From 760456acfc78419b61c9df01d944007c7f3f6d22 Mon Sep 17 00:00:00 2001
From: Kieran Bingham <kieran.bingham@ideasonboard.com>
Date: Fri, 31 Oct 2025 20:38:54 +0000
Subject: [PATCH] libcamera: base: utils: Simplify hex adaptor
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The libcamera hex string adaptor specifies and casts each type
specifically to map the size of each type.

This needlessly repeats itself for each type and further more has a bug
with signed integer extension which causes values such as 0x80 to be
printed as 0xffffffffffffff80 instead.

Remove the template specialisations for each type, and unify with a
single templated constructor of the struct hex trait.

Suggested-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
 include/libcamera/base/utils.h | 68 +++++++---------------------------
 src/libcamera/base/utils.cpp   |  3 +-
 test/meson.build               |  2 +-
 3 files changed, 17 insertions(+), 56 deletions(-)

diff --git a/include/libcamera/base/utils.h b/include/libcamera/base/utils.h
index d32bd1cd..0b7407f7 100644
--- a/include/libcamera/base/utils.h
+++ b/include/libcamera/base/utils.h
@@ -77,70 +77,30 @@ using time_point = std::chrono::steady_clock::time_point;
 struct timespec duration_to_timespec(const duration &value);
 std::string time_point_to_string(const time_point &time);
 
-#ifndef __DOXYGEN__
-struct _hex {
+namespace details {
+
+struct hex {
 	uint64_t v;
 	unsigned int w;
 };
 
+template<typename T>
+constexpr unsigned int hex_width()
+{
+	return sizeof(T) * 2;
+}
+
 std::basic_ostream<char, std::char_traits<char>> &
-operator<<(std::basic_ostream<char, std::char_traits<char>> &stream, const _hex &h);
-#endif
+operator<<(std::basic_ostream<char, std::char_traits<char>> &stream, const hex &h);
 
-template<typename T,
-	 std::enable_if_t<std::is_integral<T>::value> * = nullptr>
-_hex hex(T value, unsigned int width = 0);
+} /* namespace details */
 
-#ifndef __DOXYGEN__
-template<>
-inline _hex hex<int8_t>(int8_t value, unsigned int width)
+template<typename T, std::enable_if_t<std::is_integral_v<T>> * = nullptr>
+details::hex hex(T value, unsigned int width = details::hex_width<T>())
 {
-	return { static_cast<uint64_t>(value), width ? width : 2 };
+	return { static_cast<std::make_unsigned_t<T>>(value), width };
 }
 
-template<>
-inline _hex hex<uint8_t>(uint8_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 2 };
-}
-
-template<>
-inline _hex hex<int16_t>(int16_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 4 };
-}
-
-template<>
-inline _hex hex<uint16_t>(uint16_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 4 };
-}
-
-template<>
-inline _hex hex<int32_t>(int32_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 8 };
-}
-
-template<>
-inline _hex hex<uint32_t>(uint32_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 8 };
-}
-
-template<>
-inline _hex hex<int64_t>(int64_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 16 };
-}
-
-template<>
-inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
-{
-	return { static_cast<uint64_t>(value), width ? width : 16 };
-}
-#endif
-
 size_t strlcpy(char *dst, const char *src, size_t size);
 
 #ifndef __DOXYGEN__
diff --git a/src/libcamera/base/utils.cpp b/src/libcamera/base/utils.cpp
index cb9fe004..65d9181c 100644
--- a/src/libcamera/base/utils.cpp
+++ b/src/libcamera/base/utils.cpp
@@ -187,7 +187,8 @@ std::string time_point_to_string(const time_point &time)
 }
 
 std::basic_ostream<char, std::char_traits<char>> &
-operator<<(std::basic_ostream<char, std::char_traits<char>> &stream, const _hex &h)
+details::operator<<(std::basic_ostream<char, std::char_traits<char>> &stream,
+		    const details::hex &h)
 {
 	stream << "0x";
 
diff --git a/test/meson.build b/test/meson.build
index 96c4477f..52f04364 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -73,7 +73,7 @@ internal_tests = [
     {'name': 'timer-fail', 'sources': ['timer-fail.cpp'], 'should_fail': true},
     {'name': 'timer-thread', 'sources': ['timer-thread.cpp']},
     {'name': 'unique-fd', 'sources': ['unique-fd.cpp']},
-    {'name': 'utils', 'sources': ['utils.cpp'], 'should_fail': true},
+    {'name': 'utils', 'sources': ['utils.cpp']},
     {'name': 'vector', 'sources': ['vector.cpp']},
     {'name': 'yaml-parser', 'sources': ['yaml-parser.cpp']},
 ]