In the reproducer for PR analyzer/58237 I noticed that some events were
missing locations (and text); for example event 3 here:
| 15 | while (fgets(buf, 10, fp) != NULL)
| | ~
| | |
| | (2) following 'false' branch...
|
'f1': event 3
|
|cc1:
|
'f1': event 4
|
|<source>:19:1:
| 19 | }
| | ^
| | |
| | (4) 'fp' leaks here; was opened at (1)
|
The root cause is that various places in the analyzer compare locations
against UNKNOWN_LOCATION, which fails to detect an unknown location for
the case where an unknown_location has been wrapped into an ad-hoc
location to record a block.
This patch fixes the issue by using get_pure_location whenever testing
against UNKNOWN_LOCATION to look through ad-hoc wrappers.
For the case above, it thus picks a better location in
supernode::get_start_location for event (3) above, improving it to:
| 15 | while (fgets(buf, 10, fp) != NULL)
| | ~
| | |
| | (2) following 'false' branch...
|......
| 19 | }
| | ~
| | |
| | (3) ...to here
| | (4) 'fp' leaks here; was opened at (1)
|
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to the dmalcolm/analyzer branch on the GCC git mirror.
gcc/analyzer/ChangeLog:
PR analyzer/58237
* engine.cc (leak_stmt_finder::find_stmt): Use get_pure_location
when comparing against UNKNOWN_LOCATION.
(stmt_requires_new_enode_p): Likewise.
(exploded_graph::dump_exploded_nodes): Likewise.
* supergraph.cc (supernode::get_start_location): Likewise.
(supernode::get_end_location): Likewise.
gcc/testsuite/ChangeLog:
PR analyzer/58237
* gcc.dg/analyzer/file-paths-1.c: New test.
---
gcc/analyzer/engine.cc | 8 +++----
gcc/analyzer/supergraph.cc | 10 ++++----
gcc/testsuite/gcc.dg/analyzer/file-paths-1.c | 25 ++++++++++++++++++++
3 files changed, 35 insertions(+), 8 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/analyzer/file-paths-1.c
diff --git a/gcc/analyzer/engine.cc b/gcc/analyzer/engine.cc
index 162940a2bfa9..6bbedc2072e6 100644
--- a/gcc/analyzer/engine.cc
+++ b/gcc/analyzer/engine.cc
@@ -388,7 +388,7 @@ public:
const program_point &dst_point = dst_node->get_point ();
const gimple *stmt = dst_point.get_stmt ();
if (stmt)
- if (stmt->location != UNKNOWN_LOCATION)
+ if (get_pure_location (stmt->location) != UNKNOWN_LOCATION)
return stmt;
}
@@ -2270,8 +2270,8 @@ stmt_requires_new_enode_p (const gimple *stmt,
could be consolidated into PREV_STMT, giving us an event with
no location. Ensure that STMT gets its own exploded_node to
avoid this. */
- if (prev_stmt->location == UNKNOWN_LOCATION
- && stmt->location != UNKNOWN_LOCATION)
+ if (get_pure_location (prev_stmt->location) == UNKNOWN_LOCATION
+ && get_pure_location (stmt->location) != UNKNOWN_LOCATION)
return true;
return false;
@@ -3067,7 +3067,7 @@ exploded_graph::dump_exploded_nodes () const
{
if (const gimple *stmt = enode->get_stmt ())
{
- if (richloc.get_loc () == UNKNOWN_LOCATION)
+ if (get_pure_location (richloc.get_loc ()) == UNKNOWN_LOCATION)
richloc.set_range (0, stmt->location, SHOW_RANGE_WITH_CARET);
else
richloc.add_range (stmt->location,
diff --git a/gcc/analyzer/supergraph.cc b/gcc/analyzer/supergraph.cc
index 59c9264d5a08..ba7f7c6d2994 100644
--- a/gcc/analyzer/supergraph.cc
+++ b/gcc/analyzer/supergraph.cc
@@ -525,13 +525,14 @@ supernode::dump_dot_id (pretty_printer *pp) const
location_t
supernode::get_start_location () const
{
- if (m_returning_call && m_returning_call->location != UNKNOWN_LOCATION)
+ if (m_returning_call
+ && get_pure_location (m_returning_call->location) != UNKNOWN_LOCATION)
return m_returning_call->location;
int i;
gimple *stmt;
FOR_EACH_VEC_ELT (m_stmts, i, stmt)
- if (stmt->location != UNKNOWN_LOCATION)
+ if (get_pure_location (stmt->location) != UNKNOWN_LOCATION)
return stmt->location;
if (entry_p ())
@@ -555,10 +556,11 @@ supernode::get_end_location () const
int i;
gimple *stmt;
FOR_EACH_VEC_ELT_REVERSE (m_stmts, i, stmt)
- if (stmt->location != UNKNOWN_LOCATION)
+ if (get_pure_location (stmt->location) != UNKNOWN_LOCATION)
return stmt->location;
- if (m_returning_call && m_returning_call->location != UNKNOWN_LOCATION)
+ if (m_returning_call
+ && get_pure_location (m_returning_call->location) != UNKNOWN_LOCATION)
return m_returning_call->location;
if (entry_p ())
diff --git a/gcc/testsuite/gcc.dg/analyzer/file-paths-1.c
b/gcc/testsuite/gcc.dg/analyzer/file-paths-1.c
new file mode 100644
index 000000000000..1c8bf61dd3fd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/file-paths-1.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+/* Verify that we correctly emit CFG events in the face of buffers
+ being clobbered in these leak reports. */
+
+void f1 (const char *str)
+{
+ FILE * fp = fopen(str, "r"); /* { dg-message "opened here" } */
+ char buf[10];
+
+ while (fgets(buf, 10, fp) != NULL) /* { dg-message "following 'false'
branch\\.\\.\\." } */
+ {
+ }
+} /* { dg-warning "leak of FILE 'fp'" } */
+/* { dg-message "\\.\\.\\.to here" "" { target *-*-* } .-1 } */
+
+void f2(const char *str, int flag)
+{
+ FILE * fp = fopen(str, "r"); /* { dg-message "opened here" } */
+ char buf[10];
+
+ if (flag) /* { dg-message "when 'flag == 0'" } */
+ fclose(fp);
+} /* { dg-warning "leak of FILE 'fp'" } */
+/* { dg-message "\\.\\.\\.to here" "" { target *-*-* } .-1 } */
--
2.21.0
