[libcamera-devel] [PATCH] libcamera: controls: Replace array designated initializer

[Jacopo Mondi]

Since version 10.0 the LLVM clang++ compiler emits warning to report
usage of array designated initializer, a C99 feature that was only
supported through an extension of the compiler and will be not valid
anymore in C++20.

>From https://releases.llvm.org/10.0.0/tools/clang/docs/ReleaseNotes.html
The new warnings -Wc99-designator and -Wreorder-init-list warn about
uses of C99 initializers in C++ mode for cases that are valid in C99 but
not in C++20.

This generates the following build error in the controls.cpp file:
../src/libcamera/controls.cpp:54:2: error: array designators are a C99 extension [-Werror,-Wc99-designator]
        [ControlTypeNone]               = 0,
        ^~~~~~~~~~~~~~~~~

Fix this by replacing the plain C array with an std:map<>.

Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>

---
I would have liked the map to be immutable, but I can't due to missing
overloading for operator[]:
error: no viable overloaded operator[] for type 'const std::map<unsigned int, size_t>'

Tested with clang++ 10.0.0 and g++ 9.3.0.1
---
 src/libcamera/controls.cpp | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/libcamera/controls.cpp b/src/libcamera/controls.cpp
index 08df7f29e938..eaef45a5f62c 100644
--- a/src/libcamera/controls.cpp
+++ b/src/libcamera/controls.cpp
@@ -8,6 +8,7 @@
 #include <libcamera/controls.h>

 #include <iomanip>
+#include <map>
 #include <sstream>
 #include <string>
 #include <string.h>
@@ -50,16 +51,16 @@ LOG_DEFINE_CATEGORY(Controls)

 namespace {

-static constexpr size_t ControlValueSize[] = {
-	[ControlTypeNone]		= 0,
-	[ControlTypeBool]		= sizeof(bool),
-	[ControlTypeByte]		= sizeof(uint8_t),
-	[ControlTypeInteger32]		= sizeof(int32_t),
-	[ControlTypeInteger64]		= sizeof(int64_t),
-	[ControlTypeFloat]		= sizeof(float),
-	[ControlTypeString]		= sizeof(char),
-	[ControlTypeRectangle]		= sizeof(Rectangle),
-	[ControlTypeSize]		= sizeof(Size),
+std::map<unsigned int, size_t> ControlValueSize = {
+	{ ControlTypeNone,	0  },
+	{ ControlTypeBool,	sizeof(bool) },
+	{ ControlTypeByte,	sizeof(uint8_t) },
+	{ ControlTypeInteger32,	sizeof(int32_t) },
+	{ ControlTypeInteger64,	sizeof(int64_t) },
+	{ ControlTypeFloat,	sizeof(float) },
+	{ ControlTypeString,	sizeof(char) },
+	{ ControlTypeRectangle,	sizeof(Rectangle) },
+	{ ControlTypeSize,	sizeof(Size) },
 };

 } /* namespace */
--
2.26.2