[PATCH] libstdc++: Make __from_chars_alnum_to_val conversion explicit

[Marco Falke via Gcc-patches]

>From 2d4e7cd1d476a065d824e11045c8dbc049d5f0a0 Mon Sep 17 00:00:00 2001
From: MacroFake <falke.ma...@gmail.com>
Date: Thu, 14 Jul 2022 15:26:12 +0200
Subject: [PATCH] libstdc++: Make __from_chars_alnum_to_val conversion explicit

The optimizations from commit a54137c88061c7495728fc6b8dfd0474e812b2cb
introduced a clang integer sanitizer error.

Fix this with an explicit static_cast, similar to the fix in commit
074436cf8cdd2a9ce75cadd36deb8301f00e55b9.

libstdc++-v3/ChangeLog:

        * include/std/charconv (__from_chars_alnum_to_val): Replace
          implicit conversions from int to unsigned char with explicit
          casts.
---
 libstdc++-v3/include/std/charconv | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/charconv
b/libstdc++-v3/include/std/charconv
index 218813e4797..bdf23e4a5ad 100644
--- a/libstdc++-v3/include/std/charconv
+++ b/libstdc++-v3/include/std/charconv
@@ -436,7 +436,7 @@ namespace __detail
     __from_chars_alnum_to_val(unsigned char __c)
     {
       if _GLIBCXX17_CONSTEXPR (_DecOnly)
-    return __c - '0';
+       return static_cast<unsigned char>(__c - '0');
       else
     {
       // This initializer is deliberately made dependent in order to work
-- 
2.35.3

From 2d4e7cd1d476a065d824e11045c8dbc049d5f0a0 Mon Sep 17 00:00:00 2001
From: MacroFake <falke.ma...@gmail.com>
Date: Thu, 14 Jul 2022 15:26:12 +0200
Subject: [PATCH] libstdc++: Make __from_chars_alnum_to_val conversion explicit

The optimizations from commit a54137c88061c7495728fc6b8dfd0474e812b2cb
introduced a clang integer sanitizer error.

Fix this with an explicit static_cast, similar to the fix in commit
074436cf8cdd2a9ce75cadd36deb8301f00e55b9.

libstdc++-v3/ChangeLog:

        * include/std/charconv (__from_chars_alnum_to_val): Replace
          implicit conversions from int to unsigned char with explicit
          casts.
---
 libstdc++-v3/include/std/charconv | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/std/charconv b/libstdc++-v3/include/std/charconv
index 218813e4797..bdf23e4a5ad 100644
--- a/libstdc++-v3/include/std/charconv
+++ b/libstdc++-v3/include/std/charconv
@@ -436,7 +436,7 @@ namespace __detail
     __from_chars_alnum_to_val(unsigned char __c)
     {
       if _GLIBCXX17_CONSTEXPR (_DecOnly)
-	return __c - '0';
+       return static_cast<unsigned char>(__c - '0');
       else
 	{
 	  // This initializer is deliberately made dependent in order to work
-- 
2.35.3