diff options
Diffstat (limited to 'libbuild2/lexer.hxx')
| -rw-r--r-- | libbuild2/lexer.hxx | 64 |
1 files changed, 44 insertions, 20 deletions
diff --git a/libbuild2/lexer.hxx b/libbuild2/lexer.hxx index 02112cb..749668e 100644 --- a/libbuild2/lexer.hxx +++ b/libbuild2/lexer.hxx @@ -20,17 +20,18 @@ namespace build2 { - // Context-dependent lexing mode. Quoted modes are internal and should not - // be set explicitly. In the value mode we don't treat certain characters - // (e.g., `+`, `=`) as special so that we can use them in the variable - // values, e.g., `foo = g++`. In contrast, in the variable mode, we restrict - // certain character (e.g., `/`) from appearing in the name. The values mode - // is like value but recogizes `,` as special (used in contexts where we - // need to list multiple values). The attributes/attribute_value modes are - // like values where each value is potentially a variable assignment; they - // don't treat `{` and `}` as special (so we cannot have name groups in - // attributes) as well as recognizes `=` and `]`. The eval mode is used in - // the evaluation context. + // Context-dependent lexing mode. + // + // Quoted modes are internal and should not be set explicitly. In the value + // mode we don't treat certain characters (e.g., `+`, `=`) as special so + // that we can use them in the variable values, e.g., `foo = g++`. In + // contrast, in the variable mode, we restrict certain character (e.g., `/`) + // from appearing in the name. The values mode is like value but recogizes + // `,` as special (used in contexts where we need to list multiple + // values). The attributes/attribute_value modes are like values where each + // value is potentially a variable assignment; they don't treat `{` and `}` + // as special (so we cannot have name groups in attributes) as well as + // recognizes `=` and `]`. The eval mode is used in the evaluation context. // // A number of modes are "derived" from the value/values mode by recognizing // a few extra characters: @@ -42,10 +43,22 @@ namespace build2 // split words separated by the pair character (to disable pairs one can // pass `\0` as a pair character). // + // The normal mode recognizes `%` and `{{...` at the beginning of the line + // as special. The cmdvar mode is like normal but does not treat these + // character sequences as special. + // + // Finally, the foreign mode reads everything until encountering a line that + // contains nothing (besides whitespaces) other than the closing multi- + // curly-brace (`}}...`) (or eos) returning the contents as the word token + // followed by the multi_rcbrace (or eos). In a way it is similar to the + // single-quote mode. The number of closing braces to expect is passed as + // mode data. + // // The alternative modes must be set manually. The value/values and derived // modes automatically expires after the end of the line. The attribute mode // expires after the closing `]`. The variable mode expires after the word - // token. And the eval mode expires after the closing `)`. + // token. The eval mode expires after the closing `)`. And the foreign mode + // expires after the closing braces. // // Note that normally it is only safe to switch mode when the current token // is not quoted (or, more generally, when you are not in the double-quoted @@ -70,6 +83,7 @@ namespace build2 enum { normal = base_type::value_next, + cmdvar, variable, value, values, @@ -80,6 +94,7 @@ namespace build2 eval, single_quoted, double_quoted, + foreign, buildspec, value_next @@ -91,7 +106,7 @@ namespace build2 }; class LIBBUILD2_SYMEXPORT lexer: - public butl::char_scanner<butl::utf8_validator> + public butl::char_scanner<butl::utf8_validator, 2> { public: // If escape is not NULL then only escape sequences with characters from @@ -116,7 +131,8 @@ namespace build2 virtual void mode (lexer_mode, char pair_separator = '\0', - optional<const char*> escapes = nullopt); + optional<const char*> escapes = nullopt, + uintptr_t data = 0); // Enable attributes recognition for the next token. // @@ -157,7 +173,10 @@ namespace build2 protected: struct state { - lexer_mode mode; + lexer_mode mode; + uintptr_t data; + optional<token> hold; + bool attributes; char sep_pair; @@ -183,17 +202,22 @@ namespace build2 token next_quoted (); + token + next_foreign (); + // Lex a word assuming current is the top state (which may already have // been "expired" from the top). // virtual token word (state current, bool separated); - // Return true if we have seen any spaces. Skipped empty lines - // don't count. In other words, we are only interested in spaces - // that are on the same line as the following non-space character. + // Return true in first if we have seen any spaces. Skipped empty lines + // don't count. In other words, we are only interested in spaces that are + // on the same line as the following non-space character. Return true in + // second if we have started skipping spaces from column 1 (note that + // if this mode does not skip spaces, then second will always be false). // - bool + pair<bool, bool> skip_spaces (); // Diagnostics. @@ -232,7 +256,7 @@ namespace build2 namespace butl // ADL { inline build2::location - get_location (const butl::char_scanner<butl::utf8_validator>::xchar& c, + get_location (const butl::char_scanner<butl::utf8_validator, 2>::xchar& c, const void* data) { using namespace build2; |