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Avoid storing LateBoundDefault attribute values in Rule.
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The change that produces the desired effect is to compare the attribute value with `Attribute#getDefaultValueUnchecked`. The unchecked method returns `LateBoundDefault`, not its default value. This allows the optimization added in bazelbuild@1d03d53 to also work for `LateBoundDefault`.

Rename `getRawAttrValue` to `getAttrIfStored` to better reflect that it does not fall back to the default value.

PiperOrigin-RevId: 518720504
Change-Id: I3141a1d731aaede8ff81b46ebc819cdb6af0fa0a
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@justinhorvitz @copybara-github
justinhorvitz authored and copybara-github committed Mar 23, 2023
1 parent 745ca28 commit c82168e
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Showing 3 changed files with 86 additions and 40 deletions.
4 changes: 2 additions & 2 deletions src/main/java/com/google/devtools/build/lib/packages/AggregatingAttributeMapper.java
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Original file line number Diff line number Diff line change
Expand Up @@ -115,7 +115,7 @@ private <T> void visitLabels(
if (type.getLabelClass() == LabelClass.NONE) {
// The only way for LabelClass.NONE to contain labels is in select keys.
if (includeSelectKeys && attr.isConfigurable()) {
rawVal = rule.getRawAttrValue(i);
rawVal = rule.getAttrIfStored(i);
if (rawVal instanceof SelectorList) {
visitLabelsInSelect(
(SelectorList<T>) rawVal,
Expand All @@ -128,7 +128,7 @@ private <T> void visitLabels(
}
return;
}
rawVal = rule.getRawAttrValue(i);
rawVal = rule.getAttrIfStored(i);
if (rawVal == null) {
// Frozen rules don't store computed defaults.
if (!attr.hasComputedDefault() || rule.isFrozen()) {
Expand Down
20 changes: 13 additions & 7 deletions src/main/java/com/google/devtools/build/lib/packages/Rule.java
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Original file line number Diff line number Diff line change
Expand Up @@ -505,7 +505,7 @@ public <T> Object getAttr(String attrName, Type<T> type) {
*/
@Nullable
private Object getAttrWithIndex(int attrIndex) {
Object value = getRawAttrValue(attrIndex);
Object value = getAttrIfStored(attrIndex);
if (value != null) {
return value;
}
Expand All @@ -519,6 +519,11 @@ private Object getAttrWithIndex(int attrIndex) {
// compute the value.
return isFrozen() ? attr.getDefaultValue() : null;
}
if (attr.isLateBound()) {
// Frozen rules don't store late bound defaults.
checkState(isFrozen(), "Mutable rule missing LateBoundDefault");
return attr.getLateBoundDefault();
}
switch (attr.getName()) {
case GENERATOR_FUNCTION:
return callstack.size() > 1 ? callstack.getFrame(1).name : "";
Expand All @@ -536,7 +541,7 @@ private Object getAttrWithIndex(int attrIndex) {
* <p>Unlike {@link #getAttr}, does not fall back to the default value.
*/
@Nullable
Object getRawAttrValue(int attrIndex) {
Object getAttrIfStored(int attrIndex) {
checkPositionIndex(attrIndex, attrCount() - 1);
switch (getAttrState()) {
case MUTABLE:
Expand Down Expand Up @@ -642,8 +647,9 @@ private void checkAttrType(String attrName, Type<?> requestedType, Attribute att
* Returns {@code true} if this rule's attributes are immutable.
*
* <p>Frozen rules optimize for space by omitting storage for non-explicit attribute values that
* match the {@link Attribute} default. If {@link #getRawAttrValue} returns {@code null}, the
* value should be taken from {@link Attribute#getDefaultValue}, even for computed defaults.
* match the {@link Attribute} default. If {@link #getAttrIfStored} returns {@code null}, the
* value should be taken from either {@link Attribute#getLateBoundDefault} for late-bound defaults
* or {@link Attribute#getDefaultValue} for all other attributes (including computed defaults).
*
* <p>Mutable rules have no such optimization. During rule creation, this allows for
* distinguishing whether a computed default (which may depend on other unset attributes) is
Expand All @@ -667,7 +673,7 @@ void freeze() {
}
if (!getExplicitBit(i)) {
Attribute attr = ruleClass.getAttribute(i);
if (value.equals(attr.getDefaultValue())) {
if (value.equals(attr.getDefaultValueUnchecked())) {
// Non-explicit value matches the attribute's default. Save space by omitting storage.
continue;
}
Expand Down Expand Up @@ -774,7 +780,7 @@ public <T> BuildType.SelectorList<T> getSelectorList(String attributeName, Type<
if (index == null) {
return null;
}
Object attrValue = getRawAttrValue(index);
Object attrValue = getAttrIfStored(index);
if (!(attrValue instanceof BuildType.SelectorList)) {
return null;
}
Expand Down Expand Up @@ -1108,7 +1114,7 @@ private List<Label> getRawVisibilityLabels() {
if (visibilityIndex == null) {
return null;
}
return (List<Label>) getRawAttrValue(visibilityIndex);
return (List<Label>) getAttrIfStored(visibilityIndex);
}

