jkorous created this revision.
jkorous added reviewers: gribozavr, arphaman, dexonsmith.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.
- I assume we can cache comments for canonical declarations only, not for every
redeclaration.
- Caching that we didn't find comments seems to be unnecessary since we try to
search for comment again again next time if we find this data in cache.
- We might implement proper cache invalidation in the future and get back to
using this information.
- Origin of comment (directly from declaration / from some redeclaration) seems
to not be used anywhere.
I plan to do some performance testing before committing but like to have some
feedback first.
BTW there's another cache for comments in the `ASTContext` - `ParsedComments`.
We could try to experiment with different caching approaches to see how it
affects performance - maybe caching `mapping from canonical declarations to raw
comments` and separately caching `mapping from raw comments to full comments`.
Repository:
rC Clang
https://reviews.llvm.org/D60432
Files:
clang/include/clang/AST/ASTContext.h
clang/lib/AST/ASTContext.cpp
Index: clang/lib/AST/ASTContext.cpp
===================================================================
--- clang/lib/AST/ASTContext.cpp
+++ clang/lib/AST/ASTContext.cpp
@@ -369,71 +369,43 @@
const Decl *D,
const Decl **OriginalDecl) const {
D = adjustDeclToTemplate(D);
+ const Decl* CanonicalDecl = D->getCanonicalDecl();
// Check whether we have cached a comment for this declaration already.
{
llvm::DenseMap<const Decl *, RawCommentAndCacheFlags>::iterator Pos =
- RedeclComments.find(D);
+ RedeclComments.find(CanonicalDecl);
if (Pos != RedeclComments.end()) {
const RawCommentAndCacheFlags &Raw = Pos->second;
- if (Raw.getKind() != RawCommentAndCacheFlags::NoCommentInDecl) {
- if (OriginalDecl)
- *OriginalDecl = Raw.getOriginalDecl();
- return Raw.getRaw();
- }
+ if (OriginalDecl)
+ *OriginalDecl = Raw.getOriginalDecl();
+ return Raw.getRaw();
}
}
- // Search for comments attached to declarations in the redeclaration chain.
- const RawComment *RC = nullptr;
- const Decl *OriginalDeclForRC = nullptr;
+ // We don't have comment for D in cache - search for any comment attached to
+ // declarations in the redeclaration chain.
for (auto I : D->redecls()) {
- llvm::DenseMap<const Decl *, RawCommentAndCacheFlags>::iterator Pos =
- RedeclComments.find(I);
- if (Pos != RedeclComments.end()) {
- const RawCommentAndCacheFlags &Raw = Pos->second;
- if (Raw.getKind() != RawCommentAndCacheFlags::NoCommentInDecl) {
- RC = Raw.getRaw();
- OriginalDeclForRC = Raw.getOriginalDecl();
- break;
- }
- } else {
- RC = getRawCommentForDeclNoCache(I);
- OriginalDeclForRC = I;
- RawCommentAndCacheFlags Raw;
- if (RC) {
- // Call order swapped to work around ICE in VS2015 RTM (Release Win32)
- // https://connect.microsoft.com/VisualStudio/feedback/details/1741530
- Raw.setKind(RawCommentAndCacheFlags::FromDecl);
- Raw.setRaw(RC);
- } else
- Raw.setKind(RawCommentAndCacheFlags::NoCommentInDecl);
- Raw.setOriginalDecl(I);
- RedeclComments[I] = Raw;
- if (RC)
- break;
- }
- }
-
- // If we found a comment, it should be a documentation comment.
- assert(!RC || RC->isDocumentation() || LangOpts.CommentOpts.ParseAllComments);
+ if (const RawComment *RC = getRawCommentForDeclNoCache(I)) {
+ // If we find a comment, it should be a documentation comment.
+ assert(RC->isDocumentation() || LangOpts.CommentOpts.ParseAllComments);
- if (OriginalDecl)
- *OriginalDecl = OriginalDeclForRC;
+ if (OriginalDecl)
+ *OriginalDecl = I;
- // Update cache for every declaration in the redeclaration chain.
- RawCommentAndCacheFlags Raw;
- Raw.setRaw(RC);
- Raw.setKind(RawCommentAndCacheFlags::FromRedecl);
- Raw.setOriginalDecl(OriginalDeclForRC);
+ RawCommentAndCacheFlags NewCachedComment;
+ // Call order swapped to work around ICE in VS2015 RTM (Release Win32)
+ // https://connect.microsoft.com/VisualStudio/feedback/details/1741530
+ NewCachedComment.setRaw(RC);
+ NewCachedComment.setOriginalDecl(I);
+ RedeclComments[CanonicalDecl] = NewCachedComment;
- for (auto I : D->redecls()) {
- RawCommentAndCacheFlags &R = RedeclComments[I];
- if (R.getKind() == RawCommentAndCacheFlags::NoCommentInDecl)
- R = Raw;
+ return RC;
+ }
}
- return RC;
+ // We didn't find any comment attached to any redeclaration of D.
+ return nullptr;
}
static void addRedeclaredMethods(const ObjCMethodDecl *ObjCMethod,
Index: clang/include/clang/AST/ASTContext.h
===================================================================
--- clang/include/clang/AST/ASTContext.h
+++ clang/include/clang/AST/ASTContext.h
@@ -727,43 +727,12 @@
class RawCommentAndCacheFlags {
public:
- enum Kind {
- /// We searched for a comment attached to the particular declaration, but
- /// didn't find any.
- ///
- /// getRaw() == 0.
- NoCommentInDecl = 0,
-
- /// We have found a comment attached to this particular declaration.
- ///
- /// getRaw() != 0.
- FromDecl,
-
- /// This declaration does not have an attached comment, and we have
- /// searched the redeclaration chain.
- ///
- /// If getRaw() == 0, the whole redeclaration chain does not have any
- /// comments.
- ///
- /// If getRaw() != 0, it is a comment propagated from other
- /// redeclaration.
- FromRedecl
- };
-
- Kind getKind() const LLVM_READONLY {
- return Data.getInt();
- }
-
- void setKind(Kind K) {
- Data.setInt(K);
- }
-
const RawComment *getRaw() const LLVM_READONLY {
- return Data.getPointer();
+ return Comment;
}
void setRaw(const RawComment *RC) {
- Data.setPointer(RC);
+ Comment = RC;
}
const Decl *getOriginalDecl() const LLVM_READONLY {
@@ -775,11 +744,11 @@
}
private:
- llvm::PointerIntPair<const RawComment *, 2, Kind> Data;
+ const RawComment * Comment;
const Decl *OriginalDecl;
};
- /// Mapping from declarations to comments attached to any
+ /// Mapping from canonical declarations to comments attached to any
/// redeclaration.
///
/// Raw comments are owned by Comments list. This mapping is populated
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