Module Name: src
Committed By: rillig
Date: Mon Apr 19 23:27:17 UTC 2021
Modified Files:
src/usr.bin/make/unit-tests: varmod-ifelse.exp varmod-ifelse.mk
Log Message:
tests/make: add detailed explanation for error message in conditional
To generate a diff of this commit:
cvs rdiff -u -r1.7 -r1.8 src/usr.bin/make/unit-tests/varmod-ifelse.exp
cvs rdiff -u -r1.13 -r1.14 src/usr.bin/make/unit-tests/varmod-ifelse.mk
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/make/unit-tests/varmod-ifelse.exp
diff -u src/usr.bin/make/unit-tests/varmod-ifelse.exp:1.7 src/usr.bin/make/unit-tests/varmod-ifelse.exp:1.8
--- src/usr.bin/make/unit-tests/varmod-ifelse.exp:1.7 Mon Apr 19 22:22:27 2021
+++ src/usr.bin/make/unit-tests/varmod-ifelse.exp Mon Apr 19 23:27:17 2021
@@ -16,7 +16,9 @@ CondParser_Eval: ${VAR} == value
lhs = "value", rhs = "value", op = ==
lhs = "ok", rhs = "ok", op = !=
make: Bad conditional expression 'string == "literal" && no >= 10' in 'string == "literal" && no >= 10?yes:no'
-make: "varmod-ifelse.mk" line 127: .
+make: "varmod-ifelse.mk" line 153: .
+make: Bad conditional expression 'string == "literal" || no >= 10' in 'string == "literal" || no >= 10?yes:no'
+make: "varmod-ifelse.mk" line 154: .
make: Fatal errors encountered -- cannot continue
make: stopped in unit-tests
exit status 1
Index: src/usr.bin/make/unit-tests/varmod-ifelse.mk
diff -u src/usr.bin/make/unit-tests/varmod-ifelse.mk:1.13 src/usr.bin/make/unit-tests/varmod-ifelse.mk:1.14
--- src/usr.bin/make/unit-tests/varmod-ifelse.mk:1.13 Mon Apr 19 22:22:27 2021
+++ src/usr.bin/make/unit-tests/varmod-ifelse.mk Mon Apr 19 23:27:17 2021
@@ -1,4 +1,4 @@
-# $NetBSD: varmod-ifelse.mk,v 1.13 2021/04/19 22:22:27 rillig Exp $
+# $NetBSD: varmod-ifelse.mk,v 1.14 2021/04/19 23:27:17 rillig Exp $
#
# Tests for the ${cond:?then:else} variable modifier, which evaluates either
# the then-expression or the else-expression, depending on the condition.
@@ -111,8 +111,34 @@ VAR= value
.endif
.MAKEFLAGS: -d0
-# Seen on 2021-04-19 when building external/bsd/tmux with HAVE_LLVM=yes
-# and HAVE_GCC=no.
+# On 2021-04-19, when building external/bsd/tmux with HAVE_LLVM=yes and
+# HAVE_GCC=no, the following conditional generated this error message:
+#
+# make: Bad conditional expression 'string == "literal" && no >= 10'
+# in 'string == "literal" && no >= 10?yes:no'
+#
+# Despite the error message (which was not clearly marked with "error:"),
+# the build continued, for historical reasons, see main_Exit.
+#
+# The tricky detail here is that the condition that looks so obvious in the
+# form written in the makefile becomes tricky when it is actually evaluated.
+# This is because the condition is written in the place of the variable name
+# of the expression, and in an expression, the variable name is always
+# expanded first, before even looking at the modifiers. This happens for the
+# modifier ':?' as well, so when CondEvalExpression gets to see the
+# expression, it already looks like this:
+#
+# string == "literal" && no >= 10
+#
+# When parsing such an expression, the parser used to be strict. It first
+# evaluated the left-hand side of the operator '&&' and then started parsing
+# the right-hand side 'no >= 10'. The word 'no' is obviously a string
+# literal, not enclosed in quotes, which is ok, even on the left-hand side of
+# the comparison operator, but only because this is a condition in the
+# modifier ':?'. In an ordinary directive '.if', this would be a parse error.
+# For strings, only the comparison operators '==' and '!=' are defined,
+# therefore parsing stopped at the '>', producing the 'Bad conditional
+# expression'.
#
# TODO: make should at least describe the part of the condition that is
# wrong. In this case it is probably the "no >= 10". Ideally that should
@@ -123,5 +149,6 @@ VAR= value
# seen at compile-time" that the operand types of '>=' don't match. Only
# that the concept of "compile-time" does not really apply here.
STRING= string
-NUMBER= no
+NUMBER= no # not really a number
.info ${${STRING} == "literal" && ${NUMBER} >= 10:?yes:no}.
+.info ${${STRING} == "literal" || ${NUMBER} >= 10:?yes:no}.
