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authorBoris Kolpackov <boris@codesynthesis.com>2020-04-28 08:48:53 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2020-05-27 15:47:28 +0200
commitb808c255b6a9ddba085bf5646e7d20ec344f2e2d (patch)
tree32730291f7e6de8ef0a227905520dd66fb4ec0f3 /libbuild2/lexer.hxx
parent3552356a87402727e663131994fa87f48b3cd4fb (diff)
Initial support for ad hoc recipes (still work in progress)
Diffstat (limited to 'libbuild2/lexer.hxx')
-rw-r--r--libbuild2/lexer.hxx64
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;