如何用Rust正则匹配字符串开头且排除特定结尾，定位未转换的%lld格式符？

Let's break down how to solve this common format specifier mismatch issue. The problem arises because int64_t can map to either long int or long long int depending on your platform—using %lld (which expects long long int) with an uncasted int64_t triggers that annoying -Wformat= warning. Here's how to find all such instances in VSCode using Rust-style regex (which VSCode's search engine uses):

Step 1: The Regex Pattern #

Use this regex in VSCode's search panel to target exactly the cases you want:

(printf|fprintf|sprintf|snprintf)\s*\([^)]*%lld[^)]*\,\s*(?!\(long long\))[^,)]+

What Each Part Does: #

• (printf|fprintf|sprintf|snprintf): Matches common formatting functions you might use (add/remove entries as needed for your codebase)
• \s*\(: Accounts for any whitespace between the function name and opening parenthesis
• [^)]*%lld[^)]*: Captures the portion of the function call up to the first comma, ensuring it contains the %lld specifier
• \,\s*: Matches the comma separating the format string from the first argument, plus any surrounding whitespace
• (?!\(long long\)): Negative lookahead—this ensures the argument that follows is NOT wrapped in (long long) casting
• [^,)]+: Matches the argument content until the next comma or closing parenthesis

Step 2: Use It in VSCode #

1. Open the global search panel with Ctrl+Shift+F (Windows/Linux) or Cmd+Shift+F (Mac)
2. Click the .* button to enable regex mode
3. Paste the regex pattern into the search bar
4. (Optional) Use the file filter to narrow results to .c/.cpp files if needed

This will highlight every instance where %lld is used with an argument that hasn't been cast to long long. For example:

• Matches (needs fixing):

  int64_t fixed_size_type;
  printf("Ambiguous replacement value: %lld", fixed_size_type);
  

• Does NOT match (already fixed):

  printf("Fixed replacement value: %lld", (long long)fixed_size_type);
  

Notes for Edge Cases #

• If your code uses nested function calls as arguments (e.g., printf("%lld", get_int64_value());), the regex will still catch it since the argument isn't casted
• For multi-argument calls (e.g., printf("%lld %lld", a, (long long)b);), it will correctly flag the uncasted first argument while ignoring the casted second one
• You might need to tweak the function list in the regex if your codebase uses less common formatting functions

内容的提问来源于stack exchange，提问作者Zak