rmdir_leading() improvements #1135

alejandro-colomar · 2024-12-02T09:39:50Z

Constify the input, and move code out of the loop.

This introduces strprefix(), a string-handling API that I'll use soon for other purposes.

Revisions:

v2

Add const correctness. Now strprefix() is a const-generic macro that will return a pointer that is const-qualified iff the input string is const-qualified.

$ git range-diff master gh/rmdir_leading rmdir_leading 
1:  6bc6e17b ! 1:  68279715 lib/string/strcmp/: strprefix(): Add function
    @@ Metadata
     Author: Alejandro Colomar <[email protected]>
     
      ## Commit message ##
    -    lib/string/strcmp/: strprefix(): Add function
    +    lib/string/strcmp/: strprefix(): Add API
     
         Signed-off-by: Alejandro Colomar <[email protected]>
     
    @@ lib/string/strcmp/strprefix.c (new)
     +#include "string/strcmp/strprefix.h"
     +
     +
    -+extern inline char *strprefix(const char *s, const char *prefix);
    ++extern inline const char *strprefix_(const char *s, const char *prefix);
     
      ## lib/string/strcmp/strprefix.h (new) ##
     @@
    @@ lib/string/strcmp/strprefix.h (new)
     +#include <string.h>
     +
     +#include "attr.h"
    ++#include "cast.h"
    ++
    ++
    ++#define strprefix(s, prefix)                                          \
    ++(                                                                     \
    ++  _Generic(s,                                                   \
    ++          const char *:               strprefix_(s, p),         \
    ++          const void *:               strprefix_(s, p),         \
    ++          char *:  const_cast(char *, strprefix_(s, p)),        \
    ++          void *:  const_cast(char *, strprefix_(s, p))         \
    ++  )                                                             \
    ++)
     +
     +
     +ATTR_STRING(1)
     +ATTR_STRING(2)
    -+inline char *strprefix(const char *s, const char *prefix);
    ++inline const char *strprefix_(const char *s, const char *prefix);
     +
     +
     +/*
     + * Return NULL if s does not start with prefix.
     + * Return `s + strlen(prefix)` if s starts with prefix.
     + */
    -+inline char *
    -+strprefix(const char *s, const char *prefix)
    ++inline const char *
    ++strprefix_(const char *s, const char *prefix)
     +{
     +  if (strncmp(s, prefix, strlen(prefix)) != 0)
     +          return NULL;
     +
    -+  return (char *) s + strlen(prefix);
    ++  return s + strlen(prefix);
     +}
     +
     +
2:  5c5b69fd = 2:  8ba0d74a lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  293831c2 = 3:  4d073b01 lib/tcbfuncs.c: rmdir_leading(): Create string just once

v2b

Simplify intermediate diff.
wsfix

$ git range-diff master gh/rmdir_leading rmdir_leading 
1:  68279715 = 1:  68279715 lib/string/strcmp/: strprefix(): Add API
2:  8ba0d74a ! 2:  e3d3332c lib/tcbfuncs.c: rmdir_leading(): Constify input
    @@ lib/tcbfuncs.c: static shadowtcb_status unlink_suffs (const char *user)
     +
        while ((ind = strrchr (path, '/'))) {
                stpcpy(ind, "");
    --          if (asprintf (&dir, TCB_DIR "/%s", path) == -1) {
    +           if (asprintf (&dir, TCB_DIR "/%s", path) == -1) {
     -                  OUT_OF_MEMORY;
     -                  return SHADOWTCB_FAILURE;
    --          }
    -+          if (asprintf(&dir, TCB_DIR "/%s", path) == -1)
     +                  goto free_path;
    +           }
     +
                if (rmdir (dir) != 0) {
                        if (errno != ENOTEMPTY) {
3:  4d073b01 ! 3:  d6259969 lib/tcbfuncs.c: rmdir_leading(): Create string just once
    @@ lib/tcbfuncs.c: static shadowtcb_status unlink_suffs (const char *user)
     -  while ((ind = strrchr (path, '/'))) {
     +  while ((ind = strrchr(p, '/'))) {
                stpcpy(ind, "");
    --          if (asprintf(&dir, TCB_DIR "/%s", path) == -1)
    +-          if (asprintf (&dir, TCB_DIR "/%s", path) == -1) {
     -                  goto free_path;
    +-          }
      
