From 0f412b6beb1319255834b7062c000a1295140e4b Mon Sep 17 00:00:00 2001
From: acqn <acqn163@outlook.com>
Date: Mon, 27 Jul 2020 18:25:28 +0800
Subject: [PATCH] Small fixes according to PR review.

---
 src/cc65/datatype.c | 10 ++++++++--
 src/cc65/declare.c  |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/cc65/datatype.c b/src/cc65/datatype.c
index 3f2725659..4da9a8727 100644
--- a/src/cc65/datatype.c
+++ b/src/cc65/datatype.c
@@ -278,7 +278,8 @@ long GetIntegerTypeMin (const Type* Type)
 /* Get the smallest possible value of the integer type */
 {
     if (IsSignSigned (Type)) {
-        return (long)(0xFFFFFFFF << (CHAR_BITS * SizeOf (Type) - 1U));
+        /* The smallest possible signed value of N-byte integer is -pow(2, 8*N-1) */
+        return (long)((unsigned long)(-1L) << (CHAR_BITS * SizeOf (Type) - 1U));
     } else {
         return 0;
     }
@@ -290,9 +291,14 @@ unsigned long GetIntegerTypeMax (const Type* Type)
 /* Get the largest possible value of the integer type */
 {
     if (IsSignSigned (Type)) {
+        /* Min signed value of N-byte integer is pow(2, 8*N-1) - 1 */
         return (1UL << (CHAR_BITS * SizeOf (Type) - 1U)) - 1UL;
     } else {
-        return (1UL << (CHAR_BITS * SizeOf (Type))) - 1UL;
+        /* Max signed value of N-byte integer is pow(2, 8*N) - 1. However,
+        ** workaround is needed as in ISO C it is UB if the shift count is
+        ** equal to the bit width of the left operand type.
+        */
+        return (1UL << 1U << (CHAR_BITS * SizeOf (Type) - 1U)) - 1UL;
     }
 }
 
diff --git a/src/cc65/declare.c b/src/cc65/declare.c
index 49e233a56..ba4091c3b 100644
--- a/src/cc65/declare.c
+++ b/src/cc65/declare.c
@@ -686,7 +686,7 @@ static int ParseFieldWidth (Declaration* Decl)
     ConstAbsIntExpr (hie1, &Expr);
     if (!IsClassInt (Decl->Type)) {
         /* Only integer types may be used for bit-fields */
-        Error ("Bit-field has invalid type ''");
+        Error ("Bit-field has invalid type '%s'", GetBasicTypeName (Decl->Type));
         return -1;
     }
     if (Expr.IVal < 0) {