[clang] 7a2b1bd - [clang] Do not crash in APValue::prettyPrint() on forward-decl structs.

[Adam Czachorowski via cfe-commits]

Author: Adam Czachorowski
Date: 2021-11-10T17:17:00+01:00
New Revision: 7a2b1bdb4c8a099ebc38b7f802988244ad21fcc0

URL: https://github.com/llvm/llvm-project/commit/7a2b1bdb4c8a099ebc38b7f802988244ad21fcc0
DIFF: https://github.com/llvm/llvm-project/commit/7a2b1bdb4c8a099ebc38b7f802988244ad21fcc0.diff

LOG: [clang] Do not crash in APValue::prettyPrint() on forward-decl structs.

The call to getTypeSizeInChars() is replaced with
getTypeSizeInCharsIfKnown(), which does not crash on forward declared
structs. This only affects printing.

Differential Revision: https://reviews.llvm.org/D113570

Added: 
    

Modified: 
    clang-tools-extra/clangd/unittests/HoverTests.cpp
    clang/lib/AST/APValue.cpp

Removed: 
    


################################################################################
diff  --git a/clang-tools-extra/clangd/unittests/HoverTests.cpp b/clang-tools-extra/clangd/unittests/HoverTests.cpp
index 2e33ce4c5d101..53df965fef2fa 100644
--- a/clang-tools-extra/clangd/unittests/HoverTests.cpp
+++ b/clang-tools-extra/clangd/unittests/HoverTests.cpp
@@ -2963,6 +2963,20 @@ TEST(Hover, SpaceshipTemplateNoCrash) {
   EXPECT_EQ(HI->Documentation, "Foo bar baz");
 }
 
+TEST(Hover, ForwardStructNoCrash) {
+  Annotations T(R"cpp(
+  struct Foo;
+  int bar;
+  auto baz = (Fo^o*)&bar;
+    )cpp");
+
+  TestTU TU = TestTU::withCode(T.code());
+  auto AST = TU.build();
+  auto HI = getHover(AST, T.point(), format::getLLVMStyle(), nullptr);
+  ASSERT_TRUE(HI);
+  EXPECT_EQ(*HI->Value, "&bar");
+}
+
 } // namespace
 } // namespace clangd
 } // namespace clang

diff  --git a/clang/lib/AST/APValue.cpp b/clang/lib/AST/APValue.cpp
index 9a9233bc1ea74..ef333c7711663 100644
--- a/clang/lib/AST/APValue.cpp
+++ b/clang/lib/AST/APValue.cpp
@@ -700,7 +700,9 @@ void APValue::printPretty(raw_ostream &Out, const PrintingPolicy &Policy,
     if (!hasLValuePath()) {
       // No lvalue path: just print the offset.
       CharUnits O = getLValueOffset();
-      CharUnits S = Ctx ? Ctx->getTypeSizeInChars(InnerTy) : CharUnits::Zero();
+      CharUnits S = Ctx ? Ctx->getTypeSizeInCharsIfKnown(InnerTy).getValueOr(
+                              CharUnits::Zero())
+                        : CharUnits::Zero();
       if (!O.isZero()) {
         if (IsReference)
           Out << "*(";