Merge branch 'warnings' into blead

These several commits silence warnings specific to Microsoft compilers.
They are bogus warnings as far as we can determine, but persist through
many versions of the compilers.

commit 6879a07bc8b8e75c35d0e3b765ea718cc1c7aeb2
*Author: Tomasz Konojacki <me@xenu.pl>
 Date:   Thu Apr 4 22:39:38 2019 +0200

     implement diagnostics ignore/restore macros for Visual C++

gave the easy infrastructure to turn off such warnings, but adding lines
to take advantage of this makes the code harder to read, and we came up
with alternative methods to shut the compiler up that are less
intrusive, involving casting, and subtracting from 0 instead of a unary
minus, that should be valid across platforms.

There were several other warnings I left in, because it would have
required more research than I have time for right now to be sure that
they are bogus.

diff --git a/pp.c b/pp.c
index 1d83b08..babf348 100644 (file)
--- a/pp.c
+++ b/pp.c
@@ -1316,8 +1316,9 @@ PP(pp_multiply)
                    alow = aiv;
                    auvok = TRUE; /* effectively it's a UV now */
                } else {
-                    /* abs, auvok == false records sign */
-                   alow = -(UV)aiv;
+                    /* abs, auvok == false records sign; Using 0- here and
+                     * later to silence bogus warning from MS VC */
+                   alow = (UV) (0 - (UV) aiv);
                }
            }
            if (buvok) {
@@ -1329,7 +1330,7 @@ PP(pp_multiply)
                    buvok = TRUE; /* effectively it's a UV now */
                } else {
                     /* abs, buvok == false records sign */
-                   blow = -(UV)biv;
+                   blow = (UV) (0 - (UV) biv);
                }
            }
 
@@ -1564,7 +1565,7 @@ PP(pp_modulo)
                     right = biv;
                     right_neg = FALSE; /* effectively it's a UV now */
                 } else {
-                    right = -(UV)biv;
+                   right = (UV) (0 - (UV) biv);
                 }
             }
         }
@@ -1594,7 +1595,7 @@ PP(pp_modulo)
                         left = aiv;
                         left_neg = FALSE; /* effectively it's a UV now */
                     } else {
-                        left = -(UV)aiv;
+                        left = (UV) (0 - (UV) aiv);
                     }
                 }
         }
@@ -1893,7 +1894,7 @@ PP(pp_subtract)
                        auv = aiv;
                        auvok = 1;      /* Now acting as a sign flag.  */
                    } else {
-                       auv = -(UV)aiv;
+                        auv = (UV) (0 - (UV) aiv);
                    }
                }
                a_valid = 1;
@@ -1913,7 +1914,7 @@ PP(pp_subtract)
                    buv = biv;
                    buvok = 1;
                } else
-                    buv = -(UV)biv;
+                    buv = (UV) (0 - (UV) biv);
            }
            /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
               else "IV" now, independent of how it came in.

diff --git a/pp_hot.c b/pp_hot.c
index 7c6b3a8..7d5ffc0 100644 (file)
--- a/pp_hot.c
+++ b/pp_hot.c
@@ -1526,7 +1526,9 @@ PP(pp_add)
                        auv = aiv;
                        auvok = 1;      /* Now acting as a sign flag.  */
                    } else {
-                       auv = -(UV)aiv;
+                        /* Using 0- here and later to silence bogus warning
+                         * from MS VC */
+                        auv = (UV) (0 - (UV) aiv);
                    }
                }
                a_valid = 1;
@@ -1546,7 +1548,7 @@ PP(pp_add)
                    buv = biv;
                    buvok = 1;
                } else
-                    buv = -(UV)biv;
+                    buv = (UV) (0 - (UV) biv);
            }
            /* ?uvok if value is >= 0. basically, flagged as UV if it's +ve,
               else "IV" now, independent of how it came in.

diff --git a/regcomp.c b/regcomp.c
index c5ec281..4583236 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -14648,8 +14648,10 @@ S_regatom(pTHX_ RExC_state_t *pRExC_state, I32 *flagp, U32 depth)
           loopdone:   /* Jumped to when encounters something that shouldn't be
                          in the node */
 
-            /* Free up any over-allocated space */
-            change_engine_size(pRExC_state, - (initial_size - STR_SZ(len)));
+            /* Free up any over-allocated space; cast is to silence bogus
+             * warning in MS VC */
+            change_engine_size(pRExC_state,
+                                - (Ptrdiff_t) (initial_size - STR_SZ(len)));
 
             /* I (khw) don't know if you can get here with zero length, but the
              * old code handled this situation by creating a zero-length EXACT

diff --git a/sv.c b/sv.c
index b6d9123..7aa35ab 100644 (file)
--- a/sv.c
+++ b/sv.c
@@ -2903,7 +2903,8 @@ S_uiv_2buf(char *const buf, const IV iv, UV uv, const int is_uv, char **const pe
        uv = iv;
        sign = 0;
     } else {
-        uv = -(UV)iv;
+        /* Using 0- here to silence bogus warning from MS VC */
+        uv = (UV) (0 - (UV) iv);
        sign = 1;
     }
 
@@ -12651,7 +12652,8 @@ Perl_sv_vcatpvfn_flags(pTHX_ SV *const sv, const char *const pat, const STRLEN p
                             esignbuf[esignlen++] = plus;
                     }
                     else {
-                        uv = -(UV)iv;
+                        /* Using 0- here to silence bogus warning from MS VC */
+                        uv = (UV) (0 - (UV) iv);
                         esignbuf[esignlen++] = '-';
                     }
                 }