c++: Add C++20 #__VA_OPT__ support

The following patch implements C++20 # __VA_OPT__ (...) support.
Testcases cover what I came up with myself and what LLVM has for #__VA_OPT__
in its testsuite and the string literals are identical between the two
compilers on the va-opt-5.c testcase.

2021-08-17  Jakub Jelinek  <jakub@redhat.com>

libcpp/
	* macro.c (vaopt_state): Add m_stringify member.
	(vaopt_state::vaopt_state): Initialize it.
	(vaopt_state::update): Overwrite it.
	(vaopt_state::stringify): New method.
	(stringify_arg): Replace arg argument with first, count arguments
	and add va_opt argument.  Use first instead of arg->first and
	count instead of arg->count, for va_opt add paste_tokens handling.
	(paste_tokens): Fix up len calculation.  Don't spell rhs twice,
	instead use %.*s to supply lhs and rhs spelling lengths.  Don't call
	_cpp_backup_tokens here.
	(paste_all_tokens): Call it here instead.
	(replace_args): Adjust stringify_arg caller.  For vaopt_state::END
	if stringify is true handle __VA_OPT__ stringification.
	(create_iso_definition): Handle # __VA_OPT__ similarly to # macro_arg.
gcc/testsuite/
	* c-c++-common/cpp/va-opt-5.c: New test.
	* c-c++-common/cpp/va-opt-6.c: New test.
This commit is contained in:
Jakub Jelinek 2021-08-17 09:25:56 +02:00
parent 0215b3559e
commit d565999792
3 changed files with 157 additions and 15 deletions

View File

@ -0,0 +1,67 @@
/* { dg-do run } */
/* { dg-options "-std=gnu99" { target c } } */
/* { dg-options "-std=c++20" { target c++ } } */
#define lparen (
#define a0 fooa0
#define a1 fooa1 a0
#define a2 fooa2 a1
#define a3 fooa3 a2
#define a() b lparen )
#define b() c lparen )
#define c() d lparen )
#define g h
#define i(j) j
#define f(...) #__VA_OPT__(g i(0))
#define k(x,...) # __VA_OPT__(x) #x #__VA_OPT__(__VA_ARGS__)
#define l(x,...) #__VA_OPT__(a1 x)
#define m(x,...) "a()" #__VA_OPT__(a3 __VA_ARGS__ x ## __VA_ARGS__ ## x ## c a3) "a()"
#define n(x,...) = #__VA_OPT__(a3 __VA_ARGS__ x ## __VA_ARGS__ ## x ## c a3) #x #__VA_OPT__(a0 __VA_ARGS__ x ## __VA_ARGS__ ## x ## c a0) ;
#define o(x, ...) #__VA_OPT__(x##x x##x)
#define p(x, ...) #__VA_OPT__(_Pragma ("foobar"))
#define q(...) #__VA_OPT__(/* foo */x/* bar */)
const char *v1 = f();
const char *v2 = f(123);
const char *v3 = k(1);
const char *v4 = k(1, 2, 3 );
const char *v5 = l(a());
const char *v6 = l(a1 a(), 1);
const char *v7 = m();
const char *v8 = m(,);
const char *v9 = m(,a3);
const char *v10 = m(a3,a(),a0);
const char *v11 n()
const char *v12 n(,)
const char *v13 n(,a0)
const char *v14 n(a0, a(),a0)
const char *v15 = o(, 0);
const char *v16 = p(0);
const char *v17 = p(0, 1);
const char *v18 = q();
const char *v19 = q(1);
int
main ()
{
if (__builtin_strcmp (v1, "")
|| __builtin_strcmp (v2, "g i(0)")
|| __builtin_strcmp (v3, "1")
|| __builtin_strcmp (v4, "112, 3")
|| __builtin_strcmp (v5, "")
|| __builtin_strcmp (v6, "a1 fooa1 fooa0 b ( )")
|| __builtin_strcmp (v7, "a()a()")
|| __builtin_strcmp (v8, "a()a()")
|| __builtin_strcmp (v9, "a()a3 fooa3 fooa2 fooa1 fooa0 a3c a3a()")
|| __builtin_strcmp (v10, "a()a3 b ( ),fooa0 a3a(),a0a3c a3a()")
|| __builtin_strcmp (v11, "")
|| __builtin_strcmp (v12, "")
|| __builtin_strcmp (v13, "a3 fooa0 a0c a3a0 fooa0 a0c a0")
|| __builtin_strcmp (v14, "a3 b ( ),fooa0 a0a(),a0a0c a3a0a0 b ( ),fooa0 a0a(),a0a0c a0")
|| __builtin_strcmp (v15, "")
|| __builtin_strcmp (v16, "")
|| __builtin_strcmp (v17, "_Pragma (\"foobar\")")
|| __builtin_strcmp (v18, "")
|| __builtin_strcmp (v19, "x"))
__builtin_abort ();
return 0;
}

