[PATCH] D45418: [SimplifyLibcalls] Atoi, strtol replacements

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


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Comment at: lib/Transforms/Utils/SimplifyLibCalls.cpp:1697
+  if (ConstantInt *CInt = dyn_cast<ConstantInt>(CI->getArgOperand(2)))
+    return ConstantInt::get(CI->getType(), strtol(Str.str().c_str(), nullptr,
+                                                  CInt->getSExtValue()));
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lebedev.ri wrote:
> lebedev.ri wrote:
> > `base` is `i32`, but `strtol` returns `long int` (`i64`?), so i don't think using `CI->getType()` is correct.
> > 
> Oh, `CI` is `CallInst`, not `ConstantInt`, never mind then.
This is missing some checks.  In particular, what happens if the host's "long" is a different width from the target's "long"? What happens if strtol sets errno?  What happens if the target program is using a locale where isspace() doesn't match the C locale's isspace()?


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Comment at: lib/Transforms/Utils/SimplifyLibCalls.cpp:1685
+
+  return ConstantInt::get(CI->getType(), atoi(Str.str().c_str()));
+}
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I'm worried about host behavior leaking through here; specifically, the "undefined" values for overflow might vary. Could you use some function with more predictable behavior here?  (Maybe something based on llvm::consumeSignedInteger()?)


https://reviews.llvm.org/D45418