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Re: [PATCH v2 2/4] compat/regex: include alloca.h before undef it

From
Danh Doan <congdanhqx@gmail.com>
Date
Apr 26, 2020, 00:54 UTC
Message-ID
<20200426005451.f7pyoiijgbk4hpsj@danh.dev>
In-Reply-To
<ffcaaf4f-a43f-2d20-b70d-dfb8b1d7c687@ramsayjones.plus.com>
On 2020-04-25 21:28:05+0100, Ramsay Jones <ramsay@ramsayjones.plus.com> wrote:
Show 22 quoted lines
> 
> 
> On 24/04/2020 23:34, Danh Doan wrote:
> [snip]
> 
> > OK, I've tried with my glibc box, it doesn't have that warning.
> > On musl, it warns:
> > 
> > 	$ make compat/regex/regex.sp
> > 	GIT_VERSION = 2.26.2
> > 	    * new build flags
> > 	    SP compat/regex/regex.c
> > 	/usr/include/alloca.h:14:9: warning: preprocessor token alloca redefined
> > 	compat/regex/regex.c:66:9: this was the original definition
> > 	compat/regex/regex_internal.c:925:1: error: symbol 're_string_context_at' redeclared with different type (originally declared at compat/regex/regex_internal.h:433) - different modifiers
> > 
> > 
> 
> OK, I had a quick look at the <alloca.h> header file on a glibc
> system (linux) and new-lib system (cygwin) and they both do
> (more or less) the same thing: first #undef alloca, and then
> if being compiled by gcc, define alloca(size) to be __builtin_alloca(size).

musl people don't do that. They just go ahead define it, if any other header file requires alloca, they will include alloca.h