private RuleVisibility getDefaultVisibility() {
Expand Down
102 changes: 71 additions & 31 deletions src/test/java/com/google/devtools/build/lib/packages/RuleAttributeStorageTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@
import com.google.devtools.build.lib.analysis.util.MockRule;
import com.google.devtools.build.lib.analysis.util.MockRuleDefaults;
import com.google.devtools.build.lib.packages.Attribute.ComputedDefault;
import com.google.devtools.build.lib.packages.Attribute.LateBoundDefault;
import com.google.devtools.build.lib.testutil.TestRuleClassProvider;
import com.google.testing.junit.testparameterinjector.TestParameter;
import com.google.testing.junit.testparameterinjector.TestParameterInjector;
Expand All @@ -39,6 +40,7 @@ public final class RuleAttributeStorageTest extends BuildViewTestCase {

private static final String STRING_DEFAULT = Type.STRING.getDefaultValue();
private static final int COMPUTED_DEFAULT_OFFSET = 1;
private static final int LATE_BOUND_DEFAULT_OFFSET = 2;

private enum ContainerSize {
SMALL(16),
Expand All @@ -60,6 +62,8 @@ private enum ContainerSize {
private Attribute lastCustomAttr;
private int computedDefaultIndex;
private Attribute computedDefaultAttr;
private int lateBoundDefaultIndex;
private Attribute lateBoundDefaultAttr;

@Override
protected ConfiguredRuleClassProvider createRuleClassProvider() {
Expand All @@ -72,18 +76,29 @@ protected ConfiguredRuleClassProvider createRuleClassProvider() {
IntStream.range(0, numCustomAttrs)
.mapToObj(
i -> {
var attr = attr("attr" + i, Type.STRING);
// Make one of the attributes a computed default.
// Make one attribute a computed default and one a late bound default.
if (i == COMPUTED_DEFAULT_OFFSET) {
attr.value(
new ComputedDefault() {
@Override
public Object getDefault(AttributeMap rule) {
return "computed";
}
});
return attr("attr" + i + "_computed_default", Type.STRING)
.value(
new ComputedDefault() {
@Override
public Object getDefault(AttributeMap rule) {
return "computed";
}
});
}
return attr;
if (i == LATE_BOUND_DEFAULT_OFFSET) {
return attr(":attr" + i + "_late_bound_default", Type.STRING)
.value(
new LateBoundDefault<>(Void.class, "late_bound") {
@Override
public String resolve(
Rule rule, AttributeMap attributes, Void input) {
return "late_bound";
}
});
}
return attr("attr" + i, Type.STRING);
})
.toArray(Attribute.Builder[]::new));
var builder = new ConfiguredRuleClassProvider.Builder().addRuleDefinition(exampleRule);
Expand Down Expand Up @@ -111,6 +126,8 @@ public void setUpForRule() throws Exception {
lastCustomAttr = attrAt(lastCustomAttrIndex);
computedDefaultIndex = firstCustomAttrIndex + COMPUTED_DEFAULT_OFFSET;
computedDefaultAttr = attrAt(computedDefaultIndex);
lateBoundDefaultIndex = firstCustomAttrIndex + LATE_BOUND_DEFAULT_OFFSET;
lateBoundDefaultAttr = attrAt(lateBoundDefaultIndex);
}

