(LOCAL_SDK_VERSION) -lt $(my_min_sdk_version) ]; then \
+        echo $(my_min_sdk_version); else echo $(LOCAL_SDK_VERSION); fi)
+
+  my_ndk_source_root := \
+      $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/sources
+  my_ndk_sysroot := \
+    $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/platforms/android-$(my_ndk_api)/arch-$(my_arch)
+  my_built_ndk := $(SOONG_OUT_DIR)/ndk
+  my_ndk_triple := $($(LOCAL_2ND_ARCH_VAR_PREFIX)TARGET_NDK_TRIPLE)
+  my_ndk_sysroot_include := \
+      $(my_built_ndk)/sysroot/usr/include \
+      $(my_built_ndk)/sysroot/usr/include/$(my_ndk_triple) \
+      $(my_ndk_sysroot)/usr/include \
 
   # x86_64 and and mips64 are both multilib toolchains, so their libraries are
   # installed in /usr/lib64. Aarch64, on the other hand, is not a multilib
@@ -92,14 +117,19 @@
   # Mips32r6 is yet another variation, with libraries installed in libr6.
   #
   # For the rest, the libraries are installed simply to /usr/lib.
-  ifneq (,$(filter x86_64 mips64,$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH)))
-    my_ndk_sysroot_lib := $(my_ndk_sysroot)/usr/lib64
+  ifneq (,$(filter x86_64 mips64,$(my_arch)))
+    my_ndk_libdir_name := lib64
   else ifeq (mips32r6,$(TARGET_$(LOCAL_2ND_ARCH_VAR_PREFIX)ARCH_VARIANT))
-    my_ndk_sysroot_lib := $(my_ndk_sysroot)/usr/libr6
+    my_ndk_libdir_name := libr6
   else
-    my_ndk_sysroot_lib := $(my_ndk_sysroot)/usr/lib
+    my_ndk_libdir_name := lib
   endif
 
+  my_ndk_platform_dir := \
+      $(my_built_ndk)/platforms/android-$(my_ndk_api)/arch-$(my_arch)
+  my_built_ndk_libs := $(my_ndk_platform_dir)/usr/$(my_ndk_libdir_name)
+  my_ndk_sysroot_lib := $(my_ndk_sysroot)/usr/$(my_ndk_libdir_name)
+
   # The bionic linker now has support for packed relocations and gnu style
   # hashes (which are much faster!), but shipping to older devices requires
   # the old style hash. Fortunately, we can build with both and it'll work
@@ -180,6 +210,11 @@
   endif
   endif
   endif
+
+  my_generated_ndk_shared_libraries := \
+      $(filter $(NDK_MIGRATED_LIBS),$(my_system_shared_libraries))
+  my_system_shared_libraries := \
+      $(filter-out $(NDK_MIGRATED_LIBS),$(my_system_shared_libraries))
 endif
 
 # MinGW spits out warnings about -fPIC even for -fpie?!) being ignored because
@@ -1365,7 +1400,14 @@
     $(addprefix $(my_ndk_sysroot_lib)/, \
         $(addsuffix $(so_suffix), $(my_system_shared_libraries)))
 
-built_shared_libraries += $(my_system_shared_libraries_fullpath)
+my_built_ndk_shared_libraries_fullpath := \
+    $(addprefix $(my_built_ndk_libs)/,\
+        $(addsuffix $(so_suffix),$(my_generated_ndk_shared_libraries)))
+
+built_shared_libraries += \
+    $(my_built_ndk_shared_libraries_fullpath) \
+    $(my_system_shared_libraries_fullpath) \
+
 else
 built_shared_libraries := \
     $(addprefix $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)OUT_INTERMEDIATE_LIBRARIES)/, \
diff --git a/core/clang/tidy.mk b/core/clang/tidy.mk
index 35871f0..d50b43d 100644
--- a/core/clang/tidy.mk
+++ b/core/clang/tidy.mk
@@ -15,10 +15,12 @@
 #
 
 # Most Android source files are not clang-tidy clean yet.
-# Global tidy checks include only google* and misc-macro-parentheses,
-# but not google-readability* or google-runtime-references.
+# Global tidy checks include only google*, performance*,
+# and misc-macro-parentheses, but not google-readability*
+# or google-runtime-references.
 DEFAULT_GLOBAL_TIDY_CHECKS := \
-  -*,google*,-google-readability*,-google-runtime-references,misc-macro-parentheses
+  -*,google*,performance*,misc-macro-parentheses \
+  ,-google-readability*,-google-runtime-references
 
