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Author SHA1 Message Date
Marc Schier fac30c45e6 Add MinSupportedSamplingInterval configuration and honor it when revising sampling intervals (#4243)
# Description

PR #4194 removed the unused
`ServerConfiguration.MinMetadataSamplingInterval` and left nothing in
its place. As a result there was no way to populate
`Server.ServerCapabilities.MinSupportedSampleRate` (`i=2272`) —
`ServerInternalData.CreateServerObjectAsync` hardcoded it to `0`.
Separately, the only clamp applied when revising a monitored item's
sampling interval was the per-node
`BaseVariableState.MinimumSamplingInterval`, which defaults to
`MinimumSamplingIntervals.Continuous` (`0`), so reference-server nodes
accepted any requested interval (e.g. 10 ms) unrevised — exactly what
was reported.

This adds a configuration entry **in the exact schema slot #4194
vacated** and enforces it as a lower bound.

## Configuration

- **`ServerConfiguration.MinSupportedSamplingInterval`** — `double`
(milliseconds), default `0`, `[DataTypeField(Order = 17)]`, i.e. between
`MaxNotificationsPerPublish` (16) and `AvailableSamplingRates` (18).
- `ApplicationConfiguration.xsd` — `<xs:element
name="MinSupportedSamplingInterval" type="xs:double" minOccurs="0" />`
in the same position the removed element occupied.
- Fluent API **`SetMinSupportedSamplingInterval(double)`** on
`IApplicationConfigurationBuilderServerOptions`, in the place
`SetMinMetadataSamplingInterval` was removed from.
- The element is added to the six config XML files #4194 touched
(reference / CTT / AOT / GDS use `0`; `test-server-full.xml` uses a
distinctive non-zero value for the round-trip test).

The address-space Property keeps its OPC UA spec name, so
`Server.ServerCapabilities.MinSupportedSampleRate` and
`VariableIds.Server_ServerCapabilities_MinSupportedSampleRate` are
unchanged.

```xml
<MaxNotificationsPerPublish>1000</MaxNotificationsPerPublish>
<MinSupportedSamplingInterval>2000</MinSupportedSamplingInterval>
<AvailableSamplingRates>
```

```csharp
application.Build(applicationUri, productUri)
    .AsServer([endpointUrl])
    .SetMinSupportedSamplingInterval(2000);
```

## Behavior

- `ServerInternalData` now publishes the configured value to
`Server.ServerCapabilities.MinSupportedSampleRate`.
- New `SubscriptionManager.CalculateRevisedSamplingInterval(...)` (two
overloads, alongside the existing `CalculateRevisedQueueSize`)
centralizes the revision rule and replaces the logic that was duplicated
across four call sites — the create and modify paths of
`AsyncCustomNodeManager` and `CustomNodeManager` — which now expose a
`MinSupportedSamplingInterval` property seeded from the configuration
(mirroring how `MaxQueueSize` is initialized).

The rule:

1. A requested interval below zero resolves to the *default sampling
interval*: the **publishing interval of the subscription** on create,
and the item's **current sampling interval** on modify. The modify case
preserves 1.5.378 behavior, so a `ModifyMonitoredItems` call that leaves
the sampling interval unspecified does not silently retune the item.
2. A node declaring `MinimumSamplingIntervals.Continuous` (`0`) for the
`Value` Attribute reports **by exception** and is **not** bound by the
server-wide minimum — the requested interval is returned unchanged.
3. Every other item is raised to `max(nodeMinimumSamplingInterval,
MinSupportedSamplingInterval)`. Attributes other than `Value`, nodes
declaring `MinimumSamplingIntervals.Indeterminate` (`-1`), and
non-Variable nodes are bound only by `MinSupportedSamplingInterval`.
4. `double.MaxValue` is capped to one year (pre-existing behavior, now
in one place).

Event monitored items do not sample and are unaffected.

**Backward compatible:** with the default of `0` the computation is
identical to the previous code for every input, including `Continuous`,
`Indeterminate`, positive node minimums, non-`Value` attributes and
`NaN`. No existing configuration or deployment changes behavior.

Node managers that implement `INodeManager` directly can call the new
public helper to apply the same rule.

