[pango/harfbuzz-ng] [HB] Improve debug output and fix mprotect bug

[Behdad Esfahbod <behdad src gnome org>]

commit 77bde84243e5e03ffaf6940678ca920e00eea253
Author: Behdad Esfahbod <behdad behdad org>
Date:   Wed Aug 5 15:20:34 2009 -0400

    [HB] Improve debug output and fix mprotect bug

 pango/opentype/hb-blob.c               |   57 +++++++++++++++++++++++++++----
 pango/opentype/hb-open-type-private.hh |   30 ++++++++---------
 pango/opentype/hb-private.h            |    3 +-
 3 files changed, 65 insertions(+), 25 deletions(-)
---
diff --git a/pango/opentype/hb-blob.c b/pango/opentype/hb-blob.c
index c655aa1..59c3974 100644
--- a/pango/opentype/hb-blob.c
+++ b/pango/opentype/hb-blob.c
@@ -173,6 +173,11 @@ hb_blob_lock (hb_blob_t *blob)
   if (!HB_OBJECT_IS_INERT (blob))
     (void) _hb_reference_count_inc (blob->lock);
 
+#if HB_DEBUG
+	fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
+		 HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
+#endif
+
   return blob->data;
 }
 
@@ -183,6 +188,11 @@ hb_blob_unlock (hb_blob_t *blob)
     int old_lock = _hb_reference_count_inc (blob->lock);
     assert (old_lock > 0);
   }
+
+#if HB_DEBUG
+	fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
+		 HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
+#endif
 }
 
 hb_bool_t
@@ -195,20 +205,44 @@ hb_bool_t
 hb_blob_try_writeable_inplace (hb_blob_t *blob)
 {
   if (blob->mode == HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITEABLE) {
-    int pagesize;
-    unsigned int length;
+    unsigned int pagesize, mask, length;
     const char *addr;
 
-    pagesize = sysconf(_SC_PAGE_SIZE);
-    if (-1 == pagesize)
+#if HB_DEBUG
+	fprintf (stderr, "%p %s: making writeable\n", blob, __FUNCTION__);
+#endif
+    pagesize = (unsigned int) sysconf(_SC_PAGE_SIZE);
+    if ((unsigned int) -1 == pagesize) {
+#if HB_DEBUG
+	fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
+#endif
       return FALSE;
-
-    addr = (const char *) (((size_t) blob->data) & pagesize);
-    length = (const char *) (((size_t) blob->data + blob->length + pagesize-1) & pagesize)  - addr;
-    if (-1 == mprotect ((void *) addr, length, PROT_READ | PROT_WRITE))
+    }
+#if HB_DEBUG
+    fprintf (stderr, "%p %s: pagesize is %u\n", blob, __FUNCTION__, pagesize);
+#endif
+
+    mask = ~(pagesize-1);
+    addr = (const char *) (((size_t) blob->data) & mask);
+    length = (const char *) (((size_t) blob->data + blob->length + pagesize-1) & mask)  - addr;
+#if HB_DEBUG
+    fprintf (stderr, "%p %s: calling mprotect on [%p..%p] (%d bytes)\n",
+	     blob, __FUNCTION__,
+	     addr, addr+length, length);
+#endif
+    if (-1 == mprotect ((void *) addr, length, PROT_READ | PROT_WRITE)) {
+#if HB_DEBUG
+	fprintf (stderr, "%p %s: %s\n", blob, __FUNCTION__, strerror (errno));
+#endif
       return FALSE;
+    }
 
     blob->mode = HB_MEMORY_MODE_WRITEABLE;
+#if HB_DEBUG
+    fprintf (stderr, "%p %s: successfully made [%p..%p] (%d bytes) writeable\n",
+	     blob, __FUNCTION__,
+	     addr, addr+length, length);
+#endif
   }
 
   return blob->mode == HB_MEMORY_MODE_WRITEABLE;
@@ -224,11 +258,18 @@ hb_blob_try_writeable (hb_blob_t *blob)
   {
     char *new_data;
 
+#if HB_DEBUG
+	fprintf (stderr, "%p %s (%d) -> %p\n", blob, __FUNCTION__,
+		 HB_REFERENCE_COUNT_GET_VALUE (blob->lock), blob->data);
+#endif
     if (HB_REFERENCE_COUNT_HAS_REFERENCE (blob->lock))
       return FALSE;
 
     new_data = malloc (blob->length);
     if (new_data) {
+#if HB_DEBUG
+      fprintf (stderr, "%p %s: dupped successfully -> %p\n", blob, __FUNCTION__, blob->data);
+#endif
       memcpy (new_data, blob->data, blob->length);
       blob->data = new_data;
       blob->mode = HB_MEMORY_MODE_WRITEABLE;
diff --git a/pango/opentype/hb-open-type-private.hh b/pango/opentype/hb-open-type-private.hh
index cadba2c..9bd16e2 100644
--- a/pango/opentype/hb-open-type-private.hh
+++ b/pango/opentype/hb-open-type-private.hh
@@ -203,16 +203,16 @@ struct Null <Type> \
  * Sanitize
  */
 
