From 33932663b031e128200a45818a19fe0620ccb50f Mon Sep 17 00:00:00 2001
From: Dmitry Goncharov <dgoncharov@users.sf.net>
Date: Sat, 6 Jan 2024 17:39:43 -0500
Subject: [PATCH] [SV 65006] Allow secondary expansion of .EXTRA_PREREQS

* src/rule.c (snap_implicit_rules): Set need_2nd_expansion of each
  prerequisite of global .EXTRA_PREREQS.
* src/file.c (snap_file):  Set need_2nd_expansion of each prerequisite
  of target-specific .EXTRA_PREREQS.
* tests/scripts/variables/EXTRA_PREREQS: Add tests.

Reported by Daniel Gerber <dg@atufi.org>.
---
 src/file.c                            | 15 +++++++++---
 src/rule.c                            |  6 +++++
 tests/scripts/variables/EXTRA_PREREQS | 33 +++++++++++++++++++++++++++
 3 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/file.c b/src/file.c
index dc2ea2ae..c3f60046 100644
--- a/src/file.c
+++ b/src/file.c
@@ -722,6 +722,7 @@ snap_file (const void *item, void *arg)
 {
   struct file *f = (struct file*)item;
   struct dep *prereqs = NULL;
+  struct dep *d;
 
   /* If we're not doing second expansion then reset updating.  */
   if (!second_expansion)
@@ -741,14 +742,22 @@ snap_file (const void *item, void *arg)
 
   /* If .EXTRA_PREREQS is set, add them as ignored by automatic variables.  */
   if (f->variables)
-    prereqs = expand_extra_prereqs (lookup_variable_in_set (STRING_SIZE_TUPLE(".EXTRA_PREREQS"), f->variables->set));
-
+    {
+      prereqs = expand_extra_prereqs (lookup_variable_in_set (
+                      STRING_SIZE_TUPLE(".EXTRA_PREREQS"), f->variables->set));
+      if (second_expansion)
+        for (d = prereqs; d; d = d->next)
+          {
+            if (!d->name)
+              d->name = xstrdup (d->file->name);
+            d->need_2nd_expansion = 1;
+          }
+    }
   else if (f->is_target)
     prereqs = copy_dep_chain (arg);
 
   if (prereqs)
     {
-      struct dep *d;
       for (d = prereqs; d; d = d->next)
         if (streq (f->name, dep_name (d)))
           /* Skip circular dependencies.  */
diff --git a/src/rule.c b/src/rule.c
index bdf04e19..51e0500e 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -140,6 +140,12 @@ snap_implicit_rules (void)
       const char *d = dep_name (dep);
       size_t l = strlen (d);
 
+      if (second_expansion)
+        {
+          if (!dep->name)
+            dep->name = xstrdup (dep->file->name);
+          dep->need_2nd_expansion = 1;
+        }
       if (dep->need_2nd_expansion)
         /* When pattern_search allocates a buffer, allow 5 bytes per each % to
            substitute each % with $(*F) while avoiding realloc.  */
diff --git a/tests/scripts/variables/EXTRA_PREREQS b/tests/scripts/variables/EXTRA_PREREQS
index 57ad597e..2f72be30 100644
--- a/tests/scripts/variables/EXTRA_PREREQS
+++ b/tests/scripts/variables/EXTRA_PREREQS
@@ -145,7 +145,40 @@ tick tack: ; @echo $@
 ',
               'all', "tack\ntick\ntack tick\n");
 
+# SV 65006. Second expansion of global .EXTRA_PREQREQS.
+run_make_test('
+.SECONDEXPANSION:
+extradep:=tick tack
+.EXTRA_PREREQS=$$(extradep)
+%.x:; @echo $@
+',
+              'hello.x', "hello.x\n");
+
 unlink('tick', 'tack');
 
+# SV 65006. Second expansion of a target-specific .EXTRA_PREQREQS.
+run_make_test('
+.SECONDEXPANSION:
+all: hello.x;
+extradep=tick tack
+hello.x: .EXTRA_PREREQS=$$(extradep)
+%.x:; @echo $@
+tick tack:; @echo $@
+',
+              '', "tick\ntack\nhello.x\n");
+
+# SV 65006. Second expansion of a target-specific .EXTRA_PREQREQS.
+# The value of .EXTRA_PREQREQS contains automatic variables.
+run_make_test('
+.SECONDEXPANSION:
+all: hello.x world.x
+hello.x world.x: .EXTRA_PREREQS=$$@.d
+%.x:; @echo $@
+%.d:; @echo $@
+',
+              '', "hello.x.d\nhello.x\nworld.x.d\nworld.x\n");
+
+
+
 # This tells the test driver that the perl test script executed properly.
 1;