From 71d38ec80008afdbb9a059253407d80598b765c0 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Tue, 11 May 2021 23:54:01 +0000 Subject: [PATCH] preprocessor: Support C2X #elifdef, #elifndef C2X adds #elifdef and #elifndef preprocessor directives; these have also been proposed for C++. Implement these directives in libcpp accordingly. In this implementation, #elifdef and #elifndef are treated as non-directives for any language version other than c2x and gnu2x (if the feature is accepted for C++, it can trivially be enabled for relevant C++ versions). In strict conformance modes for prior language versions, this is required, as illustrated by the c11-elifdef-1.c test added. Bootstrapped with no regressions for x86_64-pc-linux-gnu. libcpp/ * include/cpplib.h (struct cpp_options): Add elifdef. * init.c (struct lang_flags): Add elifdef. (lang_defaults): Update to include elifdef initializers. (cpp_set_lang): Set elifdef for pfile based on language. * directives.c (STDC2X, ELIFDEF): New macros. (EXTENSION): Increase value to 3. (DIRECTIVE_TABLE): Add #elifdef and #elifndef. (_cpp_handle_directive): Do not treat ELIFDEF directives as directives for language versions without the #elifdef feature. (do_elif): Handle #elifdef and #elifndef. (do_elifdef, do_elifndef): New functions. gcc/testsuite/ * gcc.dg/cpp/c11-elifdef-1.c, gcc.dg/cpp/c2x-elifdef-1.c, gcc.dg/cpp/c2x-elifdef-2.c: New tests. --- gcc/testsuite/gcc.dg/cpp/c11-elifdef-1.c | 16 ++++++++ gcc/testsuite/gcc.dg/cpp/c2x-elifdef-1.c | 57 ++++++++++++++++++++++++++ gcc/testsuite/gcc.dg/cpp/c2x-elifdef-2.c | 63 +++++++++++++++++++++++++++++ libcpp/directives.c | 68 +++++++++++++++++++++++++++----- libcpp/include/cpplib.h | 3 ++ libcpp/init.c | 52 ++++++++++++------------ 6 files changed, 224 insertions(+), 35 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/cpp/c11-elifdef-1.c create mode 100644 gcc/testsuite/gcc.dg/cpp/c2x-elifdef-1.c create mode 100644 gcc/testsuite/gcc.dg/cpp/c2x-elifdef-2.c diff --git a/gcc/testsuite/gcc.dg/cpp/c11-elifdef-1.c b/gcc/testsuite/gcc.dg/cpp/c11-elifdef-1.c new file mode 100644 index 0000000..2d5809a --- /dev/null +++ b/gcc/testsuite/gcc.dg/cpp/c11-elifdef-1.c @@ -0,0 +1,16 @@ +/* Test #elifdef and #elifndef not in C11. */ +/* { dg-do preprocess } */ +/* { dg-options "-std=c11 -pedantic-errors" } */ + +#define A +#undef B + +#if 0 +#elifdef A +#error "#elifdef A applied" +#endif + +#if 0 +#elifndef B +#error "#elifndef B applied" +#endif diff --git a/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-1.c b/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-1.c new file mode 100644 index 0000000..b23e311 --- /dev/null +++ b/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-1.c @@ -0,0 +1,57 @@ +/* Test #elifdef and #elifndef in C2x. */ +/* { dg-do preprocess } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +#define A +#undef B + +#if 0 +#elifdef A +#define M1 1 +#endif + +#if M1 != 1 +#error "#elifdef A did not apply" +#endif + +#if 0 +#elifdef B +#error "#elifdef B applied" +#endif + +#if 0 +#elifndef A +#error "#elifndef A applied" +#endif + +#if 0 +#elifndef B +#define M2 2 +#endif + +#if M2 != 2 +#error "#elifndef B did not apply" +#endif + +#if 0 +#elifdef A +#else +#error "#elifdef A did not apply" +#endif + +#if 0 +#elifndef B +#else +#error "#elifndef B did not apply" +#endif + +/* As with #elif, the syntax of the new directives is relaxed after a + non-skipped group. */ + +#if 1 +#elifdef x * y +#endif + +#if 1 +#elifndef ! +#endif diff --git a/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-2.c b/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-2.c new file mode 100644 index 0000000..9132832 --- /dev/null +++ b/gcc/testsuite/gcc.dg/cpp/c2x-elifdef-2.c @@ -0,0 +1,63 @@ +/* Test #elifdef and #elifndef in C2x: erroneous usages. */ +/* { dg-do preprocess } */ +/* { dg-options "-std=c2x -pedantic-errors" } */ + +#define A +#undef B + +#elifdef A /* { dg-error "#elifdef without #if" } */ +#elifdef B /* { dg-error "#elifdef without #if" } */ +#elifndef A /* { dg-error "#elifndef without #if" } */ +#elifndef B /* { dg-error "#elifndef without #if" } */ + +#if 1 /* { dg-error "-:began here" } */ +#else +#elifdef A /* { dg-error "#elifdef after #else" } */ +#endif + +#if 1 /* { dg-error "-:began here" } */ +#else +#elifdef B /* { dg-error "#elifdef after #else" } */ +#endif + +#if 1 /* { dg-error "-:began here" } */ +#else +#elifndef A /* { dg-error "#elifndef after #else" } */ +#endif + +#if 1 /* { dg-error "-:began here" } */ +#else +#elifndef B /* { dg-error "#elifndef after #else" } */ +#endif + +#if 0 +#elifdef A = /* { dg-error "extra tokens at end of #elifdef directive" } */ +#endif + +#if 0 +#elifdef B = /* { dg-error "extra tokens at end of #elifdef directive" } */ +#endif + +#if 0 +#elifndef A = /* { dg-error "extra tokens at end of #elifndef directive" } */ +#endif + +#if 0 +#elifndef B = /* { dg-error "extra tokens at end of #elifndef directive" } */ +#endif + +#if 0 +#elifdef /* { dg-error "no macro name given in #elifdef directive" } */ +#endif + +#if 0 +#elifndef /* { dg-error "no macro name given in #elifndef directive" } */ +#endif + +#if 0 +#elifdef , /* { dg-error "macro names must be identifiers" } */ +#endif + +#if 0 +#elifndef , /* { dg-error "macro names must be identifiers" } */ +#endif diff --git a/libcpp/directives.c b/libcpp/directives.c index 795f93e..261a584 100644 --- a/libcpp/directives.c +++ b/libcpp/directives.c @@ -56,10 +56,12 @@ struct pragma_entry /* Values for the origin field of struct directive. KANDR directives come from traditional (K&R) C. STDC89 directives come from the - 1989 C standard. EXTENSION directives are extensions. */ + 1989 C standard. STDC2X directives come from the C2X standard. EXTENSION + directives are extensions. */ #define KANDR 0 #define STDC89 1 -#define EXTENSION 2 +#define STDC2X 2 +#define EXTENSION 3 /* Values for the flags field of struct directive. COND indicates a conditional; IF_COND an opening conditional. INCL means to treat @@ -67,13 +69,17 @@ struct pragma_entry means this directive should be handled even if -fpreprocessed is in effect (these are the directives with callback hooks). - EXPAND is set on directives that are always macro-expanded. */ + EXPAND is set on directives that are always macro-expanded. + + ELIFDEF is set on directives that are only handled for standards with the + #elifdef / #elifndef feature. */ #define COND (1 << 0) #define IF_COND (1 << 1) #define INCL (1 << 2) #define IN_I (1 << 3) #define EXPAND (1 << 4) #define DEPRECATED (1 << 5) +#define ELIFDEF (1 << 6) /* Defines one #-directive, including how to handle it. */ typedef void (*directive_handler) (cpp_reader *); @@ -148,6 +154,8 @@ static void cpp_pop_definition (cpp_reader *, struct def_pragma_macro *); D(undef, T_UNDEF, KANDR, IN_I) \ D(line, T_LINE, KANDR, EXPAND) \ D(elif, T_ELIF, STDC89, COND | EXPAND) \ + D(elifdef, T_ELIFDEF, STDC2X, COND | ELIFDEF) \ + D(elifndef, T_ELIFNDEF, STDC2X, COND | ELIFDEF) \ D(error, T_ERROR, STDC89, 0) \ D(pragma, T_PRAGMA, STDC89, IN_I) \ D(warning, T_WARNING, EXTENSION, 0) \ @@ -437,7 +445,11 @@ _cpp_handle_directive (cpp_reader *pfile, bool indented) if (dname->type == CPP_NAME) { if (dname->val.node.node->is_directive) - dir = &dtable[dname->val.node.node->directive_index]; + { + dir = &dtable[dname->val.node.node->directive_index]; + if ((dir->flags & ELIFDEF) && !CPP_OPTION (pfile, elifdef)) + dir = 0; + } } /* We do not recognize the # followed by a number extension in assembler code. */ @@ -2079,8 +2091,8 @@ do_else (cpp_reader *pfile) } } -/* Handle a #elif directive by not changing if_stack either. See the - comment above do_else. */ +/* Handle a #elif, #elifdef or #elifndef directive by not changing if_stack + either. See the comment above do_else. */ static void do_elif (cpp_reader *pfile) { @@ -2088,12 +2100,13 @@ do_elif (cpp_reader *pfile) struct if_stack *ifs = buffer->if_stack; if (ifs == NULL) - cpp_error (pfile, CPP_DL_ERROR, "#elif without #if"); + cpp_error (pfile, CPP_DL_ERROR, "#%s without #if", pfile->directive->name); else { if (ifs->type == T_ELSE) { - cpp_error (pfile, CPP_DL_ERROR, "#elif after #else"); + cpp_error (pfile, CPP_DL_ERROR, "#%s after #else", + pfile->directive->name); cpp_error_with_line (pfile, CPP_DL_ERROR, ifs->line, 0, "the conditional began here"); } @@ -2107,8 +2120,29 @@ do_elif (cpp_reader *pfile) pfile->state.skipping = 1; else { - pfile->state.skipping = ! _cpp_parse_expr (pfile, false); - ifs->skip_elses = ! pfile->state.skipping; + if (pfile->directive == &dtable[T_ELIF]) + pfile->state.skipping = !_cpp_parse_expr (pfile, false); + else + { + cpp_hashnode *node = lex_macro_node (pfile, false); + + if (node) + { + bool macro_defined = _cpp_defined_macro_p (node); + if (!