#3212 Odd scoping behavior

[Peter Iannucci]

mve.c

void b(void) {
  for (int i=0; i; i--) ;
#ifdef BAD
  int a=0;
#endif
  for (int i=0; i; i--) ;
}

When compiled with ./bin/sdcc -DBAD -S mve.c, I get the output

/Users/peteriannucci/git/radiolynx/v2-lion/mve/mve.c:6: error 0: Duplicate symbol 'i', symbol IGNORED
/Users/peteriannucci/git/radiolynx/v2-lion/mve/mve.c:2: error 177: previously defined here
/Users/peteriannucci/git/radiolynx/v2-lion/mve/mve.c:6: error 20: Undefined identifier 'i'

When compiled with ./bin/sdcc -S mve.c, compilation succeeds.

Expected behavior is that symbol "i" is scoped to the for loops, and there is no conflict either with or without -DBAD. Specifying --std-c11 doesn't change the behavior. Changing the order of the statements or enclosing loops in blocks changes the behavior.

Tested with the MacPorts version of sdcc,

SDCC : mcs51/z80/z180/r2k/r3ka/gbz80/tlcs90/ez80_z80/ds390/pic16/pic14/TININative/ds400/hc08/s08/stm8/pdk13/pdk14/pdk15 4.0.0 #11528 (Mac OS X x86_64)
published under GNU General Public License (GPL)

and with a fresh build of 4.1.0:

SDCC : mcs51/z80/z180/r2k/r2ka/r3ka/gbz80/tlcs90/ez80_z80/z80n/ds390/pic16/pic14/TININative/ds400/hc08/s08/stm8/pdk13/pdk14/pdk15 4.1.0 #12069 (Mac OS X x86_64)
published under GNU General Public License (GPL)

[Benedikt Freisen]

This bug appears to be caused by an overly pedantic sanity check related to the handling of implicit blocks that the parser enters when it encounters a declaration after a statement within the same explicit block.
The example can be simplified as follows:

void b(void) {
  {int i;}
#ifdef BAD
  int a=0;
#endif
  {int i;}
}

So far I have been able to circumvent the problem by removing the check that is supposed to prevent duplicate symbols in implicit sub-blocks of the same explicit block.

[Erik Petrich]

Fixed in [r12555]