scripts/coccinelle: Add Coccinelle script for unsigned values

Add a Coccinelle script that adds an 'U' to values assigned to
unsigned variables, according ot MISRA-C rule 7.2.

Add a 'report' mode to the script that can be used by developer/CI
and a 'patch' mode that should do the heavy lifting.

Signed-off-by: Patrik Flykt <patrik.flykt@intel.com>

scripts/coccinelle/unsigned_suffix.cocci

@@ -0,0 +1,45 @@
+/// Find assignments to unsigned variables and add an 'U' to the value
+// Copyright: (C) 2018 Intel Corporation
+// Copyright: (C) 2018 Himanshu Jha
+// Copyright: (C) 2018 Julia Lawall, Inria/LIP6
+// SPDX-License-Identifier: Apache-2.0
+// Confidence: High
+
+virtual patch
+virtual report
+
+@r_unsigned@
+typedef uint8_t, uint16_t, uint32_t, uint64_t, u8_t, u16_t, u32_t, u64_t;
+{unsigned char, unsigned short, unsigned int, uint8_t, uint16_t, uint32_t, uint64_t, u8_t, u16_t, u32_t, u64_t} v;
+constant C;
+position p;
+@@
+
+  v = C@p
+
+@script:python r_rewrite@
+C << r_unsigned.C;
+z;
+@@
+
+if C.isdigit() != True:
+    cocci.include_match(False)
+
+coccinelle.z = C + "U"
+
+@r_subst depends on patch@
+{unsigned char, unsigned short, unsigned int, uint8_t, uint16_t, uint32_t, uint64_t, u8_t, u16_t, u32_t, u64_t} r_unsigned.v;
+constant r_unsigned.C;
+identifier r_rewrite.z;
+@@
+
+  v =
+- C
++ z
+
+@script: python depends on report@
+p << r_unsigned.p;
+@@
+
+msg="WARNING: Unsigned 'U' suffix missing"
+coccilib.report.print_report(p[0], msg)