General note, please, this list is for developers of gcc to develop
gcc. Using it as a way to teach yourself how to read the C standard,
isn't ok, please stop.
On Saturday, June 18, 2005, at 07:15 AM, Paul Schlie wrote:
Maybe I didn't phrase my statement well;
I think you did, you are just wrong. Please quote the sentence that
says the the program behaves in accordance with 5.1.2.3, if you can
find none, then, trivially, there is no such requirement. If you can
find it, you can quote it. Failure to find it, means either, you
didn't look hard enough, or there is none.
Here, let me try again, in a slightly different way:
--If a program contains no violations of the rules in this
Interna-
tional Standard, a conforming implementation shall, within
its
resource limits, accept and correctly execute2) that program.
--If a program contains a violation of a rule for which no
diagnostic
is required, this International Standard places no
requirement on
implementations with respect to that program.
1.4.12 undefined behavior
[defns.undefined]
behavior, such as might arise upon use of an erroneous program
con-
struct or of erroneous data, for which the Standard
imposes no
requirements. Undefined behavior may also be expected when the
stan-
dard omits the description of any explicit definition of
behavior.
Read it slowly, carefully, then instead of replying, go ask 100
programmers not on this list what they think the words mean, listen
to them. Come back here and summarize, if the result is different
from what we represent.
I fully agree with the cited paragraph above which specifically
says a program containing unspecified behavior "shall be a
correct program and act in accordance with 5.1.2.3". Which
specifies program execution, in terms of an abstract machine model,
which correspondingly requires:
I love it, you quote 5.1.2.3, but that section has no relevance to
the program, if you can't find something that gives it relevance. Go
back and try again.
Therefore regardless of the result of an "undefined" result/
operation at
it's enclosing sequence point, the remaining program must continue
to abide
by the specified semantics of the language.
Nope. You have failed to grasp that `can do anything' actually means
can do anything. If the standard mean to say that all preceding
semantics must be observable, the standard would say that, if you can
find where it says that all observable semantics are required in all
sequence points before the one containing the undefined behavior,
then, maybe that standard doesn't say that.
