[Bug middle-end/86528] [9 Regression] strlen of constant string malfunction -- had to back out fix for PR middle-end/77357

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86528

Bernd Edlinger <bernd.edlinger at hotmail dot de> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |bernd.edlinger at hotmail dot 
de

--- Comment #3 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
I can reproduce with the following test case:

$ cat t.c
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

void test(char *data, size_t len)
{
       char *dir;
       static char const appended[] = "/./";
       char *buf = alloca (len + sizeof appended);
       memcpy (buf, data, len);
       strcpy (buf + len, &appended[data[len - 1] == '/']);
       dir = buf;
       printf("%s\n", dir);
}

int main(int argc, char **argv)
{
   if(argc > 1 && argv[1][0])
       test(argv[1], strlen(argv[1]));
   return 0;
}

$ gcc -S -O1 -fdump-tree-all-all t.c

t.c.028t.ccp1 looks okay:
  # VUSE <.MEM_14>
  _4 = *_3;
  _5 = _4 == 47;
  _6 = (intD.6) _5;
  _7 = &appended.3294D.3294[_6];
  _8 = buf_12 + len_9(D);
  # .MEM_15 = VDEF <.MEM_14>
  # USE = anything
  # CLB = anything
  strcpyD.887 (_8, _7);


t.c.029t.forwprop1 is wrong:
  # VUSE <.MEM_14>
  _4 = *_3;
  _5 = _4 == 47;
  _6 = (intD.6) _5;
  _7 = &appended.3294D.3294[_6];
  _8 = buf_12 + len_9(D);
  _18 = (long unsigned intD.10) _6;
  _19 = _18 * 18446744073709551612;
  _20 = _19 + 4;
  # .MEM_15 = VDEF <.MEM_14>
  # USE = anything
  # CLB = anything
  memcpyD.864 (_8, _7, _20);


Breakpoint 7, string_constant (arg=0x7ffff70a0dc8, ptr_offset=0x7fffffffc638)
at ../../gcc-9-20180715/gcc/expr.c:11344
11344         if (tree eltsize = TYPE_SIZE_UNIT (TREE_TYPE (array)))

here eltsize = 4, but it should probably be TYPE_SIZE_UNIT (TREE_TYPE
(TREE_TYPE (array))) ???