Enable --write-protect-code-memory by default.

R=hablich@chromium.org
BUG=v8:6792

Change-Id: Ib3bb3f84f9acec37a37803f460f5c8cdc3669867
Reviewed-on: https://chromium-review.googlesource.com/792937
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Michael Hablich <hablich@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49886}

src/flag-definitions.h

@@ -605,7 +605,7 @@ DEFINE_BOOL(incremental_marking_wrappers, true,
             "use incremental marking for marking wrappers")
 DEFINE_BOOL(parallel_scavenge, true, "parallel scavenge")
 DEFINE_BOOL(trace_parallel_scavenge, false, "trace parallel scavenge")
-DEFINE_BOOL(write_protect_code_memory, false, "write protect code memory")
+DEFINE_BOOL(write_protect_code_memory, true, "write protect code memory")
 #ifdef V8_CONCURRENT_MARKING
 #define V8_CONCURRENT_MARKING_BOOL true
 #else

tools/testrunner/local/variants.py

@@ -17,7 +17,9 @@ ALL_VARIANT_FLAGS = {
   # https://chromium-review.googlesource.com/c/452620/ for more discussion.
   "nooptimization": [["--noopt"]],
   "stress_background_compile": [["--background-compile", "--stress-background-compile"]],
-  "wasm_traps": [["--wasm_trap_handler", "--invoke-weak-callbacks", "--wasm-jit-to-native"]],
+  # TODO(7105): The --wasm-jit-to-native feature is not compatible with the
+  # --write-protect-code-memory feature (which has been enabled) yet.
+  "wasm_traps": [["--wasm_trap_handler", "--invoke-weak-callbacks", "--wasm-jit-to-native", "--no-write-protect-code-memory"]],
 }
 
 # FAST_VARIANTS implies no --always-opt.