commit f629615182e2c7fdb39ef1cb453a80a034eb0f37
from: Benjamin Stürz <benni@stuerz.xyz>
date: Thu Nov 21 09:33:20 2024 UTC

make: implement += macro assignment

commit - 3c12f67d765d9fd0ee94e3dee7ed65e8fa2765a8
commit + f629615182e2c7fdb39ef1cb453a80a034eb0f37
blob - 3ffee0beee1663f6c8a6433dfe4a5f0bb8c68d68
blob + 0f054e8453b1acec8bdfaeb083b90a715bb9e6fa
--- make/TODO.md
+++ make/TODO.md
@@ -55,18 +55,6 @@
 -s          silent, do not write commands to stdout
 
 
-# Macro Definition Operators
-## `+=`: Append Assignment
-### MyMakefile
-```make
-CFLAGS = -ansi
-.export CFLAGS
-```
-### sub/MyMakefile
-```
-CFLAGS += -Wall
-```
-
 # Templates
 ## MyMakefile
 ```make
blob - cc694d669c9d7bfe6c8b778df8d0e882ec1264be
blob + b36e5d8963bad822dcc39dc2c6accd1f1f4dbf23
--- make/make.c
+++ make/make.c
@@ -25,30 +25,35 @@
 static struct macro m_shell = {
 	.next = NULL,
 	.enext = NULL,
+	.prepend = NULL,
 	.name = "SHELL",
 	.value = SHELL,
 	.lazy = 0,
 }, m_make = {
 	.next = &m_shell,
 	.enext = &m_shell,
+	.prepend = NULL,
 	.name = "MAKE",
 	.value = NULL,
 	.lazy = 0,
 }, m_dmake = {
 	.next = &m_make,
 	.enext = &m_make,
+	.prepend = NULL,
 	.name = ".MAKE",
 	.value = NULL,
 	.lazy = 0,
 }, m_makeflags = {
 	.next = &m_dmake,
 	.enext = &m_dmake,
+	.prepend = NULL,
 	.name = "MAKEFLAGS",
 	.value = NULL,
 	.lazy = 0,
 }, m_dmakeflags = {
 	.next = &m_makeflags,
 	.enext = &m_makeflags,
+	.prepend = NULL,
 	.name = ".MAKEFLAGS",
 	.value = NULL,
 	.lazy = 0,
@@ -483,6 +488,11 @@ expand_macro (sc, m)
 struct scope *sc;
 struct macro *m;
 {
+	if (m->prepend != NULL) {
+		expand_macro (sc, m->prepend);
+		str_push (' ');
+	}
+
 	if (m->lazy) {
 		expand_into (sc, m->value, NULL);
 	} else {
@@ -864,7 +874,9 @@ char *path;
 
 			m = new (struct macro);
 			m->next = sc->dir->macros;
+			m->enext = NULL;
 			m->help = help;
+			m->prepend = NULL;
 
 			if (t[-1] == '!') {
 				t[-1] = '\0';
@@ -884,6 +896,11 @@ char *path;
 				t[t[-2] == ':' ? -2 : -1] = '\0';
 				m->lazy = 0;
 				m->value = strdup (trim (expand (sc, trim (t + 1), NULL)));
+			} else if (t[-1] == '+') {
+				t[-1] = '\0';
+				m->value = strdup (trim (t + 1));
+				m->prepend = find_macro (sc, trim (s));
+				m->lazy = 1;
 			} else {
 				m->lazy = 1;
 				m->value = strdup (trim (t + 1));
@@ -1385,7 +1402,7 @@ struct scope *sc;
 	for (m = sc->dir->macros; m != NULL; m = m->next) {
 		if (m->help != NULL)
 			printf ("\n## %s\n", m->help);
-		printf ("%s = %s\n", m->name, m->value);
+		printf ("%s %s= %s\n", m->name, m->prepend != NULL ? "+" : "", m->value);
 	}
 
 	printf ("\n");
blob - a541402897a1d3a09bcd5962f1577a6c923952f8
blob + 1633f42f1d844ff4030d29d1875de920f48a6758
--- make/make.h
+++ make/make.h
@@ -66,7 +66,7 @@ struct rule {
 };
 
 struct macro {
-	struct macro *next, *enext;
+	struct macro *next, *enext, *prepend;
 	char *name;
 	char *value;
 	char *help;