From 2d1f3ee3bc7ab2443f14391fb315ee4520d271ab Mon Sep 17 00:00:00 2001
From: Jamie Strandboge <jamie@strandboge.com>
Date: Tue, 14 Sep 2021 10:35:45 -0500
Subject: [PATCH] build: allow specifying -gcflags via env (#267)

Make targets may call '$(GO_BUILD)', but there is no facility for
specifying arguments to 'go build'. As a first step, introduce the
GCFLAGS Makefile variable that when unset, operates as always, but when
set, adds '-gcflags "$(GCFLAGS)"' to go build. Eg, when unspecified,
maintain the current behavior (though with an additional space):

$ make
CGO_ENABLED=0 go build  -ldflags ...

When specified, add the specified -gcflags:

$ GCFLAGS="all=-N -l" make
CGO_ENABLED=0 go build -gcflags "all=-N -l" -ldflags ...

This could be useful in various situations such as producing unoptimized
builds (like in the above).
---
 Makefile | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 2041772..bde32f6 100644
--- a/Makefile
+++ b/Makefile
@@ -12,7 +12,15 @@ endif
 ifdef COMMIT
 	LDFLAGS += -X main.commit=$(COMMIT)
 endif
-export GO_BUILD=go build -ldflags "$(LDFLAGS)"
+
+# Use default flags, but allow adding -gcflags "..." if desired. Eg, for debug
+# builds, may want to use GCFLAGS="all=-N -l" in the build environment.
+GCFLAGS ?=
+ifneq ($(GCFLAGS),)
+GCFLAGS := -gcflags "$(GCFLAGS)"
+endif
+
+export GO_BUILD=go build $(GCFLAGS) -ldflags "$(LDFLAGS)"
 
 # SOURCES are the files that affect building the main binary.
 SOURCES := $(shell find . -name '*.go' -not -name '*_test.go') go.mod go.sum