## Related Issues

- Fixes #4191

The issue thread also asked whether
`Subscription.MaxNotificationsPerPublish` is revised by the server. It
is (`SubscriptionManager.CalculateMaxNotificationsPerPublish`), but it
was untested and is not observable from the `CreateSubscription`
response, which carries no revised field for that parameter. Four tests
were added that assert it through
`SubscriptionDiagnostics.MaxNotificationsPerPublish` on a privileged
session, covering create and modify, the above-limit, below-limit and
`0` (server default) cases.

## Tests

- **`SamplingIntervalRevisionTests`** (17 unit tests,
`Opc.Ua.Server.Tests`) — the full revision matrix: negative request
resolving to the default interval, the `Continuous` bypass,
`Indeterminate`, node minimum above *and* below the floor, a floor of
`0` being a no-op, non-`Value` attributes, non-Variable and null nodes,
and the `double.MaxValue` cap.
- **`MinSupportedSamplingIntervalTests`** (10 integration tests,
`Opc.Ua.Subscriptions.Tests`) — against a reference server configured
with a 500 ms floor: the capabilities node reflects the configuration; a
node declaring 100 ms is lifted to 500 ms;
`Scalar_Static_Arrays2D_LocalizedText` (1000 ms) wins over the floor;
`CurrentTime` (250 ms) is lifted; a `Continuous` node keeps its 10 ms; a
non-`Value` attribute is floored; `ModifyMonitoredItems` behaves the
same in both directions; event items are unaffected.
- Restored the configuration builder and round-trip test coverage that
#4194 deleted.
- `TestFixture` gained a `protected virtual void
ConfigureServer(ApplicationConfiguration)` hook so a derived fixture can
vary the server configuration before start. Default implementation is a
no-op, so no existing fixture changes behavior.

## Documentation

- `docs/Subscriptions.md` — new **Sampling interval revision** section
with the input table, the four-step rule (including both
negative-interval fallbacks), XML and fluent configuration examples, and
guidance for custom node managers.
- `docs/migrate/2.0.x/configuration.md` — new section documenting that
`MinMetadataSamplingInterval` was removed and
`MinSupportedSamplingInterval` added. Verified against `master378`: the
old setting defaulted to `1000` but was never read, and
`MinSupportedSampleRate` was hardcoded to `0` with no server-wide floor.
The guide therefore stresses that these are **two different settings,
not a rename** — consumers should drop the old element (a default of `0`
reproduces 1.5.378 exactly) and only opt into the new one deliberately,
since reusing the old value would silently introduce a sampling floor.

## Validation

- `dotnet build UA.slnx` — **0 warnings, 0 errors** across all TFMs.
- .NET 10: `Opc.Ua.Server.Tests` 4091 passed,
`Opc.Ua.Subscriptions.Tests` 619 passed (full suite including the new
fixture), `Opc.Ua.InformationModel.Tests` 1063 passed,
`Opc.Ua.Configuration.Tests` 221 passed, `Opc.Ua.Gds.Tests` 119 passed.
- .NET Framework 4.8: new unit tests (200 incl. sampling groups), new
integration tests (17) and configuration round-trip (135) all passed.
- `ConsoleReferenceServer` starts successfully with the updated
configuration file.

## Checklist

- [x] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [x] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [x] I have addressed **all** PR feedback received.

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 79f8090c-b2a3-409c-a5bf-56b6d2a35e70
2026-08-12 17:41:29 +00:00
Marc Schier e05a820c91 Removal of the exposed diagnostics and node locks (#4188)
## What this is

Design analysis for `Opc.Ua.Server`, the two rounds of design
exploration behind it, and the first two implementation chunks it
recommends.

Draft: the analyses are ready to read, but the *conclusions* deserve
discussion before the larger phases proceed. Later chunks stack onto
this PR as they land.

| File | Kind | Lines |
|---|---|---:|
| `plans/NodeManagerAnalysis.md` | Evidence — the node-manager plugin
surface | 488 |
| `plans/ServerRuntimeAnalysis.md` | Evidence — the server runtime
cluster | 576 |
| `plans/ServerDesignExploration.md` | Design round 2 — delivery
strategy | 1,394 |
| `plans/ServerDesignExplorationAlt.md` | Design round 1 — four
interface designs | 2,119 |
| `src/Opc.Ua.Types/State/NodeState.cs` | **Code** — node self-guards
attributes | |
| `src/Opc.Ua.Types/State/BaseVariableState.cs` | **Code** — value
accessors take the lock | |
| `src/Opc.Ua.Server/NodeManager/AsyncCustomNodeManager.cs` | **Code** —
6 external locks removed | |
| `tests/…/NodeStateAttributeConcurrencyTests.cs` | **Code** —
concurrency safety net | 449 |

`docs/` is untouched — it holds shipped feature documentation, and none
of this is shipped API.

