ustack helper should derive constants dynamically

node.gyp

@@ -137,9 +137,12 @@
 
         [ 'node_use_dtrace=="true"', {
           'defines': [ 'HAVE_DTRACE=1' ],
-          'dependencies': [
-            'node_dtrace_provider_o'
-          ],
+          'dependencies': [ 'node_dtrace_provider_o' ],
+          'conditions': [ [
+            'target_arch=="ia32"', {
+              'dependencies': [ 'node_dtrace_ustack_o' ]
+            }
+          ] ],
           'libraries': [
             # generated implicitly by dependency
             '<(PRODUCT_DIR)/obj.target/node/src/node_dtrace.o'
@@ -267,9 +270,6 @@
         'src/node_dtrace.cc'
         'src/node_dtrace.h',
       ],
-      #'direct_dependent_settings': {
-      #  'libraries': [ '<(PRODUCT_DIR)/obj.target/node/src/node_dtrace.o' ]
-      #}
     },
     {
       'target_name': 'node_dtrace_provider_h',
@@ -303,6 +303,41 @@
             '-o', '<@(_outputs)' ]
         }
       ]
+    },
+    {
+      'target_name': 'v8constants',
+      'type': 'none',
+      'actions': [
+        {
+          'action_name': 'v8constants',
+          'outputs': [ '<(SHARED_INTERMEDIATE_DIR)/v8constants.h' ],
+          'inputs': [ '<(PRODUCT_DIR)/obj.target/deps/v8/tools/gyp/libv8_base.a' ],
+          'action': [
+            'tools/genv8constants.py',
+            '<@(_outputs)',
+            '<@(_inputs)'
+          ]
+        }
+      ]
+    },
+    {
+      'target_name': 'node_dtrace_ustack_o',
+      'type': 'none',
+      'dependencies': [ 'v8constants' ],
+      'direct_dependent_settings': {
+        'libraries': [ '<(SHARED_INTERMEDIATE_DIR)/node_ustack.o' ]
+      },
+      'actions': [
+        {
+          'action_name': 'node_dtrace_ustack',
+          'outputs': [ '<(SHARED_INTERMEDIATE_DIR)/node_ustack.o' ],
+          'inputs': [ 'src/v8ustack.d' ],
+          'action': [
+            'dtrace', '-32', '-I<(SHARED_INTERMEDIATE_DIR)', '-Isrc',
+            '-C', '-G', '-s', '<@(_inputs)', '-o', '<@(_outputs)',
+          ]
+        }
+      ]
     }
   ] # end targets
 }

src/v8abbr.h

@@ -0,0 +1,86 @@
+/*
+ * This header defines short names for V8 constants for use by the ustack
+ * helper.
+ */
+
+#ifndef V8_ABBR_H
+#define V8_ABBR_H
+
+/* Frame pointer offsets */
+#define V8_OFF_FP_FUNC              ((uint32_t)V8DBG_OFF_FP_FUNCTION)
+#define V8_OFF_FP_CONTEXT           ((uint32_t)V8DBG_OFF_FP_CONTEXT)
+#define V8_OFF_FP_MARKER            ((uint32_t)V8DBG_OFF_FP_MARKER)
+
+/* Stack frame types */
+#define V8_FT_ENTRY                 V8DBG_FRAMETYPE_ENTRYFRAME
+#define V8_FT_ENTRYCONSTRUCT        V8DBG_FRAMETYPE_ENTRYCONSTRUCTFRAME
+#define V8_FT_EXIT                  V8DBG_FRAMETYPE_EXITFRAME
+#define V8_FT_JAVASCRIPT            V8DBG_FRAMETYPE_JAVASCRIPTFRAME
+#define V8_FT_OPTIMIZED             V8DBG_FRAMETYPE_OPTIMIZEDFRAME
+#define V8_FT_INTERNAL              V8DBG_FRAMETYPE_INTERNALFRAME
+#define V8_FT_CONSTRUCT             V8DBG_FRAMETYPE_CONSTRUCTFRAME
+#define V8_FT_ADAPTOR               V8DBG_FRAMETYPE_ARGUMENTSADAPTORFRAME
+
+/* Identification masks and tags */
+#define V8_SmiTagMask               V8DBG_SMITAGMASK
+#define V8_SmiTag                   V8DBG_SMITAG
+#define V8_SmiValueShift            V8_SmiTagMask
+
+#define V8_HeapObjectTagMask        V8DBG_HEAPOBJECTTAGMASK
+#define V8_HeapObjectTag            V8DBG_HEAPOBJECTTAG
+
+#define V8_IsNotStringMask          V8DBG_ISNOTSTRINGMASK
+#define V8_StringTag                V8DBG_STRINGTAG
+
+#define V8_StringEncodingMask       V8DBG_STRINGENCODINGMASK
+#define V8_AsciiStringTag           V8DBG_ASCIISTRINGTAG
+
+#define V8_StringRepresentationMask V8DBG_STRINGREPRESENTATIONMASK
+#define V8_SeqStringTag             V8DBG_SEQSTRINGTAG
+#define V8_ConsStringTag            V8DBG_CONSSTRINGTAG
+#define V8_ExternalStringTag        V8DBG_EXTERNALSTRINGTAG
+
+/* Instance types */
+#define V8_IT_FIXEDARRAY            V8DBG_TYPE_FIXEDARRAY__FIXED_ARRAY_TYPE
+#define V8_IT_CODE                  V8DBG_TYPE_CODE__CODE_TYPE
+
+/* Node-specific offsets */
+#define NODE_OFF_EXTSTR_DATA        0x4
+
+/* Heap class->field offsets */
+#define V8_OFF_HEAP(off)            ((off) - 1)
+
+#define V8_OFF_FUNC_SHARED  \
+    V8_OFF_HEAP(V8DBG_CLASS_JSFUNCTION__SHARED__SHAREDFUNCTIONINFO)
+#define V8_OFF_SHARED_NAME  \
+    V8_OFF_HEAP(V8DBG_CLASS_SHAREDFUNCTIONINFO__NAME__OBJECT)
+#define V8_OFF_SHARED_INFERRED  \
+    V8_OFF_HEAP(V8DBG_CLASS_SHAREDFUNCTIONINFO__INFERRED_NAME__STRING)
+#define V8_OFF_SHARED_SCRIPT  \
+    V8_OFF_HEAP(V8DBG_CLASS_SHAREDFUNCTIONINFO__SCRIPT__OBJECT)
+#define V8_OFF_SHARED_FUNTOK  \
+    V8_OFF_HEAP(V8DBG_CLASS_SHAREDFUNCTIONINFO__FUNCTION_TOKEN_POSITION__SMI)
+#define V8_OFF_SCRIPT_NAME  \
+    V8_OFF_HEAP(V8DBG_CLASS_SCRIPT__NAME__OBJECT)
+#define V8_OFF_SCRIPT_LENDS \
+    V8_OFF_HEAP(V8DBG_CLASS_SCRIPT__LINE_ENDS__OBJECT)
+#define V8_OFF_STR_LENGTH \
+    V8_OFF_HEAP(V8DBG_CLASS_STRING__LENGTH__SMI)
+#define V8_OFF_STR_CHARS  \
+    V8_OFF_HEAP(V8DBG_CLASS_SEQASCIISTRING__CHARS__CHAR)
+#define V8_OFF_CONSSTR_CAR  \
+    V8_OFF_HEAP(V8DBG_CLASS_CONSSTRING__FIRST__STRING)
+#define V8_OFF_CONSSTR_CDR  \
+    V8_OFF_HEAP(V8DBG_CLASS_CONSSTRING__SECOND__STRING)
+#define V8_OFF_EXTSTR_RSRC  \
+    V8_OFF_HEAP(V8DBG_CLASS_EXTERNALSTRING__RESOURCE__OBJECT)
+#define V8_OFF_FA_SIZE    \
+    V8_OFF_HEAP(V8DBG_CLASS_FIXEDARRAYBASE__LENGTH__SMI)
+#define V8_OFF_FA_DATA    \
+    V8_OFF_HEAP(V8DBG_CLASS_FIXEDARRAY__DATA__UINTPTR_T)
+#define V8_OFF_HEAPOBJ_MAP  \
+    V8_OFF_HEAP(V8DBG_CLASS_HEAPOBJECT__MAP__MAP)
+#define V8_OFF_MAP_ATTRS  \
+    V8_OFF_HEAP(V8DBG_CLASS_MAP__INSTANCE_ATTRIBUTES__INT)
+
+#endif /* V8_ABBR_H */

