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| -rw-r--r-- | CODING_STANDARDS.md | 55 |
1 files changed, 51 insertions, 4 deletions
diff --git a/CODING_STANDARDS.md b/CODING_STANDARDS.md index 22c1aca5dac..a35ce57d45c 100644 --- a/CODING_STANDARDS.md +++ b/CODING_STANDARDS.md @@ -1,6 +1,8 @@ # Coding Standards This is a working document outlining the coding standard for the general MariaDB codebase. +The document can be found in the 11.0 and newer trees in the root directory as "CODING_STANDARDS.md" + It does not cover the coding standards for individual plugins, these should have their own coding standards documentation. ## Using Git with the MariaDB codebase @@ -11,7 +13,7 @@ Git commit messages must conform to the 50/72 rule. This is a de facto git standard which is automatically enforced by some editors. This means: -* 50 characters max for the first (description) line. +* 50 characters max for the first (description) line (see exception later) * A blank line. * 72 characters max for every subsequent line. @@ -26,7 +28,9 @@ the relative motion of conductors and fluxes, it’s produced by the modial interaction of magneto-reluctance and capacitive diractance. ``` -The commit messages are typically rendered in Markdown format, so markdown formatting is permitted for the message body. +The only explicitly allowed exception to the 50-72 rules is that if the first line can be MDEV-###### title', even if the title would make the line longer than 50 characters. + +The commit messages are typically rendered in [Markdown format](https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax), so markdown formatting is permitted for the message body. ### Branch handling @@ -68,11 +72,13 @@ finalthing(); #### Switch / Case statements For switch / case statements the `case` needs to be inline with the `switch`. +Preferably switch (expr) should be followed by '{' on the same line to +make the lineup of 'case:' nice: + For example: ```cpp -switch(level) -{ +switch(level) { case ERROR: sql_print_error("Error: %s", message.c_ptr_safe()); break; @@ -125,6 +131,30 @@ The code need to be able to compile on multiple platforms using different compil ### Line lengths Lines should be no more than 80 characters. +The reason for this is that it makes it easier to have multiple editor +windows open side by side and still keep code readable without line +wraps. + +When breaking long lines: +- use '()' to group expressions so that the editor can automatically help + you with the indentation. +- When breaking expressions, leave the operator (+,- etc) last on the previous + line. + +```cpp +rows= tab->table->file->multi_range_read_info(tab->ref.key, 10, 20, tab->ref.key_parts, &bufsz, &flags, &cost); +-> +rows= tab->table->file->multi_range_read_info(tab->ref.key, 10, 20, + tab->ref.key_parts, &bufsz, + &flags, &cost); +``` + +```cpp +tmp= aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa+bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb; +-> +tmp= (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa+ + bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb); +``` ### Comments @@ -162,6 +192,8 @@ a = 1; // Incorrect for the server code, // ok for Storage Engines if they use it (aka Connect) ``` +The above makes it easy to use 'grep' to find all assignments to a variable. + Please do not write conditions like this: ```cpp @@ -176,6 +208,21 @@ if (*error_code == 0) if (!*error_code) ``` +Only use one-character variables (i,j,k...) in short loops. For anything else +use descriptive names! + +### Variable declarations + +Variables should be declared at the start of it's context (start of function, inside the 'if' statement. + +The benefits of this: +- Code lines gets shorter +- It is easier to see the stack space used by a function. +- It is easer to find the declaration of the variable. +- If one has to add an 'if (error) goto end' construct, one can do + that without having to move variable declarations around. + + ### Constant integers Constant integers that are used to define elements such as buffer sizes should be defined rather than used directly. |