[clang] 02a33b7 - "Reapply "[Sema] Fix crash on invalid code with parenthesized aggrega… (#76833)

[via cfe-commits]

Author: Mark de Wever
Date: 2024-01-05T19:43:10+01:00
New Revision: 02a33b72fd21cdbf476d6bda72faa462e073e510

URL: https://github.com/llvm/llvm-project/commit/02a33b72fd21cdbf476d6bda72faa462e073e510
DIFF: https://github.com/llvm/llvm-project/commit/02a33b72fd21cdbf476d6bda72faa462e073e510.diff

LOG: "Reapply "[Sema] Fix crash on invalid code with parenthesized aggrega… (#76833)

…te initialization" (#76272)""

With updates the libc++ tests.

This reverts commit 2205d23 and relands
86dc6e1 and
7ab16fb.

Original commit was reverted because of failing libc++ tests, see #76232
for the discussion.

The errors in the tests are spurious in the first place (coming from
initialization of invalid classes), so update the tests to match new
behavior that does not show those errors.

The original patch was written by @ilya-biryukov 

To fix the CI two libc++ tests are temporary disabled for clang-18.

Added: 
    clang/test/SemaCXX/crash-GH76228.cpp

Modified: 
    clang/lib/Sema/SemaInit.cpp
    clang/test/SemaCXX/paren-list-agg-init.cpp
    libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
    libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp

Removed: 
    


################################################################################
diff  --git a/clang/lib/Sema/SemaInit.cpp b/clang/lib/Sema/SemaInit.cpp
index 60c0e3e74204ec..e469e420f14f03 100644
--- a/clang/lib/Sema/SemaInit.cpp
+++ b/clang/lib/Sema/SemaInit.cpp
@@ -5512,6 +5512,14 @@ static void TryOrBuildParenListInitialization(
   } else if (auto *RT = Entity.getType()->getAs<RecordType>()) {
     bool IsUnion = RT->isUnionType();
     const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
+    if (RD->isInvalidDecl()) {
+      // Exit early to avoid confusion when processing members.
+      // We do the same for braced list initialization in
+      // `CheckStructUnionTypes`.
+      Sequence.SetFailed(
+          clang::InitializationSequence::FK_ParenthesizedListInitFailed);
+      return;
+    }
 
     if (!IsUnion) {
       for (const CXXBaseSpecifier &Base : RD->bases()) {

diff  --git a/clang/test/SemaCXX/crash-GH76228.cpp b/clang/test/SemaCXX/crash-GH76228.cpp
new file mode 100644
index 00000000000000..33a9395823127e
--- /dev/null
+++ b/clang/test/SemaCXX/crash-GH76228.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -std=c++20 -verify %s
+// Check we don't crash on incomplete members and bases when handling parenthesized initialization.
+class incomplete; // expected-note at -0 3  {{forward declaration of 'incomplete'}}
+struct foo {
+  int a;
+  incomplete b;
+  // expected-error at -1 {{incomplete type}}
+};
+foo a1(0);
+
+struct one_int {
+    int a;
+};
+struct bar : one_int, incomplete {};
+// expected-error at -1 {{incomplete type}}
+bar a2(0);
+
+incomplete a3[3](1,2,3);
+// expected-error at -1 {{incomplete type}}
+
+struct qux : foo {
+};
+qux a4(0);
+
+struct fred {
+    foo a[3];
+};
+fred a5(0);

diff  --git a/clang/test/SemaCXX/paren-list-agg-init.cpp b/clang/test/SemaCXX/paren-list-agg-init.cpp
index f60b20e0d46568..c1964a5a9eb005 100644
--- a/clang/test/SemaCXX/paren-list-agg-init.cpp
+++ b/clang/test/SemaCXX/paren-list-agg-init.cpp
@@ -289,7 +289,7 @@ int test() {
   // used to crash
   S a(0, 1);
   S b(0);
-  S c(0, 0, 1); // beforecxx20-warning {{aggregate initialization of type 'S' from a parenthesized list of values is a C++20 extension}}
+  S c(0, 0, 1);
 
   S d {0, 1};
   S e {0};

diff  --git a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
index 965e82a7b40346..318435660c3652 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.expected/transform_error.mandates.verify.cpp
@@ -6,6 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+// https://github.com/llvm/llvm-project/pull/76232 breaks this libc++ test.
+// The fix would be to update this file. The issue is that the CI uses 2
+// versions of Clang-18
+// - An older nightly build as the main compiler
+// - A freshly bootstrap build
+// This means the test can't be used until the nightly build is updated.
+// TODO(mordante) Reenable clang-18.
+// UNSUPPORTED: clang-18
+
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // Test the mandates

diff  --git a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
index 09aa1332e98000..d9f65e9f5919cd 100644
--- a/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
+++ b/libcxx/test/libcxx/utilities/expected/expected.void/transform_error.mandates.verify.cpp
@@ -6,6 +6,15 @@
 //
 //===----------------------------------------------------------------------===//
 
+// https://github.com/llvm/llvm-project/pull/76232 breaks this libc++ test.
+// The fix would be to update this file. The issue is that the CI uses 2
+// versions of Clang-18
+// - An older nightly build as the main compiler
+// - A freshly bootstrap build
+// This means the test can't be used until the nightly build is updated.
+// TODO(mordante) Reenable clang-18.
+// UNSUPPORTED: clang-18
+
 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
 
 // Test the mandates