allow libc itself to be built with stack protector enabled
this was already essentially possible as a result of the previous
commits changing the dynamic linker/thread pointer bootstrap process.
this commit mainly adds build system infrastructure:
configure no longer attempts to disable stack protector. instead it
simply determines how so the makefile can disable stack protector for
a few translation units used during early startup.
stack protector is also disabled for memcpy and memset since compilers
(incorrectly) generate calls to them on some archs to implement
struct initialization and assignment, and such calls may creep into
early initialization.
no explicit attempt to enable stack protector is made by configure at
this time; any stack protector option supported by the compiler can be
passed to configure in CFLAGS, and if the compiler uses stack
protector by default, this default is respected.
diff --git a/configure b/configure
index 7304b13..41a73b4 100755
--- a/configure
+++ b/configure
@@ -111,6 +111,7 @@
CFLAGS_C99FSE=
CFLAGS_AUTO=
CFLAGS_MEMOPS=
+CFLAGS_NOSSP=
LDFLAGS_AUTO=
OPTIMIZE_GLOBS=
prefix=/usr/local/musl
@@ -291,6 +292,13 @@
fi
#
+# Check for options to disable stack protector, which needs to be
+# disabled for a few early-bootstrap translation units. If not found,
+# this is not an error; we assume the toolchain does not do ssp.
+#
+tryflag CFLAGS_NOSSP -fno-stack-protector
+
+#
# Check for options that may be needed to prevent the compiler from
# generating self-referential versions of memcpy,, memmove, memcmp,
# and memset. Really, we should add a check to determine if this
@@ -408,7 +416,6 @@
fi
# Some patched GCC builds have these defaults messed up...
-tryflag CFLAGS_AUTO -fno-stack-protector
tryldflag LDFLAGS_AUTO -Wl,--hash-style=both
test "$shared" = "no" || {
@@ -526,6 +533,7 @@
CFLAGS = $CFLAGS_AUTO $CFLAGS
CFLAGS_C99FSE = $CFLAGS_C99FSE
CFLAGS_MEMOPS = $CFLAGS_MEMOPS
+CFLAGS_NOSSP = $CFLAGS_NOSSP
CPPFLAGS = $CPPFLAGS
LDFLAGS = $LDFLAGS_AUTO $LDFLAGS
CROSS_COMPILE = $CROSS_COMPILE