Fix multiline backslash comments/commands regex

Author: drdv

Makefile

@@ -155,7 +155,7 @@ $(INTEGRATION_TESTS): FILE_EXPECTED = /tmp/.makefile-doc_$@_expected
 $(INTEGRATION_TESTS): FILE_ACTUAL = /tmp/.makefile-doc_$@_actual
 $(INTEGRATION_TESTS): RECIPE_CMD = $(shell head -n 1 $(INTEGRATION_TEST_DIR)/$@)
 $(INTEGRATION_TESTS): $(AWK_BIN)/$(AWK)
-	@echo "$(subst $,\$,$(RECIPE_CMD))" > $(FILE_CMD);
+	@echo "$(subst $,\$,$(RECIPE_CMD))" > $(FILE_CMD)
 	@tail -n +2 $(INTEGRATION_TEST_DIR)/$@ > $(FILE_EXPECTED)
 	@$< -f $(MAKEFILE_DOC) $(AWK_FLAGS) $(RECIPE_CMD) \
 		> $(FILE_ACTUAL).stdout 2> $(FILE_ACTUAL).stderr || exit 0

README.md

@@ -210,6 +210,8 @@ without `#`). Foreground/background can be set using the tokens `FG/BG`. Unspeci
   + [wak](https://github.com/raygard/wak) `v24.10`
   + [goawk](https://github.com/benhoyt/goawk) `v1.29.1`
 + `GNU Make`
+  + version 3.81 works fine for documentation generation
+  + I run the tests with version 4.3
 
 ## Running the tests
 

makefile-doc.awk

@@ -5,7 +5,7 @@
 #  Author: Dimitar Dimitrov
 # License: Apache-2.0
 # Project: https://github.com/drdv/makefile-doc
-# Version: v1.6
+# Version: v1.7
 #
 # Usage (see project README.md for more details):
 #   awk [-v option=value] -f makefile-doc.awk [Makefile ...]
@@ -975,6 +975,9 @@ BEGIN {
   FILES_PROCESSED = ""
   SPACES_TABS_REGEX = "^[ \t]+|[ \t]+$"
 
+  # this is equivalent to /[^\\](\\{2})*\\$/ with an extra round of escaping
+  ODD_NUMB_TERMINAL_BACKSLASHES_REGEX = "[^\\\\](\\\\{2})*\\\\$"
+
   # used to decorate double-colon targets in the documentation
   DOUBLE_COLON_SEPARATOR = "~"
 
@@ -1003,12 +1006,10 @@ FNR == 1 {
 }
 
 # Skip backslash multiline comments
-# FIXME: at some point we might allow for them to constitute anchor documentation
-#        but for the moment they are simply ignored
-/^ *#[^\\]*?([\\]{2})*\\$/ || IN_MULTILINE_BACKSLASH_COMMENT {
+$0 ~ "^ *#.*" ODD_NUMB_TERMINAL_BACKSLASHES_REGEX || IN_MULTILINE_BACKSLASH_COMMENT {
   if (!IN_MULTILINE_BACKSLASH_COMMENT) {
     IN_MULTILINE_BACKSLASH_COMMENT = 1
-  } else if (!($0 ~ /^[^\\]*?([\\]{2})*\\$/)) {
+  } else if (!($0 ~ ODD_NUMB_TERMINAL_BACKSLASHES_REGEX)) {
     IN_MULTILINE_BACKSLASH_COMMENT = 0
   }
 
@@ -1026,9 +1027,7 @@ FNR == 1 {
 
 IN_RULE && $0 ~ RECIPEPREFIX || IN_MULTILINE_BACKSLASH_COMMAND {
   forget_descriptions_data()
-
-  # match odd number of slashes at the end
-  if ($0 ~ sprintf("%s[^\\\\]*?([\\\\]{2})*\\\\$", RECIPEPREFIX)) {
+  if ($0 ~ sprintf("%s.*%s", RECIPEPREFIX, ODD_NUMB_TERMINAL_BACKSLASHES_REGEX)) {
     IN_MULTILINE_BACKSLASH_COMMAND = 1
   } else {
     IN_MULTILINE_BACKSLASH_COMMAND = 0

test/Makefile.backslash-comments

@@ -40,6 +40,16 @@ vvv5 := 1 ## 5
 z5:
 	@echo $(vvv5)
 
+## Spaces\ \
+sss2 := 1 ## 2
+s2:
+	@echo $(sss2)
+
+## Spaces\ \   \ \
+sss3 := 1 ## 3
+s3:
+	@echo $(sss3)
+
 ## should ignore this comment and the variable
 ## which is a part of the above recipe
 	BAD := 1

test/Makefile.backslash-recipe

@@ -28,6 +28,16 @@ t5: ## i-t5
 	@echo maybe\\\\\
 T5 := 1 ## v-t5 (this is not a variable)
 
+## spaces between backslashes
+s2:
+	@echo maybe\ \
+S2 := 1 ## v-s2 (this is not a variable)
+
+## spaces between backslashes
+s3:
+	@echo maybe\ \   \ \
+S3 := 1 ## v-s3 (this is not a variable)
+
 t6: ## i-t6
 	@echo maybe\
 T6_1 := 1 \

test/integration/test-backslash-recipe

@@ -8,6 +8,8 @@ Available targets:
 t3   t-t3
 t4   t-t4
 t5   t-t5
+s2   spaces between backslashes
+s3   spaces between backslashes
 t6   i-t6
 t7   i-t7
 t8   i-t7