-#if HB_DEBUG
+#if HB_DEBUG >= 5
 #define SANITIZE_DEBUG_ARG_DEF	, unsigned int sanitize_depth
 #define SANITIZE_DEBUG_ARG	, sanitize_depth + 1
 #define SANITIZE_DEBUG_ARG_INIT	, 0
 #define SANITIZE_DEBUG() \
 	HB_STMT_START { \
-		printf ("SANITIZE(%p) %-*d-> %s\n", \
-			(CONST_CHARP (this) == NullPool) ? 0 : this, \
-			sanitize_depth+1, sanitize_depth, \
-			__PRETTY_FUNCTION__); \
+		fprintf (stderr, "SANITIZE(%p) %-*d-> %s\n", \
+			 (CONST_CHARP (this) == NullPool) ? 0 : this, \
+			 sanitize_depth+1, sanitize_depth, \
+			 __PRETTY_FUNCTION__); \
 	} HB_STMT_END
 #else
 #define SANITIZE_DEBUG_ARG_DEF
@@ -239,9 +239,8 @@ _hb_sanitize_init (hb_sanitize_context_t *context,
   context->edit_count = 0;
 
 #if HB_DEBUG
-  printf ("sanitize %p init [%p..%p] (%u bytes)\n",
-	  context->blob, context->start, context->end, context->start - context->end);
-
+  fprintf (stderr, "sanitize %p init [%p..%p] (%u bytes)\n",
+	   context->blob, context->start, context->end, context->start - context->end);
 #endif
 }
 
@@ -250,9 +249,8 @@ _hb_sanitize_fini (hb_sanitize_context_t *context,
 		   bool unlock)
 {
 #if HB_DEBUG
-  printf ("sanitize %p fini [%p..%p] %u edit requests\n",
-	  context->blob, context->start, context->end, context->edit_count);
-
+  fprintf (stderr, "sanitize %p fini [%p..%p] %u edit requests\n",
+	   context->blob, context->start, context->end, context->edit_count);
 #endif
 
   if (unlock)
@@ -268,8 +266,8 @@ _hb_sanitize_edit (hb_sanitize_context_t *context,
   context->edit_count++;
 
 #if HB_DEBUG
-  printf ("sanitize %p edit %u requested for [%p..%p] (%d bytes) in [%p..%p] -> %s\n",
-	  context->blob,
+  fprintf (stderr, "sanitize %p edit %u requested for [%p..%p] (%d bytes) in [%p..%p] -> %s\n",
+	   context->blob,
 	  context->edit_count,
 	  base, base+len, len,
 	  context->start, context->end,
@@ -316,7 +314,7 @@ struct Sanitizer
 
   retry:
 #if HB_DEBUG
-    printf ("Sanitizer %p start %s\n", blob, __PRETTY_FUNCTION__);
+    fprintf (stderr, "Sanitizer %p start %s\n", blob, __PRETTY_FUNCTION__);
 #endif
 
     _hb_sanitize_init (&context, blob);
@@ -340,14 +338,14 @@ struct Sanitizer
       if (edit_count && !hb_blob_is_writeable (blob) && hb_blob_try_writeable (blob)) {
         /* ok, we made it writeable by relocating.  try again */
 #if HB_DEBUG
-	printf ("Sanitizer %p retry %s\n", blob, __PRETTY_FUNCTION__);
+	fprintf (stderr, "Sanitizer %p retry %s\n", blob, __PRETTY_FUNCTION__);
 #endif
         goto retry;
       }
     }
 
 #if HB_DEBUG
-    printf ("Sanitizer %p %s %s\n", blob, sane ? "passed" : "failed", __PRETTY_FUNCTION__);
+    fprintf (stderr, "Sanitizer %p %s %s\n", blob, sane ? "passed" : "failed", __PRETTY_FUNCTION__);
 #endif
     if (sane)
       return blob;
diff --git a/pango/opentype/hb-private.h b/pango/opentype/hb-private.h
index eaade51..55bedad 100644
--- a/pango/opentype/hb-private.h
+++ b/pango/opentype/hb-private.h
@@ -40,7 +40,8 @@
 #include <string.h>
 #include <assert.h>
 #if HB_DEBUG
-#include <stdio.h> /* XXX */
+#include <stdio.h>
+#include <errno.h>
 #endif
 
 #include "hb-common.h"