scc

commit 8840acc818b688a7b373106c0a466fdd56322d0d
parent 0b795256f75466f2b3d58fb7124a75a5e6829a9e
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue,  5 Nov 2024 09:14:28 +0100

make: Deal $$ correctly

We have to preserve $$ in any expansion, because as we
expand recursively then a nested expansion can try to
expand it. If we keep it then we have to unescape before
executing the line in execline().

Diffstat:
M
src/cmd/scc-make/parser.c
 | 
20
++++++++++++--------
M
src/cmd/scc-make/rules.c
 | 
12
++++++++++--
A
tests/make/execute/0096-escape.sh
 | 
18
++++++++++++++++++

3 files changed, 40 insertions(+), 10 deletions(-)
diff --git a/src/cmd/scc-make/parser.c b/src/cmd/scc-make/parser.c
@@ -716,16 +716,20 @@ expandstring(char *line, Target *tp, struct loc *loc)
 	n = 0;
 	s = NULL;
 	while ((c = nextc()) != EOF) {
-		if (c == '$') {
-			if ((c = nextc()) != '$') {
-				back(c);
-				expansion(tp);
-				continue;
-			}
+		if (c != '$') {
+			s = erealloc(s, ++n);
+			s[n-1] = c;
+			continue;
 		}
 
-		s = erealloc(s, ++n);
-		s[n-1] = c;
+		if ((c = nextc()) == '$') {
+			s = erealloc(s, n += 2);
+			s[n-2] = '$';
+			s[n-1] = '$';
+		} else {
+			back(c);
+			expansion(tp);
+		}
 	}
 
 	s = erealloc(s, n+1);
diff --git a/src/cmd/scc-make/rules.c b/src/cmd/scc-make/rules.c
@@ -175,9 +175,9 @@ addrule(char *target, struct action  *acts, int n)
 static int
 execline(Target *tp, char *line, int ignore, int silence)
 {
-	char *s;
+	char *s, *t;
 	Target *p, **q;
-	int r, at, plus, minus;
+	int r, at, plus, minus, l;
 
 	debug("executing '%s'", line);
 
@@ -199,6 +199,14 @@ execline(Target *tp, char *line, int ignore, int silence)
 	}
 
 out_loop:
+	/* unescape $$ */
+	for (l = strlen(s)+1, t = s; *t; --l, ++t) {
+		if (t[0] == '$' && t[1] == '$') {
+			memmove(t+1, t+2, l-2);
+			l--;
+		}
+	}
+
 	if (tflag && !plus)
 		return 0;
 
diff --git a/tests/make/execute/0096-escape.sh b/tests/make/execute/0096-escape.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+
+trap 'rm -f $tmp1 $tmp2' EXIT INT TERM QUIT HUP
+
+tmp1=tmp1.$$
+tmp2=tmp2.$$
+
+cat > $tmp1 <<EOF
+MACRO=hello
+EOF
+
+
+scc-make -f- <<'EOF' > $tmp2 2>&1
+MACRO = $$(echo hello)
+
+all:
+	@echo MACRO=$(MACRO)
+EOF