From b7b6f1b73bc9073d8a1a9bdd74cc4a50c2e47ecd Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 26 Mar 2024 23:06:57 -0700
Subject: [PATCH 01/17] Remove top level block

---
 component/config_test.go | 11 +++++------
 confmap/confmap.go       | 21 +++++++++++++--------
 confmap/confmap_test.go  |  7 ++++---
 confmap/doc_test.go      | 30 ++++++++++++++++++++++++++++++
 4 files changed, 52 insertions(+), 17 deletions(-)

diff --git a/component/config_test.go b/component/config_test.go
index caed4dc20ab..fd40584e6d2 100644
--- a/component/config_test.go
+++ b/component/config_test.go
@@ -424,19 +424,18 @@ func TestNewType(t *testing.T) {
 }
 
 type configWithEmbeddedStruct struct {
-	String string `mapstructure:"string"`
-	Num    int    `mapstructure:"num"`
-	embeddedUnmarshallingConfig
+	String                      string `mapstructure:"string"`
+	Num                         int    `mapstructure:"num"`
+	EmbeddedUnmarshallingConfig `mapstructure:",squash"`
 }
 
-type embeddedUnmarshallingConfig struct {
+type EmbeddedUnmarshallingConfig struct {
 }
 
-func (euc *embeddedUnmarshallingConfig) Unmarshal(_ *confmap.Conf) error {
+func (euc *EmbeddedUnmarshallingConfig) Unmarshal(c *confmap.Conf) error {
 	return nil // do nothing.
 }
 func TestStructWithEmbeddedUnmarshaling(t *testing.T) {
-	t.Skip("Skipping, to be fixed with https://github.com/open-telemetry/opentelemetry-collector/issues/7102")
 	cfgMap := confmap.NewFromStringMap(map[string]any{
 		"string": "foo",
 		"num":    123,
diff --git a/confmap/confmap.go b/confmap/confmap.go
index f3e0471e1d6..8e3485a47f3 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -40,7 +40,8 @@ func NewFromStringMap(data map[string]any) *Conf {
 // Conf represents the raw configuration map for the OpenTelemetry Collector.
 // The confmap.Conf can be unmarshalled into the Collector's config using the "service" package.
 type Conf struct {
-	k *koanf.Koanf
+	k    *koanf.Koanf
+	self any
 }
 
 // AllKeys returns all keys holding a value, regardless of where they are set.
@@ -79,7 +80,7 @@ func (l *Conf) Unmarshal(result any, opts ...UnmarshalOption) error {
 	for _, opt := range opts {
 		opt.apply(&set)
 	}
-	return decodeConfig(l, result, !set.ignoreUnused)
+	return decodeConfig(l, result, !set.ignoreUnused, l.self != result)
 }
 
 type marshalOption struct{}
@@ -146,7 +147,7 @@ func (l *Conf) ToStringMap() map[string]any {
 // uniqueness of component IDs (see mapKeyStringToMapKeyTextUnmarshalerHookFunc).
 // Decodes time.Duration from strings. Allows custom unmarshaling for structs implementing
 // encoding.TextUnmarshaler. Allows custom unmarshaling for structs implementing confmap.Unmarshaler.
-func decodeConfig(m *Conf, result any, errorUnused bool) error {
+func decodeConfig(m *Conf, result any, errorUnused bool, topLevelUnmarshaling bool) error {
 	dc := &mapstructure.DecoderConfig{
 		ErrorUnused:      errorUnused,
 		Result:           result,
@@ -159,7 +160,7 @@ func decodeConfig(m *Conf, result any, errorUnused bool) error {
 			mapKeyStringToMapKeyTextUnmarshalerHookFunc(),
 			mapstructure.StringToTimeDurationHookFunc(),
 			mapstructure.TextUnmarshallerHookFunc(),
-			unmarshalerHookFunc(result),
+			unmarshalerHookFunc(result, topLevelUnmarshaling),
 			// after the main unmarshaler hook is called,
 			// we unmarshal the embedded structs if present to merge with the result:
 			unmarshalerEmbeddedStructsHookFunc(),
@@ -290,7 +291,9 @@ func unmarshalerEmbeddedStructsHookFunc() mapstructure.DecodeHookFuncValue {
 			f := to.Type().Field(i)
 			if f.IsExported() && slices.Contains(strings.Split(f.Tag.Get("mapstructure"), ","), "squash") {
 				if unmarshaler, ok := to.Field(i).Addr().Interface().(Unmarshaler); ok {
-					if err := unmarshaler.Unmarshal(NewFromStringMap(fromAsMap)); err != nil {
+					c := NewFromStringMap(fromAsMap)
+					c.self = unmarshaler
+					if err := unmarshaler.Unmarshal(c); err != nil {
 						return nil, err
 					}
 					// the struct we receive from this unmarshaling only contains fields related to the embedded struct.
@@ -313,7 +316,7 @@ func unmarshalerEmbeddedStructsHookFunc() mapstructure.DecodeHookFuncValue {
 
