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Unify more invalid declaration recovery. (#3942)

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When we expect a semicolon, we should be able to provide more standard
recovery.

Note this affects a test of `base`, but it looks like a partial
improvement (the prior line was moving too far). Still, it looks like
recovery isn't handling `{}` quite right. I'm not trying to address that
here though -- leaving a TODO.
This commit is contained in:
Jon Ross-Perkins
2024-05-08 22:41:42 +00:00
committed by GitHub
parent 7ef61cd679
commit 5fa341f16a
8 changed files with 65 additions and 83 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/parse/context.cpp
+27
View File
@@ -402,6 +402,33 @@ auto Context::ConsumeListToken(NodeKind comma_kind, Lex::TokenKind close_kind,
}
}
auto Context::AddNodeExpectingDeclSemi(StateStackEntry state,
NodeKind node_kind,
Lex::TokenKind decl_kind,
bool is_def_allowed) -> void {
// TODO: This could better handle things like:
// base: { }
// var n: i32;
// ^ Ends up at `n`, instead of `var`.
if (state.has_error) {
RecoverFromDeclError(state, node_kind,
/*skip_past_likely_end=*/true);
return;
}
if (auto semi = ConsumeIf(Lex::TokenKind::Semi)) {
AddNode(node_kind, *semi, state.subtree_start, /*has_error=*/false);
} else {
if (is_def_allowed) {
DiagnoseExpectedDeclSemiOrDefinition(decl_kind);
} else {
DiagnoseExpectedDeclSemi(decl_kind);
}
RecoverFromDeclError(state, node_kind,
/*skip_past_likely_end=*/true);
}
}
auto Context::RecoverFromDeclError(StateStackEntry state, NodeKind node_kind,
bool skip_past_likely_end) -> void {
auto token = state.token;
toolchain/parse/context.h
+7
View File
@@ -281,6 +281,13 @@ class Context {
// Propagates an error up the state stack, to the parent state.
auto ReturnErrorOnState() -> void { state_stack_.back().has_error = true; }
// Adds a node for a declaration's semicolon. Includes error recovery when the
// token is not a semicolon, using `decl_kind` and `is_def_allowed` to inform
// diagnostics.
auto AddNodeExpectingDeclSemi(StateStackEntry state, NodeKind node_kind,
Lex::TokenKind decl_kind, bool is_def_allowed)
-> void;
// Emits a diagnostic for a declaration missing a semi.
auto DiagnoseExpectedDeclSemi(Lex::TokenKind expected_kind) -> void;
toolchain/parse/handle_adapt.cpp
+3 -14
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@@ -13,20 +13,9 @@ auto HandleAdaptDecl(Context& context) -> void {
// We should factor out this common work.
auto state = context.PopState();
auto semi = context.ConsumeIf(Lex::TokenKind::Semi);
if (!semi && !state.has_error) {
context.DiagnoseExpectedDeclSemi(context.tokens().GetKind(state.token));
state.has_error = true;
}
if (state.has_error) {
context.RecoverFromDeclError(state, NodeKind::AdaptDecl,
/*skip_past_likely_end=*/true);
return;
}
context.AddNode(NodeKind::AdaptDecl, *semi, state.subtree_start,
state.has_error);
context.AddNodeExpectingDeclSemi(state, NodeKind::AdaptDecl,
Lex::TokenKind::Adapt,
/*is_def_allowed=*/false);
}
} // namespace Carbon::Parse
toolchain/parse/handle_alias.cpp
+3 -14
View File
@@ -42,20 +42,9 @@ auto HandleAliasAfterName(Context& context) -> void {
auto HandleAliasFinish(Context& context) -> void {
auto state = context.PopState();
if (state.has_error) {
context.RecoverFromDeclError(state, NodeKind::Alias,
/*skip_past_likely_end=*/true);
return;
}
if (auto semi = context.ConsumeIf(Lex::TokenKind::Semi)) {
context.AddNode(NodeKind::Alias, *semi, state.subtree_start,
state.has_error);
} else {
context.DiagnoseExpectedDeclSemi(Lex::TokenKind::Alias);
context.RecoverFromDeclError(state, NodeKind::Alias,
/*skip_past_likely_end=*/true);
}
context.AddNodeExpectingDeclSemi(state, NodeKind::Alias,
Lex::TokenKind::Alias,
/*is_def_allowed=*/false);
}
} // namespace Carbon::Parse
toolchain/parse/handle_base.cpp
+3 -14
View File
@@ -10,20 +10,9 @@ namespace Carbon::Parse {
auto HandleBaseDecl(Context& context) -> void {
auto state = context.PopState();
auto semi = context.ConsumeIf(Lex::TokenKind::Semi);
if (!semi && !state.has_error) {
context.DiagnoseExpectedDeclSemi(context.tokens().GetKind(state.token));