## The analyses

Counted mechanically over `src`, `samples` and `tests`; **every figure
is reproducible** from commands printed in each document.

**Node manager surface.** `AsyncCustomNodeManager` declares **93
`virtual`/`abstract` members** (80 distinct names). Across the
repository: **112 override sites, 25 distinct names ever overridden, 55
of 80 never**. Six carry nearly all real use. For scale,
`ReferenceNodeManager` is 6,373 lines and overrides **8**.

**Server runtime.** Seven findings, **two of which recommend no
change**. Findings 1–5 are filed as #4183–#4187. The headline is an
`object`-typed sync root published on three public interfaces and taken
in **88 `lock` statements across 7 files**, including a shipped sample.

**What is deliberately not flagged.** `IStandardServer` — 9 members over
5,575 lines, 16 of 37 virtuals used — is identified as the reference
shape to preserve. `IApplicationInstance` and the already-`[Obsolete]`
`Stop()` are examined and left alone.

## The design exploration

**Round 1** explored four alternative interfaces in parallel under the
current back-compat constraint. Its value is the convergence: four
designers who never saw each other's work independently arrived at a 6–9
member `IServerContext` replacing the 57-member locator, removal of the
`object` node-manager handle, elimination of the `Processed` protocol,
and `IHistorianProvider` as the pattern to copy.

**Round 2** re-runs it with back-compat lifted and asks how to deliver:
full rewrite versus side-by-side fork. **Both option designers
independently declined to recommend their own assignment.** Three
structural facts were verified:

1. **The fork line already sits at `IAsyncNodeManager`** — old and new
node managers can coexist with zero runtime changes, so a fork
duplicates ~10% of the assembly, not all of it.
2. **`[OpcUaShim]` cannot shim an inheritance surface** — honest
auto-fix ceiling for the authoring surface is **~10%**, against ~70% for
the shipped analyzers.
3. **A second lock leak exists** — `NodeState` takes `lock (this)` under
a `CA2002` suppression whose own comment documents the contract.

Recommendation: **neither pure option**, but a staged path reaching the
rewrite end state incrementally, gated on migrating the five
framework-internal node managers that today make it impossible for the
old base to ever freeze.

## Implementation: NodeState now guards its own attributes

This removes the prose-only contract in which `NodeState` took
`lock(this)` and every external caller was required to take
`lock(source)` on the node instance. The code already carried a TODO
describing exactly this fix and noting it required updating every
external site.

- The node self-guards rather than relying on callers.
`BaseVariableState` gains a **fully private** `System.Threading.Lock`
covering its value fields; `NodeState`'s other collections keep their
existing private locks.
- All **6** `lock(this)` sites and both `CA2002`/`RCS1059` suppressions
are gone.
- `Value`, `Timestamp` and `StatusCode` on `BaseVariableState` take the
lock too — without that, a direct property write raced an attribute read
once the external lock was gone.
- **6 of 9** external sites removed. Five were already redundant
(`GetReferences`, `GetChildren`, `ReferenceExists` and
`SetAreEventsMonitored` guard themselves; `FindMethod` reaches its state
via `GetChildren`); the sixth was an attribute read now covered by the
node's own lock.
- Attribute read/write deliberately take **no** node-wide lock: both
dispatch to caller-supplied handlers (`OnReadValue` and siblings) that
may take locks of their own, and holding a lock on the node across one
gives the node no fixed place in the lock order.
- **3 deliberately retained and annotated in code**: two `CreateBrowser`
calls, which are not internally synchronized (tracked in #4216), and one
in `CustomNodeManager`, whose class is slated for deletion so
refactoring its lock would be wasted work.

