2 files changed, 96 insertions, 16 deletions

diff --git a/miscutils/make.c b/miscutils/make.c
index c69dcec8a..063d0662d 100644
--- a/miscutils/make.c
+++ b/miscutils/make.c
@@ -1419,17 +1419,74 @@ enum {
 
 #define IFDEF   0
 #define IFNDEF  1
+#define IFEQ    2
+#define IFNEQ   3
 #define ELSE    0
 #define ENDIF   1
 
 /*
+ * Extract strings following ifeq/ifneq and compare them.
+ * Return -1 on error.
+ */
+static int
+compare_strings(char *arg1)
+{
+        char *arg2, *end, term, *t1, *t2;
+        int ret;
+
+        // Get first string terminator.
+        if (arg1[0] == '(')
+                term = ',';
+        else if (arg1[0] == '"' || arg1[0] == '\'')
+                term =  arg1[0];
+        else
+                return -1;
+
+        arg2 = find_char(++arg1, term);
+        if (arg2 == NULL)
+                return -1;
+        *arg2++ = '\0';
+
+        // Get second string terminator.
+        if (term == ',') {
+                term = ')';
+        } else {
+                // Skip spaces between quoted strings.
+                while (isspace(arg2[0]))
+                        arg2++;
+                if (arg2[0] == '"' || arg2[0] == '\'')
+                        term = arg2[0];
+                else
+                        return -1;
+                ++arg2;
+        }
+
+        end = find_char(arg2, term);
+        if (end == NULL)
+                return -1;
+        *end++ = '\0';
+
+        if (gettok(&end) != NULL) {
+                warning("unexpected text");
+        }
+
+        t1 = expand_macros(arg1, FALSE);
+        t2 = expand_macros(arg2, FALSE);
+
+        ret = strcmp(t1, t2) == 0;
+        free(t1);
+        free(t2);
+        return ret;
+}
+
+/*
  * Process conditional directives and return TRUE if the current line
  * should be skipped.
  */
 static int
 skip_line(const char *str1)
 {
-        char *copy, *q, *token, *next_token;
+        char *copy, *q, *token;
         bool new_level = TRUE;
         // Default is to return skip flag for current level
         int ret = cstate[clevel] & SKIP_LINE;
@@ -1441,11 +1498,9 @@ skip_line(const char *str1)
         copy = xstrdup(str1);
         q = process_line(copy);
         if ((token = gettok(&q)) != NULL) {
-                next_token = gettok(&q);
-
                 switch (index_in_strings("else\0endif\0", token)) {
                 case ENDIF:
-                        if (next_token != NULL)
+                        if (gettok(&q) != NULL)
                                 error_unexpected("text");
                         if (clevel == 0)
                                 error_unexpected(token);
@@ -1463,23 +1518,39 @@ skip_line(const char *str1)
                         else
                                 cstate[clevel] &= ~SKIP_LINE;
 
-                        if (next_token == NULL) {
+                        token = gettok(&q);
+                        if (token == NULL) {
                                 // Simple else with no conditional directive
                                 cstate[clevel] &= ~EXPECT_ELSE;
                                 ret = TRUE;
                                 goto end;
                         } else {
                                 // A conditional directive is now required ('else if').
-                                token = next_token;
-                                next_token = gettok(&q);
                                 new_level = FALSE;
                         }
-                        break;
                 }
 
-                key = index_in_strings("ifdef\0ifndef\0", token);
+                key = index_in_strings("ifdef\0ifndef\0ifeq\0ifneq\0", token);
                 if (key != -1) {
-                        if (next_token != NULL && gettok(&q) == NULL) {
+                        int match;
+
+                        if (key == IFDEF || key == IFNDEF) {
+                                // ifdef/ifndef: find out if macro is defined.
+                                char *name = gettok(&q);
+                                if (name != NULL && gettok(&q) == NULL) {
+                                        char *t = expand_macros(name, FALSE);
+                                        struct macro *mp = getmp(t);
+                                        match = mp != NULL && mp->m_val[0] != '\0';
+                                        free(t);
+                                } else {
+                                        match = -1;
+                                }
+                        } else {
+                                // ifeq/ifneq: compare strings.
+                                match = compare_strings(q);
+                        }
+
+                        if (match >= 0) {
                                 if (new_level) {
                                         // Start a new level.
                                         if (clevel == IF_MAX)
@@ -1494,17 +1565,12 @@ skip_line(const char *str1)
                                 }
 
                                 if (!(cstate[clevel] & GOT_MATCH)) {
-                                        char *t = expand_macros(next_token, FALSE);
-                                        struct macro *mp = getmp(t);
-                                        int match = mp != NULL && mp->m_val[0] != '\0';
-
-                                        if (key == IFNDEF)
+                                        if (key == IFNDEF || key == IFNEQ)
                                                 match = !match;
                                         if (match) {
                                                 cstate[clevel] &= ~SKIP_LINE;
                                                 cstate[clevel] |= GOT_MATCH;
                                         }
-                                        free(t);
                                 }
                         } else {
                                 error("invalid condition");
diff --git a/testsuite/make.tests b/testsuite/make.tests
index 5119a77d3..ba3855973 100755
--- a/testsuite/make.tests
+++ b/testsuite/make.tests
@@ -553,6 +553,20 @@ src.o: src.c src.h
 '
 cd .. || exit 1; rm -rf make.tempdir 2>/dev/null
 
+# ifeq/ifneq conditionals are supported
+testing 'make support ifeq and ifneq conditionals' \
+        "make -f -" "A OK\nB OK\n" "" '
+A = a
+B = b
+target:
+ifeq ($(A),a)
+        @echo A OK
+endif
+ifneq "a" "$B"
+        @echo B OK
+endif
+'
+
 # An empty original suffix indicates that every word should have
 # the new suffix added.  If neither suffix is provided the words
 # remain unchanged.