configure_file: Support taking values from a dict

Closes #4218

docs/markdown/Configuration.md

@@ -121,6 +121,38 @@ you to specify which file encoding to use. It is however strongly advised to
 convert your non utf-8 file to utf-8 whenever possible. Supported file
 encodings are those of python3, see [standard-encodings](https://docs.python.org/3/library/codecs.html#standard-encodings).
 
+## Using dictionaries
+
+Since *0.49.0* `configuration_data()` takes an optional dictionary as first
+argument. If provided, each key/value pair is added into the
+`configuration_data` as if `set()` method was called for each of them.
+`configure_file()`'s `configuration` kwarg also accepts a dictionary instead of
+a configuration_data object.
+
+Example:
+```meson
+cdata = configuration_data({
+  'STRING' : '"foo"',
+  'INT' : 42,
+  'DEFINED' : true,
+  'UNDEFINED' : false,
+})
+
+configure_file(output : 'config1.h',
+  configuration : cdata,
+)
+
+configure_file(output : 'config2.h',
+  configuration : {
+    'STRING' : '"foo"',
+    'INT' : 42,
+    'DEFINED' : true,
+    'UNDEFINED' : false,
+  }
+)
+
+```
+
 # A full example
 
 Generating and using a configuration file requires the following steps:

docs/markdown/Reference-manual.md

@@ -167,13 +167,17 @@ methods section](#build-target-object) below.
 ### configuration_data()
 
 ``` meson
-    configuration_data_object = configuration_data()
+    configuration_data_object = configuration_data(...)
 ```
 
 Creates an empty configuration object. You should add your
 configuration with [its method calls](#configuration-data-object) and
 finally use it in a call to `configure_file`.
 
+Since *0.49.0* takes an optional dictionary as first argument. If provided, each
+key/value pair is added into the `configuration_data` as if `set()` method was
+called for each of them.
+
 ### configure_file()
 
 ``` meson
@@ -187,7 +191,8 @@ When a [`configuration_data()`](#configuration_data) object is passed
 to the `configuration:` keyword argument, it takes a template file as
 the `input:` (optional) and produces the `output:` (required) by
 substituting values from the configuration data as detailed in [the
-configuration file documentation](Configuration.md).
+configuration file documentation](Configuration.md). Since *0.49.0* a dictionary
+can be passed instead of a [`configuration_data()`](#configuration_data) object.
 
 When a list of strings is passed to the `command:` keyword argument,
 it takes any source or configured file as the `input:` and assumes

mesonbuild/interpreter.py

@@ -2372,9 +2372,18 @@ external dependencies (including libraries) must go to "dependencies".''')
 
     @noKwargs
     def func_configuration_data(self, node, args, kwargs):
-        if args:
-            raise InterpreterException('configuration_data takes no arguments')
-        return ConfigurationDataHolder(self.subproject)
+        if len(args) > 1:
+            raise InterpreterException('configuration_data takes only one optional positional arguments')
+        elif len(args) == 1:
+            initial_values = args[0]
+            if not isinstance(initial_values, dict):
+                raise InterpreterException('configuration_data first argument must be a dictionary')
+        else:
+            initial_values = {}
+        cdata = ConfigurationDataHolder(self.subproject)
+        for k, v in initial_values.items():
+            cdata.set_method([k, v], {})
+        return cdata
 
     def set_options(self, default_options):
         # Set default options as if they were passed to the command line.
@@ -3552,7 +3561,12 @@ root and issuing %s.
         # Perform the appropriate action
         if 'configuration' in kwargs:
             conf = kwargs['configuration']
-            if not isinstance(conf, ConfigurationDataHolder):
+            if isinstance(conf, dict):
+                cdata = ConfigurationDataHolder(self.subproject)
+                for k, v in conf.items():
+                    cdata.set_method([k, v], {})
+                conf = cdata
+            elif not isinstance(conf, ConfigurationDataHolder):
                 raise InterpreterException('Argument "configuration" is not of type configuration_data')
             mlog.log('Configuring', mlog.bold(output), 'using configuration')
             if inputfile is not None:

test cases/common/14 configure file/meson.build

@@ -246,3 +246,27 @@ test('configure-file', test_file)
 
 cdata = configuration_data()
 cdata.set('invalid_value', ['array'])
+
+# Dictionaries
+
+cdata = configuration_data({
+  'A_STRING' : '"foo"',
+  'A_INT' : 42,
+  'A_DEFINED' : true,
+  'A_UNDEFINED' : false,
+})
+
+configure_file(output : 'config9a.h',
+  configuration : cdata,
+)
+
+configure_file(output : 'config9b.h',
+  configuration : {
+    'B_STRING' : '"foo"',
+    'B_INT' : 42,
+    'B_DEFINED' : true,
+    'B_UNDEFINED' : false,
+  }
+)
+
+test('test9', executable('prog9', 'prog9.c'))

test cases/common/14 configure file/prog9.c

@@ -0,0 +1,18 @@
+#include <string.h>
+#include <config9a.h>
+#include <config9b.h>
+
+#if defined(A_UNDEFINED) || defined(B_UNDEFINED)
+#error "Should not be defined"
+#endif
+
+#if !defined(A_DEFINED) || !defined(B_DEFINED)
+#error "Should be defined"
+#endif
+
+int main(int argc, char **argv) {
+    return strcmp(A_STRING, "foo")
+        || strcmp(B_STRING, "foo")
+        || A_INT != 42
+        || B_INT != 42;
+}