From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 9134D385E02F for ; Fri, 9 Apr 2021 15:58:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 9134D385E02F Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tdevries@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id AA28BAE6D; Fri, 9 Apr 2021 15:58:35 +0000 (UTC) Subject: Re: [PATCH] Add -p native and -e native To: Michael Matz , Mark Wielaard Cc: dwz@sourceware.org, jakub@redhat.com References: <20210409092439.GA17210@delia> <20210409094231.GD30119@wildebeest.org> From: Tom de Vries Message-ID: <47b99234-cfe3-86e3-b359-d3ee480e1399@suse.de> Date: Fri, 9 Apr 2021 17:58:34 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------72D449DFE5F2F43397CB7877" Content-Language: en-US X-Spam-Status: No, score=-12.2 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, NICE_REPLY_A, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: dwz@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Dwz mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 Apr 2021 15:58:38 -0000 This is a multi-part message in MIME format. --------------72D449DFE5F2F43397CB7877 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit On 4/9/21 3:03 PM, Michael Matz wrote: > Hello, > > On Fri, 9 Apr 2021, Mark Wielaard wrote: > >>> We determine native as the result of: >>> - -p: sizeof (void *) >>> - -e: __BYTE_ORDER__ >>> when compiling using CC without CFLAGS, such that if we build dwz with -m32 on >>> x86_64 like so: >>> ... >>> $ make CFLAGS="-m32 -O2 -g" LDFLAGS=-m32 >>> ... >>> and we have: >>> ... >>> $ file ./dwz >>> dwz: ELF 32-bit LSB executable, Intel 80386 >>> ... >>> we still have: >>> ... >>> $ ./dwz -? >>> ... >>> -p, --multifile-pointer-size >>> Set pointer size of multifile, in number of bytes. >>> Native pointer size is 8. >>> Default value: auto. >>> ... >>> >>> Any comments? >> >> Except for this narrow multilib case, doesn't this actually make it >> impossible to do a cross-arch build? > > For cross the term "native" doesn't make sense, so it would seem valid to > simply not support that setting with a cross (not multilib) dwz. I.e. if > ./native can't be executed assume cross-ness and don't support -p native. > I've tried yet another variant. Instead of trying to generate an executable and execute it, we generate an object and test properties using readelf. This should no longer have the cross-build problem. WDYT? Thanks, - Tom --------------72D449DFE5F2F43397CB7877 Content-Type: text/x-patch; charset=UTF-8; name="0001-Add-p-native-and-e-native.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="0001-Add-p-native-and-e-native.patch" Add -p native and -e native Add option parameter native to options -p and -e. We determine native as the result of readelf output on an object generated by using CC without CFLAGS, such that if we build dwz with -m32 on x86_64 like so: ... $ make CFLAGS="-m32 -O2 -g" LDFLAGS=-m32 ... and we have: ... $ file ./dwz dwz: ELF 32-bit LSB executable, Intel 80386 ... we still have: ... $ ./dwz -? ... -p, --multifile-pointer-size Set pointer size of multifile, in number of bytes. Native pointer size is 8. Default value: auto. ... 2021-04-09 Tom de Vries * Makefile (args.o): Add pattern rule. (native.o): New target. (clean): Update. * util.h (XSTR, STR): New macro. * args.c (NATIVE_ENDIAN_STRING): New macro. (dwz_multi_file_options_help, usage): Mention -p native and -e native. (parse_args): Handle -p native and -e native. * dwz.1 (-p, -e): Mention native. * native.c: New file. --- Makefile | 17 ++++++++++++++++- args.c | 41 ++++++++++++++++++++++++++++++++++++----- dwz.1 | 10 ++++++---- native.c | 5 +++++ util.h | 3 +++ 5 files changed, 66 insertions(+), 10 deletions(-) diff --git a/Makefile b/Makefile index 02da6c4..5f0b2f0 100644 --- a/Makefile +++ b/Makefile @@ -20,13 +20,28 @@ OBJECTS = args.o dwz.o hashtab.o sha1.o dwarfnames.o LIBS=-lelf dwz: $(OBJECTS) $(CC) $(LDFLAGS) -o $@ $^ $(LIBS) +args.o: native.o +NATIVE_ENDIAN=$(shell readelf -h native.o \ + | grep Data \ + | sed 's/.*, //;s/ endian//') +NATIVE_POINTER_SIZE=$(shell readelf -wi native.o \ + | grep "Pointer Size:" \ + | sed 's/.