The Region Model example in the analyzer internals docs had a few
inconsistencies with the dumps. Fix these, and add a note that
heap-allocated region numbering depends on traversal order.
gcc/ChangeLog:
* doc/analyzer.texi (Region Model): Use malloc (n) in the
example to match the dump; fix the frame for the result_4
cluster; correct the heap region number; note that heap region
numbering depends on traversal order.
Signed-off-by: Egas Ribeiro <[email protected]>
---
gcc/doc/analyzer.texi | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/gcc/doc/analyzer.texi b/gcc/doc/analyzer.texi
index 05ae4ae3955..5d043dcdb4f 100644
--- a/gcc/doc/analyzer.texi
+++ b/gcc/doc/analyzer.texi
@@ -322,7 +322,7 @@ Consider this example C code:
void *
calls_malloc (size_t n)
@{
- void *result = malloc (1024);
+ void *result = malloc (n);
return result; /* HERE */
@}
@@ -373,8 +373,8 @@ various local variables within frames for @code{test} and
within @code{test} the whole cluster for @code{_1} is bound
to a @code{binop_svalue} representing @code{n * 4}, and
@item
-within @code{test} the whole cluster for @code{result_4} is bound to a
-@code{region_svalue} pointing at @code{HEAP_ALLOCATED_REGION(12)}.
+within @code{calls_malloc} the whole cluster for @code{result_4} is bound to a
+@code{region_svalue} pointing at @code{HEAP_ALLOCATED_REGION(27)}.
@end itemize
Additionally, this latter pointer has the @code{unchecked} state for the
@@ -384,6 +384,12 @@ Additionally, this latter pointer has the @code{unchecked}
state for the
We also see that the state has captured the size of the heap-allocated
region (``Dynamic Extents'').
+@noindent
+The specific numbering of heap-allocated regions (such as the ``27'' in
+@code{HEAP_ALLOCATED_REGION(27)} above) depend on what other code has been
+explored and in what order before this point is reached, and thus should not be
+relied upon.
+
This visualization can also be seen within the output of
@option{-fdump-analyzer-exploded-nodes-2} and
@option{-fdump-analyzer-exploded-nodes-3}.
--
2.54.0