     -          if (rmdir (dir) != 0) {
     +          if (rmdir(path) != 0) {
    @@ lib/tcbfuncs.c: static shadowtcb_status unlink_suffs (const char *user)
                                fprintf (shadow_logfd,
                                         _("%s: Cannot remove directory %s: %s\n"),
     -                                   shadow_progname, dir, strerror (errno));
    -+                                   shadow_progname, path, strerror (errno));
    ++                                   shadow_progname, path, strerror(errno));
                                ret = SHADOWTCB_FAILURE;
                        }
     -                  free (dir);

v3

tfix

$ git range-diff master gh/rmdir_leading rmdir_leading 
1:  68279715 ! 1:  f8deaed9 lib/string/strcmp/: strprefix(): Add API
    @@ lib/string/strcmp/strprefix.h (new)
     +#define strprefix(s, prefix)                                          \
     +(                                                                     \
     +  _Generic(s,                                                   \
    -+          const char *:               strprefix_(s, p),         \
    -+          const void *:               strprefix_(s, p),         \
    -+          char *:  const_cast(char *, strprefix_(s, p)),        \
    -+          void *:  const_cast(char *, strprefix_(s, p))         \
    ++          const char *:               strprefix_(s, prefix),    \
    ++          const void *:               strprefix_(s, prefix),    \
    ++          char *:  const_cast(char *, strprefix_(s, prefix)),   \
    ++          void *:  const_cast(char *, strprefix_(s, prefix))    \
     +  )                                                             \
     +)
     +
2:  e3d3332c = 2:  3db55209 lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  d6259969 = 3:  b1f60988 lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4

Reduce repetition

$ git range-diff master gh/rmdir_leading rmdir_leading 
1:  f8deaed9 ! 1:  ec7ba07c lib/string/strcmp/: strprefix(): Add API
    @@ lib/string/strcmp/strprefix.h (new)
     +
     +
     +#define strprefix(s, prefix)                                          \
    -+(                                                                     \
    ++({                                                                    \
    ++  const char  *p_;                                              \
    ++                                                                      \
    ++  p_ = strprefix_(s, prefix);                                   \
    ++                                                                      \
     +  _Generic(s,                                                   \
    -+          const char *:               strprefix_(s, prefix),    \
    -+          const void *:               strprefix_(s, prefix),    \
    -+          char *:  const_cast(char *, strprefix_(s, prefix)),   \
    -+          void *:  const_cast(char *, strprefix_(s, prefix))    \
    -+  )                                                             \
    -+)
    ++          const char *:                     p_,                 \
    ++          const void *:                     p_,                 \
    ++          char *:        const_cast(char *, p_),                \
    ++          void *:        const_cast(char *, p_)                 \
    ++  );
    ++})
     +
     +
     +ATTR_STRING(1)
2:  3db55209 = 2:  d889874b lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  b1f60988 = 3:  7cb4a91b lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4b

Add missing \

$ git range-diff master gh/rmdir_leading rmdir_leading 
1:  ec7ba07c ! 1:  a165d0c7 lib/string/strcmp/: strprefix(): Add API
    @@ lib/string/strcmp/strprefix.h (new)
     +          const void *:                     p_,                 \
     +          char *:        const_cast(char *, p_),                \
     +          void *:        const_cast(char *, p_)                 \
    -+  );
    ++  );                                                            \
     +})
     +
     +
2:  d889874b = 2:  d7ce4268 lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  7cb4a91b = 3:  05c4ffb4 lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4c

Rebase

$ git range-diff master..gh/rmdir_leading shadow/master..rmdir_leading 
1:  a165d0c7 = 1:  064e7a50 lib/string/strcmp/: strprefix(): Add API
2:  d7ce4268 = 2:  e134d63a lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  05c4ffb4 = 3:  4cd5dedc lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4d

