run-pass-valgrind tests fail when valgrind doesn't exist

[brson]

I get task '<main>' panicked at 'Can't find Valgrind to run Valgrind tests', /opt/dev/rust3/src/compiletest/compiletest.rs:44 when running the test suite now. These tests should probably be disabled when configure doesn't find valgrind.

[brson]

cc @nick29581

[nrc]

cc @alexcrichton, this is deliberate.

You can avoid it by using the flag --disable-valgrind-rpass

[brson]

If it is on purpose then the configure script should have failed when valgrind wasn't found.

[liigo]

I got the same error, and didn't know how to do, before I'm here and find --disable-valgrind-rpass.

[liigo]

We need a more friendly thing, like what @brson suggested.

[ghost]

An easy fix(unless I'm missing something, of course) would be adding the the following lines after this one:

rust/configure

Line 642 in 81504f2

probe CFG_VALGRIND valgrind

Looks like this(first line already existing):

probe CFG_VALGRIND         valgrind
if [ -z "$CFG_VALGRIND" ]
then
    if [ ! -z "$CFG_ENABLE_VALGRIND" ] || [ -z "$CFG_DISABLE_VALGRIND_RPASS" ]
    then
      err "Valgrind not found, but wanted. You may want to add --disable-valgrind-rpass"                      
    fi
fi

This will yell by default(./configure without params) if valgrind isn't found, unless you specifically add --disable-valgrind-rpass.

However, the reason why I didn't make a PR is because this code won't work in the case that the default values will change. I am speaking of these values from here:

rust/configure

Line 501 in 81504f2

opt valgrind 0 "run tests with valgrind (memcheck by default)"

reproduced here, these values I meant(0,0,1):

opt valgrind 0 "run tests with valgrind (memcheck by default)"
opt helgrind 0 "run tests with helgrind instead of memcheck"
opt valgrind-rpass 1 "run rpass-valgrind tests with valgrind"

adding this code within the if [ -z "$CFG_VALGRIND" ] will show what I mean when you test specific --enable and --disable parameters:

  echo "~$CFG_ENABLE_VALGRIND~$CFG_ENABLE_VALGRIND_RPASS~$CFG_DISABLE_VALGRIND_RPASS~$CFG_DISABLE_VALGRIND"

Basically, if the default value for say valgrind is 0, then --enable-valgrind will set $CFG_ENABLE_VALGRIND but, passing --disable-valgrind will not set $CFG_DISABLE_VALGRIND.
So, if anyone will change that default valgrind value to 1, or more likely the default value valgrind-rpass from 1 to 0 then the above code will have to be changed from [ -z "$CFG_DISABLE_VALGRIND_RPASS" ] to [ ! -z "$CFG_ENABLE_VALGRIND_RPASS" ].

I figure this is done this way to detect if the value was specifically requested/set by the user(via a ./configure parameter), instead of the default one(./configure without params).
So no variable will be set($CFG_ENABLE_X / $CFG_DISABLE_X) unless the user specifically requested it via ./configure --enable_X or ./configure --disable_X .

[brson]

@emanueLczirai the problem you've discovered is an unfortunate limitation of the configure system. Writing conditionals about configuration correctly requires knowing the default value.

[tamird]

Looks like this should have been closed by #24859. @brson?

[alexcrichton]

Indeed!