> So, even if <alloca.h> is #included after regex.c:66, it wouldn't
> be a problem. Since I don't have access to a musl based system,
> I don't know what that system header is doing.
musl's alloca.h is available here:
https://git.musl-libc.org/cgit/musl/tree/include/alloca.h
> However, I said *even if* above, because I don't see why it is trying
> to #include <alloca.h> in the first place! ;-)
I looked into my system again. The inclusion chain is:
compat/regex/regex.c:77
`-> compat/regex/regex_internal.h:26
    `-> /usr/include/stdlib.h:138 [*1*]
[*1*]: https://git.musl-libc.org/cgit/musl/tree/include/stdlib.h#n137
I don't know why _GNU_SOURCE and/or _BSD_SOURCE is defined.
Show 6 quoted lines
>   $ make V=1 NO_REGEX=1 compat/regex/regex.sp
>   cgcc -no-compile -Werror -Wall -Wdeclaration-after-statement -Wformat-security -Wold-style-definition -Woverflow -Wpointer-arith -Wstrict-prototypes -Wunused -Wvla -DENABLE_SHA256 -Wextra -Wmissing-prototypes -Wno-empty-body -Wno-missing-field-initializers -Wno-sign-compare -Wno-unused-parameter  -g -O2 -Wall -I. -DHAVE_SYSINFO -DGIT_HOST_CPU="\"x86_64\"" -DHAVE_ALLOCA_H  -DUSE_CURL_FOR_IMAP_SEND -DSHA1_DC -DSHA1DC_NO_STANDARD_INCLUDES -DSHA1DC_INIT_SAFE_HASH_DEFAULT=0 -DSHA1DC_CUSTOM_INCLUDE_SHA1_C="\"cache.h\"" -DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C="\"git-compat-util.h\"" -DSHA256_BLK  -DHAVE_PATHS_H -DHAVE_DEV_TTY -DHAVE_CLOCK_GETTIME -DHAVE_CLOCK_MONOTONIC -DHAVE_GETDELIM '-DPROCFS_EXECUTABLE_PATH="/proc/self/exe"'  -DFREAD_READS_DIRECTORIES -DNO_STRLCPY -Icompat/regex -DSHELL_PATH='"/bin/sh"' -DPAGER_ENV='"LESS=FRX LV=-c"' -DGAWK -DNO_MBSUPPORT \
>   	  compat/regex/regex.c
>   $ 
>   
> ... is not being set on the command-line.
Here's the invocation of cc and cgcc:
	$ make V=1  compat/regex/regex.o
	cc -o compat/regex/regex.o -c -MF compat/regex/.depend/regex.o.d -MQ compat/regex/regex.o -MMD -MP -Werror -Wall -Wdeclaration-after-statement -Wformat-security -Wold-style-definition -Woverflow -Wpointer-arith -Wstrict-prototypes -Wunused -Wvla -DENABLE_SHA256 -Wextra -Wmissing-prototypes -Wno-empty-body -Wno-missing-field-initializers -Wno-sign-compare -Wno-unused-parameter  -g -O2 -Wall -I. -DHAVE_SYSINFO -DGIT_HOST_CPU="\"x86_64\"" -DUSE_LIBPCRE2 -DHAVE_ALLOCA_H -DUSE_CURL_FOR_IMAP_SEND -DICONV_OMITS_BOM -DSHA1_DC -DSHA1DC_NO_STANDARD_INCLUDES -DSHA1DC_INIT_SAFE_HASH_DEFAULT=0 -DSHA1DC_CUSTOM_INCLUDE_SHA1_C="\"cache.h\"" -DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C="\"git-compat-util.h\"" -DSHA256_BLK  -DHAVE_PATHS_H -DHAVE_DEV_TTY -DHAVE_CLOCK_GETTIME -DHAVE_CLOCK_MONOTONIC -DHAVE_GETDELIM '-DPROCFS_EXECUTABLE_PATH="/proc/self/exe"' -DFREAD_READS_DIRECTORIES -DNO_STRLCPY -Icompat/regex -DSHELL_PATH='"/bin/sh"' -DPAGER_ENV='"LESS=FRX LV=-c"' -DGAWK -DNO_MBSUPPORT compat/regex/regex.c
	$ make V=1  compat/regex/regex.sp
	cgcc -no-compile -Werror -Wall -Wdeclaration-after-statement -Wformat-security -Wold-style-definition -Woverflow -Wpointer-arith -Wstrict-prototypes -Wunused -Wvla -DENABLE_SHA256 -Wextra -Wmissing-prototypes -Wno-empty-body -Wno-missing-field-initializers -Wno-sign-compare -Wno-unused-parameter  -g -O2 -Wall -I. -DHAVE_SYSINFO -DGIT_HOST_CPU="\"x86_64\"" -DUSE_LIBPCRE2 -DHAVE_ALLOCA_H -DUSE_CURL_FOR_IMAP_SEND -DICONV_OMITS_BOM -DSHA1_DC -DSHA1DC_NO_STANDARD_INCLUDES -DSHA1DC_INIT_SAFE_HASH_DEFAULT=0 -DSHA1DC_CUSTOM_INCLUDE_SHA1_C="\"cache.h\"" -DSHA1DC_CUSTOM_INCLUDE_UBC_CHECK_C="\"git-compat-util.h\"" -DSHA256_BLK  -DHAVE_PATHS_H -DHAVE_DEV_TTY -DHAVE_CLOCK_GETTIME -DHAVE_CLOCK_MONOTONIC -DHAVE_GETDELIM '-DPROCFS_EXECUTABLE_PATH="/proc/self/exe"' -DFREAD_READS_DIRECTORIES -DNO_STRLCPY -Icompat/regex -DSHELL_PATH='"/bin/sh"' -DPAGER_ENV='"LESS=FRX LV=-c"' -DGAWK -DNO_MBSUPPORT \
	          compat/regex/regex.c
> Hmm, do you have this set in config.mak, config.mak.autogen, or some other
> source? puzzled! ;-)