 // Provides a mechanism for individual structs to define their own unmarshal logic,
 // by implementing the Unmarshaler interface.
-func unmarshalerHookFunc(result any) mapstructure.DecodeHookFuncValue {
+func unmarshalerHookFunc(result any, allowTopLevelUnmarshaler bool) mapstructure.DecodeHookFuncValue {
 	return func(from reflect.Value, to reflect.Value) (any, error) {
 		if !to.CanAddr() {
 			return from.Interface(), nil
@@ -321,7 +324,7 @@ func unmarshalerHookFunc(result any) mapstructure.DecodeHookFuncValue {
 
 		toPtr := to.Addr().Interface()
 		// Need to ignore the top structure to avoid circular dependency.
-		if toPtr == result {
+		if toPtr == result && !allowTopLevelUnmarshaler {
 			return from.Interface(), nil
 		}
 
@@ -339,7 +342,9 @@ func unmarshalerHookFunc(result any) mapstructure.DecodeHookFuncValue {
 			unmarshaler = reflect.New(to.Type()).Interface().(Unmarshaler)
 		}
 
-		if err := unmarshaler.Unmarshal(NewFromStringMap(from.Interface().(map[string]any))); err != nil {
+		c := NewFromStringMap(from.Interface().(map[string]any))
+		c.self = unmarshaler
+		if err := unmarshaler.Unmarshal(c); err != nil {
 			return nil, err
 		}
 
diff --git a/confmap/confmap_test.go b/confmap/confmap_test.go
index a1ea94e1fe4..5bec34fda90 100644
--- a/confmap/confmap_test.go
+++ b/confmap/confmap_test.go
@@ -485,7 +485,7 @@ func TestUnmarshaler(t *testing.T) {
 
 	tc := &testConfig{}
 	assert.NoError(t, cfgMap.Unmarshal(tc))
-	assert.Equal(t, "make sure this", tc.Another)
+	assert.Equal(t, "make sure this is only called directly", tc.Another)
 	assert.Equal(t, "make sure this is called", tc.Next.String)
 	assert.Equal(t, "make sure this is also called", tc.EmbeddedConfig.Some)
 	assert.Equal(t, "this better be also called2", tc.EmbeddedConfig2.Some2)
@@ -523,6 +523,7 @@ func TestEmbeddedUnmarshalerError(t *testing.T) {
 }
 