 # Disable style rules usually not followed by external projects.
 # Every word in DEFAULT_LOCAL_TIDY_CHECKS list has the following format:
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index f1a9592..6121c45 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -199,6 +199,7 @@
 # to avoid installing the presigned apks with classes.dex unstripped.
 LOCAL_REPLACE_PREBUILT_APK_INSTALLED:=
 LOCAL_NDK_VERSION:=current
+LOCAL_COPY_TO_INTERMEDIATE_LIBRARIES:=
 LOCAL_LOGTAGS_FILES:=
 LOCAL_RECORDED_MODULE_TYPE:=
 
diff --git a/core/definitions.mk b/core/definitions.mk
index 36d8080..53a6fcd 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1692,7 +1692,7 @@
 	$(PRIVATE_TARGET_LIBGCC) \
 	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
 	$(PRIVATE_LDFLAGS) \
-	$(call normalize-target-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
+	$(PRIVATE_ALL_SHARED_LIBRARIES) \
 	-o $@ \
 	$(PRIVATE_TARGET_CRTEND_SO_O) \
 	$(PRIVATE_LDLIBS)
@@ -1780,7 +1780,7 @@
 	$(PRIVATE_TARGET_LIBGCC) \
 	$(PRIVATE_TARGET_GLOBAL_LDFLAGS) \
 	$(PRIVATE_LDFLAGS) \
-	$(call normalize-target-libraries,$(PRIVATE_ALL_SHARED_LIBRARIES)) \
+	$(PRIVATE_ALL_SHARED_LIBRARIES) \
 	-o $@ \
 	$(PRIVATE_TARGET_CRTEND_O) \
 	$(PRIVATE_LDLIBS)
diff --git a/core/main.mk b/core/main.mk
index b99de49..59e9524 100644
--- a/core/main.mk
+++ b/core/main.mk
@@ -1125,4 +1125,7 @@
 tidy_only:
 	@echo Successfully make tidy_only.
 
+ndk: $(SOONG_OUT_DIR)/ndk.timestamp
+.PHONY: ndk
+
 endif # KATI
diff --git a/core/prebuilt_internal.mk b/core/prebuilt_internal.mk
index 90e9547..701414a 100644
--- a/core/prebuilt_internal.mk
+++ b/core/prebuilt_internal.mk
@@ -46,9 +46,18 @@
   $(LOCAL_PACK_MODULE_RELOCATIONS))
 
 ifeq (SHARED_LIBRARIES,$(LOCAL_MODULE_CLASS))
-  # Put the built targets of all shared libraries in a common directory
-  # to simplify the link line.
-  OVERRIDE_BUILT_MODULE_PATH := $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)OUT_INTERMEDIATE_LIBRARIES)
+  # LOCAL_COPY_TO_INTERMEDIATE_LIBRARIES indicates that this prebuilt should be
+  # installed to the common directory of libraries. This is needed for the NDK
+  # shared libraries built by soong, as we build many different versions of each
+  # library (one for each API level). Since they all have the same basename,
+  # they'd clobber each other (as well as any platform libraries by the same
+  # name).
+  ifneq ($(LOCAL_COPY_TO_INTERMEDIATE_LIBRARIES),false)
+    # Put the built targets of all shared libraries in a common directory
+    # to simplify the link line.
+    OVERRIDE_BUILT_MODULE_PATH :=  \
+        $($(LOCAL_2ND_ARCH_VAR_PREFIX)$(my_prefix)OUT_INTERMEDIATE_LIBRARIES)
+  endif
   ifeq ($(LOCAL_IS_HOST_MODULE)$(my_strip_module),)
     # Strip but not try to add debuglink
     my_strip_module := no_debuglink
diff --git a/core/soong.mk b/core/soong.mk
index c96ca2f..cb0a0d0 100644
--- a/core/soong.mk
+++ b/core/soong.mk
@@ -25,6 +25,13 @@
 	$(hide) mkdir -p $(dir $@)
 	$(hide) BUILDDIR=$(SOONG_OUT_DIR) ./bootstrap.bash
 
