add deprecation singleton

This struct tracks and validates deprecations in the context of a
graph walk. We need a struct to keep track of the module calls that
opt-out of deprecation warnings.

Author: DanielMSchmidt

internal/deprecation/deprecation.go

@@ -0,0 +1,96 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: BUSL-1.1
+
+package deprecation
+
+import (
+	"sync"
+
+	"github.com/hashicorp/hcl/v2"
+	"github.com/hashicorp/terraform/internal/addrs"
+	"github.com/hashicorp/terraform/internal/lang/marks"
+	"github.com/hashicorp/terraform/internal/tfdiags"
+	"github.com/zclconf/go-cty/cty"
+)
+
+// Deprecations keeps track of meta-information related to deprecation, e.g. which module calls
+// suppress deprecation warnings.
+type Deprecations struct {
+	// Must hold this lock when accessing all fields after this one.
+	mu sync.Mutex
+
+	suppressedModules addrs.Set[addrs.Module]
+}
+
+func NewDeprecations() *Deprecations {
+	return &Deprecations{
+		suppressedModules: addrs.MakeSet[addrs.Module](),
+	}
+}
+
+func (d *Deprecations) SuppressModuleCallDeprecation(addr addrs.Module) {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.suppressedModules.Add(addr)
+}
+
+func (d *Deprecations) Validate(value cty.Value, module addrs.Module, rng *hcl.Range) (cty.Value, tfdiags.Diagnostics) {
+	var diags tfdiags.Diagnostics
+	deprecationMarks := marks.GetDeprecationMarks(value)
+	if len(deprecationMarks) == 0 {
+		return value, diags
+	}
+
+	notDeprecatedValue := marks.RemoveDeprecationMarks(value)
+
+	// Check if we need to suppress deprecation warnings for this module call.
+	if d.IsModuleCallDeprecationSuppressed(module) {
+		return notDeprecatedValue, diags
+	}
+
+	for _, depMark := range deprecationMarks {
+		diags = diags.Append(&hcl.Diagnostic{
+			Severity: hcl.DiagWarning,
+			Summary:  "Deprecated value used",
+			Detail:   depMark.Message,
+			Subject:  rng,
+		})
+	}
+
+	return notDeprecatedValue, diags
+}
+
+func (d *Deprecations) ValidateAsConfig(value cty.Value, module addrs.Module) tfdiags.Diagnostics {
+	var diags tfdiags.Diagnostics
+	_, pvms := value.UnmarkDeepWithPaths()
+
+	if len(pvms) == 0 || d.IsModuleCallDeprecationSuppressed(module) {
+		return diags
+	}
+
+	for _, pvm := range pvms {
+		for m := range pvm.Marks {
+			if depMark, ok := m.(marks.DeprecationMark); ok {
+				diags = diags.Append(
+					tfdiags.AttributeValue(
+						tfdiags.Warning,
+						"Deprecated value used",
+						depMark.Message,
+						pvm.Path,
+					),
+				)
+			}
+		}
+	}
+	return diags
+}
+
+func (d *Deprecations) IsModuleCallDeprecationSuppressed(addr addrs.Module) bool {
+	for _, mod := range d.suppressedModules {
+		if addr.Equal(mod) || mod.TargetContains(addr) {
+			return true
+		}
+	}
+	return false
+}

internal/terraform/context_walk.go

@@ -11,6 +11,7 @@ import (
 	"github.com/hashicorp/terraform/internal/addrs"
 	"github.com/hashicorp/terraform/internal/checks"
 	"github.com/hashicorp/terraform/internal/configs"
+	"github.com/hashicorp/terraform/internal/deprecation"
 	"github.com/hashicorp/terraform/internal/instances"
 	"github.com/hashicorp/terraform/internal/lang"
 	"github.com/hashicorp/terraform/internal/moduletest/mocking"
@@ -201,5 +202,6 @@ func (c *Context) graphWalker(graph *Graph, operation walkOperation, opts *graph
 		functionResults:         opts.FunctionResults,
 		Forget:                  opts.Forget,
 		Actions:                 actions.NewActions(),
+		Deprecations:            deprecation.NewDeprecations(),
 	}
 }