@Test
Expand All @@ -122,9 +139,9 @@ public void attributeSettingAndRetrieval(@TestParameter boolean frozen) {
rule.freeze();
}

assertThat(rule.getRawAttrValue(firstCustomAttrIndex)).isEqualTo("val1");
assertThat(rule.getAttrIfStored(firstCustomAttrIndex)).isEqualTo("val1");
assertThat(rule.isAttributeValueExplicitlySpecified(firstCustomAttr)).isTrue();
assertThat(rule.getRawAttrValue(lastCustomAttrIndex)).isEqualTo("val2");
assertThat(rule.getAttrIfStored(lastCustomAttrIndex)).isEqualTo("val2");
assertThat(rule.isAttributeValueExplicitlySpecified(lastCustomAttr)).isTrue();
}

Expand All @@ -134,7 +151,7 @@ public void indexOutOfBounds_throws(@TestParameter boolean frozen) {
rule.freeze();
}
assertThrows(
IndexOutOfBoundsException.class, () -> rule.getRawAttrValue(lastCustomAttrIndex + 1));
IndexOutOfBoundsException.class, () -> rule.getAttrIfStored(lastCustomAttrIndex + 1));
}

@Test
Expand All @@ -146,10 +163,10 @@ public void testForOffByOneError(@TestParameter boolean frozen) {
rule.freeze();
}

assertThat(rule.getRawAttrValue(firstCustomAttrIndex - 1)).isNull();
assertThat(rule.getAttrIfStored(firstCustomAttrIndex - 1)).isNull();
assertThat(rule.isAttributeValueExplicitlySpecified(attrAt(firstCustomAttrIndex - 1)))
.isFalse();
assertThat(rule.getRawAttrValue(firstCustomAttrIndex + 1)).isNull();
assertThat(rule.getAttrIfStored(firstCustomAttrIndex + 1)).isNull();
assertThat(rule.isAttributeValueExplicitlySpecified(attrAt(firstCustomAttrIndex + 1)))
.isFalse();
}
Expand All @@ -166,9 +183,9 @@ public void testFreezeWorks() {
// Double freezing is a no-op
rule.freeze();
// reads/explicit bits work as expected
assertThat(rule.getRawAttrValue(firstCustomAttrIndex)).isEqualTo("val1");
assertThat(rule.getAttrIfStored(firstCustomAttrIndex)).isEqualTo("val1");
assertThat(rule.isAttributeValueExplicitlySpecified(firstCustomAttr)).isTrue();
assertThat(rule.getRawAttrValue(lastCustomAttrIndex)).isEqualTo("val2");
assertThat(rule.getAttrIfStored(lastCustomAttrIndex)).isEqualTo("val2");
assertThat(rule.isAttributeValueExplicitlySpecified(lastCustomAttr)).isFalse();
// writes no longer work.
assertThrows(
Expand All @@ -189,7 +206,7 @@ public void allAttributesSet(@TestParameter boolean frozen) {
}

for (int i = 1; i < size; i++) { // Skip attribute 0 (name) which is never stored.
assertThat(rule.getRawAttrValue(i)).isEqualTo("value " + i);
assertThat(rule.getAttrIfStored(i)).isEqualTo("value " + i);
assertWithMessage("attribute " + i)
.that(rule.isAttributeValueExplicitlySpecified(attrAt(i)))
.isEqualTo(i % 2 == 0);
Expand Down Expand Up @@ -235,7 +252,7 @@ public void boundaryOfFrozenContainer() {

assertThat(rule.getAttr("name")).isEqualTo(ruleName);
assertThat(rule.isAttributeValueExplicitlySpecified("name")).isTrue();
assertThat(rule.getRawAttrValue(lastCustomAttrIndex)).isEqualTo("last");
assertThat(rule.getAttrIfStored(lastCustomAttrIndex)).isEqualTo("last");
assertThat(rule.isAttributeValueExplicitlySpecified(lastCustomAttr)).isTrue();
}

Expand All @@ -248,7 +265,7 @@ public void nameNotStoredAsRawAttr(@TestParameter boolean frozen) {
rule.freeze();
}

assertThat(rule.getRawAttrValue(0)).isNull();
assertThat(rule.getAttrIfStored(0)).isNull();
assertThat(rule.getRawAttrValues()).doesNotContain(ruleName);
assertThat(rule.getAttr("name")).isEqualTo(ruleName);
assertThat(rule.isAttributeValueExplicitlySpecified("name")).isTrue();
Expand All @@ -262,15 +279,15 @@ public void explicitDefaultValue_stored(@TestParameter boolean frozen) {
rule.freeze();
}

assertThat(rule.getRawAttrValue(firstCustomAttrIndex)).isNotNull();
assertThat(rule.getAttrIfStored(firstCustomAttrIndex)).isNotNull();
assertThat(rule.isAttributeValueExplicitlySpecified(firstCustomAttr)).isTrue();
}

