From f5c7b962c4d3512f32df8c3bbd3370f846239b02 Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Tue, 23 Nov 2021 11:20:03 +0200 Subject: WIP: complete --- libbuild2/make-parser.hxx | 85 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 85 insertions(+) create mode 100644 libbuild2/make-parser.hxx (limited to 'libbuild2/make-parser.hxx') diff --git a/libbuild2/make-parser.hxx b/libbuild2/make-parser.hxx new file mode 100644 index 0000000..fac2215 --- /dev/null +++ b/libbuild2/make-parser.hxx @@ -0,0 +1,85 @@ +// file : libbuild2/make-parser.hxx -*- C++ -*- +// license : MIT; see accompanying LICENSE file + +#ifndef LIBBUILD2_MAKE_PARSER_HXX +#define LIBBUILD2_MAKE_PARSER_HXX + +#include +#include + +#include + +namespace build2 +{ + // Make dependency declaration parser. + // + // The format is line-based (but with potential line continuations) so we + // parse one line at a time. This allows the caller to bail out early (for + // example, on encountering a non-existent generated file). + // + class LIBBUILD2_SYMEXPORT make_parser + { + public: + enum {begin, targets, prereqs, end} state = begin; + + // Parse next target/prerequisite on a line starting from the specified + // position. Update the position to point to the start of the following + // target/prerequisite or l.size() if there is nothing left on this + // line. May return an empty string for a valid if unlikely dependency + // declarations (see below) or if passing leading blank lines (both of + // which should normally be just skipped). Issue diagnostics and throw + // failed if the declaration is invalid. + // + // If strict is false, then allow unescaped `:` in prerequisites. + // + // Note that the (p != l.size) should be in the do-while rather than in a + // while loop. In other words, except for the leading blank lines, the + // parser needs to see the blank line to correctly identify the end of the + // declaration. See make-parser.test.cxx for a recommended usage. + // + // To parse more than one declaration, reset the state to begin after + // reaching end. + // + enum class type {target, prereq}; + + pair + next (const string&, size_t&, const location&, bool strict); + + // Lower-level stateless API. + // + public: + // Parse next target/prerequisite on a line starting from the specified + // position. Return the target/prerequisite as well as an indication of + // whether the end of the dependency declaration was reached. Update the + // position to point to the start of the following target/prerequisite, + // `:`, or l.size() if there is nothing left on this line. + // + // Note that some broken tools (notably MinGW GCC) do not escape `:` + // properly. To tolerate such cases the caller may specify that what's + // being parsed is the prerequisite list in which case unescaped `:` will + // be treated literally. + // + // Note also that this function may return an empty string (with + // end=false) for a valid if unlikely dependency declaration, for example + // (using | to represent backslash): + // + // foo:| + // | + // bar + // + // It would also return an empty string (with end=true) if passed and + // empty or whitespace-only line. + // + // Note also that in the make language line continuations introduce a + // whitespace rather than just being remove. For example, the following + // declaration has two prerequisites: + // + // foo: bar| + // baz + // + static pair + next (const string&, size_t&, optional prereq = nullopt); + }; +} + +#endif // LIBBUILD2_MAKE_PARSER_HXX -- cgit v1.1