internal/terraform/eval_context.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/terraform/internal/checks"
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
+	"github.com/hashicorp/terraform/internal/deprecation"
 	"github.com/hashicorp/terraform/internal/experiments"
 	"github.com/hashicorp/terraform/internal/instances"
 	"github.com/hashicorp/terraform/internal/lang"
@@ -222,6 +223,10 @@ type EvalContext interface {
 	// declarations and their instances that are available in this
 	// EvalContext.
 	Actions() *actions.Actions
+
+	// Deprecations returns the deprecations object that tracks meta-information
+	// about deprecation, e.g. which module calls suppress deprecation warnings.
+	Deprecations() *deprecation.Deprecations
 }
 
 func evalContextForModuleInstance(baseCtx EvalContext, addr addrs.ModuleInstance) EvalContext {

internal/terraform/eval_context_builtin.go

@@ -18,6 +18,7 @@ import (
 	"github.com/hashicorp/terraform/internal/checks"
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
+	"github.com/hashicorp/terraform/internal/deprecation"
 	"github.com/hashicorp/terraform/internal/experiments"
 	"github.com/hashicorp/terraform/internal/instances"
 	"github.com/hashicorp/terraform/internal/lang"
@@ -93,6 +94,7 @@ type BuiltinEvalContext struct {
 	MoveResultsValue        refactoring.MoveResults
 	OverrideValues          *mocking.Overrides
 	ActionsValue            *actions.Actions
+	DeprecationsValue       *deprecation.Deprecations
 }
 
 // BuiltinEvalContext implements EvalContext
@@ -643,3 +645,7 @@ func (ctx *BuiltinEvalContext) ClientCapabilities() providers.ClientCapabilities
 func (ctx *BuiltinEvalContext) Actions() *actions.Actions {
 	return ctx.ActionsValue
 }
+
+func (ctx *BuiltinEvalContext) Deprecations() *deprecation.Deprecations {
+	return ctx.DeprecationsValue
+}

internal/terraform/eval_context_mock.go

@@ -16,6 +16,7 @@ import (
 	"github.com/hashicorp/terraform/internal/checks"
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
+	"github.com/hashicorp/terraform/internal/deprecation"
 	"github.com/hashicorp/terraform/internal/experiments"
 	"github.com/hashicorp/terraform/internal/instances"
 	"github.com/hashicorp/terraform/internal/lang"
@@ -170,6 +171,9 @@ type MockEvalContext struct {
 
 	ActionsCalled bool
 	ActionsState  *actions.Actions
+
+	DeprecationCalled bool
+	DeprecationState  *deprecation.Deprecations
 }
 
 // MockEvalContext implements EvalContext
@@ -451,3 +455,11 @@ func (c *MockEvalContext) Actions() *actions.Actions {
 	c.ActionsCalled = true
 	return c.ActionsState
 }
+
+func (c *MockEvalContext) Deprecations() *deprecation.Deprecations {
+	c.DeprecationCalled = true
+	if c.DeprecationState != nil {
+		return c.DeprecationState
+	}
+	return deprecation.NewDeprecations()
+}

internal/terraform/graph_walk_context.go

@@ -14,6 +14,7 @@ import (
 	"github.com/hashicorp/terraform/internal/collections"
 	"github.com/hashicorp/terraform/internal/configs"
 	"github.com/hashicorp/terraform/internal/configs/configschema"
+	"github.com/hashicorp/terraform/internal/deprecation"
 	"github.com/hashicorp/terraform/internal/instances"
 	"github.com/hashicorp/terraform/internal/lang"
 	"github.com/hashicorp/terraform/internal/moduletest/mocking"
@@ -53,9 +54,10 @@ type ContextGraphWalker struct {
 	PlanTimestamp           time.Time
 	Overrides               *mocking.Overrides
 	// Forget if set to true will cause the plan to forget all resources. This is
-	// only allowd in the context of a destroy plan.
-	Forget  bool
-	Actions *actions.Actions
+	// only allowed in the context of a destroy plan.
+	Forget       bool
+	Actions      *actions.Actions
+	Deprecations *deprecation.Deprecations
 
 	// This is an output. Do not set this, nor read it while a graph walk
 	// is in progress.
@@ -144,6 +146,7 @@ func (w *ContextGraphWalker) EvalContext() EvalContext {
 		OverrideValues:          w.Overrides,
 		forget:                  w.Forget,
 		ActionsValue:            w.Actions,
+		DeprecationsValue:       w.Deprecations,
 	}
 
 	return ctx