[gobject-introspection/ebassi/compiler-opt: 3/4] Add --compiler argument to g-ir-scanner

[Emmanuele Bassi <ebassi src gnome org>]

commit 5609cc54dde836d3d96878f131bd721db398d1b7
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Jun 23 23:04:06 2021 +0100

    Add --compiler argument to g-ir-scanner
    
    We currently use the `CC` environment variable to find the C compiler to
    use internally in g-ir-scanner. Build systems might wish to store the
    compiler detected during the build configuration, and then pass that
    compiler to g-ir-scanner at the time of build, avoiding to put things
    into the environment.
    
    One possible solution is to have a command line argument that lets us
    specify the C compiler, with the same semantics as the `CC` environment
    variable.

 giscanner/ccompiler.py     | 8 ++++----
 giscanner/scannermain.py   | 4 ++++
 giscanner/sourcescanner.py | 6 +++++-
 3 files changed, 13 insertions(+), 5 deletions(-)
---
diff --git a/giscanner/ccompiler.py b/giscanner/ccompiler.py
index cb97e76f..a6be9ee6 100644
--- a/giscanner/ccompiler.py
+++ b/giscanner/ccompiler.py
@@ -124,9 +124,10 @@ class CCompiler(object):
                compiler_name != 'mingw32':
                 raise SystemExit('Specified Compiler \'%s\' is unsupported.' % compiler_name)
         else:
-            # XXX: Is it common practice to use a non-Unix compiler
-            #      class instance on non-Windows on platforms g-i supports?
-            compiler_name = distutils.ccompiler.get_default_compiler()
+            if compiler_name is None:
+                # XXX: Is it common practice to use a non-Unix compiler
+                #      class instance on non-Windows on platforms g-i supports?
+                compiler_name = distutils.ccompiler.get_default_compiler()
 
         # Now, create the distutils ccompiler instance based on the info we have.
         if compiler_name == 'msvc':
@@ -135,7 +136,6 @@ class CCompiler(object):
             # implementation
             from . import msvccompiler
             self.compiler = msvccompiler.get_msvc_compiler()
-
         else:
             self.compiler = distutils.ccompiler.new_compiler(compiler=compiler_name)
         customize_compiler(self.compiler)
diff --git a/giscanner/scannermain.py b/giscanner/scannermain.py
index 957ba0b7..ad2618b9 100644
--- a/giscanner/scannermain.py
+++ b/giscanner/scannermain.py
@@ -214,6 +214,9 @@ match the namespace prefix.""")
     parser.add_option("", "--filelist",
                       action="store", dest="filelist", default=[],
                       help="file containing headers and sources to be scanned")
+    parser.add_option("", "--compiler",
+                      action="store", dest="compiler", default=None,
+                      help="the C compiler to use internally")
 
     group = get_preprocessor_option_group(parser)
     parser.add_option_group(group)
@@ -455,6 +458,7 @@ def create_source_scanner(options, args):
     # Run the preprocessor, tokenize and construct simple
     # objects representing the raw C symbols
     ss = SourceScanner()
+    ss.set_compiler(options.compiler)
     ss.set_cpp_options(options.cpp_includes,
                        options.cpp_defines,
                        options.cpp_undefines,
diff --git a/giscanner/sourcescanner.py b/giscanner/sourcescanner.py
index 09f90441..9d567aee 100644
--- a/giscanner/sourcescanner.py
+++ b/giscanner/sourcescanner.py
@@ -231,6 +231,7 @@ class SourceScanner(object):
         self._scanner = CSourceScanner()
         self._filenames = []
         self._cpp_options = []
+        self._compiler = None
 
     # Public API
 
@@ -244,6 +245,9 @@ class SourceScanner(object):
                 if opt not in self._cpp_options:
                     self._cpp_options.append(opt)
 
+    def set_compiler(self, compiler):
+        self._compiler = compiler
+
     def parse_files(self, filenames):
         for filename in filenames:
             # self._scanner expects file names to be canonicalized and symlinks to be resolved
@@ -290,7 +294,7 @@ class SourceScanner(object):
         defines = ['__GI_SCANNER__']
         undefs = []
 
-        cc = CCompiler()
+        cc = CCompiler(compiler_name=self._compiler)
 
         tmp_fd_cpp, tmp_name_cpp = tempfile.mkstemp(prefix='g-ir-cpp-',
                                                     suffix='.c',