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diff --git a/src/STYLE.md b/src/STYLE.md deleted file mode 100644 index d51de78..0000000 --- a/src/STYLE.md +++ /dev/null @@ -1,197 +0,0 @@ -# BoringSSL Style Guide - -BoringSSL usually follows the -[Google C++ style guide](https://google-styleguide.googlecode.com/svn/trunk/cppguide.html). -The rest of this document describes differences and clarifications on -top of the base guide. - - -## Legacy code - -As a derivative of OpenSSL, BoringSSL contains a lot of legacy code that -does not follow this style guide. Particularly where public API is -concerned, balance consistency within a module with the benefits of a -given rule. Module-wide deviations on naming should be respected while -integer and return value conventions take precedence over consistency. - -Some modules have seen few changes, so they still retain the original -indentation style for now. When editing these, try to retain the -original style. For Emacs, `doc/c-indentation.el` from OpenSSL may be -helpful in this. - - -## Language - -The majority of the project is in C, so C++-specific rules in the -Google style guide do not apply. Support for C99 features depends on -our target platforms. Typically, Chromium's target MSVC is the most -restrictive. - -Variable declarations in the middle of a function are allowed. - -Comments should be `/* C-style */` for consistency. - -When declaration pointer types, `*` should be placed next to the variable -name, not the type. So - - uint8_t *ptr; - -not - - uint8_t* ptr; - -Rather than `malloc()` and `free()`, use the wrappers `OPENSSL_malloc()` -and `OPENSSL_free()`. Use the standard C `assert()` function freely. - -For new constants, prefer enums when the values are sequential and typed -constants for flags. If adding values to an existing set of `#define`s, -continue with `#define`. - - -## Formatting - -Single-statement blocks are not allowed. All conditions and loops must -use braces: - - if (foo) { - do_something(); - } - -not - - if (foo) - do_something(); - - -## Integers - -Prefer using explicitly-sized integers where appropriate rather than -generic C ones. For instance, to represent a byte, use `uint8_t`, not -`unsigned char`. Likewise, represent a two-byte field as `uint16_t`, not -`unsigned short`. - -Sizes are represented as `size_t`. - -Within a struct that is retained across the lifetime of an SSL -connection, if bounds of a size are known and it's easy, use a smaller -integer type like `uint8_t`. This is a "free" connection footprint -optimization for servers. Don't make code significantly more complex for -it, and do still check the bounds when passing in and out of the -struct. This narrowing should not propagate to local variables and -function parameters. - -When doing arithmetic, account for overflow conditions. - -Except with platform APIs, do not use `ssize_t`. MSVC lacks it, and -prefer out-of-band error signaling for `size_t` (see Return values). - - -## Naming - -Follow Google naming conventions in C++ files. In C files, use the -following naming conventions for consistency with existing OpenSSL and C -styles: - -Define structs with typedef named `TYPE_NAME`. The corresponding struct -should be named `struct type_name_st`. - -Name public functions as `MODULE_function_name`, unless the module -already uses a different naming scheme for legacy reasons. The module -name should be a type name if the function is a method of a particular -type. - -Some types are allocated within the library while others are initialized -into a struct allocated by the caller, often on the stack. Name these -functions `TYPE_NAME_new`/`TYPE_NAME_free` and -`TYPE_NAME_init`/`TYPE_NAME_cleanup`, respectively. All `TYPE_NAME_free` -functions must do nothing on `NULL` input. - -If a variable is the length of a pointer value, it has the suffix -`_len`. An output parameter is named `out` or has an `out_` prefix. For -instance, For instance: - - uint8_t *out, - size_t *out_len, - const uint8_t *in, - size_t in_len, - -Name public headers like `include/openssl/evp.h` with header guards like -`OPENSSL_HEADER_EVP_H`. Name internal headers like -`crypto/ec/internal.h` with header guards like -`OPENSSL_HEADER_EC_INTERNAL_H`. - -Name enums like `enum unix_hacker_t`. For instance: - - enum should_free_handshake_buffer_t { - free_handshake_buffer, - dont_free_handshake_buffer, - }; - - -## Return values - -As even `malloc` may fail in BoringSSL, the vast majority of functions -will have a failure case. Functions should return `int` with one on -success and zero on error. Do not overload the return value to both -signal success/failure and output an integer. For example: - - OPENSSL_EXPORT int CBS_get_u16(CBS *cbs, uint16_t *out); - -If a function needs more than a true/false result code, define an enum -rather than arbitrarily assigning meaning to int values. - -If a function outputs a pointer to an object on success and there are no -other outputs, return the pointer directly and `NULL` on error. - - -## Parameters - -Where not constrained by legacy code, parameter order should be: - -1. context parameters -2. output parameters -3. input parameters - -For example, - - /* CBB_add_asn sets |*out_contents| to a |CBB| into which the contents of an - * ASN.1 object can be written. The |tag| argument will be used as the tag for - * the object. It returns one on success or zero on error. */ - OPENSSL_EXPORT int CBB_add_asn1(CBB *cbb, CBB *out_contents, uint8_t tag); - - -## Documentation - -All public symbols must have a documentation comment in their header -file. The style is based on that of Go. The first sentence begins with -the symbol name, optionally prefixed with "A" or "An". Apart from the -initial mention of symbol, references to other symbols or parameter -names should be surrounded by |pipes|. - -Documentation should be concise but completely describe the exposed -behavior of the function. Pay special note to success/failure behaviors -and caller obligations on object lifetimes. If this sacrifices -conciseness, consider simplifying the function's behavior. - - /* EVP_DigestVerifyUpdate appends |len| bytes from |data| to the data which - * will be verified by |EVP_DigestVerifyFinal|. It returns one on success and - * zero otherwise. */ - OPENSSL_EXPORT int EVP_DigestVerifyUpdate(EVP_MD_CTX *ctx, const void *data, - size_t len); - -Explicitly mention any surprising edge cases or deviations from common -return value patterns in legacy functions. - - /* RSA_private_encrypt encrypts |flen| bytes from |from| with the private key in - * |rsa| and writes the encrypted data to |to|. The |to| buffer must have at - * least |RSA_size| bytes of space. It returns the number of bytes written, or - * -1 on error. The |padding| argument must be one of the |RSA_*_PADDING| - * values. If in doubt, |RSA_PKCS1_PADDING| is the most common. - * - * WARNING: this function is dangerous because it breaks the usual return value - * convention. Use |RSA_sign_raw| instead. */ - OPENSSL_EXPORT int RSA_private_encrypt(int flen, const uint8_t *from, - uint8_t *to, RSA *rsa, int padding); - -Document private functions in their `internal.h` header or, if static, -where defined. |