[backport] macos ci fixes for v1.16 (#25672)

* ci: lockdown gcc v9 for macos

Signed-off-by: Ramon Roche <mrpollo@gmail.com>

* pxh: do not use variable sized array on the stack

This is a compiler-specific extension

* ci: macos build on older gcc

Signed-off-by: Ramon Roche <mrpollo@gmail.com>

---------

Signed-off-by: Ramon Roche <mrpollo@gmail.com>
Co-authored-by: Beat Küng <beat-kueng@gmx.net>

.github/workflows/compile_macos.yml

@@ -16,7 +16,7 @@ on:
 
 jobs:
   build:
-    runs-on: macos-latest
+    runs-on: macos-14
     strategy:
       matrix:
         config: [
@@ -32,7 +32,8 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: setup
-      run: ./Tools/setup/macos.sh; ./Tools/setup/macos.sh
+      run: |
+        ./Tools/setup/macos.sh
 
     - name: Prepare ccache timestamp
       id: ccache_cache_timestamp
@@ -40,12 +41,14 @@ jobs:
       run: |
         string(TIMESTAMP current_date "%Y-%m-%d-%H;%M;%S" UTC)
         message("::set-output name=timestamp::${current_date}")
+
     - name: ccache cache files
       uses: actions/cache@v4
       with:
         path: ~/.ccache
         key: macos_${{matrix.config}}-ccache-${{steps.ccache_cache_timestamp.outputs.timestamp}}
         restore-keys: macos_${{matrix.config}}-ccache-
+
     - name: setup ccache
       run: |
           mkdir -p ~/.ccache

Tools/setup/macos.sh

@@ -42,6 +42,8 @@ else
 		echo "Installing PX4 general dependencies (homebrew px4-dev)"
 		brew tap PX4/px4
 		brew install px4-dev
+		# lock down gcc to v9 for v1.16 branch
+		brew install gcc-arm-none-eabi
 		brew install ncurses
 		brew install python-tk
 	fi

platforms/posix/src/px4/common/px4_daemon/pxh.cpp

@@ -101,7 +101,7 @@ int Pxh::process_line(const std::string &line, bool silently_fail)
 
 		// Note that argv[argc] always needs to be a nullptr.
 		// Therefore add one more entry.
-		const char *arg[words.size() + 1];
+		char **arg = new char *[words.size() + 1];
 
 		for (unsigned i = 0; i < words.size(); ++i) {
 			arg[i] = (char *)words[i].c_str();
@@ -110,7 +110,7 @@ int Pxh::process_line(const std::string &line, bool silently_fail)
 		// Explicitly set this nullptr.
 		arg[words.size()] = nullptr;
 
-		int retval = _apps[command](words.size(), (char **)arg);
+		int retval = _apps[command](words.size(), arg);
 
 		if (retval) {
 			if (!silently_fail) {
@@ -118,6 +118,8 @@ int Pxh::process_line(const std::string &line, bool silently_fail)
 			}
 		}
 
+		delete[] arg;
+
 		return retval;
 
 	} else if (command == "help") {