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Re: [PATCH] print full STRING_CST in Gimple dumps (PR 87052)

On 08/22/2018 06:48 AM, Richard Biener wrote:
On Wed, Aug 22, 2018 at 4:56 AM Martin Sebor <> wrote:

In the discussion of the fallout from the enhancement for pr71625
it was pointed out that STRING_CSts in Gimple dumps extend only
to the first nul and don't include any subsequent characters,
and that this makes the dumps harder to read and might give rise
to the question whether the code is correct.

In the attached patch I enhance the pretty_print_string() function
to print the full contents of a STRING_CST, including any embedded
nuls to make the dumps clearer.  I got rid of the single digit
escapes like '\1' since they make the string look ambiguous.
If TREE_STRING_LENGTH (node) is guaranteed to be non-zero these
days the test for it being so may be redundant but I figured it's
better to be safe than sorry.

A further enhancement might be to also distinguish the type of

And somehow indicate whether it is \0 terminated (just thinking of
the GIMPLE FE and how it parses string literals simply by relying
on libcpp).

Can you write a not \0 terminated string literal in C?

Yes: char a[2] = "12";

I briefly considered making the terminating nul visible when
there was one but there's at least one test that scans GIMPLE
for the expected string and it failed so I didn't pursue this
idea further.

The tests can certainly be changed to look for the new pattern
if we should decide to make a change here.  I'm not sure what
would be best.  Printing "12\x00" for an ordinary nul-terminated
literal looks like there might be an extra nul after the first
one.  Leaving it out doesn't distinguish it from the unterminated
array.  Using the braced-list notation (i.e.,  a = { '1', '2' }
for unterminated arrays doesn't capture the fact that it's
represented as STRING_CST).

I'm open to suggestions.


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