From c146dcf5f0ee9bcb1b44bfecacb919c0fa179e15 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 19 Jul 2005 03:42:55 +0000
Subject: [PATCH] Detect GCC 3.x versus 4.x and use -I- or -isystem,
 respectively, to avoid ugly warnings on 4.x with -I-.

---
 src/Make.config       | 12 +++++++++++-
 src/Makefile.build    |  2 +-
 src/Makefile.userprog |  2 +-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/Make.config b/src/Make.config
index 8744f0d..f9822b6 100644
--- a/src/Make.config
+++ b/src/Make.config
@@ -18,11 +18,21 @@ LD = i386-elf-ld
 OBJCOPY = i386-elf-objcopy
 endif
 
+# GCC 3.3 specifies directories for #include <> as "-I- -Idir"
+# GCC 4.x specifies directories for #include <> as "-isystem dir"
+# Figure out which format to use.
+ifeq (0, $(shell $(CC) -v 2>&1 | grep 'gcc version 4' >/dev/null 2>&1; echo $$?))
+SYSINCFLAGS = $(patsubst %,-isystem %,$(SYSINCDIRS))
+else
+SYSINCFLAGS = -I- $(patsubst %,-I%,$(SYSINCDIRS))
+endif
+
 # Compiler and assembler invocation.
 DEFINES =
 WARNINGS = -Wall -W -Wstrict-prototypes -Wmissing-prototypes -Wsystem-headers
 CFLAGS = -g -MMD -msoft-float -masm=intel
-CPPFLAGS = -nostdinc -I$(SRCDIR) -I- -I$(SRCDIR)/lib
+SYSINCDIRS = $(SRCDIR)/lib
+CPPFLAGS = -nostdinc -I$(SRCDIR) $(SYSINCFLAGS)
 ASFLAGS = -Wa,--gstabs -MMD
 LDFLAGS = 
 
diff --git a/src/Makefile.build b/src/Makefile.build
index cf0f9b6..2e1d6e9 100644
--- a/src/Makefile.build
+++ b/src/Makefile.build
@@ -9,7 +9,7 @@ include ../Make.vars
 include ../../tests/Make.tests
 
 # Compiler and assembler options.
-os.dsk: CPPFLAGS += -I$(SRCDIR)/lib/kernel
+os.dsk: SYSINCDIRS += $(SRCDIR)/lib/kernel
 
 # Core kernel.
 threads_SRC  = threads/init.c		# Main program.
diff --git a/src/Makefile.userprog b/src/Makefile.userprog
index 72e35ce..dddb1aa 100644
--- a/src/Makefile.userprog
+++ b/src/Makefile.userprog
@@ -2,7 +2,7 @@
 
 include $(SRCDIR)/Make.config
 
-$(PROGS): CPPFLAGS += -I$(SRCDIR)/lib/user -I.
+$(PROGS): SYSINCDIRS += $(SRCDIR)/lib/user
 
 # Linker flags.
 $(PROGS): LDFLAGS = -nostdlib -static -Wl,-T,$(LDSCRIPT)
-- 
2.30.2