From b5cf5fb0c4aba45fdf2b698855afba14ca439521 Mon Sep 17 00:00:00 2001
From: Sam Surtees <s.surtees@lorgames.com>
Date: Wed, 17 Sep 2025 17:56:25 +1000
Subject: [PATCH] Added ability for toolsets to specify tool output extensions

---
 modules/gmake/gmake_cpp.lua                   | 14 +++++--
 modules/gmake/tests/test_gmake_file_rules.lua | 40 +++++++++++++++++++
 src/tools/clang.lua                           |  4 ++
 src/tools/gcc.lua                             |  4 ++
 src/tools/msc.lua                             |  3 ++
 5 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/modules/gmake/gmake_cpp.lua b/modules/gmake/gmake_cpp.lua
index 0297f3ff2e..7c8624ed33 100644
--- a/modules/gmake/gmake_cpp.lua
+++ b/modules/gmake/gmake_cpp.lua
@@ -58,25 +58,33 @@
 	function cpp.initialize()
 		rule 'cpp'
 			fileExtension { ".cc", ".cpp", ".cxx", ".mm" }
-			buildoutputs  { "$(OBJDIR)/%{file.objname}.o" }
+			buildoutputs  { "$(OBJDIR)/%{file.objname}%{premake.modules.gmake.cpp.gettooloutputext('cxx', cfg)}" }
 			buildmessage  '$(notdir $<)'
 			buildcommands {'$(CXX) %{premake.modules.gmake.cpp.fileFlags(cfg, file)} $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"'}
 
 		rule 'cc'
 			fileExtension {".c", ".s", ".m"}
-			buildoutputs  { "$(OBJDIR)/%{file.objname}.o" }
+			buildoutputs  { "$(OBJDIR)/%{file.objname}%{premake.modules.gmake.cpp.gettooloutputext('cc', cfg)}" }
 			buildmessage  '$(notdir $<)'
 			buildcommands {'$(CC) %{premake.modules.gmake.cpp.fileFlags(cfg, file)} $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"'}
 
 		rule 'resource'
 			fileExtension ".rc"
-			buildoutputs  { "$(OBJDIR)/%{file.objname}.res" }
+			buildoutputs  { "$(OBJDIR)/%{file.objname}%{premake.modules.gmake.cpp.gettooloutputext('rc', cfg)}" }
 			buildmessage  '$(notdir $<)'
 			buildcommands {'$(RESCOMP) $< -O coff -o "$@" $(ALL_RESFLAGS)'}
 
 		global(nil)
 	end
 
+	function cpp.gettooloutputext(tool, cfg)
+		local toolset = gmake.getToolSet(cfg)
+		if toolset.gettooloutputext ~= nil then
+			return toolset.gettooloutputext(tool)
+		end
+
+		return iif(tool == "rc", ".res", ".o")
+	end
 
 	function cpp.createRuleTable(prj)
 		local rules = {}
diff --git a/modules/gmake/tests/test_gmake_file_rules.lua b/modules/gmake/tests/test_gmake_file_rules.lua
index d8f7bc9760..13f608746d 100644
--- a/modules/gmake/tests/test_gmake_file_rules.lua
+++ b/modules/gmake/tests/test_gmake_file_rules.lua
@@ -81,6 +81,46 @@
 	end
 
 
+--
+-- Object filenames use correct extension based on toolset
+--
+
+	function suite.objectNameExtensions_onDefault()
+		files { "src/hello.cpp", "src/test.c" }
+		prepare()
+		test.capture [[
+# File Rules
+# #############################################
+
+$(OBJDIR)/hello.o: src/hello.cpp
+	@echo "$(notdir $<)"
+	$(SILENT) $(CXX) $(ALL_CXXFLAGS) $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"
+$(OBJDIR)/test.o: src/test.c
+	@echo "$(notdir $<)"
+	$(SILENT) $(CC) $(ALL_CFLAGS) $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"
+
+]]
+	end
+
+	function suite.objectNameExtensions_onMSC()
+		toolset "msc"
+		files { "src/hello.cpp", "src/test.c" }
+		prepare()
+		test.capture [[
+# File Rules
+# #############################################
+
+$(OBJDIR)/hello.obj: src/hello.cpp
+	@echo "$(notdir $<)"
+	$(SILENT) $(CXX) $(ALL_CXXFLAGS) $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"
+$(OBJDIR)/test.obj: src/test.c
+	@echo "$(notdir $<)"
+	$(SILENT) $(CC) $(ALL_CFLAGS) $(FORCE_INCLUDE) -o "$@" -MF "$(@:%.o=%.d)" -c "$<"
+
+]]
+	end
+
+
 --
 -- Two files with the same base name should have different object files.
 --
diff --git a/src/tools/clang.lua b/src/tools/clang.lua
index 8839b8259c..4971ecd507 100644
--- a/src/tools/clang.lua
+++ b/src/tools/clang.lua
@@ -364,3 +364,7 @@
 		end
 		return value
 	end
+
+	function clang.gettooloutputext(tool)
+		return gcc.gettooloutputext(tool)
+	end
diff --git a/src/tools/gcc.lua b/src/tools/gcc.lua
index 87ddadf606..fb7c908573 100644
--- a/src/tools/gcc.lua
+++ b/src/tools/gcc.lua
@@ -724,3 +724,7 @@
 		end
 		return (cfg.gccprefix or "") .. gcc.tools[tool] .. version
 	end
+
+	function gcc.gettooloutputext(tool)
+		return iif(tool == "rc", ".res", ".o")
+	end
diff --git a/src/tools/msc.lua b/src/tools/msc.lua
index b916fc4c3d..bd648d0f89 100644
--- a/src/tools/msc.lua
+++ b/src/tools/msc.lua
@@ -494,6 +494,9 @@
 		return msc.tools[tool]
 	end
 
+	function msc.gettooloutputext(tool)
+		return iif(tool == "rc", ".res", ".obj")
+	end
 
 
 	function msc.getwarnings(cfg)