From 77881d2281035e2ace1e30800ff3528e1ef1fd98 Mon Sep 17 00:00:00 2001
From: Paul Smith <psmith@gnu.org>
Date: Sat, 16 Jul 2022 19:43:34 -0400
Subject: [PATCH] Ensure that MAKEFLAGS is set when invoking $(shell ...)

* src/main.c (main): Don't reset the jobserver if the number of
slots has not changed.
(define_makeflags): Add all normal flags even when ALL is not set.
* tests/scripts/functions/shell: Test invoking make in $(shell ...).
* tests/scripts/variables/MAKEFLAGS: Test the value of MAKEFLAGS in
$(shell ...).
---
 src/main.c                        | 40 +++++++++++++------------------
 tests/scripts/functions/shell     | 15 ++++++++++++
 tests/scripts/variables/MAKEFLAGS | 10 ++++++++
 3 files changed, 42 insertions(+), 23 deletions(-)

diff --git a/src/main.c b/src/main.c
index ef2d2c41..656eaec6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1088,7 +1088,7 @@ main (int argc, char **argv, char **envp)
   PATH_VAR (current_directory);
   unsigned int restarts = 0;
   unsigned int syncing = 0;
-  int argv_slots;
+  int argv_slots;  /* The jobslot info we got from our parent process.  */
 #ifdef WINDOWS32
   const char *unix_path = NULL;
   const char *windows32_path = NULL;
@@ -2013,7 +2013,7 @@ main (int argc, char **argv, char **envp)
     if (arg_job_slots == INVALID_JOB_SLOTS || argv_slots != INVALID_JOB_SLOTS)
       arg_job_slots = old_arg_job_slots;
 
-    else if (jobserver_auth)
+    else if (jobserver_auth && arg_job_slots != old_arg_job_slots)
       {
         /* Makefile MAKEFLAGS set -j, but we already have a jobserver.
            Make us the master of a new jobserver group.  */
@@ -3395,22 +3395,19 @@ define_makeflags (int all, int makefile)
           break;
 
         case positive_int:
-          if (all)
+          if ((cs->default_value != 0
+               && (*(unsigned int *) cs->value_ptr
+                   == *(unsigned int *) cs->default_value)))
+            break;
+          if (cs->noarg_value != 0
+              && (*(unsigned int *) cs->value_ptr ==
+                  *(unsigned int *) cs->noarg_value))
+            ADD_FLAG ("", 0); /* Optional value omitted; see below.  */
+          else
             {
-              if ((cs->default_value != 0
-                   && (*(unsigned int *) cs->value_ptr
-                       == *(unsigned int *) cs->default_value)))
-                break;
-              if (cs->noarg_value != 0
-                  && (*(unsigned int *) cs->value_ptr ==
-                      *(unsigned int *) cs->noarg_value))
-                ADD_FLAG ("", 0); /* Optional value omitted; see below.  */
-              else
-                {
-                  char *buf = alloca (30);
-                  sprintf (buf, "%u", *(unsigned int *) cs->value_ptr);
-                  ADD_FLAG (buf, strlen (buf));
-                }
+              char *buf = alloca (30);
+              sprintf (buf, "%u", *(unsigned int *) cs->value_ptr);
+              ADD_FLAG (buf, strlen (buf));
             }
           break;
 
@@ -3430,12 +3427,9 @@ define_makeflags (int all, int makefile)
           break;
 
         case string:
-          if (all)
-            {
-              p = *((char **)cs->value_ptr);
-              if (p)
-                ADD_FLAG (p, strlen (p));
-            }
+          p = *((char **)cs->value_ptr);
+          if (p)
+            ADD_FLAG (p, strlen (p));
           break;
 
         case filename:
diff --git a/tests/scripts/functions/shell b/tests/scripts/functions/shell
index 80425172..74387918 100644
--- a/tests/scripts/functions/shell
+++ b/tests/scripts/functions/shell
@@ -140,6 +140,21 @@ all: ; @echo '$(.SHELLSTATUS): $(out)'
 !,
                       '', "127: $_\n");
     }
+
+    # If we're using pipes for jobserver, then we will close them and not
+    # allow them to be available to sub-makes invoked via $(shell ...)
+    run_make_test(q!
+ifeq ($(ELT),)
+default:; @$(MAKE) -f #MAKEFILE# ELT=1
+else ifeq ($(ELT),1)
+OUTPUT := $(shell $(MAKE) -f #MAKEFILE# ELT=2)
+$(info $(OUTPUT))
+default:;: $(ELT)
+else
+default:;: $(ELT)
+endif
+!,
+                  '--no-print-directory -j2', "#MAKE#[2]: warning: jobserver unavailable: using -j1.  Add '+' to parent make rule.\n: 2\n: 1");
 }
 
 1;
diff --git a/tests/scripts/variables/MAKEFLAGS b/tests/scripts/variables/MAKEFLAGS
index c8d32631..d5fa0d28 100644
--- a/tests/scripts/variables/MAKEFLAGS
+++ b/tests/scripts/variables/MAKEFLAGS
@@ -129,4 +129,14 @@ all:; $(info makeflags='$(MAKEFLAGS)')
 '-Onone -l2.5 -l2.5 -Onone -I/tmp -iknqrswd -i -n -s -k -I/tmp',
 "/makeflags='Bdiknqrsw -I/tmp -l2.5 -Onone --trace --warn-undefined-variables'/");
 
+# Verify MAKEFLAGS are all available to shell functions
+$ENV{'MAKEFLAGS'} = 'ikB --no-print-directory --warn-undefined-variables';
+run_make_test(q!
+MAKEFLAGS := iknqrsw -I/tmp -I/tmp -Onone -Onone -l2.5 -l2.5 --no-print-directory
+XX := $(shell echo "$$MAKEFLAGS")
+all:; $(info makeflags='$(XX)')
+!,
+    '-Onone -l2.5 -l2.5 -Onone -I/tmp -iknqrs -i -n -s -k -I/tmp',
+    "makeflags='iknqrsw -I/tmp -I/tmp -Onone -Onone -l2.5 -l2.5 --no-print-directory'");
+
 1;