state.has_error = true;
}
if (state.has_error) {
context.RecoverFromDeclError(state, NodeKind::BaseDecl,
/*skip_past_likely_end=*/true);
return;
}
context.AddNode(NodeKind::BaseDecl, *semi, state.subtree_start,
state.has_error);
context.AddNodeExpectingDeclSemi(state, NodeKind::BaseDecl,
Lex::TokenKind::Base,
/*is_def_allowed=*/false);
}
} // namespace Carbon::Parse
toolchain/parse/handle_decl_definition.cpp
+4 -16
View File
@@ -13,22 +13,10 @@ static auto HandleDeclOrDefinition(Context& context, NodeKind decl_kind,
State definition_finish_state) -> void {
auto state = context.PopState();
if (state.has_error) {
context.RecoverFromDeclError(state, decl_kind,
/*skip_past_likely_end=*/true);
return;
}
if (auto semi = context.ConsumeIf(Lex::TokenKind::Semi)) {
context.AddNode(decl_kind, *semi, state.subtree_start, state.has_error);
return;
}
if (!context.PositionIs(Lex::TokenKind::OpenCurlyBrace)) {
context.DiagnoseExpectedDeclSemiOrDefinition(
context.tokens().GetKind(state.token));
context.RecoverFromDeclError(state, decl_kind,
/*skip_past_likely_end=*/true);
if (state.has_error || !context.PositionIs(Lex::TokenKind::OpenCurlyBrace)) {
context.AddNodeExpectingDeclSemi(state, decl_kind,
context.tokens().GetKind(state.token),
/*is_def_allowed=*/true);
return;
}
toolchain/parse/handle_namespace.cpp
+3 -14
View File
@@ -15,20 +15,9 @@ auto HandleNamespace(Context& context) -> void {
auto HandleNamespaceFinish(Context& context) -> void {
auto state = context.PopState();
if (state.has_error) {
context.RecoverFromDeclError(state, NodeKind::Namespace,
/*skip_past_likely_end=*/true);
return;
}
if (auto semi = context.ConsumeIf(Lex::TokenKind::Semi)) {
context.AddNode(NodeKind::Namespace, *semi, state.subtree_start,
state.has_error);
} else {
context.DiagnoseExpectedDeclSemi(Lex::TokenKind::Namespace);
context.RecoverFromDeclError(state, NodeKind::Namespace,
/*skip_past_likely_end=*/true);
}
context.AddNodeExpectingDeclSemi(state, NodeKind::Namespace,
Lex::TokenKind::Namespace,
/*is_def_allowed=*/false);
}
} // namespace Carbon::Parse
toolchain/parse/testdata/class/fail_base.carbon
Vendored
+15 -11
View File
@@ -17,11 +17,15 @@ class A {
// CHECK:STDERR:
base: ;
// CHECK:STDERR: fail_base.carbon:[[@LINE+3]]:7: ERROR: Unrecognized declaration introducer.
// CHECK:STDERR: base: { }
// CHECK:STDERR: ^
base: { }
// We should resume parsing here after the previous error.
// CHECK:STDERR: fail_base.carbon:[[@LINE+7]]:3: ERROR: `base` declarations must end with a `;`.
// CHECK:STDERR: var n: i32;
// CHECK:STDERR: ^~~
// CHECK:STDERR:
// CHECK:STDERR: fail_base.carbon:[[@LINE+3]]:7: ERROR: Unrecognized declaration introducer.
// CHECK:STDERR: var n: i32;
// CHECK:STDERR: ^
var n: i32;
}
@@ -37,14 +41,14 @@ class A {
// CHECK:STDOUT: {kind: 'BaseIntroducer', text: 'base'},
// CHECK:STDOUT: {kind: 'BaseColon', text: ':'},
// CHECK:STDOUT: {kind: 'InvalidParse', text: ';', has_error: yes},
// CHECK:STDOUT: {kind: 'BaseDecl', text: 'base', has_error: yes, subtree_size: 4},
// CHECK:STDOUT: {kind: 'InvalidParseStart', text: ':', has_error: yes},
// CHECK:STDOUT: {kind: 'InvalidParseSubtree', text: '}', has_error: yes, subtree_size: 2},
// CHECK:STDOUT: {kind: 'VariableIntroducer', text: 'var'},
// CHECK:STDOUT: {kind: 'IdentifierName', text: 'n'},
// CHECK:STDOUT: {kind: 'IntTypeLiteral', text: 'i32'},
// CHECK:STDOUT: {kind: 'BindingPattern', text: ':', subtree_size: 3},
// CHECK:STDOUT: {kind: 'VariableDecl', text: ';', subtree_size: 5},
// CHECK:STDOUT: {kind: 'BaseDecl', text: ';', has_error: yes, subtree_size: 4},
// CHECK:STDOUT: {kind: 'BaseIntroducer', text: 'base'},
// CHECK:STDOUT: {kind: 'BaseColon', text: ':'},
// CHECK:STDOUT: {kind: 'StructLiteralStart', text: '{'},
// CHECK:STDOUT: {kind: 'StructLiteral', text: '}', subtree_size: 2},
// CHECK:STDOUT: {kind: 'BaseDecl', text: 'var', has_error: yes, subtree_size: 5},
// CHECK:STDOUT: {kind: 'InvalidParseStart', text: 'n', has_error: yes},
// CHECK:STDOUT: {kind: 'InvalidParseSubtree', text: ';', has_error: yes, subtree_size: 2},
// CHECK:STDOUT: {kind: 'ClassDefinition', text: '}', subtree_size: 18},
// CHECK:STDOUT: {kind: 'FileEnd', text: ''},
// CHECK:STDOUT: ]