C#: Re-implement the git version logic using an attribute.

Author: criemen

csharp/extractor/Semmle.Extraction/Extractor/Extractor.cs

@@ -107,17 +107,14 @@ public static string Version
         {
             get
             {
-                // the resources for git information are always attached to the entry` assembly by our build system
+                // the attribute for the git information are always attached to the entry assembly by our build system
                 var assembly = Assembly.GetEntryAssembly();
-                var describeAllStream = assembly.GetManifestResourceStream("git-ql-describe-all.log");
-                var headSHAStream = assembly.GetManifestResourceStream("git-ql-rev-parse.log");
-                if (describeAllStream == null || headSHAStream == null)
+                var versionString = assembly!.GetCustomAttribute<AssemblyInformationalVersionAttribute>();
+                if (versionString == null)
                 {
                     return "unknown (not built from internal bazel workspace)";
                 }
-                var describeAll = new StreamReader(describeAllStream).ReadToEnd().Trim('\n');
-                var headSHA = new StreamReader(headSHAStream).ReadToEnd().Trim('\n');
-                return $"{describeAll} ({headSHA})";
+                return versionString.InformationalVersion;
             }
         }
 

csharp/scripts/BUILD.bazel

@@ -0,0 +1,17 @@
+py_binary(
+    name = "gen-assembly-info",
+    srcs = ["gen-assembly-info.py"],
+    deps = ["@rules_python//python/runfiles"],
+)
+
+# this is an instance of the dbscheme kept in the bazel build tree
+# this allows everything that bazel builds to be up-to-date,
+# independently from whether //go:gen was already run to update the checked in files
+genrule(
+    name = "assembly-info-src",
+    srcs = ["@semmle_code//:git_info"],
+    outs = ["AssemblyInfo.cs"],
+    cmd = "$(execpath :gen-assembly-info) $@ $(SRCS)",
+    tools = [":gen-assembly-info"],
+    visibility = ["//csharp:__subpackages__"],
+)

csharp/scripts/gen-assembly-info.py

@@ -0,0 +1,34 @@
+"""
+Generates an `AssemblyInfo.cs` file that specifies the `AssemblyInformationalVersion` attribute.
+
+This attribute is set to the git version string of the repository."""
+
+import pathlib
+import argparse
+
+
+def options():
+    p = argparse.ArgumentParser(
+        description="Generate the assembly info file that contains the git SHA and branch name"
+    )
+    p.add_argument("output", help="The path to the output file")
+    p.add_argument("gitinfo_files", nargs="+", help="The path to the gitinfo files")
+    return p.parse_args()
+
+
+opts = options()
+
+gitfiles = dict()
+for file in map(pathlib.Path, opts.gitinfo_files):
+    gitfiles[file.name] = file
+
+version_string = gitfiles["git-ql-describe-all.log"].read_text().strip()
+version_string += f" ({gitfiles['git-ql-rev-parse.log'].read_text().strip()})"
+
+output_file = pathlib.Path(opts.output)
+output_file_contents = f"""
+using System.Reflection;
+
+[assembly: AssemblyInformationalVersion("{version_string}")]
+"""
+output_file.write_text(output_file_contents)

misc/bazel/csharp.bzl

@@ -39,14 +39,15 @@ def codeql_csharp_binary(name, **kwargs):
     nullable = kwargs.pop("nullable", "enable")
     visibility = kwargs.pop("visibility", ["//visibility:public"])
     resources = kwargs.pop("resources", [])
+    srcs = kwargs.pop("srcs", [])
 
-    # the entry assembly always has the git info embedded
-    resources.append("@semmle_code//:git_info")
+    # always add the assembly info file that sets the AssemblyInformationalVersion attribute to the extractor version
+    srcs.append("//csharp/scripts:assembly-info-src")
 
     target_frameworks = kwargs.pop("target_frameworks", [TARGET_FRAMEWORK])
     csharp_binary_target = "bin/" + name
     publish_binary_target = "publish/" + name
-    csharp_binary(name = csharp_binary_target, nullable = nullable, target_frameworks = target_frameworks, resources = resources, visibility = visibility, **kwargs)
+    csharp_binary(name = csharp_binary_target, srcs = srcs, nullable = nullable, target_frameworks = target_frameworks, resources = resources, visibility = visibility, **kwargs)
     publish_binary(
         name = publish_binary_target,
         binary = csharp_binary_target,