libfetchers: remove scheme static initializers

provide a initLibFetchers function instead that runs them explicitly.

Change-Id: Ida532e6ff18b72fdc21c9f98df7aceda6713e5df

src/libexpr/eval.cc

@@ -191,6 +191,8 @@ void initLibExpr()
 
 #endif
 
+    fetchers::initLibFetchers();
+
     libexprInitialised = true;
 }
 

src/libfetchers/builtin-fetchers.hh

@@ -0,0 +1,18 @@
+#pragma once
+///@file internal header for fetcher declarations
+
+#include "fetchers.hh"
+
+namespace nix::fetchers {
+
+std::unique_ptr<InputScheme> makeIndirectInputScheme();
+std::unique_ptr<InputScheme> makePathInputScheme();
+std::unique_ptr<InputScheme> makeFileInputScheme();
+std::unique_ptr<InputScheme> makeTarballInputScheme();
+std::unique_ptr<InputScheme> makeGitInputScheme();
+std::unique_ptr<InputScheme> makeMercurialInputScheme();
+std::unique_ptr<InputScheme> makeGitHubInputScheme();
+std::unique_ptr<InputScheme> makeGitLabInputScheme();
+std::unique_ptr<InputScheme> makeSourceHutInputScheme();
+
+}

src/libfetchers/fetchers.cc

@@ -1,4 +1,5 @@
 #include "fetchers.hh"
+#include "builtin-fetchers.hh"
 #include "store-api.hh"
 #include "source-path.hh"
 #include "fetch-to-store.hh"
@@ -7,12 +8,24 @@
 
 namespace nix::fetchers {
 
-std::unique_ptr<std::vector<std::shared_ptr<InputScheme>>> inputSchemes = nullptr;
+static std::vector<std::shared_ptr<InputScheme>> inputSchemes;
 
 void registerInputScheme(std::shared_ptr<InputScheme> && inputScheme)
 {
-    if (!inputSchemes) inputSchemes = std::make_unique<std::vector<std::shared_ptr<InputScheme>>>();
-    inputSchemes->push_back(std::move(inputScheme));
+    inputSchemes.push_back(std::move(inputScheme));
+}
+
+void initLibFetchers()
+{
+    registerInputScheme(makeIndirectInputScheme());
+    registerInputScheme(makePathInputScheme());
+    registerInputScheme(makeFileInputScheme());
+    registerInputScheme(makeTarballInputScheme());
+    registerInputScheme(makeGitInputScheme());
+    registerInputScheme(makeMercurialInputScheme());
+    registerInputScheme(makeGitHubInputScheme());
+    registerInputScheme(makeGitLabInputScheme());
+    registerInputScheme(makeSourceHutInputScheme());
 }
 
 Input Input::fromURL(const std::string & url, bool requireTree)
@@ -35,7 +48,7 @@ static void fixupInput(Input & input)
 
 Input Input::fromURL(const ParsedURL & url, bool requireTree)
 {
-    for (auto & inputScheme : *inputSchemes) {
+    for (auto & inputScheme : inputSchemes) {
         auto res = inputScheme->inputFromURL(url, requireTree);
         if (res) {
             res->scheme = inputScheme;
@@ -49,7 +62,7 @@ Input Input::fromURL(const ParsedURL & url, bool requireTree)
 
 Input Input::fromAttrs(Attrs && attrs)
 {
-    for (auto & inputScheme : *inputSchemes) {
+    for (auto & inputScheme : inputSchemes) {
         auto res = inputScheme->inputFromAttrs(attrs);
         if (res) {
             res->scheme = inputScheme;

src/libfetchers/fetchers.hh

@@ -196,6 +196,8 @@ protected:
 
 void registerInputScheme(std::shared_ptr<InputScheme> && fetcher);
 
+void initLibFetchers();
+
 struct DownloadFileResult
 {
     StorePath storePath;

src/libfetchers/git.cc

@@ -2,6 +2,7 @@
 #include "fetchers.hh"
 #include "cache.hh"
 #include "globals.hh"
+#include "builtin-fetchers.hh"
 #include "processes.hh"
 #include "tarfile.hh"
 #include "store-api.hh"
@@ -795,6 +796,9 @@ struct GitInputScheme : InputScheme
     }
 };
 
-static auto rGitInputScheme = OnStartup([] { registerInputScheme(std::make_unique<GitInputScheme>()); });
+std::unique_ptr<InputScheme> makeGitInputScheme()
+{
+    return std::make_unique<GitInputScheme>();
+}
 
