mirror of https://github.com/openssl/openssl.git
34 lines
835 B
Markdown
34 lines
835 B
Markdown
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Notes on ANSI C
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===============
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When building for pure ANSI C (C89/C90), you must configure with at least
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the following configuration settings:
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- `no-asm`
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There are cases of `asm()` calls in our C source, which isn't supported
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in pure ANSI C.
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- `no-secure-memory`
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The secure memory calls aren't supported with ANSI C.
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- `-D_XOPEN_SOURCE=1`
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This macro enables the use of the following types, functions and global
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variables:
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- `timezone`
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- `-D_POSIX_C_SOURCE=200809L`
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This macro enables the use of the following types, functions and global
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variables:
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- `ssize_t`
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- `strdup()`
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It's arguable that with gcc and clang, all of these issues are removed when
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defining the macro `_DEFAULT_SOURCE`. However, that effectively sets the C
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language level to C99, which isn't ANSI C.
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