_cpp_maybe_notify_macro_use (pfile, node, + pfile->directive_line)) + /* It wasn't a macro after all. */ + macro_defined = false; + bool skip = (pfile->directive == &dtable[T_ELIFDEF] + ? !macro_defined + : macro_defined); + if (pfile->cb.used) + pfile->cb.used (pfile, pfile->directive_line, node); + check_eol (pfile, false); + pfile->state.skipping = skip; + } + } + ifs->skip_elses = !pfile->state.skipping; } /* Invalidate any controlling macro. */ @@ -2116,6 +2150,20 @@ do_elif (cpp_reader *pfile) } } +/* Handle a #elifdef directive. */ +static void +do_elifdef (cpp_reader *pfile) +{ + do_elif (pfile); +} + +/* Handle a #elifndef directive. */ +static void +do_elifndef (cpp_reader *pfile) +{ + do_elif (pfile); +} + /* #endif pops the if stack and resets pfile->state.skipping. */ static void do_endif (cpp_reader *pfile) diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h index 41d75d9..2cdaf19 100644 --- a/libcpp/include/cpplib.h +++ b/libcpp/include/cpplib.h @@ -497,6 +497,9 @@ struct cpp_options /* Nonzero for the '::' token. */ unsigned char scope; + /* Nonzero for the '#elifdef' and '#elifndef' directives. */ + unsigned char elifdef; + /* Nonzero means tokenize C++20 module directives. */ unsigned char module_directives; diff --git a/libcpp/init.c b/libcpp/init.c index 18a2341..d5d4e99 100644 --- a/libcpp/init.c +++ b/libcpp/init.c @@ -95,34 +95,35 @@ struct lang_flags char scope; char dfp_constants; char size_t_literals; + char elifdef; }; static const struct lang_flags lang_defaults[] = -{ /* c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit */ - /* GNUC89 */ { 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* GNUC99 */ { 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* GNUC11 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* GNUC17 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* GNUC2X */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0 }, - /* STDC89 */ { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, - /* STDC94 */ { 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, - /* STDC99 */ { 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, - /* STDC11 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, - /* STDC17 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 }, - /* STDC2X */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0 }, - /* GNUCXX */ { 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* CXX98 */ { 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0 }, - /* GNUCXX11 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0 }, - /* CXX11 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0 }, - /* GNUCXX14 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0 }, - /* CXX14 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0 }, - /* GNUCXX17 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0 }, - /* CXX17 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0 }, - /* GNUCXX20 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0 }, - /* CXX20 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0 }, - /* GNUCXX23 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1 }, - /* CXX23 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1 }, - /* ASM */ { 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } +{ /* c99 c++ xnum xid c11 std digr ulit rlit udlit bincst digsep trig u8chlit vaopt scope dfp szlit elifdef */ + /* GNUC89 */ { 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* GNUC99 */ { 1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* GNUC11 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* GNUC17 */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* GNUC2X */ { 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1 }, + /* STDC89 */ { 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, + /* STDC94 */ { 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, + /* STDC99 */ { 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, + /* STDC11 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, + /* STDC17 */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0 }, + /* STDC2X */ { 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1 }, + /* GNUCXX */ { 0, 1, 1, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* CXX98 */ { 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0 }, + /* GNUCXX11 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0 }, + /* CXX11 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0 }, + /* GNUCXX14 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0 }, + /* CXX14 */ { 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 0, 0 }, + /* GNUCXX17 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0 }, + /* CXX17 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 0, 0 }, + /* GNUCXX20 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0 }, + /* CXX20 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 0, 0 }, + /* GNUCXX23 */ { 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0 }, + /* CXX23 */ { 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0 }, + /* ASM */ { 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } }; /* Sets internal flags correctly for a given language. */ @@ -151,6 +152,7 @@ cpp_set_lang (cpp_reader *pfile, enum c_lang lang) CPP_OPTION (pfile, scope) = l->scope; CPP_OPTION (pfile, dfp_constants) = l->dfp_constants; CPP_OPTION (pfile, size_t_literals) = l->size_t_literals; + CPP_OPTION (pfile, elifdef) = l->elifdef; } /* Initialize library global state. */ -- 2.7.4