Make sure lexicalFrame is never null
This simplifies the code a bit.
https://github.com/bazelbuild/bazel/issues/5637
RELNOTES: None.
PiperOrigin-RevId: 210410389
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
index 888642e..387f6ef 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Environment.java
@@ -470,7 +470,7 @@
@Nullable final Continuation continuation;
/** The lexical Frame of the caller. */
- final LexicalFrame lexicalFrame;
+ final Frame lexicalFrame;
/** The global Frame of the caller. */
final GlobalFrame globalFrame;
@@ -482,7 +482,7 @@
@Nullable Continuation continuation,
BaseFunction function,
@Nullable FuncallExpression caller,
- LexicalFrame lexicalFrame,
+ Frame lexicalFrame,
GlobalFrame globalFrame,
@Nullable LinkedHashSet<String> knownGlobalVariables) {
this.continuation = continuation;
@@ -655,7 +655,7 @@
* Static Frame for lexical variables that are always looked up in the current Environment
* or for the definition Environment of the function currently being evaluated.
*/
- private LexicalFrame lexicalFrame;
+ private Frame lexicalFrame;
/**
* Static Frame for global variables; either the current lexical Frame if evaluation is currently
@@ -728,7 +728,7 @@
*/
void enterScope(
BaseFunction function,
- LexicalFrame lexical,
+ Frame lexical,
@Nullable FuncallExpression caller,
GlobalFrame globals) {
continuation =
@@ -782,7 +782,7 @@
* as opposed to inside the body of a function.
*/
boolean isGlobal() {
- return lexicalFrame == null;
+ return lexicalFrame instanceof GlobalFrame;
}
@Override
@@ -791,11 +791,6 @@
return dynamicFrame.mutability();
}
- /** Returns the current Frame, in which variable side-effects happen. */
- private Frame currentFrame() {
- return isGlobal() ? globalFrame : lexicalFrame;
- }
-
/** Returns the global variables for the Environment (not including dynamic bindings). */
public GlobalFrame getGlobals() {
return globalFrame;
@@ -863,6 +858,7 @@
@Nullable String fileContentHashCode,
Phase phase,
@Nullable Label callerLabel) {
+ this.lexicalFrame = Preconditions.checkNotNull(globalFrame);
this.globalFrame = Preconditions.checkNotNull(globalFrame);
this.dynamicFrame = Preconditions.checkNotNull(dynamicFrame);
Preconditions.checkArgument(!globalFrame.mutability().isFrozen());
@@ -990,21 +986,11 @@
* @return this Environment, in fluid style
*/
public Environment setupDynamic(String varname, Object value) {
- if (dynamicFrame.get(varname) != null) {
+ if (lookup(varname) != null) {
throw new AssertionError(
String.format("Trying to bind dynamic variable '%s' but it is already bound",
varname));
}
- if (lexicalFrame != null && lexicalFrame.get(varname) != null) {
- throw new AssertionError(
- String.format("Trying to bind dynamic variable '%s' but it is already bound lexically",
- varname));
- }
- if (globalFrame.get(varname) != null) {
- throw new AssertionError(
- String.format("Trying to bind dynamic variable '%s' but it is already bound globally",
- varname));
- }
try {
dynamicFrame.put(this, varname, value);
} catch (MutabilityException e) {
@@ -1021,7 +1007,7 @@
/** Remove variable from local bindings. */
void removeLocalBinding(String varname) {
try {
- currentFrame().remove(this, varname);
+ lexicalFrame.remove(this, varname);
} catch (MutabilityException e) {
throw new AssertionError(e);
}
@@ -1048,7 +1034,7 @@
null, String.format("Trying to update read-only global variable '%s'", varname));
}
try {
- currentFrame().put(this, varname, Preconditions.checkNotNull(value));
+ lexicalFrame.put(this, varname, Preconditions.checkNotNull(value));
} catch (MutabilityException e) {
// Note that since at this time we don't accept the global keyword, and don't have closures,
// end users should never be able to mutate a frozen Environment, and a MutabilityException
@@ -1096,11 +1082,9 @@
*/
public Object lookup(String varname) {
// Lexical frame takes precedence, then globals, then dynamics.
- if (lexicalFrame != null) {
- Object lexicalValue = lexicalFrame.get(varname);
- if (lexicalValue != null) {
- return lexicalValue;
- }
+ Object lexicalValue = lexicalFrame.get(varname);
+ if (lexicalValue != null) {
+ return lexicalValue;
}
Object globalValue = globalFrame.get(varname);
Object dynamicValue = dynamicFrame.get(varname);
@@ -1138,9 +1122,8 @@
*/
public Set<String> getVariableNames() {
LinkedHashSet<String> vars = new LinkedHashSet<>();
- if (lexicalFrame != null) {
- vars.addAll(lexicalFrame.getTransitiveBindings().keySet());
- }
+ vars.addAll(lexicalFrame.getTransitiveBindings().keySet());
+ // No-op when globalFrame = lexicalFrame
vars.addAll(globalFrame.getTransitiveBindings().keySet());
vars.addAll(dynamicFrame.getTransitiveBindings().keySet());
return vars;
@@ -1190,7 +1173,7 @@
ImmutableList.Builder<DebugFrame> frameListBuilder = ImmutableList.builder();
Continuation currentContinuation = continuation;
- Frame currentFrame = currentFrame();
+ Frame currentFrame = lexicalFrame;
// if there's a continuation then the current frame is a lexical frame
while (currentContinuation != null) {
