From deeef55ea9ab300d14e5e14b0d78d6098c80a300 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sat, 2 Jun 2018 21:01:03 +0200
Subject: [PATCH 1/4] Try and *actually* use clang for the clang build.

Fixes: #67
---
 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.travis.yml b/.travis.yml
index 5268370c8..299ac5828 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -20,5 +20,5 @@ matrix:
 git:
     depth: 10
 script:
-    - make PREFIX=/tmp/acki +ack
+    - make CC=$CC PREFIX=/tmp/acki +ack
 

From 5a886787d31a758d531fce7ecf16983d67d21259 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sat, 2 Jun 2018 21:30:52 +0200
Subject: [PATCH 2/4] Honour CFLAGS set in the Makefile.

---
 Makefile  | 5 +++--
 build.lua | 2 +-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 1bfba3939..03b87c926 100644
--- a/Makefile
+++ b/Makefile
@@ -22,9 +22,9 @@ PREFIX = $(INSDIR)
 
 BUILDDIR = $(ACK_TEMP_DIR)/ack-build
 
-# What build flags do you want to use?
+# What build flags do you want to use for native code?
 
-CFLAGS = -g
+CFLAGS = -g -O -Wno-return-type
 LDFLAGS = 
 
 # Various commands.
@@ -120,6 +120,7 @@ $(build-file): first/ackbuilder.lua Makefile $(lua-files) $(our-lua)
 		PREFIX=$(PREFIX) \
 		AR=$(AR) \
 		CC=$(CC) \
+		CFLAGS="$(CFLAGS)" \
 		> $(build-file)
 
 install:
diff --git a/build.lua b/build.lua
index 1e2405907..f1a1a20e3 100644
--- a/build.lua
+++ b/build.lua
@@ -1,5 +1,5 @@
 vars.cflags = {
-	"-g", "-O"
+	"$CFLAGS"
 }
 vars.ackcflags = {
 	"-O6"

From 911ce7ceb517a624625582d5d363bd53f0dadd6e Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sat, 2 Jun 2018 21:31:18 +0200
Subject: [PATCH 3/4] Crudely tweak some of the prototypes to please clang,
 which is pickier about K&R C than gcc is.

---
 h/con_float             |  1 -
 mach/proto/cg/equiv.c   | 72 +++++++++++++++++++++++------------------
 mach/proto/ncg/fillem.c |  2 +-
 3 files changed, 42 insertions(+), 33 deletions(-)

diff --git a/h/con_float b/h/con_float
index b2ad2908b..903c2ce5b 100644
--- a/h/con_float
+++ b/h/con_float
@@ -237,7 +237,6 @@ float_cst(str, sz, buf)
 #endif /* USE_FLT */
 
 #ifdef CODE_GENERATOR
-void
 con_float()
 {
 	char buf[8];
diff --git a/mach/proto/cg/equiv.c b/mach/proto/cg/equiv.c
index 36ef12f92..77e1c0c0a 100644
--- a/mach/proto/cg/equiv.c
+++ b/mach/proto/cg/equiv.c
@@ -22,27 +22,32 @@ static char rcsid[] = "$Id$";
 extern string myalloc();
 
 int rar[MAXCREG];
-rl_p *lar;
+rl_p* lar;
 int maxindex;
 int regclass[NREGS];
-struct perm *perms;
+struct perm* perms;
 
-struct perm *
-tuples(regls,nregneeded) rl_p *regls; {
-	int class=0;
-	register i,j;
+void permute(int index);
+
+struct perm* tuples(rl_p* regls, int nregneeded)
+{
+	int class = 0;
+	register i, j;
 
 	/*
 	 * First compute equivalence classes of registers.
 	 */
 
-	for (i=0;i<NREGS;i++) {
-		regclass[i] = class++;
-		if (getrefcount(i, FALSE) == 0) {
-			for (j=0;j<i;j++) {
-				if (eqregclass(i,j) &&
-				    eqtoken(&machregs[i].r_contents,
-					    &machregs[j].r_contents)) {
+	for (i = 0; i < NREGS; i++)
+	{
+		regclass[i] = class ++;
+		if (getrefcount(i, FALSE) == 0)
+		{
+			for (j = 0; j < i; j++)
+			{
+				if (eqregclass(i, j) && eqtoken(&machregs[i].r_contents,
+				                            &machregs[j].r_contents))
+				{
 					regclass[i] = regclass[j];
 					break;
 				}
@@ -58,37 +63,42 @@ tuples(regls,nregneeded) rl_p *regls; {
 	lar = regls;
 	perms = 0;
 	permute(0);
-	return(perms);
+	return (perms);
 }
 
-permute(index) {
-	register struct perm *pp;
+void permute(int index)
+{
+	register struct perm* pp;
 	register rl_p rlp;
-	register i,j;
+	register i, j;
 
-	if (index == maxindex) {
-		for (pp=perms; pp != 0; pp=pp->p_next) {
-			for (i=0; i<maxindex; i++)
+	if (index == maxindex)
+	{
+		for (pp = perms; pp != 0; pp = pp->p_next)
+		{
+			for (i = 0; i < maxindex; i++)
 				if (regclass[rar[i]] != regclass[pp->p_rar[i]])
 					goto diff;
-			for (i=0; i<maxindex; i++)
-				for (j=0; j<i; j++)
-					if (clash(rar[i],rar[j]) !=
-					    clash(pp->p_rar[i],pp->p_rar[j]))
+			for (i = 0; i < maxindex; i++)
+				for (j = 0; j < i; j++)
+					if (clash(rar[i], rar[j]) != clash(pp->p_rar[i], pp->p_rar[j]))
 						goto diff;
 			return;
-		    diff: ;
+		diff:;
 		}
-		pp = (struct perm *) myalloc(sizeof ( *pp ));
+		pp = (struct perm*)myalloc(sizeof(*pp));
 		pp->p_next = perms;
-		for (i=0; i<maxindex; i++)
+		for (i = 0; i < maxindex; i++)
 			pp->p_rar[i] = rar[i];
 		perms = pp;
-	} else {
-		rlp=lar[index];
-		for (i=rlp->rl_n-1; i>=0; i--) {
+	}
+	else
+	{
+		rlp = lar[index];
+		for (i = rlp->rl_n - 1; i >= 0; i--)
+		{
 			rar[index] = rlp->rl_list[i];
-			permute(index+1);
+			permute(index + 1);
 		}
 	}
 }
diff --git a/mach/proto/ncg/fillem.c b/mach/proto/ncg/fillem.c
index 07e6c9331..7f479337e 100644
--- a/mach/proto/ncg/fillem.c
+++ b/mach/proto/ncg/fillem.c
@@ -83,7 +83,7 @@ extern short em_ptyp[];
 /* machine dependent */
 void con_part(int, word);
 void con_mult(word);
-void con_float(void);
+int con_float(void); /* actually returns void, but need K&R C compatibility */
 void prolog(full nlocals);
 void mes(word);
 

From 5d292a0a36cd07fef2c0720d23b5b21e3b79fc45 Mon Sep 17 00:00:00 2001
From: David Given <dg@cowlark.com>
Date: Sat, 2 Jun 2018 21:48:18 +0200
Subject: [PATCH 4/4] Typo fix.

---
 build.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/build.lua b/build.lua
index f1a1a20e3..5ab18b45e 100644
--- a/build.lua
+++ b/build.lua
@@ -1,5 +1,5 @@
 vars.cflags = {
-	"$CFLAGS"
+	"$(CFLAGS)"
 }
 vars.ackcflags = {
 	"-O6"