[MacPorts] #71632: boost176 @1.76.0_12 does not build on PPC Mac OS X 10.4.11, Tiger, because "command execution failed"?

[MacPorts]

#71632: boost176 @1.76.0_12 does not build on PPC Mac OS X 10.4.11, Tiger, because
"command execution failed"?
------------------------+-----------------------
  Reporter:  ballapete  |      Owner:  (none)
      Type:  defect     |     Status:  new
  Priority:  Normal     |  Milestone:
 Component:  ports      |    Version:  2.10.5
Resolution:             |   Keywords:  tiger ppc
      Port:  boost176   |
------------------------+-----------------------

Comment (by kencu):

 ChatGPT's take:

 {{{
 The error in your build log indicates a conflict with the isdigit
 function. The issue arises because isdigit is already defined in the
 standard C library (<ctype.h> or <cwctype>), causing a naming conflict
 with your custom isdigit implementation in
 libs/locale/src/shared/mo_lambda.cpp.

 Here's a breakdown of the issues and potential solutions:

 Problem Explanation
 Conflict with Standard Library Functionality:
 isdigit is a standard library function that determines if a character is a
 digit. Your code redefines isdigit, causing ambiguity during compilation.
 Scope and Declaration Issues:
 The compiler interprets calls to isdigit ambiguously since it cannot
 distinguish between the custom implementation and the standard library
 function.
 Compilation Errors:
 bool isdigit(char c) conflicts with the standard isdigit(int) function.
 Usage of isdigit(*ptr) attempts to pass a char to a function expecting a
 different type, exacerbating the issue.
 Solutions
 1. Rename Your Custom isdigit Function

 Rename the conflicting function to avoid the name clash:

 bool is_custom_digit(char c) {
     return '0' <= c && c <= '9';
 }
 Update all references in mo_lambda.cpp to use is_custom_digit instead of
 isdigit.

 2. Explicit Namespace Usage

 Wrap your custom isdigit function in a unique namespace to prevent
 conflicts:

 namespace custom {
     bool isdigit(char c) {
         return '0' <= c && c <= '9';
     }
 }
 Call it explicitly using custom::isdigit(*ptr).

 3. Include <ctype.h> or <cwctype> Before Your Code

 To ensure proper resolution of the standard library function, explicitly
 include the required headers:

 #include <ctype.h>
 Then, ensure your function does not interfere by renaming it or qualifying
 its usage.

 4. Use the Standard Library Function

 If your custom isdigit function performs the same operation as the
 standard library function, consider using the standard isdigit(int c)
 directly. Note that it expects an int and may require casting:

 if (isdigit(static_cast<unsigned char>(*ptr))) {
     int_value = strtol(text + pos, &tmp_ptr, 0);
     pos = tmp_ptr - text;
     next_token = NUM;
 }
 5. Guard Against Macro Conflicts

 If isdigit is being replaced by a macro in some headers, undefine it after
 inclusion:

 #include <ctype.h>
 #undef isdigit
 Action Plan
 Search for all usages of isdigit in mo_lambda.cpp.
 Apply one of the above solutions to resolve the naming conflict.
 Rebuild the project to ensure the issue is resolved.
 Would you like help implementing a specific solution or further
 clarification on any of the steps?
 }}}

-- 
Ticket URL: <https://trac.macports.org/ticket/71632#comment:4>
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