Euphoria
Ticket #744:
case statements with multiple values
-
Reported by
SDPringle
Jan 26, 2012
Case statements with multiple values should be resolved such that multiple cases with the same value do not appear in the C source file. I consider this a bug because perfectly valid EUPHORIA can produce invalid C code.
Consider:
case C_SIZE_T, C_POINTER, C_FLOAT then
case C_DOUBLE, C_DWORDLONG, C_LONGLONG then
return 8
Now, some of the values are redundant for they happen to be the same value. Yet it runs fine. We end up with the following in C:
case 50331656:
case 50331650:
case 50331650:
/** dll.e:546 return 8*/
return 8;
This is an error in C.
Details
1. Comment by mattlewis
Jan 27, 2012
I guess it's also a question of whether we should allow this sort of thing at all. I guess that we're currently only looking for duplicate symbols, not at the values.
When they're in the same case block, there is no problem, though maybe not desirable from a purist perspective. When they're in different cases, however, this is definitely a bug.
We also would need to test for this at runtime for those switch statements where we have cases that cannot be resolved at parse time.
2. Comment by mattlewis
May 21, 2012
See: hg:euphoria/rev/504025824dd6
changeset: 5562:504025824dd6 tag: tip user: Matt Lewis date: Mon May 21 18:17:27 2012 -0400 files: docs/refman_2.txt docs/release/4.1.0.txt source/backend.e source/be_execute.c source/be_execute.h source/be_machine.c source/be_machine.h source/be_runtime.c source/compile.e source/parser.e tests/t_c_switch_dup.d/control.err tests/t_c_switch_dup.e tests/t_c_switch_rt_dup.d/control.err tests/t_c_switch_rt_dup.e tests/t_switch.e description:
- check for duplicate case values in a switch
- ticket 744
3. Comment by SDPringle
Jun 06, 2012
See: hg:euphoria/rev/e1d8f02cd376
changeset: 5580:e1d8f02cd376 branch: 4.0 tag: tip parent: 5560:cbdc7d2e4930 user: Shawn Pringle <shawn.pringle@gmail.com> date: Wed Jun 06 20:10:51 2012 -0300 files: docs/release/4.0.5.txt source/compile.e tests/t_dup_case.e description:
- duplicate case values in a switch block no longer results in a failed compile after translation.
- fixes ticket 744
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