[clang] e6bc4a7 - [libTooling] Add `describe` combinator for formatting AST nodes for diagnostics.
Yitzhak Mandelbaum via cfe-commits
cfe-commits at lists.llvm.org
Mon Dec 7 08:12:44 PST 2020
Author: Yitzhak Mandelbaum
Date: 2020-12-07T16:08:05Z
New Revision: e6bc4a71e3450d7230205683f63d6e22fbf9bf05
URL: https://github.com/llvm/llvm-project/commit/e6bc4a71e3450d7230205683f63d6e22fbf9bf05
DIFF: https://github.com/llvm/llvm-project/commit/e6bc4a71e3450d7230205683f63d6e22fbf9bf05.diff
LOG: [libTooling] Add `describe` combinator for formatting AST nodes for diagnostics.
This new stencil combinator is intended for use in diagnostics and the like.
Differential Revision: https://reviews.llvm.org/D92658
Added:
Modified:
clang/include/clang/Tooling/Transformer/Stencil.h
clang/lib/Tooling/Transformer/Stencil.cpp
clang/unittests/Tooling/StencilTest.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Tooling/Transformer/Stencil.h b/clang/include/clang/Tooling/Transformer/Stencil.h
index 1b50a670f70b..b729c826c808 100644
--- a/clang/include/clang/Tooling/Transformer/Stencil.h
+++ b/clang/include/clang/Tooling/Transformer/Stencil.h
@@ -123,6 +123,15 @@ inline Stencil ifBound(llvm::StringRef Id, llvm::StringRef TrueText,
/// Stencil. This supports user-defined extensions to the \c Stencil language.
Stencil run(MatchConsumer<std::string> C);
+/// Produces a human-readable rendering of the node bound to `Id`, suitable for
+/// diagnostics and debugging. This operator can be applied to any node, but is
+/// targeted at those whose source cannot be printed directly, including:
+///
+/// * Types. represented based on their structure. Note that namespace
+/// qualifiers are always printed, with the anonymous namespace represented
+/// explicitly. No desugaring or canonicalization is applied.
+Stencil describe(llvm::StringRef Id);
+
/// For debug use only; semantics are not guaranteed.
///
/// \returns the string resulting from calling the node's print() method.
diff --git a/clang/lib/Tooling/Transformer/Stencil.cpp b/clang/lib/Tooling/Transformer/Stencil.cpp
index 2670bf7adabf..56f145393691 100644
--- a/clang/lib/Tooling/Transformer/Stencil.cpp
+++ b/clang/lib/Tooling/Transformer/Stencil.cpp
@@ -63,6 +63,7 @@ enum class UnaryNodeOperator {
MaybeDeref,
AddressOf,
MaybeAddressOf,
+ Describe,
};
// Generic container for stencil operations with a (single) node-id argument.
@@ -133,6 +134,9 @@ std::string toStringData(const UnaryOperationData &Data) {
case UnaryNodeOperator::MaybeAddressOf:
OpName = "maybeAddressOf";
break;
+ case UnaryNodeOperator::Describe:
+ OpName = "describe";
+ break;
}
return (OpName + "(\"" + Data.Id + "\")").str();
}
@@ -174,11 +178,11 @@ Error evalData(const RawTextData &Data, const MatchFinder::MatchResult &,
return Error::success();
}
-Error evalData(const DebugPrintNodeData &Data,
- const MatchFinder::MatchResult &Match, std::string *Result) {
+static Error printNode(StringRef Id, const MatchFinder::MatchResult &Match,
+ std::string *Result) {
std::string Output;
llvm::raw_string_ostream Os(Output);
- auto NodeOrErr = getNode(Match.Nodes, Data.Id);
+ auto NodeOrErr = getNode(Match.Nodes, Id);
if (auto Err = NodeOrErr.takeError())
return Err;
NodeOrErr->print(Os, PrintingPolicy(Match.Context->getLangOpts()));
@@ -186,8 +190,18 @@ Error evalData(const DebugPrintNodeData &Data,
return Error::success();
}
+Error evalData(const DebugPrintNodeData &Data,
+ const MatchFinder::MatchResult &Match, std::string *Result) {
+ return printNode(Data.Id, Match, Result);
+}
+
Error evalData(const UnaryOperationData &Data,
const MatchFinder::MatchResult &Match, std::string *Result) {
+ // The `Describe` operation can be applied to any node, not just expressions,
+ // so it is handled here, separately.
