And the basic idea works...

Makefile

@@ -1,5 +1,5 @@
 CPPFLAGS+= -I .
-CXXFLAGS+= -std=c++2c
+CXXFLAGS+= -std=c++2c -O0 -g
 LDFLAGS+= -L ./Alepha/ -Wl,-rpath=/home/adam/proj/bake/Alepha
 LDLIBS+= -lalepha 
 CXX=g++-14

bake.cc

@@ -33,6 +33,13 @@ namespace
 		abort();
 	}
 
+	std::string
+	getExtension( const auto &entry )
+	{
+		if( entry.path().extension().string().empty() ) return "";
+		return entry.path().extension().string().substr( 1 );
+	}
+
 	auto
 	collectFiles( const std::filesystem::path where, const std::set< std::string > extensions )
 	{
@@ -43,8 +50,8 @@ namespace
 			if( C::debug ) std::cerr << "Examining file: `" << entry << "`" << std::endl;
 			if( not entry.is_regular_file() ) continue;
 			if( C::debug ) std::cerr << "Was regular file..." << std::endl;
-			if( C::debug ) std::cerr << "Examining extension: `" << entry.path().extension() << "`" << std::endl;
+			if( C::debug ) std::cerr << "Examining extension: `" << getExtension( entry ) << "`" << std::endl;
-			if( not extensions.contains( entry.path().extension().string().substr( 1 ) ) ) continue;
+			if( not extensions.contains( getExtension( entry ) ) ) continue;
 			if( C::debug ) std::cerr << "Adding collected file: `" << entry << "`" << std::endl;
 			rv.push_back( entry.path() );
 		}
@@ -88,15 +95,9 @@ namespace
 
 	struct LinkEntry
 	{
-		std::int64_t addr;
+		std::string addr;
 		std::string type;
 		std::string symbol;
-
-		friend std::istream &
-		operator >> ( std::istream &is, LinkEntry &entry )
-		{
-			return is >> entry.addr >> entry.type >> entry.symbol;
-		}
 	};
 
 	namespace C
@@ -108,18 +109,18 @@ namespace
 	std::vector< std::string >
 	findSymbols( const std::filesystem::path object, const std::string opt )
 	{
+		const std::string nmCmd= "nm --just-symbols " + opt + " " + object.string();
+		std::cerr << nmCmd << std::endl;
 		Alepha::AutoRAII inF
 		{
-			[&]{ return popen( ( "nm " + opt + " " + object.string() ).c_str(), "r" ); },
+			[&]{ return popen( nmCmd.c_str(), "r" ); },
 			pclose
 		};
 		std::ifstream in{ "/dev/null" };
 		const int handle= in.native_handle();
 		::dup2( fileno( inF ), handle );
 
-		std::vector< std::string > rv;
+		std::vector< std::string > rv{ std::istream_iterator< std::string >{ in }, std::istream_iterator< std::string >{} };
-		std::transform( std::istream_iterator< LinkEntry >{ in }, std::istream_iterator< LinkEntry >{},
-				back_inserter( rv ), []( const auto &element ) { return element.symbol; } );
 
 		return rv;
 	}
@@ -178,17 +179,31 @@ namespace
 		components.insert( program );
 
 		auto unresolved= findUndefs( program ) | std::ranges::to< std::set >();
+		std::cerr << "In linking `" << program.stem().stem() << "` we have the following unresolved symbols: " << std::endl;
+		for( const auto sym: unresolved )
+		{
+			std::cerr << " - `" << sym << "`" << std::endl;
+		}
 
 		while( not unresolved.empty() )
 		{
 			auto sym= *unresolved.begin();
+			if( sym.starts_with( "_ZNS" ) or sym.starts_with( "_ZSt" ) or sym == "_GLOBAL_OFFSET_TABLE_" )
+			{
+				unresolved.erase( sym );
+				continue;
+			}
 			if( not providers.contains( sym ) )
 			{
 				throw std::runtime_error{ "Unable to find a provider for symbol `" + sym + "` when linking `"
 						+ program.stem().string() };
 			}
 
+
 			const auto provider= providers.lower_bound( sym )->second;
+
+			std::cerr << "Using `" << provider << "` to satisfy `" << sym << "`" << std::endl;
+
 			const auto provided= findDefs( provider );
 			const auto needed= findUndefs( provider );
 
@@ -258,14 +273,15 @@ namespace
 			std::filesystem::create_directories( ".bake"/source.parent_path() );
 			const auto targetBase= ".bake"/source;
 
+			const auto cmdline= compiler() + " " + source.string() + " " + preprocOptions() + " -E -o " + targetBase.string()+".E.new";
+			std::cerr << cmdline << std::endl;
+			::system( cmdline.c_str() );
+
 			if( not std::filesystem::exists( targetBase.string()+".E" ) )
 			{
 				rv.push_back( source );
 				continue;
 			}
-			const auto cmdline= compiler() + " " + preprocOptions() + " -E -o " + targetBase.string()+".E.new";
-			std::cerr << cmdline << std::endl;
-			::system( cmdline.c_str() );
 			if( diff( targetBase.string()+".E", targetBase.string()+".E.new" ) ) rv.push_back( source );
 		}
 
@@ -284,6 +300,7 @@ namespace
 			const auto cmdline=compiler() + " " + compileOptions() + " -c -o " + targetBase.string()+".o " + source.string();
 			std::cerr << cmdline << std::endl;
 			system( cmdline.c_str() );
+			std::filesystem::rename( targetBase.string()+".E.new", targetBase.string()+".E" );
 		}
 	}
 

test-bake/lib.cc

@@ -1,7 +1,17 @@
 #include "lib.h"
 
+namespace lib
+{
+	void func2();
+}
+
 int
 lib::func()
 {
 	return 42;
 }
+
+void
+lib::func2()
+{
+}

test-bake/lib.h

@@ -1,4 +1,6 @@
 namespace lib
 {
 	int func();
+
+	void func2();
 }

test-bake/main.cc

@@ -1,9 +1,11 @@
+#include <iostream>
+
 #include "lib.h"
 
 int
 main()
 {
-	lib::func();
+	std::cout << lib::func() << std::endl;
 
 	return 0;
 }