From 656fffe6265af3b5b000cd2e8c314e164fdf5a50 Mon Sep 17 00:00:00 2001
From: Steven Watanabe <steven@providere-consulting.com>
Date: Mon, 30 Apr 2012 16:49:42 +0000
Subject: [PATCH] Don't assume that make1a processes targets in the same order
 as make0.  It doesn't.  Start a new stack when rescanning to avoid spurious
 cycles which cause a seg-fault.

[SVN r78281]
---
 src/engine/make1.c | 38 ++++++++++++++++++++++++--------------
 src/engine/rules.h |  4 ++--
 2 files changed, 26 insertions(+), 16 deletions(-)

diff --git a/src/engine/make1.c b/src/engine/make1.c
index 451ef6983..912062206 100644
--- a/src/engine/make1.c
+++ b/src/engine/make1.c
@@ -270,13 +270,13 @@ int make1( TARGET * t )
 
 static void make1a( state * pState )
 {
-    TARGET * t = target_scc( pState->t );
+
+    TARGET * t = pState->t;
+    TARGET * scc_root = target_scc( t );
     TARGETS * c;
 
-    if ( pState->parent == NULL || target_scc( pState->parent ) != t )
-        pState->t = t;
-    else
-        t = pState->t;
+    if ( pState->parent == NULL || target_scc( pState->parent ) != scc_root )
+        pState->t = t = scc_root;
 
     /* If the parent is the first to try to build this target or this target is
      * in the make1c() quagmire, arrange for the parent to be notified when this
@@ -288,9 +288,12 @@ static void make1a( state * pState )
         switch ( t->progress )
         {
             case T_MAKE_ONSTACK:
-                if ( target_scc( pState->parent ) != t )
-                    make1breakcycle( pState->parent, t );
-                break;
+                if ( t->depth == handling_rescan )
+                {
+                    if ( target_scc( pState->parent ) != scc_root )
+                        make1breakcycle( pState->parent, t );
+                    break;
+                }
             case T_MAKE_ACTIVE:
                 if ( handling_rescan && ( cycle_root = make1findcycle( t ) ) )
                 {
@@ -346,6 +349,7 @@ static void make1a( state * pState )
 
     /* Guard against circular dependencies. */
     t->progress = T_MAKE_ONSTACK;
+    t->depth = handling_rescan;
 
     {
         stack temp_stack = { NULL };
@@ -1238,11 +1242,15 @@ static TARGET * make1findcycle_impl( TARGET * t, TARGET * scc_root )
     TARGET * result;
 
     if ( t->progress == T_MAKE_ONSTACK )
-        return t;
-    else if ( t->progress != T_MAKE_ACTIVE )
+        if ( t->depth == handling_rescan )
+            return t;
+        else
+            t->progress = T_MAKE_FINDCYCLE_ONSTACK;
+    else if ( t->progress == T_MAKE_ACTIVE )
+        t->progress = T_MAKE_FINDCYCLE_ACTIVE;
+    else
         return 0;
 
-    t->progress = T_MAKE_FINDCYCLE;
 
     for ( c = t->depends; c; c = c->next )
         if ( ( result = make1findcycle_impl( c->target, scc_root ) ) )
@@ -1258,11 +1266,13 @@ static void make1findcycle_cleanup( TARGET * t )
 {
     TARGETS * c;
 
-    if ( t->progress != T_MAKE_FINDCYCLE )
+    if ( t->progress == T_MAKE_FINDCYCLE_ACTIVE )
+        t->progress = T_MAKE_ACTIVE;
+    else if ( t->progress == T_MAKE_FINDCYCLE_ONSTACK )
+        t->progress = T_MAKE_ONSTACK;
+    else
         return;
 
-    t->progress = T_MAKE_ACTIVE;
-
     for ( c = t->depends; c; c = c->next )
         make1findcycle_cleanup( c->target );
 }
diff --git a/src/engine/rules.h b/src/engine/rules.h
index 758e53644..f38e2a2b7 100644
--- a/src/engine/rules.h
+++ b/src/engine/rules.h
@@ -212,8 +212,8 @@ struct _target
 #define T_MAKE_RUNNING        3       /* make1(target) running commands */
 #define T_MAKE_DONE           4       /* make1(target) done */
 #define T_MAKE_NOEXEC_DONE    5       /* make1(target) done with -n in effect */
-#define T_MAKE_FINDCYCLE      6       /* make1(target) searching for cyclic includes after
-                                         rescanning a generated file. */
+#define T_MAKE_FINDCYCLE_ONSTACK  6   /* make1(target) searching for cyclic includes after */
+#define T_MAKE_FINDCYCLE_ACTIVE   7   /* rescanning a generated file. */
 
 #ifdef OPT_SEMAPHORE
     #define T_MAKE_SEMAPHORE  5       /* Special target type for semaphores */