From: David Malcolm <dmalcolm@redhat.com>
Date: Fri, 15 Sep 2023 17:47:42 +0000 (-0400)
Subject: analyzer: handle volatile ops
X-Git-Tag: basepoints/gcc-15~6099
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6319b5b2d4669077e4ddf1e249eeb5602394693c;p=thirdparty%2Fgcc.git

analyzer: handle volatile ops

gcc/analyzer/ChangeLog:
	* region-model.cc (region_model::get_gassign_result): Handle
	volatile ops by using a conjured_svalue.

gcc/testsuite/ChangeLog:
	* c-c++-common/analyzer/volatile-1.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>
---

diff --git a/gcc/analyzer/region-model.cc b/gcc/analyzer/region-model.cc
index 2e774c2824e7..c4e68661ef1e 100644
--- a/gcc/analyzer/region-model.cc
+++ b/gcc/analyzer/region-model.cc
@@ -729,6 +729,17 @@ region_model::get_gassign_result (const gassign *assign,
 				   region_model_context *ctxt)
 {
   tree lhs = gimple_assign_lhs (assign);
+
+  if (gimple_has_volatile_ops (assign)
+      && !gimple_clobber_p (assign))
+    {
+      conjured_purge p (this, ctxt);
+      return m_mgr->get_or_create_conjured_svalue (TREE_TYPE (lhs),
+						   assign,
+						   get_lvalue (lhs, ctxt),
+						   p);
+    }
+
   tree rhs1 = gimple_assign_rhs1 (assign);
   enum tree_code op = gimple_assign_rhs_code (assign);
   switch (op)
diff --git a/gcc/testsuite/c-c++-common/analyzer/volatile-1.c b/gcc/testsuite/c-c++-common/analyzer/volatile-1.c
new file mode 100644
index 000000000000..f8440d412201
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/analyzer/volatile-1.c
@@ -0,0 +1,18 @@
+#include "../../gcc.dg/analyzer/analyzer-decls.h"
+
+volatile int g;
+
+void test_global (void)
+{
+  int v1 = g;
+  int v2 = g;
+  __analyzer_eval (v1 == v2); /* { dg-warning "UNKNOWN" } */
+}
+
+void test_local (void)
+{
+  volatile int x = 0;
+  int v1 = x;
+  int v2 = x;
+  __analyzer_eval (v1 == v2); /* { dg-warning "UNKNOWN" } */
+}