aedi: do not set c/c++ compilers and sdk paths without a platform

default pathlib's path means '.' (the current directory) but not an invalid path

aedi/state.py

@@ -67,13 +67,13 @@ class BuildState:
         return self.platform.os_version if self.platform else None
 
     def sdk_path(self) -> Path:
-        return self.platform.sdk_path if self.platform else Path()
+        return self.platform.sdk_path if self.platform else None
 
     def c_compiler(self) -> Path:
-        return self.platform.c_compiler if self.platform else Path()
+        return self.platform.c_compiler if self.platform else None
 
     def cxx_compiler(self) -> Path:
-        return self.platform.cxx_compiler if self.platform else Path()
+        return self.platform.cxx_compiler if self.platform else None
 
     def checkout_git(self, url: str, branch: str = None):
         if self.source.exists():

aedi/target/base.py

@@ -99,8 +99,10 @@ class BuildTarget(Target):
         if state.xcode:
             return
 
-        env['CC'] = str(state.c_compiler())
-        env['CXX'] = str(state.cxx_compiler())
+        if c_compiler := state.c_compiler():
+            env['CC'] = str(c_compiler)
+        if cxx_compiler := state.cxx_compiler():
+            env['CXX'] = str(cxx_compiler)
 
         for prefix in ('CPP', 'C', 'CXX', 'OBJC', 'OBJCXX'):
             var_name = f'{prefix}FLAGS'
@@ -281,9 +283,13 @@ class MakeTarget(BuildTarget):
         args = [
             self.tool,
             '-j', state.jobs,
-            f'CC={state.c_compiler()}',
-            f'CXX={state.cxx_compiler()}',
         ]
+
+        if c_compiler := state.c_compiler():
+            args.append(f'CC={c_compiler}')
+        if cxx_compiler := state.cxx_compiler():
+            args.append(f'CXX={cxx_compiler}')
+
         args += state.options.to_list()
 
         work_path = state.build_path / self.src_root
@@ -395,8 +401,11 @@ class CMakeTarget(BuildTarget):
             args.append('-GXcode')
         else:
             args.append('-GUnix Makefiles')
-            args.append(f'-DCMAKE_C_COMPILER={state.c_compiler()}')
-            args.append(f'-DCMAKE_CXX_COMPILER={state.cxx_compiler()}')
+
+            if c_compiler := state.c_compiler():
+                args.append(f'-DCMAKE_C_COMPILER={c_compiler}')
+            if cxx_compiler := state.cxx_compiler():
+                args.append(f'-DCMAKE_CXX_COMPILER={cxx_compiler}')
 
             architecture = state.architecture()
             if architecture != machine():

aedi/target/library_tier1.py

@@ -157,6 +157,12 @@ class GlibTarget(BuildTarget):
         environment = state.environment
         environment['LDFLAGS'] += ' -framework CoreFoundation -framework Foundation'
 
+        c_compiler = state.c_compiler()
+        assert c_compiler
+
+        cxx_compiler = state.cxx_compiler()
+        assert cxx_compiler
+
         cpu = state.architecture()
         cpu_family = 'arm' if 'arm64' == cpu else cpu
 
@@ -164,10 +170,10 @@ class GlibTarget(BuildTarget):
         with open(cross_file, 'w') as f:
             f.write(f'''
 [binaries]
-c = '{state.c_compiler()}'
-cpp = '{state.cxx_compiler()}'
-objc = '{state.c_compiler()}'
-objcpp = '{state.cxx_compiler()}'
+c = '{c_compiler}'
+cpp = '{cxx_compiler}'
+objc = '{c_compiler}'
+objcpp = '{cxx_compiler}'
 pkgconfig = '{state.prefix_path}/bin/pkg-config'
 strip = '/usr/bin/strip'
 

aedi/target/tools.py

@@ -217,8 +217,11 @@ class ZipTarget(MakeTarget):
         return state.has_source_file('zip.h')
 
     def build(self, state: BuildState):
+        c_compiler = state.c_compiler()
+        assert c_compiler
+
         args = [
-            str(state.c_compiler()),
+            str(c_compiler),
             '-O3', '-I.', '-DUNIX',
             '-DBZIP2_SUPPORT', '-DLARGE_FILE_SUPPORT', '-DUNICODE_SUPPORT',
             '-DHAVE_DIRENT_H', '-DHAVE_TERMIOS_H',