@Test
public void nonExplicitDefaultValue_mutable_stored() {
rule.setAttributeValue(firstCustomAttr, STRING_DEFAULT, /* explicit= */ false);

assertThat(rule.getRawAttrValue(firstCustomAttrIndex)).isNotNull();
assertThat(rule.getAttrIfStored(firstCustomAttrIndex)).isNotNull();
assertThat(rule.isAttributeValueExplicitlySpecified(firstCustomAttr)).isFalse();
}

Expand All @@ -280,37 +297,60 @@ public void nonExplicitDefaultValue_frozen_notStored() {

rule.freeze();

assertThat(rule.getRawAttrValue(firstCustomAttrIndex)).isNull();
assertThat(rule.getAttrIfStored(firstCustomAttrIndex)).isNull();
assertThat(rule.isAttributeValueExplicitlySpecified(firstCustomAttr)).isFalse();
}

@Test
public void computedDefault_mutable_stored() {
Attribute attr = rule.getRuleClassObject().getAttribute(computedDefaultIndex);
var computedDefault = attr.getDefaultValue();
assertThat(attr.hasComputedDefault()).isTrue();
var computedDefault = computedDefaultAttr.getDefaultValue();
assertThat(computedDefaultAttr.hasComputedDefault()).isTrue();
assertThat(computedDefault).isInstanceOf(ComputedDefault.class);

rule.setAttributeValue(computedDefaultAttr, computedDefault, /* explicit= */ false);

assertThat(rule.getRawAttrValue(computedDefaultIndex)).isEqualTo(computedDefault);
assertThat(rule.getAttrIfStored(computedDefaultIndex)).isEqualTo(computedDefault);
assertThat(rule.getAttr(computedDefaultAttr.getName())).isEqualTo(computedDefault);
assertThat(rule.isAttributeValueExplicitlySpecified(computedDefaultAttr)).isFalse();
}

@Test
public void computedDefault_frozen_notStored() {
Attribute attr = rule.getRuleClassObject().getAttribute(computedDefaultIndex);
var computedDefault = attr.getDefaultValue();
assertThat(attr.hasComputedDefault()).isTrue();
var computedDefault = computedDefaultAttr.getDefaultValue();
assertThat(computedDefaultAttr.hasComputedDefault()).isTrue();
assertThat(computedDefault).isInstanceOf(ComputedDefault.class);

rule.setAttributeValue(computedDefaultAttr, computedDefault, /* explicit= */ false);
rule.freeze();

assertThat(rule.getRawAttrValue(computedDefaultIndex)).isNull();
assertThat(rule.getAttrIfStored(computedDefaultIndex)).isNull();
assertThat(rule.getAttr(computedDefaultAttr.getName())).isEqualTo(computedDefault);
assertThat(rule.isAttributeValueExplicitlySpecified(computedDefaultAttr)).isFalse();
}

@Test
public void lateBoundDefault_mutable_stored() {
var lateBoundDefault = lateBoundDefaultAttr.getLateBoundDefault();

rule.setAttributeValue(lateBoundDefaultAttr, lateBoundDefault, /* explicit= */ false);

assertThat(rule.getAttrIfStored(lateBoundDefaultIndex)).isEqualTo(lateBoundDefault);
assertThat(rule.getAttr(lateBoundDefaultAttr.getName())).isEqualTo(lateBoundDefault);
assertThat(rule.isAttributeValueExplicitlySpecified(lateBoundDefaultAttr)).isFalse();
}

@Test
public void lateBoundDefault_frozen_notStored() {
var lateBoundDefault = lateBoundDefaultAttr.getLateBoundDefault();

rule.setAttributeValue(lateBoundDefaultAttr, lateBoundDefault, /* explicit= */ false);
rule.freeze();

assertThat(rule.getAttrIfStored(lateBoundDefaultIndex)).isNull();
assertThat(rule.getAttr(lateBoundDefaultAttr.getName())).isEqualTo(lateBoundDefault);
assertThat(rule.isAttributeValueExplicitlySpecified(lateBoundDefaultAttr)).isFalse();
}

private Attribute attrAt(int attrIndex) {
return rule.getRuleClassObject().getAttribute(attrIndex);
}
Expand Down

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