misc/cgo/life: fix, add to build
#pragma dynexport is no longer needed for
this use of cgo, since the gcc and gc code are
now linked together into the same binary.
It may still be necessary later.
On the Mac, you cannot use the GOT to resolve
symbols that exist in the current binary, so 6l and 8l
translate the GOT-loading mov instructions into lea
instructions.
On ELF systems, we could use the GOT for those
symbols, but for consistency 6l and 8l apply the
same translation.
The translation is sketchy in the extreme
(depending on the relocation being in a mov
instruction) but it verifies that the instruction
is a mov before rewriting it to lea.
Also makes typedefs global across files.
Fixes #1335.
Fixes #1345.
R=iant, r
CC=golang-dev
https://golang.org/cl/3650042
diff --git a/src/Make.pkg b/src/Make.pkg
index 6aa5e29..420f610 100644
--- a/src/Make.pkg
+++ b/src/Make.pkg
@@ -37,8 +37,8 @@
# must be done here so they apply to the main rules.
ifdef CGOFILES
GOFILES+=$(patsubst %.go,%.cgo1.go,$(CGOFILES)) _cgo_gotypes.go
-GCC_OFILES=$(patsubst %.go,%.cgo2.o,$(CGOFILES))
-OFILES+=_cgo_defun.$O _cgo_import.$O $(GCC_OFILES)
+CGO_OFILES+=$(patsubst %.go,%.cgo2.o,$(CGOFILES)) _cgo_export.o
+OFILES+=_cgo_defun.$O _cgo_import.$O $(CGO_OFILES)
endif
PREREQ+=$(patsubst %,%.make,$(DEPS))
@@ -111,8 +111,10 @@
# x.cgo2.c - C implementations compiled with gcc to create a dynamic library
#
+ifdef CGOFILES
_cgo_defun.c: $(CGOFILES)
CGOPKGPATH=$(dir) cgo -- $(CGO_CFLAGS) $(CGOFILES)
+endif
# Ugly but necessary
_cgo_gotypes.go _cgo_export.c _cgo_export.h: _cgo_defun.c
@@ -122,24 +124,25 @@
@true
# Compile rules for gcc source files.
-%.cgo2.o: %.cgo2.c
- $(HOST_CC) $(_CGO_CFLAGS_$(GOARCH)) -g -fPIC -O2 -o $@ -c $(CGO_CFLAGS) $*.cgo2.c
-
-_cgo_export.o: _cgo_export.c _cgo_export.h
- $(HOST_CC) $(_CGO_CFLAGS_$(GOARCH)) -g -fPIC -O2 -o $@ -c $(CGO_CFLAGS) _cgo_export.c
+%.o: %.c
+ $(HOST_CC) $(_CGO_CFLAGS_$(GOARCH)) -g -fPIC -O2 -o $@ -c $(CGO_CFLAGS) $*.c
# To find out which symbols are needed from external libraries
# and which libraries are needed, we build a simple a.out that
# links all the objects we just created and then use cgo -dynimport
# to inspect it. That is, we make gcc tell us which dynamic symbols
# and libraries are involved, instead of duplicating gcc's logic ourselves.
-_cgo_main.c:
+# After main we have to define all the symbols that will be provided
+# by Go code. That's crosscall2 and any exported symbols.
+_cgo_main.c: _cgo_defun.c
echo 'int main() { return 0; }' >$@
+ echo 'int crosscall2;' >>$@
+ awk -F'(' '/^_cgoexp_/ {print "int " $$1 ";"}' _cgo_defun.c >>$@
_cgo_main.o: _cgo_main.c
$(HOST_CC) $(_CGO_CFLAGS_$(GOARCH)) -g -fPIC -O2 -o $@ -c $(CGO_CFLAGS) _cgo_main.c
-_cgo1_.o: _cgo_main.o $(GCC_OFILES)
+_cgo1_.o: _cgo_main.o $(CGO_OFILES)
$(HOST_CC) $(_CGO_CFLAGS_$(GOARCH)) -g -fPIC -O2 -o $@ $^ $(CGO_LDFLAGS)
_cgo_import.c: _cgo1_.o