### No lock is exposed anywhere, to anyone

An earlier revision put the attribute lock on `NodeState` as `private
protected`, which still published a lock-sharing contract on the
inheritance surface. Review pushed back and it is gone:
`BaseVariableState` was the only user, so the lock moved there as a
plain `private readonly Lock`. There is no member for a derived type to
call, in this assembly or any other.

`BaseVariableValue` was the last public leak — it handed out the lock
guarding its value through a `public Lock` property, so any caller could
hold it across a call back into the stack. That property is removed:

- Derived value classes (what the source generator emits for every
structure variable) synchronize through a `protected EnterLock()` /
`ExitLock()` pair. Callback helpers were the first choice, but the
generated bodies pass `ref Variant` / `ref StatusCode` / `ref
DateTimeUtc`, and `ref` arguments cannot be captured by a lambda. The
lock *object* stays private either way.
- `NodeStateTemplates` emits the new form.
- `ServerInternalData`, the one cross-assembly caller, was reading the
lock back off a value it had itself constructed with that lock. It now
takes `m_diagnosticsLock` directly.

`NodeBrowser.DataLock` remains `protected` and is tracked in #4215: a
subclass extending `Next()` legitimately needs its enumeration state
atomic with the base browser's, so the fix needs a base-owned
acquisition rather than a deletion.

### Migration coverage for the removed lock members

None of the removed lock members get an `[Obsolete]` shim, and the
migration guide now says why: a shim would have to be `object`-typed to
keep old call sites compiling, and on .NET 9+ `lock (o)` on a
statically-`object` reference is `Monitor.Enter`, which does **not**
interlock with `Lock.Enter()`. It would compile, run, and silently
synchronize nothing — strictly worse than a compile error. Re-adding a
member to a downstream-implemented interface is also a break in its own
right on `net48` / `netstandard2.0`, where there are no default
interface methods.

Instead, every removed member has a named replacement on the migration
path:

| Rule | Covers | Replacement it names |
|---|---|---|
| `UA0024` | `IServerInternal` / `ISession` / `ISubscription`
`DiagnosticsLock`, `DiagnosticsWriteLock` |
`UpdateServerDiagnostics(...)` / `UpdateDiagnostics(...)`,
`ReadServerDiagnostics` / `ReadDiagnostics` |
| `UA0025` | `ILocalNode.DataLock`, `Node.DataLock` | a lock the caller
owns; the node guards its own state |
| `UA0026` | `BaseVariableValue.Lock` | a lock passed to the
`BaseVariableValue` constructor |

Each rule fires on sources still written against 1.5.378, where the
compiler only says a member is missing. `docs/MigrationGuide.md` gains a
section per removal with before/after.

### The tests earned their keep

The four concurrency tests were landed **first**, against the unmodified
code, because removing a synchronization contract cannot be verified by
the compiler and the existing `NodeStateHandlerConcurrencyTests` covers
a different concern (racing a handler assignment against a write, not
reader/writer exclusion). They now run with **no external locking**,
which is what demonstrates the node guards itself.

They caught two real problems, and one of them was mine:

- The `Value`/`StatusCode`/`Timestamp` setters bypassed the new lock — a
genuine race.
- One test asserted an invariant the design does not offer. Two property
setters are two lock acquisitions, so that pair was **never** atomic; it
only passed originally because the test held a lock across both. It now
uses a single attribute write carrying a whole `DataValue`, which
genuinely is atomic and is the path the server uses.

A third issue was found and fixed before it shipped: the reader loops
gated on `!writer.IsCompleted`, so a reader scheduled after the writer
finished performed zero reads — failing two runs in three on `net48`.
Converted to `do…while`; now five consecutive green runs.

**Verified:** `Stack.State` 116 passed on `net10.0` *and* `net48`; the
concurrency category green 5/5 consecutive on `net48`;
`Opc.Ua.Types.Tests` 8,456 passed; the server node-manager suite 1,205
passed, including `NodeManagerLifecycleTests` and
`AsyncCustomNodeManagerTests` which exercise the changed paths.

## Two corrections to my own published figures

Both were found while starting implementation, and both are recorded on
#4183.

**`ForceDiagnosticsScan()` was overstated.** The analysis claimed the
`DiagnosticsWriteLock` getter *"triggers a full address-space
diagnostics rescan"*. It is in fact a single flag assignment
(`DiagnosticsNodeManager.cs:700-703`) consumed by the read paths and the
periodic timer. The defect stands — a side-effecting property getter
with a racy write on a synchronisation path — but its cost was
misstated.

