[clang] FEAT: one byte for "true" & "false" (PR #138649)

[via cfe-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-clang

Author: SAKSHAM JOSHI (saksham-joshi)

<details>
<summary>Changes</summary>

### 1 byte is enough for bool

- In C programming language,

- the size of **"true"** and **"false"** macros is 4 byte and size of macro "bool" (typedef of _Bool) is 1 byte.

- By this simple change, we can set the size of "true" and "false" to 1 byte.

- This change will decrease the memory usage made by using true & false macros in C.

---
Full diff: https://github.com/llvm/llvm-project/pull/138649.diff


1 Files Affected:

- (modified) clang/lib/Headers/stdbool.h (+2-2) 


``````````diff
diff --git a/clang/lib/Headers/stdbool.h b/clang/lib/Headers/stdbool.h
index dfaad2b65a9b5..e9142327f0ffd 100644
--- a/clang/lib/Headers/stdbool.h
+++ b/clang/lib/Headers/stdbool.h
@@ -22,8 +22,8 @@
  */
 #elif !defined(__cplusplus)
 #define bool _Bool
-#define true 1
-#define false 0
+#define true (bool)1
+#define false (bool)0
 #elif defined(__GNUC__) && !defined(__STRICT_ANSI__)
 /* Define _Bool as a GNU extension. */
 #define _Bool bool

``````````

</details>


https://github.com/llvm/llvm-project/pull/138649