View File

@ -0,0 +1,17 @@
/* { dg-do preprocess } */
/* { dg-options "-std=gnu99" { target c } } */
/* { dg-options "-std=c++20" { target c++ } } */
#define a ""
#define b(...) a ## #__VA_OPT__(1) /* { dg-error "pasting \"a\" and \"\"\"\" does not give a valid preprocessing token" } */
#define c(...) a ## #__VA_OPT__(1) /* { dg-error "pasting \"a\" and \"\"1\"\" does not give a valid preprocessing token" } */
#define d(...) #__VA_OPT__(1) ## !
#define e(...) #__VA_OPT__(1) ## !
#define f(...) #__VA_OPT__(. ## !)
#define g(...) #__VA_OPT__(. ## !)
b()
c(1)
d( ) /* { dg-error "pasting \"\"\"\" and \"!\" does not give a valid preprocessing token" } */
e( 1 ) /* { dg-error "pasting \"\"1\"\" and \"!\" does not give a valid preprocessing token" } */
f()
g(0) /* { dg-error "pasting \".\" and \"!\" does not give a valid preprocessing token" } */

View File

@ -118,6 +118,7 @@ class vaopt_state {
m_arg (arg),
m_variadic (is_variadic),
m_last_was_paste (false),
m_stringify (false),
m_state (0),
m_paste_location (0),
m_location (0),
@ -145,6 +146,7 @@ class vaopt_state {
}
++m_state;
m_location = token->src_loc;
m_stringify = (token->flags & STRINGIFY_ARG) != 0;
return BEGIN;
}
else if (m_state == 1)
@ -234,6 +236,12 @@ class vaopt_state {
return m_state == 0;
}
/* Return true for # __VA_OPT__. */
bool stringify () const
{
return m_stringify;
}
private:
/* The cpp_reader. */
@ -247,6 +255,8 @@ class vaopt_state {
/* If true, the previous token was ##. This is used to detect when
a paste occurs at the end of the sequence. */
bool m_last_was_paste;
/* True for #__VA_OPT__. */
bool m_stringify;
/* The state variable:
0 means not parsing
@ -284,7 +294,8 @@ static _cpp_buff *collect_args (cpp_reader *, const cpp_hashnode *,
static cpp_context *next_context (cpp_reader *);
static const cpp_token *padding_token (cpp_reader *, const cpp_token *);
static const cpp_token *new_string_token (cpp_reader *, uchar *, unsigned int);
static const cpp_token *stringify_arg (cpp_reader *, macro_arg *);
static const cpp_token *stringify_arg (cpp_reader *, const cpp_token **,
unsigned int, bool);
static void paste_all_tokens (cpp_reader *, const cpp_token *);
static bool paste_tokens (cpp_reader *, location_t,
const cpp_token **, const cpp_token *);
@ -818,10 +829,11 @@ cpp_quote_string (uchar *dest, const uchar *src, unsigned int len)
return dest;
}
/* Convert a token sequence ARG to a single string token according to
the rules of the ISO C #-operator. */
/* Convert a token sequence FIRST to FIRST+COUNT-1 to a single string token
according to the rules of the ISO C #-operator. */
static const cpp_token *
stringify_arg (cpp_reader *pfile, macro_arg *arg)
stringify_arg (cpp_reader *pfile, const cpp_token **first, unsigned int count,
bool va_opt)
{
unsigned char *dest;
unsigned int i, escape_it, backslash_count = 0;
@ -834,9 +846,27 @@ stringify_arg (cpp_reader *pfile, macro_arg *arg)
*dest++ = '"';
/* Loop, reading in the argument's tokens. */
for (i = 0; i < arg->count; i++)
for (i = 0; i < count; i++)
{
const cpp_token *token = arg->first[i];
const cpp_token *token = first[i];
if (va_opt && (token->flags & PASTE_LEFT))
{
