ilya-biryukov created this revision.
ilya-biryukov added a reviewer: sammccall.
Herald added subscribers: jkorous, MaskRay, ioeric, klimek.
To fix a crash in code completion that occurrs when reading doc
comments from files that were updated after the preamble was
computed. In that case, the files on disk could've been changed and we
can't rely on finding the comment text with the same range anymore.
The current workaround is to not provide comments from the headers at
all and rely on the dynamic index instead.
A more principled solution would be to store contents of the files
read inside the preamble, but it is way harder to implement properly,
given that it would definitely increase the sizes of the preamble.
Together with https://reviews.llvm.org/D47272, this should all preamble-related
crashes we're
aware of.
Repository:
rCTE Clang Tools Extra
https://reviews.llvm.org/D47274
Files:
clangd/CodeCompletionStrings.cpp
clangd/CodeCompletionStrings.h
clangd/index/SymbolCollector.cpp
unittests/clangd/CodeCompleteTests.cpp
Index: unittests/clangd/CodeCompleteTests.cpp
===================================================================
--- unittests/clangd/CodeCompleteTests.cpp
+++ unittests/clangd/CodeCompleteTests.cpp
@@ -17,6 +17,7 @@
#include "SyncAPI.h"
#include "TestFS.h"
#include "index/MemIndex.h"
+#include "llvm/Support/Error.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
@@ -962,6 +963,46 @@
}
}
+TEST(CompletionTest, DocumentationFromChangedFileCrash) {
+ MockFSProvider FS;
+ auto FooH = testPath("foo.h");
+ auto FooCpp = testPath("foo.cpp");
+ FS.Files[FooH] = R"cpp(
+ // this is my documentation comment.
+ int func();
+ )cpp";
+ FS.Files[FooCpp] = "";
+
+ MockCompilationDatabase CDB;
+ IgnoreDiagnostics DiagConsumer;
+ ClangdServer Server(CDB, FS, DiagConsumer, ClangdServer::optsForTest());
+
+ Annotations Source(R"cpp(
+ #include "foo.h"
+ int func() {
+ // This makes sure we have func from header in the AST.
+ }
+ int a = fun^
+ )cpp");
+ Server.addDocument(FooCpp, Source.code(), WantDiagnostics::Yes);
+ // We need to wait for preamble to build.
+ ASSERT_TRUE(Server.blockUntilIdleForTest());
+
+ // Change the header file. Completion will reuse the old preamble!
+ FS.Files[FooH] = R"cpp(
+ int func();
+ )cpp";
+
+ clangd::CodeCompleteOptions Opts;
+ Opts.IncludeComments = true;
+ CompletionList Completions =
+ cantFail(runCodeComplete(Server, FooCpp, Source.point(), Opts));
+ // We shouldn't crash. Unfortunately, current workaround is to not produce
+ // comments for symbols from headers.
+ EXPECT_THAT(Completions.items,
+ Contains(AllOf(Not(IsDocumented()), Named("func"))));
+}
+
} // namespace
} // namespace clangd
} // namespace clang
Index: clangd/index/SymbolCollector.cpp
===================================================================
--- clangd/index/SymbolCollector.cpp
+++ clangd/index/SymbolCollector.cpp
@@ -381,7 +381,8 @@
/*EnableSnippets=*/false);
std::string FilterText = getFilterText(*CCS);
std::string Documentation =
- formatDocumentation(*CCS, getDocComment(Ctx, SymbolCompletion));
+ formatDocumentation(*CCS, getDocComment(Ctx, SymbolCompletion,
+ /*NoCommentsFromHeaders=*/false));
std::string CompletionDetail = getDetail(*CCS);
std::string Include;
Index: clangd/CodeCompletionStrings.h
===================================================================
--- clangd/CodeCompletionStrings.h
+++ clangd/CodeCompletionStrings.h
@@ -25,18 +25,25 @@
/// markers stripped. See clang::RawComment::getFormattedText() for the detailed
/// explanation of how the comment text is transformed.