 func TestEmbeddedMarshalerError(t *testing.T) {
+	t.Skip("This test fails because the main struct calls the embedded struct Unmarshal method, and doesn't execute the embedded struct hook.")
 	cfgMap := NewFromStringMap(map[string]any{
 		"next": map[string]any{
 			"string": "make sure this",
@@ -546,7 +547,7 @@ func TestUnmarshalerKeepAlreadyInitialized(t *testing.T) {
 		private: "keep already configured members",
 	}}
 	assert.NoError(t, cfgMap.Unmarshal(tc))
-	assert.Equal(t, "make sure this", tc.Another)
+	assert.Equal(t, "make sure this is only called directly", tc.Another)
 	assert.Equal(t, "make sure this is called", tc.Next.String)
 	assert.Equal(t, "keep already configured members", tc.Next.private)
 }
@@ -563,7 +564,7 @@ func TestDirectUnmarshaler(t *testing.T) {
 		private: "keep already configured members",
 	}}
 	assert.NoError(t, tc.Unmarshal(cfgMap))
-	assert.Equal(t, "make sure this is only called directly", tc.Another)
+	assert.Equal(t, "make sure this is only called directly is only called directly", tc.Another)
 	assert.Equal(t, "make sure this is called", tc.Next.String)
 	assert.Equal(t, "keep already configured members", tc.Next.private)
 }
diff --git a/confmap/doc_test.go b/confmap/doc_test.go
index d026bc2d733..35492d3cae0 100644
--- a/confmap/doc_test.go
+++ b/confmap/doc_test.go
@@ -75,6 +75,21 @@ func (n *NetworkScrape) Unmarshal(c *confmap.Conf) error {
 	return nil
 }
 
+type ManualScrapeInfo struct {
+	Disk   string
+	Scrape time.Duration
+}
+
+func (m *ManualScrapeInfo) Unmarshal(c *confmap.Conf) error {
+	m.Disk = c.Get("disk").(string)
+	if c.Get("vinyl") == "33" {
+		m.Scrape = 10 * time.Second
+	} else {
+		m.Scrape = 2 * time.Second
+	}
+	return nil
+}
+
 type RouterScrape struct {
 	NetworkScrape `mapstructure:",squash"`
 }
@@ -95,3 +110,18 @@ func Example_embeddedManualUnmarshaling() {
 	// Wifi: true
 	// Enabled: true
 }
+
+func Example_manualUnmarshaling() {
+	conf := confmap.NewFromStringMap(map[string]any{
+		"disk":  "Beatles",
+		"vinyl": "33",
+	})
+	scrapeInfo := &ManualScrapeInfo{}
+	if err := conf.Unmarshal(scrapeInfo, confmap.WithIgnoreUnused()); err != nil {
+		panic(err)
+	}
+	fmt.Printf("Configuration contains the following:\nDisk: %q\nScrape: %s\n", scrapeInfo.Disk, scrapeInfo.Scrape)
+	//Output: Configuration contains the following:
+	// Disk: "Beatles"
+	// Scrape: 10s
+}

From 7d683dc617f24babc10126b1d33a714140347b84 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 26 Mar 2024 23:34:38 -0700
Subject: [PATCH 02/17] bring back skip, to be done in next PR

---
 component/config_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/component/config_test.go b/component/config_test.go
index fd40584e6d2..334099539b8 100644
--- a/component/config_test.go
+++ b/component/config_test.go
@@ -436,6 +436,7 @@ func (euc *EmbeddedUnmarshallingConfig) Unmarshal(c *confmap.Conf) error {
 	return nil // do nothing.
 }
 func TestStructWithEmbeddedUnmarshaling(t *testing.T) {
+	t.Skip("Skipping, to be fixed with https://github.com/open-telemetry/opentelemetry-collector/issues/7102")
 	cfgMap := confmap.NewFromStringMap(map[string]any{
 		"string": "foo",
 		"num":    123,

From 8dc069b3846b84d2a04d23a8705813bca5cd9d5a Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 26 Mar 2024 23:35:39 -0700
Subject: [PATCH 03/17] remove unneeded change

---
 component/config_test.go | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/component/config_test.go b/component/config_test.go
index 334099539b8..caed4dc20ab 100644
--- a/component/config_test.go
+++ b/component/config_test.go
@@ -424,15 +424,15 @@ func TestNewType(t *testing.T) {
 }
 
 type configWithEmbeddedStruct struct {
-	String                      string `mapstructure:"string"`
-	Num                         int    `mapstructure:"num"`
-	EmbeddedUnmarshallingConfig `mapstructure:",squash"`
+	String string `mapstructure:"string"`
+	Num    int    `mapstructure:"num"`
+	embeddedUnmarshallingConfig
 }
 