*: *//') +args.o: %.o: %.c + $(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $< \ + -DNATIVE_ENDIAN=$(NATIVE_ENDIAN) \ + -DNATIVE_POINTER_SIZE=$(NATIVE_POINTER_SIZE) +%.o: %.c + $(CC) $(CPPFLAGS) $(CFLAGS) -c -o $@ $< install: dwz install -D dwz $(DESTDIR)$(bindir)/dwz install -D -m 644 $(srcdir)/dwz.1 $(DESTDIR)$(mandir)/man1/dwz.1 clean: rm -f $(OBJECTS) *~ core* dwz $(TEST_EXECS) $(DWZ_TEST_OBJECTS) \ - dwz.log dwz.sum + dwz.log dwz.sum native.o rm -Rf testsuite-bin tmp.* +native.o: native.c + $(CC) -o $@ $< -c -g PWD:=$(shell pwd -P) diff --git a/args.c b/args.c index cb11f25..e374c26 100644 --- a/args.c +++ b/args.c @@ -220,6 +220,15 @@ static struct option_help dwz_single_file_options_help[] = "Place the output in OUTFILE." } }; +#if NATIVE_ENDIAN == little +#define NATIVE_ENDIAN_VAL __ORDER_LITTLE_ENDIAN__ +#elif NATIVE_ENDIAN == big +#define NATIVE_ENDIAN_VAL __ORDER_LITTLE_ENDIAN__ +#else +#define NATIVE_ENDIAN not available +#define NATIVE_ENDIAN_VAL 0 +#endif + /* Describe mult-file command line options. */ static struct option_help dwz_multi_file_options_help[] = { @@ -236,10 +245,12 @@ static struct option_help dwz_multi_file_options_help[] = { "5", "dwarf-5", NULL, NULL, "Emit DWARF 5 standardized supplementary object files instead of" " GNU extension .debug_altlink." }, - { "p", "multifile-pointer-size", "", "auto", - "Set pointer size of multifile, in number of bytes." }, - { "e", "multifile-endian", "", "auto", - "Set endianity of multifile." }, + { "p", "multifile-pointer-size", "", "auto", + "Set pointer size of multifile, in number of bytes." + " Native pointer size is " XSTR (NATIVE_POINTER_SIZE) "." }, + { "e", "multifile-endian", "", "auto", + "Set endianity of multifile." + " Native endianity is " XSTR (NATIVE_ENDIAN) "." }, { "j", "jobs", "", "number of processors / 2", "Process files in parallel." } }; @@ -385,7 +396,7 @@ usage (int failing) FILE *stream = failing ? stderr : stdout; const char *header_lines[] = { "dwz [common options] [-h] [-m COMMONFILE] [-M NAME | -r] [-5]", - " [-p ] [-e ] [-j N] [FILES]", + " [-p ] [-e ] [-j N] [FILES]", "dwz [common options] -o OUTFILE FILE", "dwz [ -v | -? ]" }; @@ -650,6 +661,11 @@ parse_args (int argc, char *argv[], bool *hardlink, const char **outfile) multifile_force_ptr_size = 0; break; } + if (strcmp (optarg, "native") == 0) + { + multifile_force_ptr_size = NATIVE_POINTER_SIZE; + break; + } l = strtoul (optarg, &end, 0); if (*end != '\0' || optarg == end || (unsigned int) l != l) error (1, 0, "invalid argument -l %s", optarg); @@ -662,6 +678,21 @@ parse_args (int argc, char *argv[], bool *hardlink, const char **outfile) multifile_force_endian = 0; break; } + if (strcmp (optarg, "native") == 0) + { + switch (NATIVE_ENDIAN_VAL) + { + case __ORDER_LITTLE_ENDIAN__: + multifile_force_endian = ELFDATA2LSB; + break; + case __ORDER_BIG_ENDIAN__: + multifile_force_endian = ELFDATA2MSB; + break; + default: + error (1, 0, "Cannot determine native endian"); + } + break; + } if (strlen (optarg) != 1) error (1, 0, "invalid argument -l %s", optarg); switch (optarg[0]) diff --git a/dwz.1 b/dwz.1 index 6fec6ed..1cff329 100644 --- a/dwz.1 +++ b/dwz.1 @@ -77,13 +77,15 @@ the executable or shared library to the file named in the argument of the \fB-m\fR option. Either \fB-M\fR or \fB-r\fR option can be specified, but not both. .TP -.B \-p N \-\-multifile-pointer-size +.B \-p N \-\-multifile-pointer-size Specify the pointer size of the multifile, in bytes. If auto, use the -pointer size of the files, provided they match. +pointer size of the files, provided they match. If native, use native pointer +size, as specified in the help message. .TP -.B \-p \-\-multifile-endian +.B \-p \-\-multifile-endian Specify the endianity of the multifile. If auto, use the endianity of -the files, provided they match. +the files, provided they match. If native, use native endianity, as specified +in the help message. .TP .B \-q \-\-quiet Silence up some of the most common messages. diff --git a/native.c b/native.c new file mode 100644 index 0000000..398ec67 --- /dev/null +++ b/native.c @@ -0,0 +1,5 @@ +int +main (void) +{ + return 0; +} diff --git a/util.h b/util.h index 7caac06..d542942 100644 --- a/util.h +++ b/util.h @@ -25,6 +25,9 @@ #define MAX(A, B) ((A) > (B) ? (A) : (B)) #define MIN(A, B) ((A) < (B) ? (A) : (B)) +#define XSTR(s) STR(s) +#define STR(s) #s + #ifndef USE_GNUC #ifdef __GNUC__ #define USE_GNUC 1 --------------72D449DFE5F2F43397CB7877--