scc

commit d323767195562ff8b8784044206b1d2945160546
parent 1d0baf52bd4313b0d6d6ed6fb595273f21aa9b14
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 29 Oct 2024 12:47:22 +0100

make: Enable use of expansions in items

An item can be composed by the concatenation of digits and the
expansion of a macro. This change smells a bit, because we are
duplicating the call to expand in too many different places,
but the different behaviour of rules, actions and assignments
drives to something like this, or a nextc() function with
too many globals and conditions.

Diffstat:
M
src/cmd/scc-make/parser.c
 | 
82
+++++++++++++++++++++++++++++++++++++++++++++----------------------------------
A
tests/make/execute/0091-expansion.sh
 | 
23
+++++++++++++++++++++++
A
tests/make/execute/0092-expansion.sh
 | 
30
++++++++++++++++++++++++++++++

3 files changed, 100 insertions(+), 35 deletions(-)
diff --git a/src/cmd/scc-make/parser.c b/src/cmd/scc-make/parser.c
@@ -350,6 +350,18 @@ nextc(void)
 	return input->buf[input->pos++];
 }
 
+/*
+ * This function only can be called after a call to nextc
+ * that didn't return EOF. It can return '\0', but as
+ * it is used only to check against '$' then it is not
+ * a problem.
+ */
+static int
+ahead(void)
+{
+	return input->buf[input->pos];
+}
+
 static int
 back(int c)
 {
@@ -388,28 +400,6 @@ validchar(int c)
 	return c == '.' || c == '/' || c == '_' || c == '-' || isalnum(c);
 }
 
-static int
-item(void)
-{
-	int c;
-	char *s;
-
-	for (s = token; s < &token[MAXTOKEN] - 1; *s++ = c) {
-		c = nextc();
-		if (!validchar(c))
-			break;
-	}
-
-	if (s >= &token[MAXTOKEN] - 1)
-		error("token too long");
-	if (s == token)
-		error("invalid empty token");
-	*s = '\0';
-	back(c);
-
-	return ITEM;
-}
-
 static void
 expandmacro(char *name, char *repl, char *to)
 {
@@ -609,23 +599,31 @@ expandstring(char *line, Target *tp)
 }
 
 static int
-readchar(void)
+item(void)
 {
 	int c;
+	char *s;
+	char buf[MAXTOKEN];
 
-	while ((c = nextc()) != EOF) {
-		if (c == ' ' || c == '\t')
-			continue;
-		if (c == '\\') {
-			if ((c = nextc()) == '\n')
-				continue;
-			back(c);
-			c = '\\';
-		}
-		break;
+	for (s = buf; s < &buf[MAXTOKEN] - 1; ) {
+		c = nextc();
+		if (c == '$' && ahead() != '$')
+			expansion(NULL);
+		else if (validchar(c))
+			*s++ = c;
+		else
+			break;
 	}
+	back(c);
+
+	if (s >= &buf[MAXTOKEN] - 1)
+		error("token too long");
+	if (s == buf)
+		error("invalid empty token");
+	*s++ = '\0';
+	memcpy(token, buf, s - buf);
 
-	return c;
+	return ITEM;
 }
 
 static int
@@ -634,7 +632,21 @@ next(void)
 	int c;
 
 repeat:
-	c = readchar();
+	/*
+	 * It is better to avoid skipspaces() here, because
+	 * it can generate the need for 2 calls to back(),
+	 * and we need the character anyway.
+	 */
+	c = nextc();
+	if (c == ' ' || c == '\t')
+		goto repeat;
+
+	if (c == '\\') {
+		if ((c = nextc()) == '\n')
+			goto repeat;
+		back(c);
+		c = '\\';
+	}
 
 	switch (c) {
 	case EOF:
diff --git a/tests/make/execute/0091-expansion.sh b/tests/make/execute/0091-expansion.sh
@@ -0,0 +1,23 @@
+#!/bin/sh
+
+trap 'rm -f $tmp1 $tmp2' EXIT INT TERM QUIT HUP
+
+tmp1=tmp1.$$
+tmp2=tmp2.$$
+
+cat >$tmp2 <<EOF
+But before!
+Hello World!
+EOF
+
+scc-make -f- <<'EOF' > $tmp1 2>&1
+STARGET = all
+
+b.$(STARGET): b$(STARGET)
+	@echo Hello World!
+
+ball:
+	@echo But before!
+EOF
+
+diff -u $tmp1 $tmp2
diff --git a/tests/make/execute/0092-expansion.sh b/tests/make/execute/0092-expansion.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+trap 'rm -f $tmp1 $tmp2' EXIT INT TERM QUIT HUP
+
+tmp1=tmp1.$$
+tmp2=tmp2.$$
+
+cat >$tmp2 <<EOF
+yeah!
+done
+EOF
+
+scc-make -f- <<'EOF' > $tmp1 2>&1
+VAR =\
+        all\
+        f1\
+        f2\
+
+OBJS = f.$O
+
+O = e
+
+$(VAR) all : $(OBJS)
+	@echo done
+
+f.$O:
+	@echo yeah!
+EOF
+
+diff $tmp1 $tmp2