+ if (Data.Op == UnaryNodeOperator::Describe)
+ return printNode(Data.Id, Match, Result);
+
const auto *E = Match.Nodes.getNodeAs<Expr>(Data.Id);
if (E == nullptr)
return llvm::make_error<StringError>(
@@ -217,6 +231,8 @@ Error evalData(const UnaryOperationData &Data,
}
Source = tooling::buildAddressOf(*E, *Match.Context);
break;
+ case UnaryNodeOperator::Describe:
+ llvm_unreachable("This case is handled at the start of the function");
}
if (!Source)
return llvm::make_error<StringError>(
@@ -359,6 +375,11 @@ Stencil transformer::maybeAddressOf(llvm::StringRef ExprId) {
UnaryNodeOperator::MaybeAddressOf, std::string(ExprId));
}
+Stencil transformer::describe(StringRef Id) {
+ return std::make_shared<StencilImpl<UnaryOperationData>>(
+ UnaryNodeOperator::Describe, std::string(Id));
+}
+
Stencil transformer::access(StringRef BaseId, Stencil Member) {
return std::make_shared<StencilImpl<AccessData>>(BaseId, std::move(Member));
}
diff --git a/clang/unittests/Tooling/StencilTest.cpp b/clang/unittests/Tooling/StencilTest.cpp
index c843e33dd0da..56e81431e558 100644
--- a/clang/unittests/Tooling/StencilTest.cpp
+++ b/clang/unittests/Tooling/StencilTest.cpp
@@ -30,7 +30,9 @@ using MatchResult = MatchFinder::MatchResult;
// Create a valid translation-unit from a statement.
static std::string wrapSnippet(StringRef StatementCode) {
- return ("struct S { int field; }; auto stencil_test_snippet = []{" +
+ return ("namespace N { class C {}; } "
+ "namespace { class AnonC {}; } "
+ "struct S { int field; }; auto stencil_test_snippet = []{" +
StatementCode + "};")
.str();
}
@@ -55,14 +57,14 @@ struct TestMatch {
// `StatementCode` may contain other statements not described by `Matcher`.
static llvm::Optional<TestMatch> matchStmt(StringRef StatementCode,
StatementMatcher Matcher) {
- auto AstUnit = tooling::buildASTFromCode(wrapSnippet(StatementCode));
+ auto AstUnit = tooling::buildASTFromCodeWithArgs(wrapSnippet(StatementCode),
+ {"-Wno-unused-value"});
if (AstUnit == nullptr) {
ADD_FAILURE() << "AST construction failed";
return llvm::None;
}
ASTContext &Context = AstUnit->getASTContext();
- auto Matches = ast_matchers::match(
- traverse(ast_type_traits::TK_AsIs, wrapMatcher(Matcher)), Context);
+ auto Matches = ast_matchers::match(wrapMatcher(Matcher), Context);
// We expect a single, exact match for the statement.
if (Matches.size() != 1) {
ADD_FAILURE() << "Wrong number of matches: " << Matches.size();
@@ -365,6 +367,66 @@ TEST_F(StencilTest, AccessOpImplicitThis) {
EXPECT_THAT_EXPECTED(Stencil->eval(StmtMatch->Result), HasValue("field"));
}
+TEST_F(StencilTest, DescribeType) {
+ std::string Snippet = "int *x; x;";
+ std::string Expected = "int *";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
+TEST_F(StencilTest, DescribeSugaredType) {
+ std::string Snippet = "using Ty = int; Ty *x; x;";
+ std::string Expected = "Ty *";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
+TEST_F(StencilTest, DescribeDeclType) {
+ std::string Snippet = "S s; s;";
+ std::string Expected = "S";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
+TEST_F(StencilTest, DescribeQualifiedType) {
+ std::string Snippet = "N::C c; c;";
+ std::string Expected = "N::C";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
+TEST_F(StencilTest, DescribeUnqualifiedType) {
+ std::string Snippet = "using N::C; C c; c;";
+ std::string Expected = "N::C";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
+TEST_F(StencilTest, DescribeAnonNamespaceType) {
+ std::string Snippet = "AnonC c; c;";
+ std::string Expected = "(anonymous namespace)::AnonC";
+ auto StmtMatch =
+ matchStmt(Snippet, declRefExpr(hasType(qualType().bind("type"))));
+ ASSERT_TRUE(StmtMatch);
+ EXPECT_THAT_EXPECTED(describe("type")->eval(StmtMatch->Result),
+ HasValue(std::string(Expected)));
+}
+
TEST_F(StencilTest, RunOp) {
StringRef Id = "id";
auto SimpleFn = [Id](const MatchResult &R) {
@@ -436,6 +498,12 @@ TEST_F(StencilTest, CatOfInvalidRangeFails) {
});
}
+// The `StencilToStringTest` tests verify that the string representation of the
+// stencil combinator matches (as best possible) the spelling of the
+// combinator's construction. Exceptions include those combinators that have no
+// explicit spelling (like raw text) and those supporting non-printable
+// arguments (like `run`, `selection`).
+
TEST(StencilToStringTest, RawTextOp) {
auto S = cat("foo bar baz");
StringRef Expected = R"("foo bar baz")";
@@ -448,6 +516,12 @@ TEST(StencilToStringTest, RawTextOpEscaping) {
EXPECT_EQ(S->toString(), Expected);
}
+TEST(StencilToStringTest, DescribeOp) {
+ auto S = describe("Id");
+ StringRef Expected = R"repr(describe("Id"))repr";
+ EXPECT_EQ(S->toString(), Expected);
+}
+
TEST(StencilToStringTest, DebugPrintNodeOp) {
auto S = dPrint("Id");
StringRef Expected = R"repr(dPrint("Id"))repr";
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