[PATCH] D85990: [Clang] Fix BZ47169, loader_uninitialized on incomplete types

[Jon Chesterfield via Phabricator via cfe-commits]

JonChesterfield created this revision.
JonChesterfield added reviewers: erichkeane, aaron.ballman, rjmccall.
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[Clang] Fix BZ47169, loader_uninitialized on incomplete types

Reported by @erichkeane. Fix proposed by @erichkeane works, tests included.
Bug introduced in D74361 <https://reviews.llvm.org/D74361>. Crash was on querying a CXXRecordDecl for
hasTrivialDefaultConstructor on an incomplete type. Fixed by calling
RequireCompleteType in the right place.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D85990

Files:
  clang/lib/Sema/SemaDecl.cpp
  clang/test/CodeGenCXX/attr-loader-uninitialized.cpp
  clang/test/Sema/attr-loader-uninitialized.c
  clang/test/Sema/attr-loader-uninitialized.cpp


Index: clang/test/Sema/attr-loader-uninitialized.cpp
===================================================================
--- clang/test/Sema/attr-loader-uninitialized.cpp
+++ clang/test/Sema/attr-loader-uninitialized.cpp
@@ -9,6 +9,11 @@
 extern int external_rejected __attribute__((loader_uninitialized));
 // expected-error at -1 {{variable 'external_rejected' cannot be declared both 'extern' and with the 'loader_uninitialized' attribute}}
 
+struct S;
+extern S incomplete_external_rejected __attribute__((loader_uninitialized));
+// expected-error at -1 {{variable has incomplete type 'S'}}
+// expected-note at -3 {{forward declaration of 'S'}}
+
 int noargs __attribute__((loader_uninitialized(0)));
 // expected-error at -1 {{'loader_uninitialized' attribute takes no arguments}}
 
@@ -58,3 +63,12 @@
 
 nontrivial needs_trivial_ctor __attribute__((loader_uninitialized));
 // expected-error at -1 {{variable with 'loader_uninitialized' attribute must have a trivial default constructor}}
+
+struct Incomplete;
+Incomplete incomplete __attribute__((loader_uninitialized));
+// expected-error at -1 {{variable has incomplete type 'Incomplete'}}
+// expected-note at -3 {{forward declaration of 'Incomplete'}}
+
+struct Incomplete s_incomplete __attribute__((loader_uninitialized));
+// expected-error at -1 {{variable has incomplete type 'struct Incomplete'}}
+// expected-note at -7 {{forward declaration of 'Incomplete'}}
Index: clang/test/Sema/attr-loader-uninitialized.c
===================================================================
--- clang/test/Sema/attr-loader-uninitialized.c
+++ clang/test/Sema/attr-loader-uninitialized.c
@@ -10,6 +10,11 @@
 extern int external_rejected __attribute__((loader_uninitialized));
 // expected-error at -1 {{variable 'external_rejected' cannot be declared both 'extern' and with the 'loader_uninitialized' attribute}}
 
+struct S;
+extern struct S incomplete_external_rejected __attribute__((loader_uninitialized));
+// expected-error at -1 {{variable has incomplete type 'struct S'}}
+// expected-note at -3 {{forward declaration of 'struct S'}}
+
 int noargs __attribute__((loader_uninitialized(0)));
 // expected-error at -1 {{'loader_uninitialized' attribute takes no arguments}}
 
@@ -35,3 +40,8 @@
 
 extern __attribute__((visibility("hidden"))) int extern_hidden __attribute__((loader_uninitialized));
 // expected-error at -1 {{variable 'extern_hidden' cannot be declared both 'extern' and with the 'loader_uninitialized' attribute}}
+
+struct Incomplete;
+struct Incomplete incomplete __attribute__((loader_uninitialized));
+// expected-error at -1 {{variable has incomplete type 'struct Incomplete'}}
+// expected-note at -3 {{forward declaration of 'struct Incomplete'}}
Index: clang/test/CodeGenCXX/attr-loader-uninitialized.cpp
===================================================================
--- clang/test/CodeGenCXX/attr-loader-uninitialized.cpp
+++ clang/test/CodeGenCXX/attr-loader-uninitialized.cpp
@@ -28,3 +28,15 @@
 // Defining as arr2[] [[clang..]] raises the error: attribute cannot be applied to types
 // CHECK: @arr2 = global [4 x double] undef
 double arr2 [[clang::loader_uninitialized]] [4];
+
+template<typename T> struct templ{T * t;};
+
+// CHECK: @templ_int = global %struct.templ undef, align 8
+templ<int> templ_int [[clang::loader_uninitialized]];
+
+// CHECK: @templ_trivial = global %struct.templ.0 undef, align 8
+templ<trivial> templ_trivial [[clang::loader_uninitialized]];
+
+// CHECK: @templ_incomplete = global %struct.templ.1 undef, align 8
+struct incomplete;
+templ<incomplete> templ_incomplete [[clang::loader_uninitialized]];
Index: clang/lib/Sema/SemaDecl.cpp
===================================================================
--- clang/lib/Sema/SemaDecl.cpp
+++ clang/lib/Sema/SemaDecl.cpp
@@ -12476,6 +12476,11 @@
     }
 
     if (!Var->isInvalidDecl() && RealDecl->hasAttr<LoaderUninitializedAttr>()) {
+      if (RequireCompleteType(Var->getLocation(), Var->getType(),
+                              diag::err_typecheck_decl_incomplete_type)) {
+        Var->setInvalidDecl();
+        return;
+      }
       if (CXXRecordDecl *RD = Var->getType()->getAsCXXRecordDecl()) {
         if (!RD->hasTrivialDefaultConstructor()) {
           Diag(Var->getLocation(), diag::err_loader_uninitialized_trivial_ctor);


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