+BINDER32BIT :=
+ifneq ($(TARGET_USES_64_BIT_BINDER),true)
+ifneq ($(TARGET_IS_64_BIT),true)
+BINDER32BIT := true
+endif
+endif
+
 # Create soong.variables with copies of makefile settings.  Runs every build,
 # but only updates soong.variables if it changes
 SOONG_VARIABLES_TMP := $(SOONG_VARIABLES).$$$$
@@ -44,6 +51,7 @@
 	echo '    "HostStaticBinaries": $(if $(strip $(BUILD_HOST_static)),true,false),'; \
 	echo '    "Cpusets": $(if $(strip $(ENABLE_CPUSETS)),true,false),'; \
 	echo '    "Schedboost": $(if $(strip $(ENABLE_SCHEDBOOST)),true,false),'; \
+	echo '    "Binder32bit": $(if $(BINDER32BIT),true,false),'; \
 	echo ''; \
 	echo '    "DeviceName": "$(TARGET_DEVICE)",'; \
 	echo '    "DeviceArch": "$(TARGET_ARCH)",'; \
diff --git a/tools/releasetools/check_target_files_signatures.py b/tools/releasetools/check_target_files_signatures.py
index 5c541ab..3048488 100755
--- a/tools/releasetools/check_target_files_signatures.py
+++ b/tools/releasetools/check_target_files_signatures.py
@@ -245,7 +245,7 @@
             fullname = os.path.join(dirpath, fn)
             displayname = fullname[len(d)+1:]
             apk = APK(fullname, displayname)
-            self.apks[apk.package] = apk
+            self.apks[apk.filename] = apk
             self.apks_by_basename[os.path.basename(apk.filename)] = apk
 
             self.max_pkg_len = max(self.max_pkg_len, len(apk.package))
@@ -316,8 +316,7 @@
                                         self.max_pkg_len, apk.package,
                                         apk.shared_uid)
         else:
-          print "  %-*s  %-*s" % (self.max_fn_len, apk.filename,
-                                  self.max_pkg_len, apk.package)
+          print "  %-*s  %s" % (self.max_fn_len, apk.filename, apk.package)
       print
 