**The contract was 15 sites, not 19.** A naive search matched ten
comment and `#pragma` lines that *mention* `lock(source)` while
explaining it. The documents now carry a counting command that excludes
comment matches.

A third finding expanded scope the other way: the `object`-typed lock
leak is **repo-wide**, with ten such members across `Opc.Ua.Core`,
`Opc.Ua.Types` and `Opc.Ua.Server` — including `Node.DataLock => this`
and `ApplicationConfiguration.PropertiesLock => m_properties`, the same
defect class as `Subscription.DiagnosticsLock`.

## Caveats stated in the documents

- **Nothing in the designs is implemented or benchmarked.** Every
performance claim across all seven designs is a design intention, not a
measurement.
- The larger phases are a **major undertaking against a live plugin
API**; the documents say so rather than letting the neatness of the
proposals imply otherwise.
- The recommended sequencing puts low-risk, self-contained steps first
and notes they are **worth doing regardless** of which strategy is
eventually chosen.
- Round 2 notes the two option designers' cost estimates are **not
independent of their assignments**.

## Review guidance

The two analyses make factual claims checkable by running the included
commands. The design explorations are exploratory and need not be agreed
with to merge. The code change is small, test-backed, and independent of
which delivery strategy is eventually chosen.

Reasonable outcomes include merging as-is, merging only the analyses and
the lock fix, or disagreeing with the recommendation while keeping the
evidence.

---

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: e9c13dd0-a6e3-4ad2-8ad6-1c3fe6323041
Copilot-Session: d18f87e9-2484-44ce-98ce-463ba6cf5f63
2026-08-10 06:47:50 +02:00
Copilot d8aca69444 Remove unused MinMetadataSamplingInterval configuration option (#4194)
## Description

Server-side `MonitoredItem` sampling interval revision is based on the
per-node `BaseVariableState.MinimumSamplingInterval` attribute, not on
any global server setting —
`ServerConfiguration.MinMetadataSamplingInterval` was dead configuration
that was never read by any code path. Per maintainer feedback, this PR
removes it instead of wiring it into revision logic that was never meant
to consume it.

Separately, the concern that `Subscription.MaxNotificationsPerPublish`
isn't revised by the server was verified against existing coverage:
`CreateSubscriptionWithNotificationLimitsUsesEffectiveLimitAsync` /
`ModifySubscriptionWithNotificationLimitsUsesEffectiveLimitAsync` in
`SubscriptionTests.cs` already assert the server clamps a
client-requested value down to the configured server limit (e.g.
requested `25` vs. server limit `10` → revised `10`).

### Removed `MinMetadataSamplingInterval`
- Dropped the `ServerConfiguration.MinMetadataSamplingInterval` property
(`ApplicationConfiguration.cs`) and its XSD element
- Dropped `SetMinMetadataSamplingInterval` from
`IApplicationConfigurationBuilder` / `ApplicationConfigurationBuilder`
- Removed the element from sample and test server configuration XML
files (`Ctt.ReferenceServer.Config.xml`,
`Quickstarts.ReferenceServer.Config.xml`, GDS test configs,
`test-server-full.xml`)
- Updated `ApplicationConfigurationBuilderTests` and
`ConfigurationRoundTripTests` to drop assertions on the removed property

## Related Issues

## Checklist

- [ ] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [ ] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [ ] I have added all necessary documentation.
- [ ] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [ ] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

<!-- START COPILOT CODING AGENT SUFFIX -->

- Fixes #4191

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: marcschier <11168470+marcschier@users.noreply.github.com>
2026-08-08 17:11:42 +02:00
Marc Schier 76d33cb139 Remove SourceGenerator.Foundations, ship analyzers under Roslyn-versioned folders for VS2022 and VS2026, and validate the packages (#4120)
# Description