location_t virt_loc = pfile->invocation_location;
const cpp_token *rhs;
do
{
if (i == count)
abort ();
rhs = first[++i];
if (!paste_tokens (pfile, virt_loc, &token, rhs))
{
--i;
break;
}
}
while (rhs->flags & PASTE_LEFT);
}
if (token->type == CPP_PADDING)
{
@ -923,7 +953,7 @@ paste_tokens (cpp_reader *pfile, location_t location,
cpp_token *lhs;
unsigned int len;
len = cpp_token_len (*plhs) + cpp_token_len (rhs) + 1;
len = cpp_token_len (*plhs) + cpp_token_len (rhs) + 2;
buf = (unsigned char *) alloca (len);
end = lhsend = cpp_spell_token (pfile, *plhs, buf, true);
@ -949,8 +979,10 @@ paste_tokens (cpp_reader *pfile, location_t location,
location_t saved_loc = lhs->src_loc;
_cpp_pop_buffer (pfile);
_cpp_backup_tokens (pfile, 1);
*lhsend = '\0';
unsigned char *rhsstart = lhsend;
if ((*plhs)->type == CPP_DIV && rhs->type != CPP_EQ)
rhsstart++;
/* We have to remove the PASTE_LEFT flag from the old lhs, but
we want to keep the new location. */
@ -962,8 +994,10 @@ paste_tokens (cpp_reader *pfile, location_t location,
/* Mandatory error for all apart from assembler. */
if (CPP_OPTION (pfile, lang) != CLK_ASM)
cpp_error_with_line (pfile, CPP_DL_ERROR, location, 0,
"pasting \"%s\" and \"%s\" does not give a valid preprocessing token",
buf, cpp_token_as_text (pfile, rhs));
"pasting \"%.*s\" and \"%.*s\" does not give "
"a valid preprocessing token",
(int) (lhsend - buf), buf,
(int) (end - rhsstart), rhsstart);
return false;
}
@ -1039,7 +1073,10 @@ paste_all_tokens (cpp_reader *pfile, const cpp_token *lhs)
abort ();
}
if (!paste_tokens (pfile, virt_loc, &lhs, rhs))
break;
{
_cpp_backup_tokens (pfile, 1);
break;
}
}
while (rhs->flags & PASTE_LEFT);
@ -1906,7 +1943,8 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
if (src->flags & STRINGIFY_ARG)
{
if (!arg->stringified)
arg->stringified = stringify_arg (pfile, arg);
arg->stringified = stringify_arg (pfile, arg->first, arg->count,
false);
}
else if ((src->flags & PASTE_LEFT)
|| (src != macro->exp.tokens && (src[-1].flags & PASTE_LEFT)))
@ -2029,7 +2067,24 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
paste_flag = tokens_buff_last_token_ptr (buff);
}
if (src->flags & PASTE_LEFT)
if (vaopt_tracker.stringify ())
{
unsigned int count
= start ? paste_flag - start : tokens_buff_count (buff);
const cpp_token *t
= stringify_arg (pfile,
start ? start + 1
: (const cpp_token **) (buff->base),
count, true);
while (count--)
tokens_buff_remove_last_token (buff);
if (src->flags & PASTE_LEFT)
copy_paste_flag (pfile, &t, src);
tokens_buff_add_token (buff, virt_locs,
t, t->src_loc, t->src_loc,
NULL, 0);
}
else if (src->flags & PASTE_LEFT)
{
/* With a non-empty __VA_OPT__ on the LHS of ##, the last
token should be flagged PASTE_LEFT. */
@ -3585,7 +3640,10 @@ create_iso_definition (cpp_reader *pfile)
function-like macros when lexing the subsequent token. */
if (macro->count > 1 && token[-1].type == CPP_HASH && macro->fun_like)
{
if (token->type == CPP_MACRO_ARG)
if (token->type == CPP_MACRO_ARG
|| (macro->variadic
&& token->type == CPP_NAME
&& token->val.node.node == pfile->spec_nodes.n__VA_OPT__))
{
if (token->flags & PREV_WHITE)
token->flags |= SP_PREV_WHITE;