view contrib/chg/Makefile @ 45095:8e04607023e5

procutil: ensure that procutil.std{out,err}.write() writes all bytes

Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.

When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).

Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.

TARGET = chg
SRCS = chg.c hgclient.c procutil.c util.c
OBJS = $(SRCS:.c=.o)

CFLAGS ?= -O2 -Wall -Wextra -pedantic -g
CPPFLAGS ?= -D_FORTIFY_SOURCE=2 -D_GNU_SOURCE
override CFLAGS += -std=gnu99
ifdef HGPATH
override CPPFLAGS += -DHGPATH=\"$(HGPATH)\"
endif

DESTDIR =
PREFIX = /usr/local
MANDIR = $(PREFIX)/share/man/man1

.PHONY: all
all: $(TARGET)

$(TARGET): $(OBJS)
	$(CC) $(LDFLAGS) -o $@ $(OBJS)

chg.o: hgclient.h procutil.h util.h
hgclient.o: hgclient.h procutil.h util.h
procutil.o: procutil.h util.h
util.o: util.h

.PHONY: install
install: $(TARGET)
	install -d "$(DESTDIR)$(PREFIX)"/bin
	install -m 755 "$(TARGET)" "$(DESTDIR)$(PREFIX)"/bin
	install -d "$(DESTDIR)$(MANDIR)"
	install -m 644 chg.1 "$(DESTDIR)$(MANDIR)"

.PHONY: clean
clean:
	$(RM) $(OBJS)

.PHONY: distclean
distclean:
	$(RM) $(OBJS) $(TARGET)