[build] Add more v8 build options and fix existing ones.

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index 58bdb6b6531c57afdfcd02c606e5c8e9584a604e..bcd3c45175b401448dc7ec1022fb5fa683682210 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -21,7 +21,7 @@ declare_args() {
   v8_android_log_stdout = false
 
   # Sets -DVERIFY_HEAP.
-  v8_enable_verify_heap = false
+  v8_enable_verify_heap = ""
 
   # Sets -DVERIFY_PREDICTABLE
   v8_enable_verify_predictable = false
@@ -54,6 +54,12 @@ declare_args() {
   # Sets -dOBJECT_PRINT.
   v8_object_print = ""
 
+  # Sets -dTRACE_MAPS.
+  v8_enable_trace_maps = ""
+
+  # Sets -dV8_ENABLE_CHECKS.
+  v8_enable_v8_checks = ""

[Michael Achenbach, 2017/01/13 14:34:06]

How about just calling it v8_enable_checks just like the define?

[Igor Sheludko, 2017/01/13 16:04:59]

Given the flags naming scheme (v8_enable_blah_blah) the v8_enable_checks will
sound like this flag controls all the checks in V8 while it controls checks in
v8.h only. I'd leave it as is.

[Michael Achenbach, 2017/01/13 16:17:49]

Acknowledged.

+
   # With post mortem support enabled, metadata is embedded into libv8 that
   # describes various parameters of the VM for use by debuggers. See
   # tools/gen-postmortem-metadata.py for details.
@@ -90,12 +96,21 @@ if (v8_enable_gdbjit == "") {
 }
 
 # Derived defaults.
+if (v8_enable_verify_heap == "") {
+  v8_enable_verify_heap = is_debug
+}
 if (v8_object_print == "") {

[Michael Achenbach, 2017/01/13 14:34:06]

object_print, enable_disassembler and trace_maps were enabled by default in all
debug builds by the code in line 356 on the left. Now they will only be enabled
in non-optimized debug builds.

Is that really what we want? How about removing the && !v8_optimized_debug here
to not change semantics now?

[Igor Sheludko, 2017/01/13 16:04:59]

Good point. Done.

   v8_object_print = is_debug && !v8_optimized_debug
 }
 if (v8_enable_disassembler == "") {
   v8_enable_disassembler = is_debug && !v8_optimized_debug
 }
+if (v8_enable_trace_maps == "") {
+  v8_enable_trace_maps = is_debug && !v8_optimized_debug
+}
+if (v8_enable_v8_checks == "") {
+  v8_enable_v8_checks = is_debug
+}
 
 # Specifies if the target build is a simulator build. Comparing target cpu
 # with v8 target cpu to not affect simulator builds for making cross-compile
@@ -189,6 +204,12 @@ config("features") {
   if (v8_enable_verify_predictable) {
     defines += [ "VERIFY_PREDICTABLE" ]
   }
+  if (v8_enable_trace_maps) {
+    defines += [ "TRACE_MAPS" ]
+  }
+  if (v8_enable_v8_checks) {
+    defines += [ "V8_ENABLE_CHECKS" ]
+  }
   if (v8_interpreted_regexp) {
     defines += [ "V8_INTERPRETED_REGEXP" ]
   }
@@ -352,15 +373,7 @@ config("toolchain") {
       ldflags += [ "-rdynamic" ]
     }
 
-    # TODO(jochen): Add support for different debug optimization levels.
-    defines += [
-      "ENABLE_DISASSEMBLER",
-      "V8_ENABLE_CHECKS",
-      "OBJECT_PRINT",
-      "VERIFY_HEAP",
-      "DEBUG",
-      "TRACE_MAPS",
-    ]
+    defines += [ "DEBUG" ]
     if (v8_enable_slow_dchecks) {
       defines += [ "ENABLE_SLOW_DCHECKS" ]
     }