mir/passes: lower vcs_tag into a CustomTarget`

Which allows normal lowering code to proceed as normal. This is the most
basic implementation possible, it doesn't check any VCS values, only the
version set in the project() call for a fallback.

Author: dcbaker

src/mir/passes/free_functions.cpp

@@ -585,6 +585,53 @@ std::optional<Instruction> lower_add_arguments(const FunctionCall & func, const
     return AddArguments{std::move(mapping), func.name.substr(0, 10) == "add_global"};
 };
 
+std::optional<Instruction> lower_vcs_tag(const FunctionCall & f, const State::Persistant & p) {
+    if (!f.pos_args.empty()) {
+        throw Util::Exceptions::InvalidArguments(
+            "vcs_tag: does not take any positional arguments.");
+    }
+    if (f.kw_args.find("input") == f.kw_args.end()) {
+        throw Util::Exceptions::InvalidArguments(
+            "vcs_tag: missing required keyword argument input.");
+    }
+    if (f.kw_args.find("output") == f.kw_args.end()) {
+        throw Util::Exceptions::InvalidArguments(
+            "vcs_tag: missing required keyword argument output.");
+    }
+    if (f.kw_args.find("command") != f.kw_args.end()) {
+        throw Util::Exceptions::MesonException(
+            "Not implemented: vcs_tag 'command' keyword argument");
+    }
+
+    Instruction input = src_to_file(f.kw_args.find("input")->second, p, f.source_dir);
+    auto output = extract_keyword_argument<MIR::String>(f.kw_args, "output",
+                                                        f.name + ": 'output' must be a string")
+                      .value();
+    // TODO: get version from project() call
+    auto fallback = extract_keyword_argument<MIR::String>(f.kw_args, "fallback",
+                                                          f.name + ": 'fallback' must be a string")
+                        .value_or(MIR::String{p.project_version});
+    auto replace_string =
+        extract_keyword_argument<MIR::String>(f.kw_args, "replace_string",
+                                              f.name + ": 'replace_string' must be a string")
+            .value_or(MIR::String{"@VCS_TAG@"});
+
+    File outfile{output.value, f.source_dir, true, p.source_root, p.build_root};
+    const auto & src = std::get<File>(*src_to_file(input, p, f.source_dir).obj_ptr);
+
+    std::vector<std::string> command{
+        p.mesonpp,
+        "vcs_tag",
+        src.relative_to_build_dir(),
+        outfile.relative_to_build_dir(),
+        fallback.value,
+        replace_string.value,
+    };
+
+    return CustomTarget{
+        outfile.name, {std::move(input)}, {std::move(outfile)}, command, f.source_dir};
+}
+
 bool holds_reduced(const Instruction & obj);
 
 bool holds_reduced_array(const Instruction & obj) {
@@ -663,6 +710,8 @@ std::optional<Instruction> lower_free_funcs_impl(const Instruction & obj,
         i = lower_build_target<StaticLibrary>(f, pstate);
     } else if (f.name == "declare_dependency") {
         i = lower_declare_dependency(f, pstate);
+    } else if (f.name == "vcs_tag") {
+        i = lower_vcs_tag(f, pstate);
     } else if (f.name == "test") {
         i = lower_test(f, pstate);
     } else if (f.name == "add_project_arguments") {

tests/dsl/13 vcs_tag/basic.expected

@@ -0,0 +1,2 @@
+This is a 1.0.0 and 1.0.0
+    1.0.0 @1.0.0 @VCS_TAG

tests/dsl/13 vcs_tag/basic.in

@@ -0,0 +1,2 @@
+This is a @VCS_TAG@ and @VCS_TAG@
+    @VCS_TAG@ @@VCS_TAG@ @VCS_TAG

tests/dsl/13 vcs_tag/compare.py

@@ -0,0 +1,28 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: Apache-2.0
+# Copyright © 2024 Intel Corporation
+
+from __future__ import annotations
+import argparse
+import filecmp
+import sys
+import typing as T
+
+if T.TYPE_CHECKING:
+    class Arguments(T.Protocol):
+        result: str
+        expected: str
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument('result')
+    parser.add_argument('expected')
+    args: Arguments = parser.parse_args()
+
+    same = filecmp.cmp(args.result, args.expected)
+    return 0 if same else 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())

tests/dsl/13 vcs_tag/fallback.expected

@@ -0,0 +1,2 @@
+This is a "fallback version" and "fallback version"
+    "fallback version" @"fallback version" @VCS_TAG

tests/dsl/13 vcs_tag/meson.build

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright © 2024 Intel Corporation
+
+project(
+  'vcs_tag test',
+  version: '1.0.0',
+)
+
+python = find_program('python')
+tester = files('compare.py')
+
+# TODO: this will not work correctly whenever we implement support for VCs.
+x = vcs_tag(input: 'basic.in', output: 'basic.out')
+test('basic', python, args: [tester, x, files('basic.expected')])
+
+x = vcs_tag(input: 'basic.in', output: 'fallback.out', fallback : '"fallback version"')
+test('fallback', python, args: [tester, x, files('fallback.expected')])

tests/meson.build

@@ -17,6 +17,7 @@ test_cases = {
     '10 dependency methods',
     '11 test types',
     '12 add arguments',
+    '13 vcs_tag',
   ],
 }