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authorChia-I Wu <olv@lunarg.com>2011-08-18 17:12:29 +0800
committerChia-I Wu <olv@lunarg.com>2011-08-23 09:11:58 +0800
commit582b5d869c0f05814d4d567636a743d3fdddf431 (patch)
treee6fbbd7e6acb045f3cd950dc63342d45953e64eb /scons/source_list.py
parent6c8ea1eed66e9da82fb2b49b1e7f6d7f6064dbc4 (diff)
scons: add ParseSourceList method
ParseSourceList() can be used to parse a source list file and returns the source files defined in it. It is supposed to be used like this # get the list of source files from C_SOURCES in Makefile.sources sources = env.ParseSourceList('Makefile.sources', 'C_SOURCES') The syntax of a source list file is compatible with GNU Make. This effectively allows SConscript and Makefile to share the source lists. Acked-by: José Fonseca <jfonseca@vmware.com> Acked-by: Chad Versace <chad@chad-versace.us>
Diffstat (limited to 'scons/source_list.py')
-rw-r--r--scons/source_list.py123
1 files changed, 123 insertions, 0 deletions
diff --git a/scons/source_list.py b/scons/source_list.py
new file mode 100644
index 00000000000..fbd3ef7dc17
--- /dev/null
+++ b/scons/source_list.py
@@ -0,0 +1,123 @@
+"""Source List Parser
+
+The syntax of a source list file is a very small subset of GNU Make. These
+features are supported
+
+ operators: +=, :=
+ line continuation
+ non-nested variable expansion
+ comment
+
+The goal is to allow Makefile's and SConscript's to share source listing.
+"""
+
+class SourceListParser(object):
+ def __init__(self):
+ self._reset()
+
+ def _reset(self, filename=None):
+ self.filename = filename
+
+ self.line_no = 1
+ self.line_cont = ''
+ self.symbol_table = {}
+
+ def _error(self, msg):
+ raise RuntimeError('%s:%d: %s' % (self.filename, self.line_no, msg))
+
+ def _next_dereference(self, val, cur):
+ """Locate the next $(...) in value."""
+ deref_pos = val.find('$', cur)
+ if deref_pos < 0:
+ return (-1, -1)
+ elif val[deref_pos + 1] != '(':
+ self._error('non-variable dereference')
+
+ deref_end = val.find(')', deref_pos + 2)
+ if deref_end < 0:
+ self._error('unterminated variable dereference')
+
+ return (deref_pos, deref_end + 1)
+
+ def _expand_value(self, val):
+ """Perform variable expansion."""
+ expanded = ''
+ cur = 0
+ while True:
+ deref_pos, deref_end = self._next_dereference(val, cur)
+ if deref_pos < 0:
+ expanded += val[cur:]
+ break
+
+ sym = val[(deref_pos + 2):(deref_end - 1)]
+ expanded += val[cur:deref_pos] + self.symbol_table[sym]
+ cur = deref_end
+
+ return expanded
+
+ def _parse_definition(self, line):
+ """Parse a variable definition line."""
+ op_pos = line.find('=')
+ op_end = op_pos + 1
+ if op_pos < 0:
+ self._error('not a variable definition')
+
+ if op_pos > 0 and line[op_pos - 1] in [':', '+']:
+ op_pos -= 1
+ else:
+ self._error('only := and += are supported')
+
+ # set op, sym, and val
+ op = line[op_pos:op_end]
+ sym = line[:op_pos].strip()
+ val = self._expand_value(line[op_end:].lstrip())
+
+ if op == ':=':
+ self.symbol_table[sym] = val
+ elif op == '+=':
+ self.symbol_table[sym] += ' ' + val
+
+ def _parse_line(self, line):
+ """Parse a source list line."""
+ # more lines to come
+ if line and line[-1] == '\\':
+ # spaces around "\\\n" are replaced by a single space
+ if self.line_cont:
+ self.line_cont += line[:-1].strip() + ' '
+ else:
+ self.line_cont = line[:-1].rstrip() + ' '
+ return 0
+
+ # combine with previous lines
+ if self.line_cont:
+ line = self.line_cont + line.lstrip()
+ self.line_cont = ''
+
+ if line:
+ begins_with_tab = (line[0] == '\t')
+
+ line = line.lstrip()
+ if line[0] != '#':
+ if begins_with_tab:
+ self._error('recipe line not supported')
+ else:
+ self._parse_definition(line)
+
+ return 1
+
+ def parse(self, filename):
+ """Parse a source list file."""
+ if self.filename != filename:
+ fp = open(filename)
+ lines = fp.read().splitlines()
+ fp.close()
+
+ try:
+ self._reset(filename)
+ for line in lines:
+ self.line_no += self._parse_line(line)
+ except:
+ self._reset()
+ raise
+
+ return self.symbol_table