   def CompareWith(self, other):
diff --git a/tools/warn.py b/tools/warn.py
index 51349af..f17e8ac 100755
--- a/tools/warn.py
+++ b/tools/warn.py
@@ -10,6 +10,10 @@
                     help='Generate a CSV file with number of various warnings',
                     action="store_true",
                     default=False)
+parser.add_argument('--byproject',
+                    help='Separate warnings in HTML output by project names',
+                    action="store_true",
+                    default=False)
 parser.add_argument('--url',
                     help='Root URL of an Android source code tree prefixed '
                     'before files in warnings')
@@ -1660,6 +1664,7 @@
     { 'category':'C/C++',   'severity':severity.MEDIUM,     'members':[], 'option':'',
         'description':'Undefined result',
         'patterns':[r".*: warning: The result of .+ is undefined",
+                    r".*: warning: passing an object that .+ has undefined behavior \[-Wvarargs\]",
                     r".*: warning: 'this' pointer cannot be null in well-defined C\+\+ code;",
                     r".*: warning: shifting a negative signed value is undefined"] },
     { 'category':'C/C++',   'severity':severity.MEDIUM,     'members':[], 'option':'',
@@ -1774,6 +1779,21 @@
         'description':'clang-tidy misc',
         'patterns':[r".*: .+\[misc-.+\]$"] },
     { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
+        'description':'clang-tidy performance-faster-string-find',
+        'patterns':[r".*: .+\[performance-faster-string-find\]$"] },
+    { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
+        'description':'clang-tidy performance-for-range-copy',
+        'patterns':[r".*: .+\[performance-for-range-copy\]$"] },
+    { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
+        'description':'clang-tidy performance-implicit-cast-in-loop',
+        'patterns':[r".*: .+\[performance-implicit-cast-in-loop\]$"] },
+    { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
+        'description':'clang-tidy performance-unnecessary-copy-initialization',
+        'patterns':[r".*: .+\[performance-unnecessary-copy-initialization\]$"] },
+    { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
+        'description':'clang-tidy performance-unnecessary-value-param',
+        'patterns':[r".*: .+\[performance-unnecessary-value-param\]$"] },
+    { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
         'description':'clang-tidy CERT',
         'patterns':[r".*: .+\[cert-.+\]$"] },
     { 'category':'C/C++',   'severity':severity.TIDY,     'members':[], 'option':'',
@@ -1796,43 +1816,52 @@
 # A list of [project_name, file_path_pattern].
 # project_name should not contain comma, to be used in CSV output.
 projectlist = [
-    ['art',         r"(^|.*/)art/.*: warning:"],
-    ['bionic',      r"(^|.*/)bionic/.*: warning:"],
-    ['bootable',    r"(^|.*/)bootable/.*: warning:"],
-    ['build',       r"(^|.*/)build/.*: warning:"],
-    ['cts',         r"(^|.*/)cts/.*: warning:"],
-    ['dalvik',      r"(^|.*/)dalvik/.*: warning:"],
-    ['developers',  r"(^|.*/)developers/.*: warning:"],
-    ['development', r"(^|.*/)development/.*: warning:"],
-    ['device',      r"(^|.*/)device/.*: warning:"],
-    ['doc',         r"(^|.*/)doc/.*: warning:"],
-    ['external',    r"(^|.*/)external/.*: warning:"],
-    ['frameworks',  r"(^|.*/)frameworks/.*: warning:"],
-    ['hardware',    r"(^|.*/)hardware/.*: warning:"],
-    ['kernel',      r"(^|.*/)kernel/.*: warning:"],
-    ['libcore',     r"(^|.*/)libcore/.*: warning:"],
-    ['libnativehelper', r"(^|.*/)libnativehelper/.*: warning:"],
-    ['ndk',         r"(^|.*/)ndk/.*: warning:"],
-    ['packages',    r"(^|.*/)packages/.*: warning:"],
-    ['pdk',         r"(^|.*/)pdk/.*: warning:"],
-    ['prebuilts',   r"(^|.*/)prebuilts/.*: warning:"],
-    ['system',      r"(^|.*/)system/.*: warning:"],
-    ['toolchain',   r"(^|.*/)toolchain/.*: warning:"],
-    ['test',        r"(^|.*/)test/.*: warning:"],
-    ['tools',       r"(^|.*/)tools/.*: warning:"],
-    ['vendor',      r"(^|.*/)vendor/.*: warning:"],
-    ['out/obj',     r".*/(gen|obj[^/]*)/(include|EXECUTABLES|SHARED_LIBRARIES|STATIC_LIBRARIES)/.*: warning:"],
-    ['other',       r".*: warning:"],
+    ['art',                 r"(^|.*/)art/.*: warning:"],
+    ['bionic',              r"(^|.*/)bionic/.*: warning:"],
+    ['bootable',            r"(^|.*/)bootable/.*: warning:"],
+    ['build',               r"(^|.*/)build/.*: warning:"],
+    ['cts',                 r"(^|.*/)cts/.*: warning:"],
+    ['dalvik',              r"(^|.*/)dalvik/.*: warning:"],
+    ['developers',          r"(^|.*/)developers/.*: warning:"],
+    ['development',         r"(^|.*/)development/.*: warning:"],
+    ['device',              r"(^|.*/)device/.*: warning:"],
+    ['doc',                 r"(^|.*/)doc/.*: warning:"],
+    # match external/google* before external/
+    ['external/google',     r"(^|.*/)external/google.*: warning:"],
+    ['external/non-google', r"(^|.*/)external/.*: warning:"],
+    ['frameworks',          r"(^|.*/)frameworks/.*: warning:"],
+    ['hardware',            r"(^|.*/)hardware/.*: warning:"],
+    ['kernel',              r"(^|.*/)kernel/.*: warning:"],
+    ['libcore',             r"(^|.*/)libcore/.*: warning:"],
+    ['libnativehelper',      r"(^|.*/)libnativehelper/.*: warning:"],
+    ['ndk',                 r"(^|.*/)ndk/.*: warning:"],
+    ['packages',            r"(^|.*/)packages/.*: warning:"],
+    ['pdk',                 r"(^|.*/)pdk/.*: warning:"],
+    ['prebuilts',           r"(^|.*/)prebuilts/.*: warning:"],
+    ['system',              r"(^|.*/)system/.*: warning:"],
+    ['toolchain',           r"(^|.*/)toolchain/.*: warning:"],
+    ['test',                r"(^|.*/)test/.*: warning:"],
+    ['tools',               r"(^|.*/)tools/.*: warning:"],
+    # match vendor/google* before vendor/
+    ['vendor/google',       r"(^|.*/)vendor/google.*: warning:"],
+    ['vendor/non-google',   r"(^|.*/)vendor/.*: warning:"],
+    # keep out/obj and other patterns at the end.
+    ['out/obj', r".*/(gen|obj[^/]*)/(include|EXECUTABLES|SHARED_LIBRARIES|STATIC_LIBRARIES)/.*: warning:"],
+    ['other',   r".*: warning:"],
 ]
 
 projectpatterns = []
 for p in projectlist:
     projectpatterns.append({'description':p[0], 'members':[], 'pattern':re.compile(p[1])})
 