Rebase

$ git range-diff master..gh/rmdir_leading shadow/master..rmdir_leading 
1:  064e7a50 = 1:  024ee8e0 lib/string/strcmp/: strprefix(): Add API
2:  e134d63a = 2:  caf89f8e lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  4cd5dedc = 3:  04d59a59 lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4e

Rebase

$ git range-diff master..gh/rmdir_leading shadow/master..rmdir_leading 
1:  024ee8e0 = 1:  1f0a9146 lib/string/strcmp/: strprefix(): Add API
2:  caf89f8e = 2:  0bfe0cfa lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  04d59a59 = 3:  bd50dbcc lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4f

Rebase

$ git range-diff master..gh/rmdir_leading shadow/master..rmdir_leading 
1:  1f0a9146 = 1:  962d9a6e lib/string/strcmp/: strprefix(): Add API
2:  0bfe0cfa = 2:  52770ba2 lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  bd50dbcc = 3:  4c491145 lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4g

Rebase

$ git range-diff alx/master..gh/rmdir_leading master..rmdir_leading 
1:  962d9a6e = 1:  5e5ec22c lib/string/strcmp/: strprefix(): Add API
2:  52770ba2 = 2:  88bf3c7a lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  4c491145 = 3:  52b40efd lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4h

Rebase

$ git range-diff alx/master..gh/rmdir_leading master..rmdir_leading 
1:  5e5ec22c = 1:  51b7da6b lib/string/strcmp/: strprefix(): Add API
2:  88bf3c7a = 2:  b351c7b4 lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  52b40efd = 3:  200c2deb lib/tcbfuncs.c: rmdir_leading(): Create string just once

v4i

Rebase

$ git range-diff master..gh/rmdir_leading shadow/master..rmdir_leading 
1:  51b7da6b = 1:  ca1eded7 lib/string/strcmp/: strprefix(): Add API
2:  b351c7b4 = 2:  ecc493a6 lib/tcbfuncs.c: rmdir_leading(): Constify input
3:  200c2deb = 3:  ee0f6c2e lib/tcbfuncs.c: rmdir_leading(): Create string just once

alejandro-colomar · 2024-12-06T12:15:56Z

Queued after the release of 4.17.0.

Signed-off-by: Alejandro Colomar <[email protected]>

alejandro-colomar mentioned this pull request Dec 2, 2024

4.17 release plan #1122

Open

alejandro-colomar requested a review from hallyn December 2, 2024 12:24

alejandro-colomar force-pushed the rmdir_leading branch 8 times, most recently from 04d59a5 to bd50dbc Compare December 6, 2024 11:49

alejandro-colomar marked this pull request as draft December 6, 2024 12:16

alejandro-colomar force-pushed the rmdir_leading branch from bd50dbc to 4c49114 Compare December 17, 2024 23:20

alejandro-colomar marked this pull request as ready for review December 22, 2024 11:59

alejandro-colomar force-pushed the rmdir_leading branch from 4c49114 to 52b40ef Compare January 10, 2025 13:20

alejandro-colomar force-pushed the rmdir_leading branch from 52b40ef to 200c2de Compare January 18, 2025 22:29

alejandro-colomar added 3 commits January 24, 2025 16:03

lib/string/strcmp/: strprefix(): Add API

ca1eded

Signed-off-by: Alejandro Colomar <[email protected]>

lib/tcbfuncs.c: rmdir_leading(): Constify input

ecc493a

Signed-off-by: Alejandro Colomar <[email protected]>

lib/tcbfuncs.c: rmdir_leading(): Create string just once

ee0f6c2

Signed-off-by: Alejandro Colomar <[email protected]>

alejandro-colomar force-pushed the rmdir_leading branch from 200c2de to ee0f6c2 Compare January 24, 2025 15:04

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rmdir_leading() improvements #1135

rmdir_leading() improvements #1135

alejandro-colomar commented Dec 2, 2024 •

edited

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alejandro-colomar commented Dec 6, 2024

rmdir_leading() improvements #1135

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rmdir_leading() improvements #1135

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alejandro-colomar commented Dec 6, 2024

alejandro-colomar commented Dec 2, 2024 •

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