Fix up gperf's pointer to int casting

Pointers are only guaranteed to be castable to an integer of at least
the same size.

gperf currently generates something like
{(int)(long)&(foo), bar},

Replace it with
{static_cast<int>(reinterpret_cast<uintptr_t>(&(foo)), bar},

Bug: 1059231
Change-Id: Ic68a92f8239ec0d51485f17ac5ada91b7617636e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2098763Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Arthur Eubanks <aeubanks@google.com>
Cr-Commit-Position: refs/heads/master@{#749354}

third_party/blink/renderer/build/scripts/gperf.py

@@ -40,6 +40,13 @@ def generate_gperf(gperf_path, gperf_input, gperf_args):
         # https://savannah.gnu.org/bugs/index.php?53029
         gperf_output = gperf_output.replace('/*FALLTHROUGH*/',
                                             '  FALLTHROUGH;')
+        # -Wpointer-to-int-cast warns about casting pointers to smaller ints
+        # Replace {(int)(long)&(foo), bar} with
+        # {static_cast<int>(reinterpret_cast<uintptr_t>(&(foo)), bar}
+        gperf_output = re.sub(
+            r'\(int\)\(long\)(.*?),',
+            r'static_cast<int>(reinterpret_cast<uintptr_t>(\1)),',
+            gperf_output)
         script = 'third_party/blink/renderer/build/scripts/gperf.py'
         return '// Generated by %s\n' % script + gperf_output
     except OSError: