riscv64: strange behavior of exception handling

[kxxt]

Version

v19.8.1

Platform

Linux kxxt 6.2.10-arch1-1 #1 SMP PREEMPT_DYNAMIC Fri, 07 Apr 2023 02:10:43 +0000 riscv64 GNU/Linux

Subsystem

No response

What steps will reproduce the bug?

1. Setup an arch linux RISC-V development environment following this article: https://github.com/felixonmars/archriscv-packages/wiki/Setup-Arch-Linux-RISC-V-Development-Environment
2. Start the arch rv64 container and switch to a non-root user
3. Install necessary dependencies via pacman: pacman -S base-devel asp npm nodejs
4. Checkout the gitea repo(v1.18): git clone https://github.com/go-gitea/gitea -b release/v1.18 --depth=1 && cd gitea
5. Install dependencies via npm: npm i
6. Run lessc: npx lessc web_src/less/index.less out

How often does it reproduce? Is there a required condition?

100%. No condition is required.

What is the expected behavior? Why is that the expected behavior?

The generated css can be found in file out and lessc exit with code 0.

This is the behavior on x86_64 platform so it is the expected behavior.

What do you see instead?

SyntaxError: Cannot create property '_fileInfo' on string '!important' in /home/kxxt/gitea/web_src/less/_tribute.less on line 4, column 3:
3 .tribute-container {
4   box-shadow: 0 .25rem .5rem rgba(0, 0, 0, .25);
5   border-radius: .25rem;

Additional information

By adding some logging :

1. In node_modules/less/lib/less/less-error.js to show the stack trace.

var LessError = function (e, fileContentMap, currentFilename) {
    Error.call(this);
    var filename = e.filename || currentFilename;
    this.message = e.message;
    this.stack = e.stack;
    if (fileContentMap && filename) {
+       console.log("Trace: ", e.stack);

2. In node_modules/less/lib/less/parser/parser.js

var Parser = function Parser(context, imports, fileInfo) {
    ...
    function parseNode(str, parseList, currentIndex, fileInfo, callback) {
        var result;
        var returnNodes = [];
        var parser = parserInput;
        try {
            parser.start(str, false, function fail(msg, index) {
                callback({
                    message: msg,
                    index: index + currentIndex
                });
            });
            for (var x = 0, p = void 0, i = void 0; (p = parseList[x]); x++) {
                i = parser.i;
                result = parsers[p]();
                if (result) {
                    try {
+                       console.log("The result is", result);
                        result._index = i + currentIndex;
                        result._fileInfo = fileInfo;
+                       console.log("OK");
                    }
                    catch (e) {
+                       console.log("Caught exception", e);
                    }
                    returnNodes.push(result);
                }
                else {
                    returnNodes.push(null);
                }
            }
            var endInfo = parser.end();
            if (endInfo.isFinished) {
                callback(null, returnNodes);
            }
            else {
                callback(true, null);
            }
        }
        catch (e) {
            throw new less_error_1.default({
                index: e.index + currentIndex,
                message: e.message
            }, imports, fileInfo.filename);
        }
    }

We can get the following output:

Output

The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is [
  Node {
    extendList: undefined,
    condition: undefined,
    evaldCondition: true,
    _index: 1,
    _fileInfo: {
      rewriteUrls: false,
      entryPath: '/home/kxxt/gitea/web_src/less/',
      rootpath: '',
      rootFilename: '/home/kxxt/gitea/web_src/less/index.less',
      currentDirectory: '/home/kxxt/gitea/web_src/less/',
      filename: '/home/kxxt/gitea/web_src/less/helpers.less'
    },
    elements: [ [Node] ],
    mixinElements_: undefined
  }
]
OK
The result is Node { value: [ Node { value: [Array], noSpacing: undefined } ] }
OK
The result is !important
OK
The result is Node { value: [ Node { value: [Array], noSpacing: undefined } ] }
OK
The result is !important
OK
The result is Node { value: [ Node { value: [Array], noSpacing: undefined } ] }
OK
The result is Node { value: [ Node { value: [Array], noSpacing: undefined } ] }
OK
Trace:  TypeError: Cannot create property '_fileInfo' on string '!important'
    at Object.parseNode (/home/kxxt/gitea/node_modules/less/lib/less/parser/parser.js:103:42)
    at Ruleset.transformDeclaration (/home/kxxt/gitea/node_modules/less/lib/less/tree/ruleset.js:322:32)
    at Ruleset.parseValue (/home/kxxt/gitea/node_modules/less/lib/less/tree/ruleset.js:343:41)
    at Ruleset.variable (/home/kxxt/gitea/node_modules/less/lib/less/tree/ruleset.js:300:25)
    at Array.<anonymous> (/home/kxxt/gitea/node_modules/less/lib/less/tree/variable.js:26:27)
    at Variable.find (/home/kxxt/gitea/node_modules/less/lib/less/tree/variable.js:54:21)
    at Variable.eval (/home/kxxt/gitea/node_modules/less/lib/less/tree/variable.js:25:25)
    at Operation.eval (/home/kxxt/gitea/node_modules/less/lib/less/tree/operation.js:20:34)
    at Expression.eval (/home/kxxt/gitea/node_modules/less/lib/less/tree/expression.js:40:41)
    at Value.eval (/home/kxxt/gitea/node_modules/less/lib/less/tree/value.js:25:34)
�[31mSyntaxError: Cannot create property '_fileInfo' on string '!important'�[39m�[31m in �[39m/home/kxxt/gitea/web_src/less/_tribute.less�[90m on line 4, column 3:�[39m
�[90m3 .tribute-container {�[39m
4   �[7m�[31m�[1mb�[22mox-shadow: 0 .25rem .5rem rgba(0, 0, 0, .25);�[39m�[27m
�[90m5   border-radius: .25rem;�[39m�[0m�[0m