I don't have `config.make.autogen`, Here is config.mak

	$ cat config.mak
	USE_ASCIIDOCTOR=Yes
	DEVELOPER=1
	DEFAULT_TEST_TARGET=prove
	prefix = /home/danh/.local
	USE_LIBPCRE2=YesPlease
	ICONV_OMITS_BOM=Yes
	NO_REGEX=YesPlease
> BTW, why are you compiling with NO_REGEX set anyway?
Because I use musl-libc, and musl-libc doesn't have StartEnd
-- 
Danh
Previous: Ramsay JonesNext: Danh Doan
Message 28 of 51 in “fix make sparse warning”
  1. 0/4 fix make sparse warningĐoàn Trần Công Danh, Apr 23, 2020
  2. 1/4 C: s/0/NULL/ for pointer typeĐoàn Trần Công Danh, Apr 23, 2020
  3. Ramsay JonesApr 24, 2020
  4. Junio C HamanoApr 24, 2020
  5. Danh DoanApr 24, 2020
  6. Junio C HamanoApr 24, 2020
  7. Luc Van OostenryckMay 14, 2020
  8. 2/4 compat/regex: silence `make sparse` warningĐoàn Trần Công Danh, Apr 23, 2020
  9. Ramsay JonesApr 24, 2020
  10. Danh DoanApr 24, 2020
  11. 3/4 graph.c: limit linkage of internal variableĐoàn Trần Công Danh, Apr 23, 2020
  12. Ramsay JonesApr 24, 2020
  13. 4/4 progress.c: silence cgcc suggestion about internal linkageĐoàn Trần Công Danh, Apr 23, 2020
  14. Ramsay JonesApr 24, 2020
  15. Jeff KingApr 24, 2020
  16. 5/4 fmt-merge-msg.c: fix `make sparse` on nextĐoàn Trần Công Danh, Apr 23, 2020
  17. Ramsay JonesApr 23, 2020
  18. Danh DoanApr 23, 2020
  19. Ramsay JonesApr 24, 2020
  20. 0/4 Fix Sparse WarningĐoàn Trần Công Danh, Apr 24, 2020
  21. 1/4 test-parse-pathspec-file.c: s/0/NULL/ for pointer typeĐoàn Trần Công Danh, Apr 24, 2020
  22. 2/4 compat/regex: include alloca.h before undef itĐoàn Trần Công Danh, Apr 24, 2020
  23. Ramsay JonesApr 24, 2020
  24. Danh DoanApr 24, 2020
  25. Ramsay JonesApr 24, 2020
  26. Danh DoanApr 24, 2020
  27. Ramsay JonesApr 25, 2020
  28. Danh DoanApr 26, 2020
  29. Danh DoanApr 26, 2020
  30. Ramsay JonesApr 26, 2020
  31. Ramsay JonesApr 26, 2020
  32. Junio C HamanoApr 26, 2020
  33. Danh DoanApr 27, 2020
  34. Ramsay JonesApr 27, 2020
  35. Danh DoanApr 27, 2020
  36. Ramsay JonesApr 27, 2020
  37. 3/4 graph.c: limit linkage of internal variableĐoàn Trần Công Danh, Apr 24, 2020
  38. 4/4 progress.c: silence cgcc suggestion about internal linkageĐoàn Trần Công Danh, Apr 24, 2020
  39. Ramsay JonesApr 24, 2020
  40. Johannes SchindelinApr 25, 2020
  41. Danh DoanApr 26, 2020
  42. Ramsay JonesApr 26, 2020
  43. Johannes SchindelinMay 1, 2020
  44. 0/4 Partial fix `make sparse`Đoàn Trần Công Danh, Apr 27, 2020
  45. 1/4 test-parse-pathspec-file.c: s/0/NULL/ for pointer typeĐoàn Trần Công Danh, Apr 27, 2020
  46. 2/4 compat/regex: move stdlib.h up in inclusion chainĐoàn Trần Công Danh, Apr 27, 2020
  47. Ramsay JonesApr 27, 2020
  48. 3/4 graph.c: limit linkage of internal variableĐoàn Trần Công Danh, Apr 27, 2020
  49. 4/4 progress.c: silence cgcc suggestion about internal linkageĐoàn Trần Công Danh, Apr 27, 2020
  50. Johannes SchindelinMay 1, 2020
  51. Ramsay JonesApr 27, 2020

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