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Re: [gortran, PATCH] Fix PR 18937


Toon Moene wrote:
Tobias Schlüter wrote:

Of course, life is not as simple as one would hope: in order to determine if a branch is valid we have to know if the branch target is an END {DO,SELECT,IF} statement (can someone point me to the relevant quote in the standard, I couldn't seem to find it.

Quoting the 2003 Standard:


IF statement (page 156-157):

An ELSE IF statement or an ELSE statement shall not be a branch target statement. It is permissible to branch to an END IF statement only from with its IF construct.

CASE statement (page 159):

A CASE statement shall not be a branch target statement. It is permissible to branch to an [END SELECT statement] only from within its CASE construct.

DO statement (page 167):

In a block DO construct, a transfer of control to the [END DO statement] has the same effect as execution of a CYCLE statement belonging to that construct.

(page 168):

(4) Transfer of control from a statement within the range of a DO
    construct to a statement that is neither the [END DO statement]
    nor within the range of the same DO construct [terminates the
    loop].

I think I've got them all ...

Thanks, now that look over this I see that 8.2 has all this collected in one place. Wonder how I missed this before. Anyway, trying a few corner cases, I already found a weird preexisting bug and I see a few additional things I'll have to do. Sigh, why aren't labels on statements that are not branch-target statements disallowed or at least deprecated?


Cheers,
- Tobi


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