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bpo-36618: Don't add -fmax-type-align flag to old clang (GH-12811) · python/cpython@a304b13

3 files changed

lines changed

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@@ -4,5 +4,5 @@ alignment on 16 bytes by default and so uses MOVAPS instruction which can

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lead to segmentation fault. Instruct clang that Python is limited to

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alignemnt on 8 bytes to use MOVUPS instruction instead: slower but don't

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trigger a SIGSEGV if the memory is not aligned on 16 bytes. Sadly, the flag

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must be expected to ``CFLAGS`` and not just ``CFLAGS_NODIST``, since third

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party C extensions can have the same issue.

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must be added to ``CFLAGS`` and not just ``CFLAGS_NODIST``, since third party C

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extensions can have the same issue.

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@@ -6889,9 +6889,14 @@ then

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# instead: slower but don't trigger a SIGSEGV if the memory is not aligned

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# on 16 bytes.

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#

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# Sadly, the flag must be expected to CFLAGS and not just CFLAGS_NODIST,

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# Sadly, the flag must be added to CFLAGS and not just CFLAGS_NODIST,

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# since third party C extensions can have the same issue.

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CFLAGS="$CFLAGS -fmax-type-align=8"

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#

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# Check if -fmax-type-align flag is supported (it's not supported by old

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# clang versions):

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if "$CC" -v --help 2>/dev/null |grep -- -fmax-type-align > /dev/null; then

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CFLAGS="$CFLAGS -fmax-type-align=8"

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fi

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fi

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@@ -1540,9 +1540,14 @@ then

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# instead: slower but don't trigger a SIGSEGV if the memory is not aligned

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# on 16 bytes.

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#

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# Sadly, the flag must be expected to CFLAGS and not just CFLAGS_NODIST,

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# Sadly, the flag must be added to CFLAGS and not just CFLAGS_NODIST,

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# since third party C extensions can have the same issue.

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CFLAGS="$CFLAGS -fmax-type-align=8"

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#

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# Check if -fmax-type-align flag is supported (it's not supported by old

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# clang versions):

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if "$CC" -v --help 2>/dev/null |grep -- -fmax-type-align > /dev/null; then

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CFLAGS="$CFLAGS -fmax-type-align=8"

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fi

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fi

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AC_SUBST(BASECFLAGS)