PVS/V1028: cast operands, not the result

3 files changed, 33 insertions, 19 deletions

diff --git a/src/nvim/assert.h b/src/nvim/assert.h
index 48c5363d5a..3f985475a7 100644
--- a/src/nvim/assert.h
+++ b/src/nvim/assert.h
@@ -15,10 +15,6 @@
 # define __has_extension __has_feature
 #endif
 
-#ifndef __has_builtin
-# define __has_builtin __has_feature
-#endif
-
 /// @def STATIC_ASSERT
 /// @brief Assert at compile time if condition is not satisfied.
 ///
@@ -136,20 +132,22 @@
 ///
 /// @param MAX Maximum value of the narrowest type of operand.
 ///            Not used if compiler supports __builtin_add_overflow.
-#if __has_builtin(__builtin_add_overflow)
-# define STRICT_ADD(a, b, c) \
+#if (defined(__clang__) && __has_builtin(__builtin_add_overflow)) \
+  || (__GNUC__ >= 5)
+# define STRICT_ADD(a, b, c, t) \
   do { if (__builtin_add_overflow(a, b, c)) { abort(); } } while (0)
 #else
-# define STRICT_ADD(a, b, c) \
-  do { *c = a + b; } while (0)
+# define STRICT_ADD(a, b, c, t) \
+  do { *(c) = (t)(a + b); } while (0)
 #endif
 
-#if __has_builtin(__builtin_sub_overflow)
-# define STRICT_SUB(a, b, c) \
+#if (defined(__clang__) && __has_builtin(__builtin_sub_overflow)) \
+  || (__GNUC__ >= 5)
+# define STRICT_SUB(a, b, c, t) \
   do { if (__builtin_sub_overflow(a, b, c)) { abort(); } } while (0)
 #else
-# define STRICT_SUB(a, b, c) \
-  do { *c = a - b; } while (0)
+# define STRICT_SUB(a, b, c, t) \
+  do { *(c) = (t)(a - b); } while (0)
 #endif
 
 #endif  // NVIM_ASSERT_H
diff --git a/src/nvim/cursor.c b/src/nvim/cursor.c
index ee1bc6cf31..409eb653a0 100644
--- a/src/nvim/cursor.c
+++ b/src/nvim/cursor.c
@@ -4,6 +4,7 @@
 #include <stdbool.h>
 #include <inttypes.h>
 
+#include "nvim/assert.h"
 #include "nvim/cursor.h"
 #include "nvim/charset.h"
 #include "nvim/fold.h"
@@ -170,7 +171,9 @@ static int coladvance2(
       if (line[idx] == NUL) {
         /* Append spaces */
         int correct = wcol - col;
-        char_u *newline = xmallocz((size_t)(idx + correct));
+        size_t newline_size;
+        STRICT_ADD(idx, correct, &newline_size, size_t);
+        char_u *newline = xmallocz(newline_size);
         memcpy(newline, line, (size_t)idx);
         memset(newline + idx, ' ', (size_t)correct);
 
@@ -187,14 +190,17 @@ static int coladvance2(
         if (-correct > csize)
           return FAIL;
 
-        newline = xmallocz((size_t)(linelen - 1 + csize));
+        size_t n;
+        STRICT_ADD(linelen - 1, csize, &n, size_t);
+        newline = xmallocz(n);
         // Copy first idx chars
         memcpy(newline, line, (size_t)idx);
         // Replace idx'th char with csize spaces
         memset(newline + idx, ' ', (size_t)csize);
         // Copy the rest of the line
-        memcpy(newline + idx + csize, line + idx + 1,
-               (size_t)(linelen - idx - 1));
+        STRICT_SUB(linelen, idx, &n, size_t);
+        STRICT_SUB(n, 1, &n, size_t);
+        memcpy(newline + idx + csize, line + idx + 1, n);
 
         ml_replace(pos->lnum, newline, false);
         changed_bytes(pos->lnum, idx);
diff --git a/src/nvim/indent.c b/src/nvim/indent.c
index 7c3f354c13..13534ac1a9 100644
--- a/src/nvim/indent.c
+++ b/src/nvim/indent.c
@@ -6,6 +6,7 @@
 #include <stdbool.h>
 
 #include "nvim/ascii.h"
+#include "nvim/assert.h"
 #include "nvim/indent.h"
 #include "nvim/eval.h"
 #include "nvim/charset.h"
@@ -204,7 +205,12 @@ int set_indent(int size, int flags)
   // after the if (!curbuf->b_p_et) below.
   if (orig_char_len != -1) {
     assert(orig_char_len + size - ind_done + line_len >= 0);
-    newline = xmalloc((size_t)(orig_char_len + size - ind_done + line_len));
+    size_t n;  // = orig_char_len + size - ind_done + line_len
+    size_t n2;
+    STRICT_ADD(orig_char_len, size, &n, size_t);
+    STRICT_ADD(ind_done, line_len, &n2, size_t);
+    STRICT_SUB(n, n2, &n, size_t);
+    newline = xmalloc(n);
     todo = size - ind_done;
 
     // Set total length of indent in characters, which may have been
@@ -226,7 +232,9 @@ int set_indent(int size, int flags)
   } else {
     todo = size;
     assert(ind_len + line_len >= 0);
-    newline = xmalloc((size_t)(ind_len + line_len));
+    size_t newline_size;
+    STRICT_ADD(ind_len, line_len, &newline_size, size_t);
+    newline = xmalloc(newline_size);
     s = newline;
   }
 
@@ -392,7 +400,9 @@ int copy_indent(int size, char_u *src)
       // and the rest of the line.
       line_len = (int)STRLEN(get_cursor_line_ptr()) + 1;
       assert(ind_len + line_len >= 0);
-      line = xmalloc((size_t)(ind_len + line_len));
+      size_t line_size;
+      STRICT_ADD(ind_len, line_len, &line_size, size_t);
+      line = xmalloc(line_size);
       p = line;
     }
   }