The two OPC UA source generators were built on
`SourceGenerator.Foundations` (SGF), whose only job was getting the
generator's dependency closure loaded inside the compiler. It does so
with a **process-wide, first-generator-wins `AppDomain.AssemblyResolve`
hook backed by a non-concurrent `Dictionary` mutated from `AssemblyLoad`
callbacks**. Concurrent compilations in a shared `VBCSCompiler` race it,
which is the root cause of the intermittent clean-build failure:

```
CSC : error CS8784: Generator 'StackSourceGeneratorHoist' failed to initialize. ...
Exception was of type 'FileNotFoundException' with message 'Could not load file or assembly
'SourceGenerator.Foundations.Contracts, Version=2.0.14.0, ...'
```

The repository already solves that problem deterministically — #4041
made the NuGet packages ship the full closure under
`analyzers/dotnet/.../cs`, and `Directory.Build.targets` registers the
same closure as `Analyzer` items for in-repo `ProjectReference`
consumers. SGF was therefore pure liability and is removed.

## What changed

**1. SourceGenerator.Foundations removed.** `ModelSourceGenerator` and
`StackSourceGenerator` are plain `[Generator(LanguageNames.CSharp)]
IIncrementalGenerator` implementations again. SGF's implicit crash
handling is replaced by an explicit `SourceGenerator.Guard` that reports
`MODELGEN003` / `STACKGEN003` and rethrows cancellation. Its logger sink
was already dead code and is dropped.
`Opc.Ua.SourceGeneration.Stack.dll` shrank from **18 MB** (embedded
closure) to **29 KB**.

**2. Analyzers now ship under Roslyn-versioned folders.**
`analyzers/dotnet/roslyn4.14/cs` and `analyzers/dotnet/roslyn5.0/cs`
instead of `analyzers/dotnet/cs`, driven by `roslyn.props` at the
repository root, with new `*.Pack` projects owning the package identity.
The versioned folder matters: a host older than the band **skips** the
analyzer instead of loading it and failing inside generator
initialization.

**3. Dependencies flow automatically.** Both delivery paths discover the
payload by globbing the generator's output directory, so adding a
package to a generator's dependency tree requires **no** `.csproj`,
`.targets`, `.nuspec` or validation-script edit. Verified by temporarily
adding a `PackageReference` and watching it appear in the payload with
no other file touched.

## Two Roslyn bands: VS2022 and VS2026

Analyzers ship twice, once per band. The .NET SDK loads the highest band
its compiler supports and **silently skips** anything above it, so a
single-band package leaves every consumer below that band with no
diagnostics and no generated code.

| Band | Built against | Loaded by |
| --- | --- | --- |
| `roslyn4.14` | `Microsoft.CodeAnalysis.CSharp 4.14.0` | Visual Studio
2022 17.14+ / .NET 9 SDK |
| `roslyn5.0` | `Microsoft.CodeAnalysis.CSharp 5.0.0` | Visual Studio
2026 18.0+ / .NET 10 SDK |

Getting this wrong is invisible, which is most of why it took three
attempts. The rule:

> An analyzer must reference the **lowest**
`System.Collections.Immutable` / `System.Reflection.Metadata` across all
hosts it claims to support, and must never ship them. .NET binds a
reference *upward* but never downward.

Every failure mode is a compiler **warning**:

| Diagnostic | Cause |
| --- | --- |
| `CS9057` | Built against a newer Roslyn than the host, so it is
skipped entirely |
| `CS8784` | Loaded, then `MissingMethodException` - a shipped S.C.I
bound a second `ImmutableArray<T>` |
| `CS8032` | Analyzer instance could not be created |

This PR first shipped a `roslyn4.8` band that **never loaded** -
confirmed against a real Roslyn 4.8 compiler:

```
warning CS8784: Generator 'ModelSourceGenerator' failed to initialize ...
MissingMethodException: Method not found:
'IncrementalValueProvider`1<ImmutableArray`1<!!0>>
 IncrementalValueProviderExtensions.Collect(IncrementalValuesProvider`1<!!0>)'
```

That band was removed, and **this is not a regression**: master had the
same defect, pinned to Roslyn 4.14 while referencing
`System.Collections.Immutable 10.0.0.0`, so no 4.x host ever worked
there either.

