0.7.0-alpha.1 fails to build: `Undefined symbols for architecture ppc: "_getsectiondata", referenced from: _get_embedded_avm`

[barracuda156]

[913/1000] : && /opt/local/bin/gcc-mp-14 -pipe -Os -DNDEBUG -isystem/opt/local/include/LegacySupport -I/opt/local/include -arch ppc -mmacosx-version-min=10.6 -Wl,-search_paths_first -Wl,-headerpad_max_install_names -Wl,-headerpad_max_install_names -L/opt/local/lib -lMacportsLegacySupport src/platforms/generic_unix/CMakeFiles/AtomVM.dir/main.c.o -o src/AtomVM  -Wl,-rpath,/opt/local/lib  src/platforms/generic_unix/libAtomVM/liblibAtomVM.a  src/platforms/generic_unix/lib/liblibAtomVMDarwin-powerpc.a  src/platforms/generic_unix/libAtomVM/liblibAtomVM.a  src/platforms/generic_unix/lib/liblibAtomVMDarwin-powerpc.a  -lm  /opt/local/lib/libz.dylib  /opt/local/lib/libmbedtls.3.6.6.dylib  /opt/local/lib/libmbedx509.3.6.6.dylib  /opt/local/lib/libmbedcrypto.3.6.6.dylib  /opt/local/lib/libeverest.a  /opt/local/lib/libp256m.a && :
FAILED: [code=1] src/AtomVM 
: && /opt/local/bin/gcc-mp-14 -pipe -Os -DNDEBUG -isystem/opt/local/include/LegacySupport -I/opt/local/include -arch ppc -mmacosx-version-min=10.6 -Wl,-search_paths_first -Wl,-headerpad_max_install_names -Wl,-headerpad_max_install_names -L/opt/local/lib -lMacportsLegacySupport src/platforms/generic_unix/CMakeFiles/AtomVM.dir/main.c.o -o src/AtomVM  -Wl,-rpath,/opt/local/lib  src/platforms/generic_unix/libAtomVM/liblibAtomVM.a  src/platforms/generic_unix/lib/liblibAtomVMDarwin-powerpc.a  src/platforms/generic_unix/libAtomVM/liblibAtomVM.a  src/platforms/generic_unix/lib/liblibAtomVMDarwin-powerpc.a  -lm  /opt/local/lib/libz.dylib  /opt/local/lib/libmbedtls.3.6.6.dylib  /opt/local/lib/libmbedx509.3.6.6.dylib  /opt/local/lib/libmbedcrypto.3.6.6.dylib  /opt/local/lib/libeverest.a  /opt/local/lib/libp256m.a && :
Undefined symbols for architecture ppc:
  "_getsectiondata", referenced from:
      _get_embedded_avm in main.c.o
ld: symbol(s) not found for architecture ppc
collect2: error: ld returned 1 exit status
[914/1000] cd /opt/local/var/macports/build/atomvm-43bfe78f/work/build/examples/elixir/stm32 && elixirc /opt/local/var/macports/build/atomvm-43bfe78f/work/atomvm-0.7.0-alpha.1/examples/elixir/stm32/MultiBlink.ex
ninja: build stopped: subcommand failed.

[barracuda156]

@pguyot Looks like the breakage originates from 6a4bab2

[petermm]

Per AMP code:

The breakage is in src/platforms/generic_unix/main.c: the __APPLE__ branch of get_embedded_avm() unconditionally calls getsectiondata() from <mach-o/getsect.h>. That symbol is only available in the modern macOS SDK / libSystem; it is not present on the legacy Mac OS X 10.5/10.6 PowerPC SDK that MacPorts uses for -arch ppc (-mmacosx-version-min=10.6), hence the Undefined symbols for architecture ppc: "_getsectiondata" link error.

Suggested minimal fix — fall through to the existing no-embedded-AVM #else branch on platforms where getsectiondata isn't available (same path FreeBSD already takes):

--- a/src/platforms/generic_unix/main.c
+++ b/src/platforms/generic_unix/main.c
@@
-#ifdef __APPLE__
+#include <Availability.h>
+
+#if defined(__APPLE__) && defined(__MAC_OS_X_VERSION_MIN_REQUIRED) \
+    && __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070
+#define ATOMVM_APPLE_HAS_GETSECTIONDATA 1
+#endif
+
+#ifdef ATOMVM_APPLE_HAS_GETSECTIONDATA
 #include <mach-o/getsect.h>
 #include <mach-o/ldsyms.h>
 #elif defined(__linux__)
@@
 bool get_embedded_avm(const void **data, size_t *size)
 {
-#ifdef __APPLE__
+#ifdef ATOMVM_APPLE_HAS_GETSECTIONDATA
     // On macOS, look for the __ATOMVM,__avm_data section
     unsigned long section_size = 0;
     const void *section_data = getsectiondata(&_mh_execute_header, "__ATOMVM", "__avm_data", &section_size);

getsectiondata() was introduced in the 10.7 SDK, so gating the embedded-AVM support on __MAC_OS_X_VERSION_MIN_REQUIRED >= 1070 lets PPC (and any other pre-10.7 deployment target) fall through to the existing #else branch — embedded AVM is simply unsupported there, matching the FreeBSD path. Alternatively the legacy getsectdata()/getsectbyname() APIs could be used for old PPC macOS, but the simple fallback is probably enough since embedded escriptize on legacy PPC is unlikely to be a real use case.

[pguyot]

Thank you for the report. We have no (reasonable) way to compile and test AtomVM for 10.7 on CI, so I'd rather disable the embedded AVM feature.