-# Each warning pattern has a dictionary that maps
-# a project name to number of warnings in that project.
+# Each warning pattern has 3 dictionaries:
+# (1) 'projects' maps a project name to number of warnings in that project.
+# (2) 'projectanchor' maps a project name to its anchor number for HTML.
+# (3) 'projectwarning' maps a project name to a list of warning of that project.
 for w in warnpatterns:
     w['projects'] = {}
+    w['projectanchor'] = {}
+    w['projectwarning'] = {}
 
 platformversion = 'unknown'
 targetproduct = 'unknown'
@@ -1937,17 +1966,12 @@
     output('<blockquote>\n')
     for i in warnpatterns:
       if i['severity'] == sev and len(i['members']) > 0:
-          output('\n<table frame="box">\n')
           anchor += 1
           i['anchor'] = str(anchor)
-          mark = str(anchor) + '_mark'
-          output('<tr bgcolor="' + colorforseverity(sev) + '">' +
-                 '<td><button class="bt" id="' + mark +
-                 '" onclick="expand(\'' + str(anchor) + '\');">' +
-                 '&#x2295</button> ' + descriptionfor(i) +
-                 ' (' + str(len(i['members'])) + ')</td></tr>\n')
-          output('</table>\n')
-          dumpcategory(i)
+          if args.byproject:
+              dumpcategorybyproject(sev, i)
+          else:
+              dumpcategory(sev, i)
     output('</blockquote>\n')
 
 def allpatterns(cat):
@@ -2002,19 +2026,35 @@
     else:
         return '<a href="' + args.url + '/' + filepath + '">' + filepath + '</a>:' + linenumber + ':' + warning
 
-# dump a category, provided it is not marked as 'SKIP' and has more than 0 occurrences
-def dumpcategory(cat):
-    if cat['severity'] != severity.SKIP and len(cat['members']) != 0:
-        header = [descriptionfor(cat),str(len(cat['members'])) + ' occurences:']
-        if cat['option'] != '':
-            header[1:1] = [' (related option: ' + cat['option'] +')']
+def dumpgroup(sev, anchor, description, warnings):
+    mark = anchor + '_mark'
+    output('\n<table frame="box">\n')
+    output('<tr bgcolor="' + colorforseverity(sev) + '">' +
+           '<td><button class="bt" id="' + mark +
+           '" onclick="expand(\'' + anchor + '\');">' +
+           '&#x2295</button> ' + description + '</td></tr>\n')
+    output('</table>\n')
+    output('<div id="' + anchor + '" style="display:none;">')
+    output('<table>\n')
+    for i in warnings:
+        tablerow(warningwithurl(i))
+    output('</table></div>\n')
 
-        output('<div id="' + cat['anchor'] + '" style="display:none;">')
-        output('<table>\n')
-        for i in cat['members']:
-            tablerow(warningwithurl(i))
-        output('</table></div>\n')
+# dump warnings in a category
+def dumpcategory(sev, cat):
+    description = descriptionfor(cat) + ' (' + str(len(cat['members'])) + ')'
+    dumpgroup(sev, cat['anchor'], description, cat['members'])
 
+# similar to dumpcategory but output one table per project.
+def dumpcategorybyproject(sev, cat):
+    warning = descriptionfor(cat)
+    projects = cat['projectwarning'].keys()
+    projects.sort()
+    for p in projects:
+        anchor = cat['projectanchor'][p]
+        projectwarnings = cat['projectwarning'][p]
+        description = '{}, in {} ({})'.format(warning, p, len(projectwarnings))
+        dumpgroup(sev, anchor, description, projectwarnings)
 
 def findproject(line):
     for p in projectpatterns:
@@ -2023,15 +2063,26 @@
     return '???'
 
 def classifywarning(line):
+    global anchor
     for i in warnpatterns:
         for cpat in i['compiledpatterns']:
             if cpat.match(line):
                 i['members'].append(line)
                 pname = findproject(line)
+                # Count warnings by project.
                 if pname in i['projects']:
-                  i['projects'][pname] += 1
+                    i['projects'][pname] += 1
                 else:
-                  i['projects'][pname] = 1
+                    i['projects'][pname] = 1
+                # Collect warnings by project.
+                if args.byproject:
+                    if pname in i['projectwarning']:
+                        i['projectwarning'][pname].append(line)
+                    else:
+                        i['projectwarning'][pname] = [line]
+                    if pname not in i['projectanchor']:
+                        anchor += 1
+                        i['projectanchor'][pname] = str(anchor)
                 return
             else:
                 # If we end up here, there was a problem parsing the log