lib/string/strchr/: strnul(), streq(), strcaseeq(): Simplify implementations

[alejandro-colomar]

Cc: @kees, @bhaible

This avoids an __auto_type local variable, and a GNU statement expression.

---

Revisions:

v1b

• Rebase

$ git rd 
1:  35250c4b = 1:  f27656af lib/string/strchr/: strnul(): Simplify implementation

v2

• Also simplify streq(3).

$ git rd 
1:  f27656af = 1:  f27656af lib/string/strchr/: strnul(): Simplify implementation
-:  -------- > 2:  ff33ecae lib/string/strcmp/: streq(): Simplify implementation

v3

• Also simplify strcaseeq().

$ git rd 
1:  f27656af = 1:  f27656af lib/string/strchr/: strnul(): Simplify implementation
2:  ff33ecae ! 2:  3ecdb6a1 lib/string/strcmp/: streq(): Simplify implementation
    @@ Metadata
     Author: Alejandro Colomar <[email protected]>
     
      ## Commit message ##
    -    lib/string/strcmp/: streq(): Simplify implementation
    +    lib/string/strcmp/: str{,case}eq(): Simplify implementation
     
         A one-liner macro is simpler, and works just fine.
     
    @@ Commit message
     
         Signed-off-by: Alejandro Colomar <[email protected]>
     
    + ## lib/string/strcmp/strcaseeq.c ##
    +@@
    +-// SPDX-FileCopyrightText: 2024-2025, Alejandro Colomar <[email protected]>
    ++// SPDX-FileCopyrightText: 2024-2026, Alejandro Colomar <[email protected]>
    + // SPDX-License-Identifier: BSD-3-Clause
    + 
    + 
    + #include "config.h"
    + 
    +-#include <stdbool.h>
    +-
    + #include "string/strcmp/strcaseeq.h"
    +-
    +-
    +-extern inline bool strcaseeq(const char *s1, const char *s2);
    +
    + ## lib/string/strcmp/strcaseeq.h ##
    +@@
    +-// SPDX-FileCopyrightText: 2024-2025, Alejandro Colomar <[email protected]>
    ++// SPDX-FileCopyrightText: 2024-2026, Alejandro Colomar <[email protected]>
    + // SPDX-License-Identifier: BSD-3-Clause
    + 
    + 
    +@@
    + 
    + #include "config.h"
    + 
    +-#include <stdbool.h>
    + #include <strings.h>
    + 
    +-#include "attr.h"
    + 
    +-
    +-ATTR_STRING(1) ATTR_STRING(2)
    +-inline bool strcaseeq(const char *s1, const char *s2);
    +-
    +-
    +-// strings case-insensitive equal
    +-// streq(), but case-insensitive.
    +-inline bool
    +-strcaseeq(const char *s1, const char *s2)
    +-{
    +-  return strcasecmp(s1, s2) == 0;
    +-}
    ++// strcaseeq - strings case-insensitive equal
    ++#define strcaseeq(s1, s2)  (!strcasecmp(s1, s2))
    + 
    + 
    + #endif  // include guard
    +
      ## lib/string/strcmp/streq.c ##
     @@
     -// SPDX-FileCopyrightText: 2024, Alejandro Colomar <[email protected]>

v3b

• Reviewed-by: @kees (I interpret this from his message and approval)

$ git rd 
1:  f27656af ! 1:  cd359d6c lib/string/strchr/: strnul(): Simplify implementation
    @@ Commit message
         This avoids an __auto_type local variable, and a GNU statement
         expression.
     
    +    Reviewed-by: Kees Cook <[email protected]>
         Signed-off-by: Alejandro Colomar <[email protected]>
     
      ## lib/string/strchr/strnul.h ##
2:  3ecdb6a1 ! 2:  a861778f lib/string/strcmp/: str{,case}eq(): Simplify implementation
    @@ Commit message
         detail; we could cast it to bool, but we don't really need that, so keep
         it simple.
     
    +    Reviewed-by: Kees Cook <[email protected]>
         Signed-off-by: Alejandro Colomar <[email protected]>
     
      ## lib/string/strcmp/strcaseeq.c ##

[kees]

Looks like a nice cleanup to me.

[alejandro-colomar]

Looks like a nice cleanup to me.

@kees

Thanks! Should I interpret that as an Acked-by or Reviewed-by?

[alejandro-colomar]

@hallyn , would you mind merging? This is approved by @kees .