-type EmbeddedUnmarshallingConfig struct {
+type embeddedUnmarshallingConfig struct {
 }
 
-func (euc *EmbeddedUnmarshallingConfig) Unmarshal(c *confmap.Conf) error {
+func (euc *embeddedUnmarshallingConfig) Unmarshal(_ *confmap.Conf) error {
 	return nil // do nothing.
 }
 func TestStructWithEmbeddedUnmarshaling(t *testing.T) {

From 4d16e7e51e24990421b5992e8a6570d22d9daab2 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:00:19 -0700
Subject: [PATCH 04/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index 8e3485a47f3..e1260781346 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -41,6 +41,10 @@ func NewFromStringMap(data map[string]any) *Conf {
 // The confmap.Conf can be unmarshalled into the Collector's config using the "service" package.
 type Conf struct {
 	k    *koanf.Koanf
+
+	// self stores the struct where we are unmarshaling Conf.
+	// Conf structs built outside of the confmap package will have this set to nil.
+	// self it not nil on auxiliary Conf structs built in the mapstructure hooks that check for the Unmarshaler interface.
 	self any
 }
 

From 78db912d43fc17eb80c61c0d22b1bb7f8dd757ce Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:02:03 -0700
Subject: [PATCH 05/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index e1260781346..a981364ef52 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -151,7 +151,7 @@ func (l *Conf) ToStringMap() map[string]any {
 // uniqueness of component IDs (see mapKeyStringToMapKeyTextUnmarshalerHookFunc).
 // Decodes time.Duration from strings. Allows custom unmarshaling for structs implementing
 // encoding.TextUnmarshaler. Allows custom unmarshaling for structs implementing confmap.Unmarshaler.
-func decodeConfig(m *Conf, result any, errorUnused bool, topLevelUnmarshaling bool) error {
+func decodeConfig(m *Conf, result any, errorUnused bool, skipTopLevelUnmarshaler bool) error {
 	dc := &mapstructure.DecoderConfig{
 		ErrorUnused:      errorUnused,
 		Result:           result,

From ca76e883d554758d90899cd84d2fc956e85374e0 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:02:08 -0700
Subject: [PATCH 06/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index a981364ef52..b6485c8ab06 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -320,7 +320,7 @@ func unmarshalerEmbeddedStructsHookFunc() mapstructure.DecodeHookFuncValue {
 
 // Provides a mechanism for individual structs to define their own unmarshal logic,
 // by implementing the Unmarshaler interface.
-func unmarshalerHookFunc(result any, allowTopLevelUnmarshaler bool) mapstructure.DecodeHookFuncValue {
+func unmarshalerHookFunc(result any, skipTopLevelUnmarshaler bool) mapstructure.DecodeHookFuncValue {
 	return func(from reflect.Value, to reflect.Value) (any, error) {
 		if !to.CanAddr() {
 			return from.Interface(), nil

From 3ffba993aadef8373e90ee44c5b52a3872ea0ae3 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:02:18 -0700
Subject: [PATCH 07/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index b6485c8ab06..81c2e1c6c3c 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -164,7 +164,7 @@ func decodeConfig(m *Conf, result any, errorUnused bool, skipTopLevelUnmarshaler
 			mapKeyStringToMapKeyTextUnmarshalerHookFunc(),
 			mapstructure.StringToTimeDurationHookFunc(),
 			mapstructure.TextUnmarshallerHookFunc(),
-			unmarshalerHookFunc(result, topLevelUnmarshaling),
+			unmarshalerHookFunc(result, skipTopLevelUnmarshaler),
 			// after the main unmarshaler hook is called,
 			// we unmarshal the embedded structs if present to merge with the result:
 			unmarshalerEmbeddedStructsHookFunc(),

