Support full paths in FC

source/fab/cli.py

@@ -6,6 +6,7 @@
 import sys
 from pathlib import Path
 from typing import Dict, Optional
+import os
 
 from fab.steps.analyse import analyse
 from fab.steps.c_pragma_injector import c_pragma_injector
@@ -20,6 +21,7 @@
 from fab.steps.grab.folder import grab_folder
 from fab.steps.preprocess import preprocess_c, preprocess_fortran
 from fab.util import common_arg_parser
+from fab.tools import get_tool
 
 
 def _generic_build_config(folder: Path, kwargs=None) -> BuildConfig:
@@ -61,15 +63,18 @@ def calc_linker_flags():
         # todo: test this and get it running
         # 'ifort': (..., [...])
     }
+
     try:
-        linker, linker_flags = linkers[fc]
-    except KeyError:
-        raise NotImplementedError(f"Fab's zero configuration mode does not yet work with compiler '{fc}'")
+        # Get linker from $LD
+        linker, linker_flags = get_tool(os.environ.get("LD", None))
+    except ValueError:
+        # Get linker from linkers, or else just use $FC
+        linker, linker_flags = linkers.get(os.path.basename(fc), (fc, []))
 
     return linker, linker_flags
 
 
-def cli_fab(folder: Path, kwargs: Optional[Dict] = None):
+def cli_fab(folder: Path = None, kwargs: Optional[Dict] = None):
     """
     Running Fab from the command line will attempt to build the project in the current or given folder.
     The following params are used for testing. When run normally any parameters will be caught

source/fab/steps/compile_fortran.py

@@ -136,7 +136,7 @@ def handle_compiler_args(common_flags=None, path_flags=None):
 
     # Do we know this compiler? If so we can manage the flags a little, to avoid duplication or misconfiguration.
     # todo: This has been raised for discussion - we might never want to modify incoming flags...
-    known_compiler = COMPILERS.get(compiler)
+    known_compiler = COMPILERS.get(os.path.basename(compiler))
     if known_compiler:
         common_flags = remove_managed_flags(compiler, common_flags)
     else:
@@ -342,7 +342,7 @@ def compile_file(analysed_file, flags, output_fpath, mp_common_args):
 
     # tool
     command = [mp_common_args.compiler]
-    known_compiler = COMPILERS.get(mp_common_args.compiler)
+    known_compiler = COMPILERS.get(os.path.basename(mp_common_args.compiler))
 
     # Compile flag.
     # If it's an unknown compiler, we rely on the user config to specify this.

tests/system_tests/zero_config/test_zero_config.py

@@ -1,6 +1,9 @@
 from pathlib import Path
 
 from fab.cli import cli_fab
+import shutil
+import os
+from unittest import mock
 
 
 class TestZeroConfig(object):
@@ -25,3 +28,17 @@ def test_c_fortran_interop(self, tmp_path):
             kwargs=kwargs)
 
         assert (config.project_workspace / 'main').exists()
+
+    def test_fortran_explicit_gfortran(self, tmp_path):
+        # test the sample project in the fortran dependencies system test
+        kwargs = {'project_label': 'fortran explicit gfortran', 'fab_workspace': tmp_path, 'multiprocessing': False}
+
+        cc = shutil.which('gcc')
+        fc = shutil.which('gfortran')
+
+        with mock.patch.dict(os.environ, CC=cc, FC=fc, LD=fc):
+            config = cli_fab(
+                folder=Path(__file__).parent.parent / 'CFortranInterop',
+                kwargs=kwargs)
+
+        assert (config.project_workspace / 'main').exists()