ENH: add optional control to use clang lld linker (#2449)

Eg,
    export WM_COMPILER=Clang130
    export WM_COMPILE_CONTROL="version=13.0 +lld"

- also support the mold linker (+mold) for clang

STYLE: report as 'link' stage instead of 'ld' in short messages

etc/bashrc

@@ -6,7 +6,7 @@
 #    \\/     M anipulation  |
 #------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
-#     Copyright (C) 2016-2021 OpenCFD Ltd.
+#     Copyright (C) 2016-2022 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -86,6 +86,8 @@ export WM_COMPILE_OPTION=Opt
 
 # [WM_COMPILE_CONTROL] - additional control for compiler rules
 #   +gold   : with gold linker
+#   +lld    : with  lld linker (with clang)
+#   +mold   : with mold linker (with clang)
 #   ~openmp : without openmp
 #   version=... : compiler suffix (eg, "11" for gcc-11)
 #export WM_COMPILE_CONTROL="+gold"

etc/cshrc

@@ -6,7 +6,7 @@
 #    \\/     M anipulation  |
 #------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
-#     Copyright (C) 2016-2021 OpenCFD Ltd.
+#     Copyright (C) 2016-2022 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -86,6 +86,8 @@ setenv WM_COMPILE_OPTION Opt
 
 # [WM_COMPILE_CONTROL] - additional control for compiler rules
 #   +gold   : with gold linker
+#   +lld    : with  lld linker (with clang)
+#   +mold   : with mold linker (with clang)
 #   ~openmp : without openmp
 #   version=... : compiler suffix (eg, "11" for gcc-11)
 #setenv WM_COMPILE_CONTROL "+gold"

wmake/makefiles/general

@@ -6,7 +6,7 @@
 #    \\/     M anipulation  |
 #------------------------------------------------------------------------------
 #     Copyright (C) 2011-2016 OpenFOAM Foundation
-#     Copyright (C) 2019-2020 OpenCFD Ltd.
+#     Copyright (C) 2019-2022 OpenCFD Ltd.
 #------------------------------------------------------------------------------
 # License
 #     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
@@ -146,7 +146,7 @@ silent:
 
 $(EXE)$(EXT_EXE): $(OBJECTS)
 	@$(WM_SCRIPTS)/makeTargetDir $(EXE)
-	$(call QUIET_MESSAGE,ld,$(EXE)$(EXT_EXE))
+	$(call QUIET_MESSAGE,link,$(EXE)$(EXT_EXE))
 	$E $(LINKEXE) $(OBJECTS) -L$(LIB_PLATFORMS) \
 	    $(EXE_LIBS) $(PROJECT_LIBS) $(SYS_LIBS) \
 	    $(LINK_LIBS) $(GLIBS) -o $(EXE)$(EXT_EXE)
@@ -156,7 +156,7 @@ exe: $(SEXE)$(EXT_EXE) | silent
 
 $(SEXE)$(EXT_EXE): $(OBJECTS)
 	@$(WM_SCRIPTS)/makeTargetDir $(SEXE)
-	$(call QUIET_MESSAGE,ld,$(SEXE)$(EXT_EXE))
+	$(call QUIET_MESSAGE,link,$(SEXE)$(EXT_EXE))
 	$E $(LINKEXE) $(OBJECTS) $(EXE_LIBS) \
 	    $(SYS_LIBS) $(LINK_LIBS) $(GLIBS) -o $(SEXE)$(EXT_EXE)
 
@@ -174,13 +174,13 @@ libso: $(LIB)$(EXT_SO) | silent
 ifneq (,$(findstring windows,$(WM_OSTYPE)))
 $(LIB)$(EXT_SO): $(OBJECTS)
 	@$(WM_SCRIPTS)/makeTargetDir $(LIB)
-	$(call QUIET_MESSAGE,ld,$(LIB)$(EXT_SO))
+	$(call QUIET_MESSAGE,link,$(LIB)$(EXT_SO))
 	$E $(LINKLIBSO) $(OBJECTS) -L$(LIB_PLATFORMS) \
 	    $(PROJECT_LIBS) $(LIB_LIBS) $(GLIB_LIBS) -o $(LIB)$(EXT_SO)
 else
 $(LIB)$(EXT_SO): $(OBJECTS)
 	@$(WM_SCRIPTS)/makeTargetDir $(LIB)
-	$(call QUIET_MESSAGE,ld,$(LIB)$(EXT_SO))
+	$(call QUIET_MESSAGE,link,$(LIB)$(EXT_SO))
 	$E $(LINKLIBSO) $(OBJECTS) -L$(LIB_PLATFORMS) \
 	    $(LIB_LIBS) $(GLIB_LIBS) -o $(LIB)$(EXT_SO)
 endif

wmake/rules/General/Clang/link-lld-c++

+LINK_LIBS   = $(c++DBUG)
+
+LINKLIBSO   = $(CC) $(c++FLAGS) -shared \
+    -fuse-ld=lld \
+    $(FOAM_EXTRA_LDFLAGS)
+
+LINKEXE     = $(CC) $(c++FLAGS) \
+    -fuse-ld=lld \
+    -L$(FOAM_LIBBIN)/dummy -lPstream \
+    $(FOAM_EXTRA_LDFLAGS)

wmake/rules/General/Clang/link-mold-c++

+LINK_LIBS   = $(c++DBUG)
+
+LINKLIBSO   = $(CC) $(c++FLAGS) -shared \
+    -fuse-ld=mold \
+    $(FOAM_EXTRA_LDFLAGS)
+
+LINKEXE     = $(CC) $(c++FLAGS) \
+    -fuse-ld=mold \
+    -L$(FOAM_LIBBIN)/dummy -lPstream \
+    $(FOAM_EXTRA_LDFLAGS)

wmake/rules/linux64Clang/c++

@@ -12,8 +12,17 @@ cctoo       = $(Ctoo)
 cpptoo      = $(Ctoo)
 cxxtoo      = $(Ctoo)
 
+# Linking:
+
 ifneq (,$(findstring +gold,$(WM_COMPILE_CONTROL)))
     include $(GENERAL_RULES)/Clang/link-gold-c++
+
+else ifneq (,$(findstring +mold,$(WM_COMPILE_CONTROL)))
+    include $(GENERAL_RULES)/Clang/link-mold-c++
+
+else ifneq (,$(findstring +lld,$(WM_COMPILE_CONTROL)))
+    include $(GENERAL_RULES)/Clang/link-lld-c++
+
 else
     include $(GENERAL_RULES)/Clang/link-c++
 endif

wmake/rules/linuxClang/c++

@@ -12,8 +12,17 @@ cctoo       = $(Ctoo)
 cpptoo      = $(Ctoo)
 cxxtoo      = $(Ctoo)
 
+# Linking:
+
 ifneq (,$(findstring +gold,$(WM_COMPILE_CONTROL)))
     include $(GENERAL_RULES)/Clang/link-gold-c++
+
+else ifneq (,$(findstring +mold,$(WM_COMPILE_CONTROL)))
+    include $(GENERAL_RULES)/Clang/link-mold-c++
+
+else ifneq (,$(findstring +lld,$(WM_COMPILE_CONTROL)))
+    include $(GENERAL_RULES)/Clang/link-lld-c++
+
 else
     include $(GENERAL_RULES)/Clang/link-c++
 endif