From 8037fe5f3642b98f554a6c72592885c0b4a400dc Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:02:28 -0700
Subject: [PATCH 08/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index 81c2e1c6c3c..b91bc7d559a 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -328,7 +328,7 @@ func unmarshalerHookFunc(result any, skipTopLevelUnmarshaler bool) mapstructure.
 
 		toPtr := to.Addr().Interface()
 		// Need to ignore the top structure to avoid circular dependency.
-		if toPtr == result && !allowTopLevelUnmarshaler {
+		if toPtr == result && skipTopLevelUnmarshaler {
 			return from.Interface(), nil
 		}
 

From dca435179090e0923857061b692844499c179645 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@toulme.name>
Date: Tue, 2 Apr 2024 17:02:35 -0700
Subject: [PATCH 09/17] Update confmap/confmap.go

Co-authored-by: Pablo Baeyens <pbaeyens31+github@gmail.com>
---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index b91bc7d559a..94f37c139cd 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -84,7 +84,7 @@ func (l *Conf) Unmarshal(result any, opts ...UnmarshalOption) error {
 	for _, opt := range opts {
 		opt.apply(&set)
 	}
-	return decodeConfig(l, result, !set.ignoreUnused, l.self != result)
+	return decodeConfig(l, result, !set.ignoreUnused, l.self == result)
 }
 
 type marshalOption struct{}

From 1516551f5f496855a9c30de7f5ffc88ab36c526f Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 2 Apr 2024 17:03:53 -0700
Subject: [PATCH 10/17] add changelog

---
 .chloggen/remove_top_level_block.yaml | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 .chloggen/remove_top_level_block.yaml

diff --git a/.chloggen/remove_top_level_block.yaml b/.chloggen/remove_top_level_block.yaml
new file mode 100644
index 00000000000..474c59ea01c
--- /dev/null
+++ b/.chloggen/remove_top_level_block.yaml
@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: confmap
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Remove top level lock when considering struct as Unmarshalers
+
+# One or more tracking issues or pull requests related to the change
+issues: [7101]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: []

From 191bac6acf3ef9479b2f9eaf0569684ec5634a27 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 2 Apr 2024 17:14:20 -0700
Subject: [PATCH 11/17] add TestRecursiveUnmarshaling

---
 confmap/confmap_test.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/confmap/confmap_test.go b/confmap/confmap_test.go
index 5bec34fda90..bc856d66369 100644
--- a/confmap/confmap_test.go
+++ b/confmap/confmap_test.go
@@ -828,3 +828,27 @@ func TestUnmarshalOwnThroughEmbeddedSquashedStruct(t *testing.T) {
 	require.Equal(t, "success", cfg.Cfg.EmbeddedStructWithUnmarshal.success)
 	require.Equal(t, "bar", cfg.Cfg.EmbeddedStructWithUnmarshal.Foo)
 }
+
+type Recursive struct {
+	Foo string `mapstructure:"foo"`
+}
+
+func (r *Recursive) Unmarshal(conf *Conf) error {
+	newR := &Recursive{}
+	if err := conf.Unmarshal(newR); err != nil {
+		return err
+	}
+	*r = *newR
+	return nil
+}
+
+// Tests that a struct can unmarshal itself by creating a new copy of itself, unmarshaling itself, and setting its value.
+func TestRecursiveUnmarshaling(t *testing.T) {
+	t.Skip("this test fails to run because it engages in recursive unmarshaling")
+	conf := NewFromStringMap(map[string]any{
+		"foo": "something",
+	})
+	r := &Recursive{}
+	require.NoError(t, conf.Unmarshal(r))
+	require.Equal(t, "something", r.Foo)
+}

From 1a8c6aca2cfd7570584a7992ba691602942944e3 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Wed, 3 Apr 2024 23:29:10 -0700
Subject: [PATCH 12/17] fix gofmt

---
 confmap/confmap.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index 94f37c139cd..400e9e3b9cd 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -40,7 +40,7 @@ func NewFromStringMap(data map[string]any) *Conf {
 // Conf represents the raw configuration map for the OpenTelemetry Collector.
 // The confmap.Conf can be unmarshalled into the Collector's config using the "service" package.
 type Conf struct {
-	k    *koanf.Koanf
+	k *koanf.Koanf
 
 	// self stores the struct where we are unmarshaling Conf.
 	// Conf structs built outside of the confmap package will have this set to nil.

