removed usage of static buffers (#7005)

* copied commit from local branch

* restore uint64_t

* new signature in two new call sites

* restore diff lost to sloppy merge

* corrected error from conflict resolution

* scrapped and redone

---------

Co-authored-by: Michael Chirico <[email protected]>
Co-authored-by: Michael Chirico <[email protected]>

Author: badasahog

src/fread.c

@@ -210,19 +210,14 @@ static inline int64_t clamp_i64t(int64_t x, int64_t lower, int64_t upper) {
  * is constructed manually (using say snprintf) that warning(), stop()
  * and Rprintf() are all called as warning(_("%s"), msg) and not warning(msg).
  */
-static const char* strlim(const char *ch, size_t limit) {
-  static char buf[1002];
-  static int flip = 0;
-  char *ptr = buf + 501 * flip;
-  flip = 1 - flip;
-  char *ch2 = ptr;
-  limit = imin(limit, 500);
+static const char* strlim(const char *ch, char buf[static 500], size_t limit) {
+  char *ch2 = buf;
   size_t width = 0;
   while ((*ch > '\r' || (*ch != '\0' && *ch != '\r' && *ch != '\n')) && width++ < limit) {
     *ch2++ = *ch++;
   }
   *ch2 = '\0';
-  return ptr;
+  return buf;
 }
 
 static const char *typeLetter = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
@@ -1638,7 +1633,7 @@ int freadMain(freadMainArgs _args) {
   if (ch >= eof) STOP(_("Input is either empty, fully whitespace, or skip has been set after the last non-whitespace."));
   if (verbose) {
     if (lineStart > ch) DTPRINT(_("  Moved forward to first non-blank line (%d)\n"), row1line);
-    DTPRINT(_("  Positioned on line %d starting: <<%s>>\n"), row1line, strlim(lineStart, 30));
+    DTPRINT(_("  Positioned on line %d starting: <<%s>>\n"), row1line, strlim(lineStart, (char[500]) {}, 30));
   }
   ch = pos = lineStart;
   }
@@ -1829,7 +1824,7 @@ int freadMain(freadMainArgs _args) {
     if (!fill && tt != ncol) INTERNAL_STOP("first line has field count %d but expecting %d", tt, ncol); // # nocov
     if (verbose) {
       DTPRINT(_("  Detected %d columns on line %d. This line is either column names or first data row. Line starts as: <<%s>>\n"),
-              tt, row1line, strlim(pos, 30));
+              tt, row1line, strlim(pos, (char[500]) {}, 30));
       DTPRINT(_("  Quote rule picked = %d\n"), quoteRule);
       DTPRINT(_("  fill=%s and the most number of columns found is %d\n"), fill ? "true" : "false", ncol);
     }
@@ -2759,23 +2754,23 @@ int freadMain(freadMainArgs _args) {
       while (ch < eof && *ch != '\n' && *ch != '\r') ch++;
       while (ch < eof && isspace(*ch)) ch++;
       if (ch == eof) {
-        DTWARN(_("Discarded single-line footer: <<%s>>"), strlim(skippedFooter, 500));
+        DTWARN(_("Discarded single-line footer: <<%s>>"), strlim(skippedFooter, (char[500]) {}, 500));
       }
       else {
         ch = headPos;
         int tt = countfields(&ch);
         if (fill > 0) {
           DTWARN(_("Stopped early on line %"PRId64". Expected %d fields but found %d. Consider fill=%d or even more based on your knowledge of the input file. Use fill=Inf for reading the whole file for detecting the number of fields. First discarded non-empty line: <<%s>>"),
-          DTi+row1line, ncol, tt, tt, strlim(skippedFooter, 500));
+          DTi+row1line, ncol, tt, tt, strlim(skippedFooter, (char[500]) {}, 500));
         } else {
           DTWARN(_("Stopped early on line %"PRId64". Expected %d fields but found %d. Consider fill=TRUE. First discarded non-empty line: <<%s>>"),
-          DTi+row1line, ncol, tt, strlim(skippedFooter, 500));
+          DTi+row1line, ncol, tt, strlim(skippedFooter, (char[500]) {}, 500));
         }
       }
     }
   }
   if (quoteRuleBumpedCh != NULL && quoteRuleBumpedCh<headPos) {
-    DTWARN(_("Found and resolved improper quoting out-of-sample. First healed line %"PRId64": <<%s>>. If the fields are not quoted (e.g. field separator does not appear within any field), try quote=\"\" to avoid this warning."), quoteRuleBumpedLine, strlim(quoteRuleBumpedCh, 500));
+    DTWARN(_("Found and resolved improper quoting out-of-sample. First healed line %"PRId64": <<%s>>. If the fields are not quoted (e.g. field separator does not appear within any field), try quote=\"\" to avoid this warning."), quoteRuleBumpedLine, strlim(quoteRuleBumpedCh, (char[500]) {}, 500));
   }
 
   if (verbose) {