From db613e8fa841259f74740665ee9e508bd73ea1c4 Mon Sep 17 00:00:00 2001
From: David Malcolm <dmalcolm@redhat.com>
Date: Tue, 26 Jul 2022 17:17:18 -0400
Subject: [PATCH] analyzer: fix false +ves from -Wanalyzer-va-arg-type-mismatch
 on int promotion [PR106319]

gcc/analyzer/ChangeLog:
	PR analyzer/106319
	* store.cc (store::set_value): Don't strip away casts if the
	region has NULL type.

gcc/testsuite/ChangeLog:
	PR analyzer/106319
	* gcc.dg/analyzer/stdarg-types-3.c: New test.
	* gcc.dg/analyzer/stdarg-types-4.c: New test.

Signed-off-by: David Malcolm <dmalcolm@redhat.com>
---
 gcc/analyzer/store.cc                          |  4 +-
 gcc/testsuite/gcc.dg/analyzer/stdarg-types-3.c | 67 ++++++++++++++++++++++++++
 gcc/testsuite/gcc.dg/analyzer/stdarg-types-4.c | 22 +++++++++
 3 files changed, 92 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/analyzer/stdarg-types-3.c
 create mode 100644 gcc/testsuite/gcc.dg/analyzer/stdarg-types-4.c

diff --git a/gcc/analyzer/store.cc b/gcc/analyzer/store.cc
index 0b3fb37..46475f6 100644
--- a/gcc/analyzer/store.cc
+++ b/gcc/analyzer/store.cc
@@ -2445,7 +2445,9 @@ store::set_value (store_manager *mgr, const region *lhs_reg,
 
   remove_overlapping_bindings (mgr, lhs_reg, uncertainty);
 
-  rhs_sval = simplify_for_binding (rhs_sval);
+  if (lhs_reg->get_type ())
+    rhs_sval = simplify_for_binding (rhs_sval);
+  /* ...but if we have no type for the region, retain any cast.  */
 
   const region *lhs_base_reg = lhs_reg->get_base_region ();
   binding_cluster *lhs_cluster;
diff --git a/gcc/testsuite/gcc.dg/analyzer/stdarg-types-3.c b/gcc/testsuite/gcc.dg/analyzer/stdarg-types-3.c
new file mode 100644
index 0000000..7351261
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/stdarg-types-3.c
@@ -0,0 +1,67 @@
+static void __attribute__((noinline))
+__analyzer_consume_n_ints (int num, ...)
+{
+  __builtin_va_list ap;
+  __builtin_va_start (ap, num);
+
+  int i, v;
+  for (i = 0; i < num; i++)
+    v = __builtin_va_arg (ap, int);
+
+  __builtin_va_end (ap);
+}
+
+void test_int (int x)
+{
+  __analyzer_consume_n_ints (1, x);
+}
+
+void test_3_ints (int x, int y, int z)
+{
+  __analyzer_consume_n_ints (3, x, y, z);
+}
+
+/* Verify that we don't complain about types that get promoted to int
+   at the variadic call.  */
+
+void test_short (short s)
+{
+  __analyzer_consume_n_ints (1, s);
+}
+
+void test_ushort (unsigned short s)
+{
+  __analyzer_consume_n_ints (1, s);
+}
+
+void test_schar (signed char ch)
+{
+  __analyzer_consume_n_ints (1, ch);
+}
+
+void test_uchar (unsigned char ch)
+{
+  __analyzer_consume_n_ints (1, ch);
+}
+
+struct ust
+{
+  int b0123 : 4;
+  int b4567 : 4;
+};
+
+void test_signed_bitfield (struct ust s)
+{
+  __analyzer_consume_n_ints (2, s.b0123, s.b4567);
+}
+
+struct sst
+{
+  unsigned int b0123 : 4;
+  unsigned int b4567 : 4;
+};
+
+void test_unsigned_bitfield (struct sst s)
+{
+  __analyzer_consume_n_ints (2, s.b0123, s.b4567);
+}
diff --git a/gcc/testsuite/gcc.dg/analyzer/stdarg-types-4.c b/gcc/testsuite/gcc.dg/analyzer/stdarg-types-4.c
new file mode 100644
index 0000000..920ecce
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/analyzer/stdarg-types-4.c
@@ -0,0 +1,22 @@
+static void __attribute__((noinline))
+__analyzer_consume_n_uints (int num, ...)
+{
+  __builtin_va_list ap;
+  __builtin_va_start (ap, num);
+
+  int i, v;
+  for (i = 0; i < num; i++)
+    v = __builtin_va_arg (ap, unsigned int);
+
+  __builtin_va_end (ap);
+}
+
+void test_uint (unsigned int x)
+{
+  __analyzer_consume_n_uints (1, x);
+}
+
+void test_3_uints (unsigned int x, unsigned int y, unsigned int z)
+{
+  __analyzer_consume_n_uints (3, x, y, z);
+}
-- 
2.7.4