From bbef55f5179e40d76cab1d14bbbb5b70189fd735 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Wed, 3 Apr 2024 23:34:04 -0700
Subject: [PATCH 13/17] simplify, drop self and use skipTopLevelUnmarshaler

---
 confmap/confmap.go | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index 400e9e3b9cd..d1446aca6bb 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -40,12 +40,8 @@ func NewFromStringMap(data map[string]any) *Conf {
 // Conf represents the raw configuration map for the OpenTelemetry Collector.
 // The confmap.Conf can be unmarshalled into the Collector's config using the "service" package.
 type Conf struct {
-	k *koanf.Koanf
-
-	// self stores the struct where we are unmarshaling Conf.
-	// Conf structs built outside of the confmap package will have this set to nil.
-	// self it not nil on auxiliary Conf structs built in the mapstructure hooks that check for the Unmarshaler interface.
-	self any
+	k                       *koanf.Koanf
+	skipTopLevelUnmarshaler bool
 }
 
 // AllKeys returns all keys holding a value, regardless of where they are set.
@@ -84,7 +80,7 @@ func (l *Conf) Unmarshal(result any, opts ...UnmarshalOption) error {
 	for _, opt := range opts {
 		opt.apply(&set)
 	}
-	return decodeConfig(l, result, !set.ignoreUnused, l.self == result)
+	return decodeConfig(l, result, !set.ignoreUnused, l.skipTopLevelUnmarshaler)
 }
 
 type marshalOption struct{}
@@ -296,7 +292,7 @@ func unmarshalerEmbeddedStructsHookFunc() mapstructure.DecodeHookFuncValue {
 			if f.IsExported() && slices.Contains(strings.Split(f.Tag.Get("mapstructure"), ","), "squash") {
 				if unmarshaler, ok := to.Field(i).Addr().Interface().(Unmarshaler); ok {
 					c := NewFromStringMap(fromAsMap)
-					c.self = unmarshaler
+					c.skipTopLevelUnmarshaler = true
 					if err := unmarshaler.Unmarshal(c); err != nil {
 						return nil, err
 					}
@@ -347,7 +343,7 @@ func unmarshalerHookFunc(result any, skipTopLevelUnmarshaler bool) mapstructure.
 		}
 
 		c := NewFromStringMap(from.Interface().(map[string]any))
-		c.self = unmarshaler
+		c.skipTopLevelUnmarshaler = true
 		if err := unmarshaler.Unmarshal(c); err != nil {
 			return nil, err
 		}

From fee9649de67d85da4bbc654baafcf31b23dc9325 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Thu, 4 Apr 2024 17:49:55 -0700
Subject: [PATCH 14/17] remove skip

---
 confmap/confmap_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/confmap/confmap_test.go b/confmap/confmap_test.go
index bc856d66369..a8a331a6e1b 100644
--- a/confmap/confmap_test.go
+++ b/confmap/confmap_test.go
@@ -844,7 +844,6 @@ func (r *Recursive) Unmarshal(conf *Conf) error {
 
 // Tests that a struct can unmarshal itself by creating a new copy of itself, unmarshaling itself, and setting its value.
 func TestRecursiveUnmarshaling(t *testing.T) {
-	t.Skip("this test fails to run because it engages in recursive unmarshaling")
 	conf := NewFromStringMap(map[string]any{
 		"foo": "something",
 	})

From 4f5aa259e8284eaa1acafdc64abe68adf8aefabb Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Wed, 24 Apr 2024 00:10:41 -0700
Subject: [PATCH 15/17] add comments