It seems that

1. the catch in node_modules/less/lib/less/parser/parser.js didn't catch the exception because there are no "Caught Exception" in the log.
2. the attempt to create property _fileInfo on string "!important" seems to be successful because "OK" is logged.

There are some failed jstest on riscv64 due to Missing expected exception. Maybe it is caused by the same error.

The nodejs build recipe used on arch riscv64

The nodejs-v8-jit-fix.patch is equivalient to #47399

# Maintainer: Felix Yan <felixonmars@archlinux.org>
# Contributor  Bartłomiej Piotrowski <bpiotrowski@archlinux.org>
# Contributor: Thomas Dziedzic < gostrc at gmail >
# Contributor: James Campos <james.r.campos@gmail.com>
# Contributor: BlackEagle < ike DOT devolder AT gmail DOT com >
# Contributor: Dongsheng Cai <dongsheng at moodle dot com>
# Contributor: Masutu Subric <masutu.arch at googlemail dot com>
# Contributor: TIanyi Cui <tianyicui@gmail.com>

pkgname=nodejs
pkgver=19.8.1
_commit=e808076389ed1ad8235177562f6dadcd616eb81b
pkgrel=1
pkgdesc='Evented I/O for V8 javascript'
arch=(x86_64 riscv64)
url='https://nodejs.org/'
license=('MIT')
options=(!lto)
depends=('brotli' 'openssl' 'zlib' 'icu' 'libuv' 'libnghttp2' 'c-ares') # 'http-parser' 'v8')
makedepends=('git' 'python' 'procps-ng')
optdepends=('npm: nodejs package manager')
source=("git+https://github.com/nodejs/node.git#commit=$_commit"
        "nodejs-v8-jit-fix.patch")
sha512sums=('SKIP'
            'fb4fa53b99e69ab7ae9c7d1483bb73169e2adba36edfc4e76e2edbcce7f054d17580405977d02e34f712696be7770d3dfde01501b507f92383c6e44ec899c74f')

prepare() {
  cd node
  patch -Np1 -i ../nodejs-v8-jit-fix.patch
}

build() {
  cd node

  ./configure \
    --prefix=/usr \
    --with-intl=system-icu \
    --without-npm \
    --shared \
    --shared-openssl \
    --shared-zlib \
    --shared-libuv \
    --experimental-http-parser \
    --shared-nghttp2 \
    --shared-cares \
    --shared-brotli
    # --shared-v8
    # --shared-http-parser

  # -fno-strict-aliasing for gcc>=10: https://github.com/nodejs/node/issues/33899
  make CFLAGS="-fno-strict-aliasing $CFLAGS" CXXFLAGS="-fno-strict-aliasing $CXXFLAGS"
}

check() {
  cd node
  make CFLAGS="-fno-strict-aliasing $CFLAGS" CXXFLAGS="-fno-strict-aliasing $CXXFLAGS" test || :
}

package() {
  cd node
  make DESTDIR="$pkgdir" install
  install -Dm644 LICENSE -t "$pkgdir"/usr/share/licenses/nodejs/

  cd "$pkgdir"/usr/lib
  ln -s libnode.so.* libnode.so
}
# vim:set ts=2 sw=2 et:

This issue is also reproducible with JIT disabled: NODE_OPTIONS=--jitless npx lessc web_src/less/index.less out

[kxxt]

cc @luyahan

[bnoordhuis]

I'll leave the issue open for a few days so @luyahan can chime in but, as this is a bug in V8's riscv backend, Node's bug tracker isn't really the right place to report or discuss it.

[kxxt]

Moved to https://bugs.chromium.org/p/v8/issues/detail?id=13930

[thesamesam]

Hi! At least part of this issue, possibly the whole thing, was debugged by @WhatAmISupposedToPutHere and reported at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116057.

It appears it wasn't an issue in the V8 backend for a specific platform, but rather a miscompilation by GCC of V8. It's still not completely clear whether there may be either UB or ill-advised code in V8, but GCC's fixed it on their side. As of writing, it's not yet been backported. Thanks.