The band that landed instead is `4.14`, and it is nearly free:
`Microsoft.CodeAnalysis 4.14` depends on the **same S.C.I 9.0.0 as
5.0.0** and its `csc` runs on `net9.0`. Both bands therefore share
`$(RoslynRuntimeVersion)`, so `Opc.Ua.Types` and
`Opc.Ua.SourceGeneration.Core` are compiled **once** and serve both;
only the five Roslyn-referencing assemblies get a second build, each
from a 12-line project that glob-links the primary sources and overrides
`RoslynApiVersion`. Going lower still - 4.8 wants S.C.I 7.x - would mean
rebuilding that whole closure, `Opc.Ua.Types` included, and remains out
of scope. (`System.Collections.Immutable 7.0.0` also does not resolve in
this repository: `NU1603`, 8.0.0 substituted.)

**Nothing else in the repository exercises the down-level payload**, and
since every failure is a warning, a broken band would ship silently -
exactly as the 4.8 one did. So `validate-source-generator-packages.ps1`
now restores a real `Microsoft.Net.Compilers.Toolset 4.14.0`, runs its
`csc.dll` over the packed `roslyn4.14` payload, and asserts **both**
that none of `CS9057`/`CS8784`/`CS8032`/`CS8034` is emitted **and** that
`/reportanalyzer` lists the generator as having executed - silence alone
would also pass if the generator were never handed to the compiler. The
migration analyzer, whose payload comes from a hand-written nuspec
rather than `SourceGeneratorPack.targets`, gets the same check plus a
band/assembly manifest assertion.

To stop the trap recurring, `Microsoft.CodeAnalysis*`,
`System.Collections.Immutable` and `System.Reflection.Metadata` are
excluded from both the package payload and the in-repo analyzer closure,
and asserted against in the validation script. `roslyn.props` and
`docs/DeveloperGuide.md` document what adding a band requires.
## The shipped package set is unchanged

Evaluating `PackageId`/`IsPackable` across every project in
`preview-pack.slnx` gives the **same 47 package ids** on `master` and on
this branch, and a full Release build plus `dotnet pack --no-build`
produces exactly those 47. Only the owning project changed:

| Package | master | this PR |
| --- | --- | --- |
| `…Opc.Ua.SourceGeneration` | `Opc.Ua.SourceGeneration.csproj` |
`Opc.Ua.SourceGeneration.Pack.csproj` |
| `…Opc.Ua.SourceGeneration.Stack` |
`Opc.Ua.SourceGeneration.Stack.csproj` |
`Opc.Ua.SourceGeneration.Stack.Pack.csproj` |

`.azurepipelines/expected-packages.txt` pins the expected set and the
validation script fails when the packed output drifts.

## Two new package checks

**`build/<PackageId>.props` naming.** NuGet only auto-imports that exact
name, and the file declares every `CompilerVisibleProperty` /
`CompilerVisibleItemMetadata` the model generator relies on. It was
previously packed as
`build/OPCFoundation.Opc.Ua.SourceGeneration.props`, which does **not**
match the package id — so **no NuGet consumer ever imported it**, and
every `ModelSourceGenerator*` property and `AdditionalFiles` metadata
was silently invisible. In-repo projects were unaffected because they
import it by relative path.

**An end-to-end consumer that actually drives the generator.** The
pre-existing clean-consumer check only proved the analyzer *loads*.
`Test-SourceGeneratingConsumer` builds a standalone project that feeds a
real NodeSet2 in as an `AdditionalFile`, pins a
`ModelSourceGeneratorPrefix` that cannot be derived from the model, and
references the emitted types from hand-written code. It deliberately
does **not** import the props by path, so the package's auto-import is
what is under test. Both checks were verified to fail against a package
rebuilt with the misnamed props.

## CI: parallelism re-enabled

`buildandtest.yml` pinned three `dotnet build` invocations to
`/p:UseSharedCompilation=false` and `-maxcpucount:1`. `dotnet build`
defaults to all logical processors, so `-maxcpucount:1` actively
disabled parallelism. Both flags were introduced silently in unrelated
PRs (`f358078b1`, `208c601b0`) and suppress exactly the conditions the
SGF race needed — now structurally gone. Compilation is ~72 % of what
that workflow executes (233 of 323 job-minutes in run `29916768976`), so
the queue-independent `Build` step durations are the baseline:

| Measurement | Baseline |
| --- | --- |
| `Build` step, 26 `test-*` jobs | mean 5.53 min, sum 143.9 min |
| `build-linux-all-tfm` | 56.3 min |
| `build-windows-all-tfm` | 32.5 min |

`codeql-analysis.yml` keeps the flag — the CodeQL tracer requires it.