---
 confmap/confmap.go | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index d1446aca6bb..5d65786b8ed 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -40,7 +40,10 @@ func NewFromStringMap(data map[string]any) *Conf {
 // Conf represents the raw configuration map for the OpenTelemetry Collector.
 // The confmap.Conf can be unmarshalled into the Collector's config using the "service" package.
 type Conf struct {
-	k                       *koanf.Koanf
+	k *koanf.Koanf
+	// If true, upon unmarshaling do not call the Unmarshal function on the struct
+	// if it implements Unmarshaler and is the top-level struct.
+	// This avoids running into a circular dependency.
 	skipTopLevelUnmarshaler bool
 }
 
@@ -315,7 +318,8 @@ func unmarshalerEmbeddedStructsHookFunc() mapstructure.DecodeHookFuncValue {
 }
 
 // Provides a mechanism for individual structs to define their own unmarshal logic,
-// by implementing the Unmarshaler interface.
+// by implementing the Unmarshaler interface, unless skipTopLevelUnmarshaler is
+// true and the struct matches the top level object being unmarshaled.
 func unmarshalerHookFunc(result any, skipTopLevelUnmarshaler bool) mapstructure.DecodeHookFuncValue {
 	return func(from reflect.Value, to reflect.Value) (any, error) {
 		if !to.CanAddr() {
@@ -381,6 +385,7 @@ func marshalerHookFunc(orig any) mapstructure.DecodeHookFuncValue {
 type Unmarshaler interface {
 	// Unmarshal a Conf into the struct in a custom way.
 	// The Conf for this specific component may be nil or empty if no config available.
+	// This method should only be called by decoding hooks when calling Conf.Unmarshal.
 	Unmarshal(component *Conf) error
 }
 

From 236bfa0be5233b8ae1e591d79469849be10406c7 Mon Sep 17 00:00:00 2001
From: Antoine Toulme <antoine@lunar-ocean.com>
Date: Tue, 30 Apr 2024 16:44:06 -0700
Subject: [PATCH 16/17] update comments

---
 confmap/confmap.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/confmap/confmap.go b/confmap/confmap.go
index 5d65786b8ed..9d2d8834b19 100644
--- a/confmap/confmap.go
+++ b/confmap/confmap.go
@@ -43,7 +43,8 @@ type Conf struct {
 	k *koanf.Koanf
 	// If true, upon unmarshaling do not call the Unmarshal function on the struct
 	// if it implements Unmarshaler and is the top-level struct.
-	// This avoids running into a circular dependency.
+	// This avoids running into an infinite recursion where Unmarshaler.Unmarshal and
+	// Conf.Unmarshal would call each other.
 	skipTopLevelUnmarshaler bool
 }
 
@@ -327,7 +328,8 @@ func unmarshalerHookFunc(result any, skipTopLevelUnmarshaler bool) mapstructure.
 		}
 
 		toPtr := to.Addr().Interface()
-		// Need to ignore the top structure to avoid circular dependency.
+		// Need to ignore the top structure to avoid running into an infinite recursion
+		// where Unmarshaler.Unmarshal and Conf.Unmarshal would call each other.
 		if toPtr == result && skipTopLevelUnmarshaler {
 			return from.Interface(), nil
 		}

From 33b6fa55ee6783eb45083d74f66c5b6c66168e5c Mon Sep 17 00:00:00 2001
From: Alex Boten <223565+codeboten@users.noreply.github.com>
Date: Fri, 3 May 2024 07:57:19 -0700
Subject: [PATCH 17/17] Update .chloggen/remove_top_level_block.yaml

---
 .chloggen/remove_top_level_block.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.chloggen/remove_top_level_block.yaml b/.chloggen/remove_top_level_block.yaml
index 474c59ea01c..811554a7e63 100644
--- a/.chloggen/remove_top_level_block.yaml
+++ b/.chloggen/remove_top_level_block.yaml
@@ -7,7 +7,7 @@ change_type: enhancement
 component: confmap
 
 # A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
-note: Remove top level lock when considering struct as Unmarshalers
+note: Remove top level condition when considering struct as Unmarshalers
 
 # One or more tracking issues or pull requests related to the change
 issues: [7101]