diff mbox series

multipath-tools: fix compilation with latest userspace-rcu code

Message ID 20250203214342.503983-1-bmarzins@redhat.com (mailing list archive)
State Not Applicable, archived
Delegated to: Benjamin Marzinski
Headers show
Series multipath-tools: fix compilation with latest userspace-rcu code | expand

Commit Message

Benjamin Marzinski Feb. 3, 2025, 9:43 p.m. UTC 
starting with version 0.15, userspace-rcu can be compiled with
CONFIG_RCU_USE_ATOMIC_BUILTINS. If it is, then any programs using it
must be compiled with at least the C11 standard. See:
https://github.com/urcu/userspace-rcu/commit/89280d020bf064d1055c360fb9974f128051043f

To deal with this, check if compiling with gnu99 fails, and if so,
switch to using gnu11.

Based-on-patch-by: Yaakov Selkowitz <yselkowi@redhat.com>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 Makefile.inc     |  2 +-
 create-config.mk | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/Makefile.inc b/Makefile.inc
index 729618bd..65f6efc8 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -115,7 +115,7 @@  CPPFLAGS	:= $(FORTIFY_OPT) $(CPPFLAGS) $(D_URCU_VERSION) \
 		   -DRUNTIME_DIR=\"$(runtimedir)\" -DCONFIG_DIR=\"$(TGTDIR)$(configdir)\" \
 		   -DDEFAULT_CONFIGFILE=\"$(TGTDIR)$(configfile)\" -DSTATE_DIR=\"$(TGTDIR)$(statedir)\" \
 		   -DEXTRAVERSION=\"$(EXTRAVERSION)\" -MMD -MP
-CFLAGS		:= -std=gnu99 $(CFLAGS) $(OPTFLAGS) $(WARNFLAGS) -pipe \
+CFLAGS		:= -std=$(C_STD) $(CFLAGS) $(OPTFLAGS) $(WARNFLAGS) -pipe \
 		   -fexceptions
 BIN_CFLAGS	:= -fPIE -DPIE
 LIB_CFLAGS	:= -fPIC
diff --git a/create-config.mk b/create-config.mk
index 8bd2c20c..ab163ed1 100644
--- a/create-config.mk
+++ b/create-config.mk
@@ -157,6 +157,18 @@  FORTIFY_OPT := $(shell \
 		echo "-D_FORTIFY_SOURCE=2"; \
 	fi)
 
+# Check is you can compile with the urcu.h header, using the C99 standard.
+# If urcu/config-<arch>.h defines CONFIG_RCU_USE_ATOMIC_BUILTINS, then anything
+# including urcu.h must be compiled with at least the C11 standard. See:
+# https://github.com/urcu/userspace-rcu/commit/89280d020bf064d1055c360fb9974f128051043f
+C_STD := $(shell \
+	if printf '$(__HASH__)include <urcu.h>\nint main(void) { return 0; }\n' | $(CC) -o /dev/null -c -xc --std=gnu99 - 2>/dev/null; \
+	then \
+		echo "gnu99"; \
+	else \
+		echo "gnu11"; \
+	fi)
+
 STACKPROT :=
 
 all:	$(TOPDIR)/config.mk
@@ -182,3 +194,4 @@  $(TOPDIR)/config.mk:	$(multipathdir)/autoconfig.h
 	@echo "W_MISSING_INITIALIZERS := $(call TEST_MISSING_INITIALIZERS)" >>$@
 	@echo "W_URCU_TYPE_LIMITS := $(call TEST_URCU_TYPE_LIMITS)" >>$@
 	@echo "ENABLE_LIBDMMP := $(ENABLE_LIBDMMP)" >>$@
+	@echo "C_STD := $(C_STD)" >>$@