[dpdk-dev] [PATCH v3 1/2] mk: fix build with gcc 4.4 and clang

[Thomas Monjalon]

With GCC 4.4.7 from CentOS 6.5, the following errors arise:

lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_dev_rx_queue_setup':
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: missing initializer
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:2509: error: (near initialization for 'dev_info.driver_name')

lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_set_rsc':
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: missing initializer
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:4072: error: (near initialization for 'dev_info.driver_name')

lib/librte_pmd_ixgbe/ixgbe_rxtx.c: In function 'ixgbe_recv_pkts_lro_single_alloc':
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1479: error: 'next_rsc_entry' may be used uninitialized in this function
lib/librte_pmd_ixgbe/ixgbe_rxtx.c:1480: error: 'next_rxe' may be used uninitialized in this function

The "missing initializer" warning is a GCC bug which seems fixed in 4.7.
The same warning is thrown by clang.
The "may be used uninitialized" warning is another GCC bug which seems fixed in 4.7.

Fixes: 8eecb3295aed ("ixgbe: add LRO support")

Signed-off-by: Thomas Monjalon <thomas.monjalon at 6wind.com>
---
changes in v2:
- option -Wno-missing-field-initializers for old GCC instead of code workaround
changes in v3:
- option -Wno-missing-field-initializers for clang
- option -Wno-uninitialized for old GCC instead of code workaround (=NULL)
- remove redundants -Wno-uninitialized from ixgbe Makefile

 lib/librte_pmd_ixgbe/Makefile  | 4 ----
 mk/toolchain/clang/rte.vars.mk | 3 +++
 mk/toolchain/gcc/rte.vars.mk   | 9 +++++++++
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/librte_pmd_ixgbe/Makefile b/lib/librte_pmd_ixgbe/Makefile
index ae36202..fbf6966 100644
--- a/lib/librte_pmd_ixgbe/Makefile
+++ b/lib/librte_pmd_ixgbe/Makefile
@@ -76,10 +76,6 @@ ifeq ($(shell test $(GCC_VERSION) -ge 50 && echo 1), 1)
 CFLAGS_ixgbe_common.o += -Wno-logical-not-parentheses
 endif
 
-ifeq ($(shell test $(GCC_VERSION) -le 46 && echo 1), 1)
-CFLAGS_ixgbe_x550.o += -Wno-uninitialized
-CFLAGS_ixgbe_phy.o += -Wno-uninitialized
-endif
 endif
 
 #
diff --git a/mk/toolchain/clang/rte.vars.mk b/mk/toolchain/clang/rte.vars.mk
index 40cb389..245ea7e 100644
--- a/mk/toolchain/clang/rte.vars.mk
+++ b/mk/toolchain/clang/rte.vars.mk
@@ -72,5 +72,8 @@ WERROR_FLAGS += -Wundef -Wwrite-strings
 # process cpu flags
 include $(RTE_SDK)/mk/toolchain/$(RTE_TOOLCHAIN)/rte.toolchain-compat.mk
 
+# workaround clang bug with warning "missing field initializer" for "= {0}"
+WERROR_FLAGS += -Wno-missing-field-initializers
+
 export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
 export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
diff --git a/mk/toolchain/gcc/rte.vars.mk b/mk/toolchain/gcc/rte.vars.mk
index 88f235c..0f51c66 100644
--- a/mk/toolchain/gcc/rte.vars.mk
+++ b/mk/toolchain/gcc/rte.vars.mk
@@ -80,5 +80,14 @@ WERROR_FLAGS += -Wundef -Wwrite-strings
 # process cpu flags
 include $(RTE_SDK)/mk/toolchain/$(RTE_TOOLCHAIN)/rte.toolchain-compat.mk
 
+# workaround GCC bug with warning "missing initializer" for "= {0}"
+ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
+WERROR_FLAGS += -Wno-missing-field-initializers
+endif
+# workaround GCC bug with warning "may be used uninitialized"
+ifeq ($(shell test $(GCC_VERSION) -lt 47 && echo 1), 1)
+WERROR_FLAGS += -Wno-uninitialized
+endif
+
 export CC AS AR LD OBJCOPY OBJDUMP STRIP READELF
 export TOOLCHAIN_CFLAGS TOOLCHAIN_LDFLAGS TOOLCHAIN_ASFLAGS
-- 
2.2.2