side-effect, so that we don't allow speculative evaluation of such expressions
during code generation.
This caused a diagnostic quality regression, so fix constant expression
diagnostics to prefer either the first "can't be constant folded" diagnostic or
the first "not a constant expression" diagnostic depending on the kind of
evaluation we're doing. This was always the intent, but didn't quite work
correctly before.
This results in certain initializers that used to be constant initializers to
no longer be; in particular, things like:
float f = 1e100;
are no longer accepted in C. This seems appropriate, as such constructs would
lead to code being executed if sanitizers are enabled.
llvm-svn: 254574
This patch was submitted to the list for review and didn't receive a LGTM.
(In fact one explicit objection and one query were raised.)
This reverts commit r197295.
llvm-svn: 197299
String literals (including unicode ones) can contain non-Unicode codepoints
if they were written using \x or similar. Write those out using \x, but be
careful that the following character can't be misinterpreted as part of the
\x escape sequence. Convert UTF-16 surrogate pairs back to codepoints before
rendering them.
llvm-svn: 154069
Also temporarily remove the assumption from IR gen that we can emit IR for every
constant we can fold, since it isn't currently true in C++11, to fix PR11676.
Original comment from r147271:
constexpr: perform zero-initialization prior to / instead of performing a
constructor call when appropriate. Thanks to Eli for spotting this.
llvm-svn: 147384
variable is initialized by a non-constant expression, and pass in the variable
being declared so that earlier-initialized fields' values can be used.
Rearrange VarDecl init evaluation to make this possible, and in so doing fix a
long-standing issue in our C++ constant expression handling, where we would
mishandle cases like:
extern const int a;
const int n = a;
const int a = 5;
int arr[n];
Here, n is not initialized by a constant expression, so can't be used in an ICE,
even though the initialization expression would be an ICE if it appeared later
in the TU. This requires computing whether the initializer is an ICE eagerly,
and saving that information in PCH files.
llvm-svn: 146856
fails within a call to a constexpr function. Add -fconstexpr-backtrace-limit
argument to driver and frontend, to control the maximum number of notes so
produced (default 10). Fix APValue printing to be able to pretty-print all
APValue types, and move the testing for this functionality from a unittest to
a -verify test now that it's visible in clang's output.
llvm-svn: 146749
Tim Northover