[clang] [clang-repl] Fix Value for platforms where unqualified char is unsigned (PR #86118)

[Stefan Gränitz via cfe-commits]

https://github.com/weliveindetail created https://github.com/llvm/llvm-project/pull/86118

Signedness of unqualified `char` is unspecified and varies between platforms. This patch adds `Char_U` in `REPL_BUILTIN_TYPES` to account for platforms that default to `unsigned char`.

>From e0cdd176e35d0bd255d1394eff6bee314c0e3cd6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Gr=C3=A4nitz?= <stefan.graenitz at gmail.com>
Date: Thu, 21 Mar 2024 14:04:10 +0100
Subject: [PATCH 1/3] Add reproducer

---
 clang/unittests/Interpreter/InterpreterTest.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/clang/unittests/Interpreter/InterpreterTest.cpp b/clang/unittests/Interpreter/InterpreterTest.cpp
index e76c0677db5ead..25f6e4f900c882 100644
--- a/clang/unittests/Interpreter/InterpreterTest.cpp
+++ b/clang/unittests/Interpreter/InterpreterTest.cpp
@@ -340,6 +340,11 @@ TEST(InterpreterTest, Value) {
   EXPECT_EQ(V1.getKind(), Value::K_Int);
   EXPECT_FALSE(V1.isManuallyAlloc());
 
+  Value V1b;
+  llvm::cantFail(Interp->ParseAndExecute("char x = 42;"));
+  llvm::cantFail(Interp->ParseAndExecute("c", &V1b));
+  EXPECT_TRUE(V1b.getKind() == Value::K_Char_S);
+
   Value V2;
   llvm::cantFail(Interp->ParseAndExecute("double y = 3.14;"));
   llvm::cantFail(Interp->ParseAndExecute("y", &V2));

>From fa3d6e1973c5d2fe13c85993cf851f18e41f0f32 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Gr=C3=A4nitz?= <stefan.graenitz at gmail.com>
Date: Thu, 21 Mar 2024 14:05:05 +0100
Subject: [PATCH 2/3] Add missing REPL_BUILTIN_TYPE

---
 clang/include/clang/Interpreter/Value.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/clang/include/clang/Interpreter/Value.h b/clang/include/clang/Interpreter/Value.h
index c380cd91550def..d70e8f8719026b 100644
--- a/clang/include/clang/Interpreter/Value.h
+++ b/clang/include/clang/Interpreter/Value.h
@@ -76,6 +76,7 @@ class QualType;
   X(bool, Bool)                                                                \
   X(char, Char_S)                                                              \
   X(signed char, SChar)                                                        \
+  X(unsigned char, Char_U)                                                     \
   X(unsigned char, UChar)                                                      \
   X(short, Short)                                                              \
   X(unsigned short, UShort)                                                    \

>From 3ade711f907758814d13852edae71cec746fcb7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20Gr=C3=A4nitz?= <stefan.graenitz at gmail.com>
Date: Thu, 21 Mar 2024 14:33:50 +0100
Subject: [PATCH 3/3] Accept signed or unsigned for unqualified char in
 reproducer

---
 clang/unittests/Interpreter/InterpreterTest.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/clang/unittests/Interpreter/InterpreterTest.cpp b/clang/unittests/Interpreter/InterpreterTest.cpp
index 25f6e4f900c882..4b5d73769e5da7 100644
--- a/clang/unittests/Interpreter/InterpreterTest.cpp
+++ b/clang/unittests/Interpreter/InterpreterTest.cpp
@@ -343,7 +343,8 @@ TEST(InterpreterTest, Value) {
   Value V1b;
   llvm::cantFail(Interp->ParseAndExecute("char x = 42;"));
   llvm::cantFail(Interp->ParseAndExecute("c", &V1b));
-  EXPECT_TRUE(V1b.getKind() == Value::K_Char_S);
+  EXPECT_TRUE(V1b.getKind() == Value::K_Char_S ||
+              V1b.getKind() == Value::K_Char_U);
 
   Value V2;
   llvm::cantFail(Interp->ParseAndExecute("double y = 3.14;"));