Adjust sytem headers #8
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include/stdint.h
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| * Useful integer type names that we can't pick up from the compile-time | ||
| * environment. | ||
| */ | ||
| typedef char int8_t; |
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Clang (and I believe modern GCC) defines all of these for you. You get macros like __UINT8_TYPE__, and even the __UINT_LEAST16_TYPE__, __UINT_FAST32_TYPE__ etc. Given this header is wrong for 32-bit systems I would suggest just using all those; CheriOS would conceivably be highly useful for RV32 CHERI-RISC-V given its utility in embedded systems, once the issue of type bits is addressed.
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If this just works, seconded.
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Can we just do #include_next <stdint.h> to pick up the compiler-provided one? (https://github.com/CTSRD-CHERI/llvm-project/blob/master/clang/lib/Headers/stdint.h)
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Yes, that works if we get rid of -nostdinc. Are we going to have -ibuiltininc soon on CTSRD-CHERI/llvm-project?
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Currently it's Darwin-only upstream.
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Weird for that to be OS-specific. Would it be easy to add to our frontend? I feel a little jittery about removing -nostdinc from cherios. It's probably fine for my segregated build environment where the cherios builds can't see the mainline/cheribsd builds and their sysroots, but...
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Our usual "hack" is --sysroot=/no/such/path...
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And yeah, well, -nostdinc is already OS-specific, don't ask me why. There are some really bad decisions in the structuring of Clang's drivers. And no, no reason not to add it to the FreeBSD driver, though it's not strictly required and does diverge from upstream. But when Lawrence adds a CheriOS triple and driver, that driver can always support -ibuiltininc :)
include/stdint.h
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| * Useful integer type names that we can't pick up from the compile-time | ||
| * environment. | ||
| */ | ||
| typedef char int8_t; |
There was a problem hiding this comment.
Currently it's Darwin-only upstream.
This requires appealing to the compiler's builtin headers, which means we have to disable -nostdinc. Apparently there's an -ibuiltininc coming soon, which we probably want to adopt as soon as our compiler has it.
While trying to build
mbedtls, a number of errors were reported that ultimately stemmed from the standard headers not quite agreeing with the standard.In one case,
mbedtls#define-dADDfor its own EC math, which conflicted with the definition incheric.h, which is basically globally in scope.