 }

src/libfetchers/github.cc

@@ -2,6 +2,7 @@
 #include "filetransfer.hh"
 #include "cache.hh"
 #include "globals.hh"
+#include "builtin-fetchers.hh"
 #include "store-api.hh"
 #include "types.hh"
 #include "url-parts.hh"
@@ -477,8 +478,18 @@ struct SourceHutInputScheme : GitArchiveInputScheme
     }
 };
 
-static auto rGitHubInputScheme = OnStartup([] { registerInputScheme(std::make_unique<GitHubInputScheme>()); });
-static auto rGitLabInputScheme = OnStartup([] { registerInputScheme(std::make_unique<GitLabInputScheme>()); });
-static auto rSourceHutInputScheme = OnStartup([] { registerInputScheme(std::make_unique<SourceHutInputScheme>()); });
+std::unique_ptr<InputScheme> makeGitHubInputScheme()
+{
+    return std::make_unique<GitHubInputScheme>();
+}
 
+std::unique_ptr<InputScheme> makeGitLabInputScheme()
+{
+    return std::make_unique<GitLabInputScheme>();
+}
+
+std::unique_ptr<InputScheme> makeSourceHutInputScheme()
+{
+    return std::make_unique<SourceHutInputScheme>();
+}
 }

src/libfetchers/indirect.cc

@@ -1,4 +1,5 @@
 #include "fetchers.hh"
+#include "builtin-fetchers.hh"
 #include "url-parts.hh"
 #include "path.hh"
 
@@ -107,6 +108,9 @@ struct IndirectInputScheme : InputScheme
     }
 };
 
-static auto rIndirectInputScheme = OnStartup([] { registerInputScheme(std::make_unique<IndirectInputScheme>()); });
+std::unique_ptr<InputScheme> makeIndirectInputScheme()
+{
+    return std::make_unique<IndirectInputScheme>();
+}
 
 }

src/libfetchers/mercurial.cc

@@ -1,5 +1,6 @@
 #include "fetchers.hh"
 #include "cache.hh"
+#include "builtin-fetchers.hh"
 #include "processes.hh"
 #include "store-api.hh"
 #include "temporary-dir.hh"
@@ -330,6 +331,9 @@ struct MercurialInputScheme : InputScheme
     }
 };
 
-static auto rMercurialInputScheme = OnStartup([] { registerInputScheme(std::make_unique<MercurialInputScheme>()); });
+std::unique_ptr<InputScheme> makeMercurialInputScheme()
+{
+    return std::make_unique<MercurialInputScheme>();
+}
 
 }

src/libfetchers/path.cc

@@ -1,4 +1,5 @@
 #include "fetchers.hh"
+#include "builtin-fetchers.hh"
 #include "store-api.hh"
 #include "archive.hh"
 
@@ -139,6 +140,9 @@ struct PathInputScheme : InputScheme
     }
 };
 
-static auto rPathInputScheme = OnStartup([] { registerInputScheme(std::make_unique<PathInputScheme>()); });
+std::unique_ptr<InputScheme> makePathInputScheme()
+{
+    return std::make_unique<PathInputScheme>();
+}
 
 }

src/libfetchers/tarball.cc

@@ -2,6 +2,7 @@
 #include "cache.hh"
 #include "filetransfer.hh"
 #include "globals.hh"
+#include "builtin-fetchers.hh"
 #include "store-api.hh"
 #include "archive.hh"
 #include "tarfile.hh"
@@ -307,7 +308,14 @@ struct TarballInputScheme : CurlInputScheme
     }
 };
 
-static auto rTarballInputScheme = OnStartup([] { registerInputScheme(std::make_unique<TarballInputScheme>()); });
-static auto rFileInputScheme = OnStartup([] { registerInputScheme(std::make_unique<FileInputScheme>()); });
+std::unique_ptr<InputScheme> makeFileInputScheme()
+{
+    return std::make_unique<TarballInputScheme>();
+}
+
+std::unique_ptr<InputScheme> makeTarballInputScheme()
+{
+    return std::make_unique<FileInputScheme>();
+}
 
 }

src/libutil/types.hh

@@ -32,15 +32,6 @@ typedef std::set<Path> PathSet;
 
 typedef std::vector<std::pair<std::string, std::string>> Headers;
 
-/**
- * Helper class to run code at startup.
- */
-template<typename T>
-struct OnStartup
-{
-    OnStartup(T && t) { t(); }
-};
-
 /**
  * Wrap bools to prevent string literals (i.e. 'char *') from being
  * cast to a bool in Attr.