[GHC] #11312: GHC inlining primitive string literals can affect program output

[GHC]

#11312: GHC inlining primitive string literals can affect program output
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        Reporter:  RyanGlScott       |                Owner:
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.10.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect result  |  Unknown/Multiple
  at runtime                         |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11292            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by xnyhps):

 I hacked around with this a bit, these are my findings:

 * `ByteArray#` is represented as `StgArrBytes`, which includes a 1 word
 header and 1 word to indicate the size and is word aligned. This may be
 very convenient for things that want to use static `ByteArray#`s, but for
 usual string literals it sounds quite wasteful: on x86-64 it would require
 24 bytes of padding to store a one-character string, instead of 2 for a
 zero-terminated string.

   (The alignment changes of #9577 would conflict with this, but it should
 still be possible to mark the sections as mergeable.)

   Considering that, and the existence of `byteArrayContents#`, I think it
 would be preferable to introduce a new primitive type `String#` that is
 used ''only'' for string literals.

 * Whichever different type `""#` gets, bootstrapping the compiler becomes
 tricky: the template for both Alex and Happy defines `""#` literals. What
 makes it worse is that this means stage 1 and stage 2 need a different
 template.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11312#comment:6>
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