[PATCH] D82882: [ASTImporter] Fix AST import crash for a friend decl

[Vince Bridgers via Phabricator via cfe-commits]

vabridgers created this revision.
vabridgers added a reviewer: martong.
Herald added subscribers: cfe-commits, teemperor, rnkovacs, kristof.beyls.
Herald added a reviewer: a.sidorin.
Herald added a project: clang.

Running CTU testing, we found that VisitFriendDecl in
ASTImporterLookup.cpp was not handling a particular non-dependent case,
so we reached the llvm_unreachable case.

The FriendDecl and QualType not handled were:

(gdb) p D->dump()
FriendDecl 0x7ffff5cf1958
< <<srcfile>>, 'nlohmann::basic_json<std::map, std::vector,

  std::basic_string<char>, bool, long long, unsigned long long, double,
  std::allocator, adl_serializer, std::vector<unsigned char,
  std::allocator<unsigned char>>>':'nlohmann::basic_json<std::map,
  std::vector, std::basic_string<char>, bool, long long, unsigned long
  long, double, std::allocator, adl_serializer, std::vector<unsigned char,
  std::allocator<unsigned char>>>'

(gdb) p Ty->dump()
SubstTemplateTypeParmType 0x7ffff5cf0df0 'class
nlohmann::basic_json<std::map, std::vector, class

  std::basic_string<char>, _Bool, long long, unsigned long long, double,
  std::allocator, adl_serializer, class std::vector<unsigned char, class
  std::allocator<unsigned char> > >' sugar

| -TemplateTypeParmType 0x7ffff643ea40 'BasicJsonType' dependent depth 0 |
|

index 0

| `-TemplateTypeParm 0x7ffff643e9e8 'BasicJsonType' |
|

`-RecordType 0x1012ad20 'class nlohmann::basic_json<std::map,
std::vector, class std::basic_string<char>, _Bool, long long, unsigned
long long, double, std::allocator, adl_serializer, class
std::vector<unsigned char, class std::allocator<unsigned char> > >'

  `-ClassTemplateSpecialization 0x1012ab68 'basic_json'


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D82882

Files:
  clang/lib/AST/ASTImporterLookupTable.cpp


Index: clang/lib/AST/ASTImporterLookupTable.cpp
===================================================================
--- clang/lib/AST/ASTImporterLookupTable.cpp
+++ clang/lib/AST/ASTImporterLookupTable.cpp
@@ -45,7 +45,10 @@
           LT.add(RTy->getAsCXXRecordDecl());
         else if (const auto *SpecTy = dyn_cast<TemplateSpecializationType>(Ty))
           LT.add(SpecTy->getAsCXXRecordDecl());
-        else if (isa<TypedefType>(Ty)) {
+        else if (const auto *SubstTy = dyn_cast<SubstTemplateTypeParmType>(Ty)) {
+          if (SubstTy->getAsCXXRecordDecl())
+              LT.add(SubstTy->getAsCXXRecordDecl());
+        } else if (isa<TypedefType>(Ty)) {
           // We do not put friend typedefs to the lookup table because
           // ASTImporter does not organize typedefs into redecl chains.
         } else {


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