From 6d4d11f1b6b69f73963fbebb5cc3e2d35230d2b2 Mon Sep 17 00:00:00 2001
From: Mark Gates <mgates3@icl.utk.edu>
Date: Wed, 28 Apr 2021 10:22:25 -0400
Subject: [PATCH] allow overriding LD

---
 GNUmakefile | 12 +++++++++---
 INSTALL.md  |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/GNUmakefile b/GNUmakefile
index 3330246d..0fcaf71d 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -4,7 +4,7 @@
 # Configuration
 # Variables defined in make.inc, or use make's defaults:
 #   CXX, CXXFLAGS   -- C compiler and flags
-#   LDFLAGS, LIBS   -- Linker options, library paths, and libraries
+#   LD, LDFLAGS, LIBS -- Linker, options, library paths, and libraries
 #   AR, RANLIB      -- Archiver, ranlib updates library TOC
 #   prefix          -- where to install BLAS++
 
@@ -30,6 +30,11 @@ make.inc:
 RANLIB   ?= ranlib
 prefix   ?= /opt/slate
 
+# Default LD=ld won't work; use CXX. Can override in make.inc or environment.
+ifeq ($(origin LD),default)
+    LD = $(CXX)
+endif
+
 # auto-detect OS
 # $OSTYPE may not be exported from the shell, so echo it
 ostype := $(shell echo $${OSTYPE})
@@ -156,7 +161,7 @@ lib    = lib/libblaspp.$(lib_ext)
 
 $(lib_so): $(lib_obj)
 	mkdir -p lib
-	$(CXX) $(LDFLAGS) -shared $(install_name) $(lib_obj) $(LIBS) -o $@
+	$(LD) $(LDFLAGS) -shared $(install_name) $(lib_obj) $(LIBS) -o $@
 
 $(lib_a): $(lib_obj)
 	mkdir -p lib
@@ -180,7 +185,7 @@ endif
 #-------------------------------------------------------------------------------
 # tester
 $(tester): $(tester_obj) $(lib) $(testsweeper)
-	$(CXX) $(TEST_LDFLAGS) $(LDFLAGS) $(tester_obj) \
+	$(LD) $(TEST_LDFLAGS) $(LDFLAGS) $(tester_obj) \
 		$(TEST_LIBS) $(LIBS) -o $@
 
 # sub-directory rules
@@ -314,6 +319,7 @@ echo:
 	@echo "CXX           = $(CXX)"
 	@echo "CXXFLAGS      = $(CXXFLAGS)"
 	@echo
+	@echo "LD            = $(LD)"
 	@echo "LDFLAGS       = $(LDFLAGS)"
 	@echo "LIBS          = $(LIBS)"
 	@echo
diff --git a/INSTALL.md b/INSTALL.md
index 5c4dee4a..f0fa4755 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -26,6 +26,7 @@ Environment variables (Makefile and CMake)
 Standard environment variables affect both Makefile (configure.py) and CMake.
 These include:
 
+    LD                  Linker; defaults to CXX
     CXX                 C++ compiler
     CXXFLAGS            C++ compiler flags
     LDFLAGS             linker flags