## Incidental fixes

- `Microsoft.CodeAnalysis.CSharp` declares an exact `[version]` range on
`Microsoft.CodeAnalysis.Common`, so with
`CentralPackageTransitivePinningEnabled` the central pins must move in
lockstep or restore fails with `NU1109`. They now derive from
`$(RoslynApiVersionVS2026)`.
- `MigrationGeneratorTests` created its generator driver without parse
options — silently fine under Roslyn 4.14, `Inconsistent language
versions` under 5.0.
- The migration analyzer props injected `<Analyzer>` items by hand from
`analyzers/dotnet/cs`; NuGet registers analyzers itself and selects the
matching folder, so the injection was obsolete and would now force the
wrong assembly to load.
- Exception diagnostics reported `ex.StackTrace` (null for an exception
that never left its throw site, and carrying neither type nor inner
chain) — now `ex.ToString()` at all three call sites.
- The pack guard tested the flattened assembly list, so it only fired
when *no* variant produced output; it now checks each declared variant
contributed assemblies.
- `GeneratePackageOnBuild` is disabled for the generators; packing
happens in CI or on an explicit `dotnet pack`.

## Note for reviewers

**Building this repository requires a Roslyn 5.x host** (the .NET 10 SDK
or Visual Studio 2026). That is already the documented prerequisite and
every CI leg installs `10.0.x` last, but it is now a hard requirement.

## Related Issues

_No tracking issue: this is a follow-up to the CS8784 clean-build
failure reported against #4041, which fixed the packaged delivery path
but left the in-repo project-reference path relying on the SGF
resolver._

- Follow-up to #4041

## Checklist

_Put an `x` in the boxes that apply. You can complete these step by step
after opening the PR._

- [x] I have signed the
[CLA](https://opcfoundation.org/license/cla/ContributorLicenseAgreementv1.0.pdf)
and read the
[CONTRIBUTING](https://github.com/OPCFoundation/UA-.NETStandard/blob/master/CONTRIBUTING.md)
doc.
- [x] I have added tests that prove my fix is effective or that my
feature works and increased code coverage.
- [x] I have added all necessary documentation.
- [x] I have verified that my changes do not introduce (new) build or
analyzer warnings.
- [x] I ran **all** tests locally using the **UA.slnx** solution against
at least .net **framework** and .net **10**, and all passed.
- [ ] I fixed **all** failing and flaky tests in the CI pipelines and
**all** CodeQL warnings.
- [ ] I have addressed **all** PR feedback received.

### Verification detail

| Check | Result |
| --- | --- |
| `dotnet build UA.slnx` (clean, and after merging master) | 0 errors;
18 warnings, all pre-existing `CA1873` in `Opc.Ua.Client` |
| `Opc.Ua.SourceGeneration.Tests` | 81/81 on net10.0 and net48 |
| `Opc.Ua.SourceGeneration.Stack.Tests` | 92/92 on net10.0, 89/89 on
net48 |
| `Opc.Ua.SourceGeneration.Core.Tests` | 3722 passed, 8 skipped |
| `Opc.Ua.MigrationAnalyzer.Tests` | 121/121 on net10.0 and net48 |
| Package id set, master vs branch | identical, 47 packages |
| Release build + `dotnet pack --no-build` | 47 packages, matching the
manifest; both `roslyn4.14` and `roslyn5.0` present; no host-provided
assemblies shipped |
| `validate-source-generator-packages.ps1` | passes, including manifest,
props-naming, end-to-end generator consumer and down-level host checks |
| Down-level band under real csc 4.14.0 | all three analyzer packages
load **and run** |
| Negative tests | misnamed props → both checks fail as designed; hidden
variant output → pack guard fires; 5.0 build placed in `roslyn4.14` →
real `CS9057`; non-running generator name → execution assertion fires;
expecting a `roslyn4.8` band → manifest check fires |

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 9ed53262-5cfa-429a-820e-bf6146a00d8b
2026-07-31 15:46:17 +00:00
Marc Schier 8538f531e7 Update paths for the consolidated repository layout 2026-07-16 06:26:05 +02:00
Marc Schier 7cec2d614d Move repository files to the consolidated layout 2026-07-16 06:25:54 +02:00