The C and C++ standards disallow using universal character names to
refer to some characters, such as basic ascii and control characters,
so we reject these sequences in the lexer. However, when the
preprocessor isn't being used on C or C++, it doesn't make sense to
apply these restrictions.
Notably, accepting these characters avoids issues with unicode escapes
when GHC uses the compiler as a preprocessor on haskell sources.
Fixes rdar://problem/14742289
llvm-svn: 193067
literal operators. Also, for now, allow the proposed C++1y "il", "i", and "if"
suffixes too. (Will revert the latter if LWG decides not to go ahead with that
change after all.)
llvm-svn: 191274
Before this patch, Lex() would recurse whenever the current lexer changed (e.g.
upon entry into a macro). This patch turns the recursion into a loop: the
various lex routines now don't return a token when the current lexer changes,
and at the top level Preprocessor::Lex() now loops until it finds a token.
Normally, the recursion wouldn't end up being very deep, but the recursion depth
can explode in edge cases like a bunch of consecutive macros which expand to
nothing (like in the testcase test/Preprocessor/macro_expand_empty.c in this
patch).
<rdar://problem/14569770>
llvm-svn: 190980
Apparently, gcc's -traditional-cpp behaves slightly differently in C++ mode;
specifically, it discards "//" comments. Match gcc's behavior.
<rdar://problem/14808126>
llvm-svn: 189515
If the user has requested this warning, we should emit it, even if it's not
an extension in the current language mode. However, being an extension is
more important, so prefer the pedantic warning or the pedantic-compatibility
warning if those are enabled.
<rdar://problem/12922063>
llvm-svn: 189110
It's beneficial when compiling to treat // as the start of a line
comment even in -std=c89 mode, since it's not valid C code (with a few
rare exceptions) and is usually intended as such. We emit a pedantic
warning and then continue on as if line comments were enabled.
This has been our behavior for quite some time.
However, people use the preprocessor for things besides C source files.
In today's prompting example, the input contains (unquoted) URLs, which
contain // but should still be preserved.
This change instructs the lexer to treat // as a plain token if Clang is
in C90 mode and generating preprocessed output rather than actually compiling.
<rdar://problem/13338743>
llvm-svn: 176526
Add warnings under -Wc++11-compat, -Wc++98-compat, and -Wc99-compat when a
particular UCN is incompatible with a different standard, and -Wunicode when
a UCN refers to a surrogate character in C++03.
llvm-svn: 174788
Rewriting the same predicates over and over again is bad for code size and
code maintainence. Using the functions in <ctype.h> is generally unsafe
unless they are specified to be locale-independent (i.e. only isdigit and
isxdigit).
The next commit will try to clean up uses of <ctype.h> functions within Clang.
llvm-svn: 174765
This allows people to use Unicode in their #pragma mark and in macros
that exist only to be string-ized.
<rdar://problem/13107323&13121362>
llvm-svn: 174081
People use the C preprocessor for things other than C files. Some of them
have Unicode characters. We shouldn't warn about Unicode characters
appearing outside of identifiers in this case.
There's not currently a way for the preprocessor to tell if it's in -E mode,
so I added a new flag, derived from the PreprocessorOutputOptions. This is
only used by the Unicode warnings for now, but could conceivably be used by
other warnings or even behavioral differences later.
<rdar://problem/13107323>
llvm-svn: 173881
This is a missing piece for C99 conformance.
This patch handles UCNs by adding a '\\' case to LexTokenInternal and
LexIdentifier -- if we see a backslash, we tentatively try to read in a UCN.
If the UCN is not syntactically well-formed, we fall back to the old
treatment: a backslash followed by an identifier beginning with 'u' (or 'U').
Because the spelling of an identifier with UCNs still has the UCN in it, we
need to convert that to UTF-8 in Preprocessor::LookUpIdentifierInfo.
Of course, valid code that does *not* use UCNs will see only a very minimal
performance hit (checks after each identifier for non-ASCII characters,
checks when converting raw_identifiers to identifiers that they do not
contain UCNs, and checks when getting the spelling of an identifier that it
does not contain a UCN).
This patch also adds basic support for actual UTF-8 in the source. This is
treated almost exactly the same as UCNs except that we consider stray
Unicode characters to be mistakes and offer a fixit to remove them.
llvm-svn: 173369
uncovered.
This required manually correcting all of the incorrect main-module
headers I could find, and running the new llvm/utils/sort_includes.py
script over the files.
I also manually added quite a few missing headers that were uncovered by
shuffling the order or moving headers up to be main-module-headers.
llvm-svn: 169237
string literal needs cleaning (because it contains line-splicing in the
encoding prefix or in the ud-suffix), do not clean the section between the
double-quotes -- that's the "raw" bit!
llvm-svn: 168776
This makes LexCharConstant() look more like LexStringLiteral(), which doesn't
have this bug. Add tests for eof after \ for several other cases.
llvm-svn: 168269
Justin Bogner