Hi David, (added net-dev, awt-dev, security-dev since part of these fixes are in their territory)
On Mon, Mar 25, 2019 at 1:34 AM David Holmes <david.hol...@oracle.com> wrote: > Hi Thomas, > > A few queries, comments and concerns ... > > On 25/03/2019 6:58 am, Thomas Stüfe wrote: > > Hi all, > > > > After a long time I tried to build a Windows 32bit VM (VS2017) and > failed; > > I'm somewhat surprised as I thought someone was actively doing Windows > 32-bit builds out there, plus there are shared code changes that should > also have been caught by non-Windows 32-bit builds. :( > > Not sure what others do. I did a 32bit windows build, slowdebug, warning enabled, and it failed with those 5+ issues. > > multiple errors and warnings. Lets reverse the bitrot: > > > > cr: > > > http://cr.openjdk.java.net/~stuefe/webrevs/8221375--windows-32bit-build-(vs2017)-broken-in-many-places/webrev.00/webrev/ > > > > Issue: https://bugs.openjdk.java.net/browse/JDK-8221375 > > > > Most of the fixes are trivial: Calling convention mismatches (awt DTRACE > > callbacks), printf specifiers etc. > > > > Had to supress a warning in os_windows_x86.cpp - I was surprised by this > > since this did not look 32bit specifc, do we disable warnings on Windows > > 64bit builds? > > What version of VS2017? We use VS2017 15.9.6 and we don't disable warnings. > > I use VS2017 CE. Not sure which version spcifically, but my compiler is at Microsoft (R) C/C++ Optimizing Compiler Version 19.14.26431 for x86 > > The error I had in vmStructs.cpp was a bit weird: compiler complained > about > > an assignment of an enum value defined like this: > > > > hash_mask_in_place = (address_word)hash_mask << hash_shift > > > > to an uint64_t variable, complaining about narrowing. I did not find out > > what his problem was. In the end, I decided to add an explicit cast to > > GENERATE_VM_LONG_CONSTANT_ENTRY(name) (see vmStructs.hpp). > > Not at all sure that's the right fix. In markOop.hpp we see that value > gets special treatment on Windows-x64: > > #ifndef _WIN64 > ,hash_mask = right_n_bits(hash_bits), > hash_mask_in_place = (address_word)hash_mask << hash_shift > #endif > }; > > // Alignment of JavaThread pointers encoded in object header required > by biased locking > enum { biased_lock_alignment = 2 << (epoch_shift + epoch_bits) > }; > > #ifdef _WIN64 > // These values are too big for Win64 > const static uintptr_t hash_mask = right_n_bits(hash_bits); > const static uintptr_t hash_mask_in_place = > (address_word)hash_mask << hash_shift; > #endif > > perhaps something special is needed for Windows-x86. I'm unclear how the > values can be "too big" ?? > > I banged my head against this for an hour or so and I think this is a compiler bug. What I get is: warning C4838: conversion from '' to 'uint64_t' requires a narrowing conversion (Note the empty "from" string.) Here are my tries to provoke the error: VMLongConstantEntry iii[] = { { "hallo", markOopDesc::hash_mask_in_place }, {0,0}}; <<< this fails VMLongConstantEntry iii = { "hallo", markOopDesc::hash_mask_in_place }; << but this succeeds uint64_t iii = markOopDesc::hash_mask_in_place; << this succeeds too I have no clue what this means. It is difficult to fix since the expression is hidden in such a macro pile. But I think either we go with my change or we disable the warning for win32 for the whole section. > > > > With this patch we can build with warnings enabled on 32bit and 64bit > > windows. > > > > Since patch fixes both hotspot and JDK parts, I'm sending it to hs-dev > and > > core-libs-dev. > > Don't see anything that actually comes under core-libs-dev. Looks like > one net-dev, one awt-dev and one security-dev. Sorry. > > Okay, I will add them. > Cheers, > David > ----- > > Thanks for reviewing, Thomas > > Thanks, Thomas > > >
