handle (most) escaped newlines in command string

1 files changed, 11 insertions, 2 deletions

diff --git a/yapymake/makefile/__init__.py b/yapymake/makefile/__init__.py
index e46179e..23cd144 100644
--- a/yapymake/makefile/__init__.py
+++ b/yapymake/makefile/__init__.py
@@ -145,10 +145,19 @@ class Makefile:
                 else:
                     prerequisite_tokens, command_tokens = semicolon_split
                     prerequisites = self.expand_macros(prerequisite_tokens).split()
+                    # TODO handle escaped newline in this case
                     command_token_strings = [command_tokens]
                 while (peeked := lines_iter.peek()) is not None and peeked.startswith('\t'):
-                    # TODO handle escaped newlines
-                    command_token_strings.append(tokenize(next(lines_iter).lstrip('\t').rstrip('\n')))
+                    next_line = next(lines_iter)
+                    # > When an escaped <newline> is found in a command line in a makefile, the command line shall
+                    # > contain the <backslash>, the <newline>, and the next line, except that the first character of
+                    # > the next line shall not be included if it is a <tab>.
+                    while next_line.endswith('\\\n'):
+                        line_after = next(lines_iter)
+                        if line_after.startswith('\t'):
+                            line_after = line_after[1:]
+                        next_line += line_after
+                    command_token_strings.append(tokenize(next_line.lstrip('\t').rstrip('\n')))
                 commands = [CommandLine(c) for c in command_token_strings]
 
                 # we don't know yet if it's a target rule or an inference rule