src/v8ustack.d

@@ -11,6 +11,7 @@
  */
 
 #include <v8constants.h>
+#include <v8abbr.h>
 
 /*
  * V8 represents small integers (SMI) using the upper 31 bits of a 32-bit

tools/genv8constants.py

@@ -0,0 +1,82 @@
+#!/usr/bin/env python
+
+#
+# genv8constants.py output_file libv8_base.a
+#
+# Emits v8dbg constants stored in libv8_base.a in a format suitable for the V8
+# ustack helper.
+#
+
+import re
+import subprocess
+import sys
+
+if len(sys.argv) != 3:
+	print "usage: objsym.py outfile libv8_base.a"
+	sys.exit(2);
+
+outfile = file(sys.argv[1], 'w');
+pipe = subprocess.Popen([ 'objdump', '-z', '-D', sys.argv[2] ],
+    stdout=subprocess.PIPE).stdout;
+pattern = re.compile('00000000 <(v8dbg_.*)>:');
+numpattern = re.compile('[0-9a-fA-F]{2}');
+
+outfile.write("""
+/*
+ * File automatically generated by genv8constants. Do not edit.
+ *
+ * The following offsets are dynamically from libv8_base.a.  See src/v8ustack.d
+ * for details on how these values are used.
+ */
+
+#ifndef V8_CONSTANTS_H
+#define V8_CONSTANTS_H
+
+#if defined(__i386)
+""");
+
+curr_sym = None;
+curr_val = 0;
+curr_octet = 0;
+
+for line in pipe:
+	if curr_sym != None:
+		#
+		# This bit of code has nasty knowledge of the objdump text output
+		# format, but this is the most obvious robust approach.  We could almost
+		# rely on looking at numbered fields, but some instructions look very
+		# much like hex numbers (e.g., "adc"), and we don't want to risk picking
+		# those up by mistake, so we look at character-based columns intead.
+		#
+		for i in range (0, 3):
+			# 6-character margin, 2-characters + 1 space for each field
+			idx = 6 + i * 3;
+			octetstr = line[idx:idx+2]
+			if not numpattern.match(octetstr):
+				break;
+
+			curr_val += int('0x%s' % octetstr, 16) << (curr_octet * 8);
+			curr_octet += 1;
+
+		if curr_octet < 4:
+			continue;
+
+		outfile.write("#define %s 0x%x\n" % (curr_sym.upper(), curr_val));
+		curr_sym = None;
+		curr_val = 0;
+		curr_octet = 0;
+		continue;
+
+	match = pattern.match(line)
+	if match == None:
+		continue;
+
+	curr_sym = match.group(1);
+
+outfile.write("""
+#else
+#error "only i386 is supported for DTrace ustack helper"
+#endif
+
+#endif /* V8_CONSTANTS_H */
+""");