[PATCH 2/2] options: Replace use of VLAs in C++

[Khem Raj]

Clang++ 18 is fussy about this with new warning checks.

   ../git/src/apps/common/options.cpp:882:20: error: variable length arrays in C++ are a Clang extension [-Werror,-Wvla-cxx-extension]
      882 |         char shortOptions[optionsMap_.size() * 3 + 2];
          |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~

Therefore replace using VLAs with alloca and malloc/free

Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 src/apps/common/options.cpp      |  4 ++--
 src/libcamera/ipc_unixsocket.cpp | 12 ++++++++----
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/apps/common/options.cpp b/src/apps/common/options.cpp
index 4f7e8691..b020f603 100644
--- a/src/apps/common/options.cpp
+++ b/src/apps/common/options.cpp
@@ -879,8 +879,8 @@ OptionsParser::Options OptionsParser::parse(int argc, char **argv)
 	 * Allocate short and long options arrays large enough to contain all
 	 * options.
 	 */
-	char shortOptions[optionsMap_.size() * 3 + 2];
-	struct option longOptions[optionsMap_.size() + 1];
+	char *shortOptions = (char*)alloca(optionsMap_.size() * 3 + 2);
+	struct option *longOptions = (struct option*)alloca(optionsMap_.size() + 1);
 	unsigned int ids = 0;
 	unsigned int idl = 0;
 
diff --git a/src/libcamera/ipc_unixsocket.cpp b/src/libcamera/ipc_unixsocket.cpp
index 1980d374..3a7f8ee6 100644
--- a/src/libcamera/ipc_unixsocket.cpp
+++ b/src/libcamera/ipc_unixsocket.cpp
@@ -247,8 +247,8 @@ int IPCUnixSocket::sendData(const void *buffer, size_t length,
 	iov[0].iov_base = const_cast<void *>(buffer);
 	iov[0].iov_len = length;
 
-	char buf[CMSG_SPACE(num * sizeof(uint32_t))];
-	memset(buf, 0, sizeof(buf));
+	char *buf = (char*)malloc(CMSG_SPACE(num * sizeof(uint32_t)));
+	memset((void*)buf, 0, sizeof(buf));
 
 	struct cmsghdr *cmsg = (struct cmsghdr *)buf;
 	cmsg->cmsg_len = CMSG_LEN(num * sizeof(uint32_t));
@@ -270,9 +270,11 @@ int IPCUnixSocket::sendData(const void *buffer, size_t length,
 		int ret = -errno;
 		LOG(IPCUnixSocket, Error)
 			<< "Failed to sendmsg: " << strerror(-ret);
+    free(buf);
 		return ret;
 	}
 
+  free(buf);
 	return 0;
 }
 
@@ -283,8 +285,8 @@ int IPCUnixSocket::recvData(void *buffer, size_t length,
 	iov[0].iov_base = buffer;
 	iov[0].iov_len = length;
 
-	char buf[CMSG_SPACE(num * sizeof(uint32_t))];
-	memset(buf, 0, sizeof(buf));
+	char *buf = (char*)malloc(CMSG_SPACE(num * sizeof(uint32_t)));
+	memset((void*)buf, 0, sizeof(buf));
 
 	struct cmsghdr *cmsg = (struct cmsghdr *)buf;
 	cmsg->cmsg_len = CMSG_LEN(num * sizeof(uint32_t));
@@ -305,12 +307,14 @@ int IPCUnixSocket::recvData(void *buffer, size_t length,
 		if (ret != -EAGAIN)
 			LOG(IPCUnixSocket, Error)
 				<< "Failed to recvmsg: " << strerror(-ret);
+    free(buf);
 		return ret;
 	}
 
 	if (fds)
 		memcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));
 
+  free(buf);
 	return 0;
 }
 
-- 
2.43.0