libgo: handle linking to NetBSD's versioned symbols

On NetBSD, for backwards compatibility, various libc symbols are
renamed to a symbol with a version suffix. For example, this is the
(abbreviated) definition of sigaction:

    int sigaction(...) __asm__ ("__sigaction14")

This poses a challenge for libgo, which attempts to link sigaction by
way of an "//extern" comment:

    //extern sigaction
    func sigaction(...)

This results in a reference to the deprecated compatibility symbol
"sigaction", rather than the desired "__sigaction14" symbol.

This patch introduces a new "//extern-sysinfo" comment to handle this
situation. The new mklinknames.awk script scans a package for these
comments and outputs a "//go:linkname" directive that links the wrapper
to the correct versioned symbol, as determined by parsing the __asm__
annotation on the function's declaration in gen-sysinfo.go.

For now, only the following packages are scanned by mklinknames.awk:

    os
    os/user
    runtime
    syscall

gotools/:
	* Makefile.am (check-runtime): Add runtime_linknames.go to
	--extrafiles.
	* Makefile.in: Regenerate.

Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/265125
This commit is contained in:
Nikhil Benesch
2020-10-26 18:42:08 +00:00
committed by Ian Lance Taylor
parent e93aae4a49
commit 0cdde1e7ae
18 changed files with 202 additions and 39 deletions
+2 -2
View File
@@ -241,14 +241,14 @@ check-runtime: go$(EXEEXT) $(noinst_PROGRAMS) check-head check-gccgo check-gcc
export LD_LIBRARY_PATH; \
GOARCH=`$(abs_builddir)/go$(EXEEXT) env GOARCH`; \
GOOS=`$(abs_builddir)/go$(EXEEXT) env GOOS`; \
files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_linknames.go $(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
echo "$(ECHO_ENV) GC='$(abs_builddir)/check-gccgo -fgo-compiling-runtime' GOARCH=$${GOARCH} GOOS=$${GOOS} $(SHELL) $(libgosrcdir)/../testsuite/gotest --goarch=$${GOARCH} --goos=$${GOOS} --basedir=$(libgosrcdir)/.. --srcdir=$(libgosrcdir)/runtime --pkgpath=runtime --pkgfiles='$${files}' $(GOTESTFLAGS) -test.timeout=$(GOTOOLS_TEST_TIMEOUT)s -test.v" > runtime-testlog
$(CHECK_ENV) \
GC="$${GCCGO} -fgo-compiling-runtime"; \
export GC; \
GOARCH=`$(abs_builddir)/go$(EXEEXT) env GOARCH`; \
GOOS=`$(abs_builddir)/go$(EXEEXT) env GOOS`; \
files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_linknames.go $(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
$(SHELL) $(libgosrcdir)/../testsuite/gotest --goarch=$${GOARCH} --goos=$${GOOS} --basedir=$(libgosrcdir)/.. --srcdir=$(libgosrcdir)/runtime --pkgpath=runtime --pkgfiles="$${files}" $(GOTESTFLAGS) -test.timeout=$(GOTOOLS_TEST_TIMEOUT)s -test.v >> runtime-testlog 2>&1 || echo "--- $${fl}: go test runtime (0.00s)" >> runtime-testlog
grep '^--- ' runtime-testlog | sed -e 's/^--- \(.*\) ([^)]*)$$/\1/' | sort -k 2
+2 -2
View File
@@ -912,14 +912,14 @@ mostlyclean-local:
@NATIVE_TRUE@ export LD_LIBRARY_PATH; \
@NATIVE_TRUE@ GOARCH=`$(abs_builddir)/go$(EXEEXT) env GOARCH`; \
@NATIVE_TRUE@ GOOS=`$(abs_builddir)/go$(EXEEXT) env GOOS`; \
@NATIVE_TRUE@ files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
@NATIVE_TRUE@ files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_linknames.go $(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
@NATIVE_TRUE@ echo "$(ECHO_ENV) GC='$(abs_builddir)/check-gccgo -fgo-compiling-runtime' GOARCH=$${GOARCH} GOOS=$${GOOS} $(SHELL) $(libgosrcdir)/../testsuite/gotest --goarch=$${GOARCH} --goos=$${GOOS} --basedir=$(libgosrcdir)/.. --srcdir=$(libgosrcdir)/runtime --pkgpath=runtime --pkgfiles='$${files}' $(GOTESTFLAGS) -test.timeout=$(GOTOOLS_TEST_TIMEOUT)s -test.v" > runtime-testlog
@NATIVE_TRUE@ $(CHECK_ENV) \
@NATIVE_TRUE@ GC="$${GCCGO} -fgo-compiling-runtime"; \
@NATIVE_TRUE@ export GC; \
@NATIVE_TRUE@ GOARCH=`$(abs_builddir)/go$(EXEEXT) env GOARCH`; \
@NATIVE_TRUE@ GOOS=`$(abs_builddir)/go$(EXEEXT) env GOOS`; \
@NATIVE_TRUE@ files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
@NATIVE_TRUE@ files=`$(SHELL) $(libgosrcdir)/../match.sh --goarch=$${GOARCH} --goos=$${GOOS} --srcdir=$(libgosrcdir)/runtime --extrafiles="$(libgodir)/runtime_linknames.go $(libgodir)/runtime_sysinfo.go $(libgodir)/sigtab.go" --tag=libffi`; \
@NATIVE_TRUE@ $(SHELL) $(libgosrcdir)/../testsuite/gotest --goarch=$${GOARCH} --goos=$${GOOS} --basedir=$(libgosrcdir)/.. --srcdir=$(libgosrcdir)/runtime --pkgpath=runtime --pkgfiles="$${files}" $(GOTESTFLAGS) -test.timeout=$(GOTOOLS_TEST_TIMEOUT)s -test.v >> runtime-testlog 2>&1 || echo "--- $${fl}: go test runtime (0.00s)" >> runtime-testlog
@NATIVE_TRUE@ grep '^--- ' runtime-testlog | sed -e 's/^--- \(.*\) ([^)]*)$$/\1/' | sort -k 2