1 files changed, 107 insertions, 0 deletions
diff --git a/toolkit/components/telemetry/gen-histogram-enum.py b/toolkit/components/telemetry/gen-histogram-enum.py
new file mode 100644
index 000000000..8e08bc484
--- /dev/null
+++ b/toolkit/components/telemetry/gen-histogram-enum.py
@@ -0,0 +1,107 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+# Write out a C++ enum definition whose members are the names of
+# histograms as well as the following other members:
+#
+#   - HistogramCount
+#   - HistogramFirstUseCounter
+#   - HistogramLastUseCounter
+#   - HistogramUseCounterCount
+#
+# The histograms are defined in files provided as command-line arguments.
+
+from __future__ import print_function
+
+import histogram_tools
+import itertools
+import sys
+
+banner = """/* This file is auto-generated, see gen-histogram-enum.py.  */
+"""
+
+header = """
+#ifndef mozilla_TelemetryHistogramEnums_h
+#define mozilla_TelemetryHistogramEnums_h
+
+#include "mozilla/TemplateLib.h"
+
+namespace mozilla {
+namespace Telemetry {
+"""
+
+footer = """
+} // namespace mozilla
+} // namespace Telemetry
+#endif // mozilla_TelemetryHistogramEnums_h"""
+
+def main(output, *filenames):
+    # Print header.
+    print(banner, file=output)
+    print(header, file=output)
+
+    # Load the histograms.
+    all_histograms = list(histogram_tools.from_files(filenames))
+    groups = itertools.groupby(all_histograms,
+                               lambda h: h.name().startswith("USE_COUNTER2_"))
+
+    # Print the histogram enums.
+    # Note that histogram_tools.py guarantees that all of the USE_COUNTER2_*
+    # histograms are defined in a contiguous block.  We therefore assume
+    # that there's at most one group for which use_counter_group is true.
+    print("enum ID : uint32_t {", file=output)
+    seen_use_counters = False
+    for (use_counter_group, histograms) in groups:
+        if use_counter_group:
+            seen_use_counters = True
+
+        # The HistogramDUMMY* enum variables are used to make the computation
+        # of Histogram{First,Last}UseCounter easier.  Otherwise, we'd have to
+        # special case the first and last histogram in the group.
+        if use_counter_group:
+            print("  HistogramFirstUseCounter,", file=output)
+            print("  HistogramDUMMY1 = HistogramFirstUseCounter - 1,", file=output)
+
+        for histogram in histograms:
+            cpp_guard = histogram.cpp_guard()
+            if cpp_guard:
+                print("#if defined(%s)" % cpp_guard, file=output)
+            print("  %s," % histogram.name(), file=output)
+            if cpp_guard:
+                print("#endif", file=output)
+
+        if use_counter_group:
+            print("  HistogramDUMMY2,", file=output)
+            print("  HistogramLastUseCounter = HistogramDUMMY2 - 1,", file=output)
+
+    print("  HistogramCount,", file=output)
+    if seen_use_counters:
+        print("  HistogramUseCounterCount = HistogramLastUseCounter - HistogramFirstUseCounter + 1", file=output)
+    else:
+        print("  HistogramFirstUseCounter = 0,", file=output)
+        print("  HistogramLastUseCounter = 0,", file=output)
+        print("  HistogramUseCounterCount = 0", file=output)
+    print("};", file=output)
+
+    # Write categorical label enums.
+    categorical = filter(lambda h: h.kind() == "categorical", all_histograms)
+    enums = [("LABELS_" + h.name(), h.labels(), h.name()) for h in categorical]
+    for name,labels,_ in enums:
+        print("\nenum class %s : uint32_t {" % name, file=output)
+        print("  %s" % ",\n  ".join(labels), file=output)
+        print("};", file=output)
+
+    print("\ntemplate<class T> struct IsCategoricalLabelEnum : FalseType {};", file=output)
+    for name,_,_ in enums:
+        print("template<> struct IsCategoricalLabelEnum<%s> : TrueType {};" % name, file=output)
+
+    print("\ntemplate<class T> struct CategoricalLabelId {};", file=output)
+    for name,_,id in enums:
+        print("template<> struct CategoricalLabelId<%s> : IntegralConstant<uint32_t, %s> {};" % (name, id), file=output)
+
+    # Footer.
+    print(footer, file=output)
+
+if __name__ == '__main__':
+    main(sys.stdout, *sys.argv[1:])