54 lines
2.2 KiB
Diff
54 lines
2.2 KiB
Diff
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From: Valentine Barshak <gvaxon@gmail.com>
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Date: Mon, 22 Jul 2019 10:47:50 +0100
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Subject: Workaround compilation error with gcc 9.1
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References: bsc#1121464
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Compiling with gcc 9.1 generates lots of "taking address of packed
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member of ... may result in an unaligned pointer value" warnings.
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Some of these warnings are genuine, and indicate correctly that parts
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of iPXE currently require the CPU (or runtime environment) to support
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unaligned accesses. For example: the TCP/IP receive data path will
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attempt to access 32-bit fields that may not be aligned to a 32-bit
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boundary.
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Other warnings are either spurious (such as when the pointer is to a
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variable-length byte array, which can have no alignment requirement
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anyway) or unhelpful (such as when the pointer is used solely to
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provide a debug colour value for the DBGC() macro).
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There appears to be no easy way to silence the spurious warnings.
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Since the ability to perform unaligned accesses is already a
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requirement for iPXE, work around the problem by silencing this class
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of warnings.
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Signed-off-by: Valentine Barshak <gvaxon@gmail.com>
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Modified-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Michael Brown <mcb30@ipxe.org>
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Signed-off-by: Bruce Rogers <brogers@suse.com>
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---
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src/Makefile.housekeeping | 9 +++++++++
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1 file changed, 9 insertions(+)
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diff --git a/roms/ipxe/src/Makefile.housekeeping b/roms/ipxe/src/Makefile.housekeeping
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index 97fa325bb52314e05192d0414436..e5f6927de889167d286ccfcdda92 100644
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--- a/roms/ipxe/src/Makefile.housekeeping
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+++ b/roms/ipxe/src/Makefile.housekeeping
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@@ -185,6 +185,15 @@ WNST_TEST = $(CC) -Wstringop-truncation -x c -c /dev/null -o /dev/null \
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>/dev/null 2>&1
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WNST_FLAGS := $(shell $(WNST_TEST) && $(ECHO) '-Wno-stringop-truncation')
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WORKAROUND_CFLAGS += $(WNST_FLAGS)
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+
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+# gcc 9.1 generates warnings for taking address of packed member which
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+# may result in an unaligned pointer value. Inhibit the warnings.
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+#
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+WNAPM_TEST = $(CC) -Wno-address-of-packed-member -x c -c /dev/null \
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+ -o /dev/null >/dev/null 2>&1
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+WNAPM_FLAGS := $(shell $(WNAPM_TEST) && \
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+ $(ECHO) '-Wno-address-of-packed-member')
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+WORKAROUND_CFLAGS += $(WNAPM_FLAGS)
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endif
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# Some versions of gas choke on division operators, treating them as
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