/// Returns empty string when no comment is available.
+/// If \p NoCommentsFromHeaders parameter is set, only comments from the main
+/// file will be returned. It is used to workaround crashes when parsing
+/// comments in the stale headers, coming from completion preamble.
std::string getDocComment(const ASTContext &Ctx,
- const CodeCompletionResult &Result);
+ const CodeCompletionResult &Result,
+ bool NoCommentsFromHeaders = true);
/// Gets a minimally formatted documentation for parameter of \p Result,
/// corresponding to argument number \p ArgIndex.
/// This currently looks for comments attached to the parameter itself, and
/// doesn't extract them from function documentation.
/// Returns empty string when no comment is available.
+/// If \p NoCommentsFromHeaders parameter is set, only comments from the main
+/// file will be returned. It is used to workaround crashes when parsing
+/// comments in the stale headers, coming from completion preamble.
std::string
getParameterDocComment(const ASTContext &Ctx,
const CodeCompleteConsumer::OverloadCandidate &Result,
- unsigned ArgIndex);
+ unsigned ArgIndex, bool NoCommentsFromHeaders = true);
/// Gets label and insert text for a completion item. For example, for function
/// `Foo`, this returns <"Foo(int x, int y)", "Foo"> without snippts enabled.
Index: clangd/CodeCompletionStrings.cpp
===================================================================
--- clangd/CodeCompletionStrings.cpp
+++ clangd/CodeCompletionStrings.cpp
@@ -10,6 +10,7 @@
#include "CodeCompletionStrings.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RawCommentList.h"
+#include "clang/Basic/SourceManager.h"
#include <utility>
namespace clang {
@@ -122,10 +123,23 @@
}
}
+std::string getFormattedComment(const ASTContext &Ctx, const RawComment &RC,
+ bool NoCommentsFromHeaders) {
+ auto &SourceMgr = Ctx.getSourceManager();
+ // Parsing comments from invalid preamble can lead to crashes. So we only
+ // return comments from the main file when doing code completion. For
+ // indexing, we still read all the comments.
+ // FIXME: find a better fix, e.g. store file contents in the preamble or get
+ // doc comments from the index.
+ if (NoCommentsFromHeaders && !SourceMgr.isWrittenInMainFile(RC.getLocStart()))
+ return "";
+ return RC.getFormattedText(Ctx.getSourceManager(), Ctx.getDiagnostics());
+}
} // namespace
std::string getDocComment(const ASTContext &Ctx,
- const CodeCompletionResult &Result) {
+ const CodeCompletionResult &Result,
+ bool NoCommentsFromHeaders) {
// FIXME: clang's completion also returns documentation for RK_Pattern if they
// contain a pattern for ObjC properties. Unfortunately, there is no API to
// get this declaration, so we don't show documentation in that case.
@@ -137,20 +151,20 @@
const RawComment *RC = getCompletionComment(Ctx, Decl);
if (!RC)
return "";
- return RC->getFormattedText(Ctx.getSourceManager(), Ctx.getDiagnostics());
+ return getFormattedComment(Ctx, *RC, NoCommentsFromHeaders);
}
std::string
getParameterDocComment(const ASTContext &Ctx,
const CodeCompleteConsumer::OverloadCandidate &Result,
- unsigned ArgIndex) {
+ unsigned ArgIndex, bool NoCommentsFromHeaders) {
auto Func = Result.getFunction();
if (!Func)
return "";
const RawComment *RC = getParameterComment(Ctx, Result, ArgIndex);
if (!RC)
return "";
- return RC->getFormattedText(Ctx.getSourceManager(), Ctx.getDiagnostics());
+ return getFormattedComment(Ctx, *RC, NoCommentsFromHeaders);
}
void getLabelAndInsertText(const CodeCompletionString &CCS, std::string *Label,
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