diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f187c313572c255f967e9f65d873e011c1a9b4f5..e3bd0e4324a945ac1482a2e4ad3df7b3fa31912f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,17 @@
+2006-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR c/27747
+	* gcc.dg/cpp/_Pragma6.c: New test.
+
+	PR c++/27748
+	* g++.dg/cpp/_Pragma1.C: New test.
+
+	PR preprocessor/27746
+	* gcc.dg/gomp/macro-3.c: New test.
+	* gcc.dg/gomp/macro-4.c: New test.
+	* g++.dg/gomp/macro-3.C: New test.
+	* g++.dg/gomp/macro-4.C: New test.
+
 2006-06-09  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/26998
diff --git a/gcc/testsuite/g++.dg/cpp/_Pragma1.C b/gcc/testsuite/g++.dg/cpp/_Pragma1.C
new file mode 100644
index 0000000000000000000000000000000000000000..25a79f8863e4f0fba61bbc99e3b87cf5f19d8ed3
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp/_Pragma1.C
@@ -0,0 +1,10 @@
+// PR c++/27748
+// This is supposed to succeed only if
+// the target doesn't define HANDLE_PRAGMA_PACK_WITH_EXPANSION.
+// { dg-do compile { target { ! *-*-solaris2* } } }
+
+#define push bar
+#define foo _Pragma ("pack(push)")
+foo
+int i;
+#pragma pack(pop)
diff --git a/gcc/testsuite/g++.dg/gomp/macro-3.C b/gcc/testsuite/g++.dg/gomp/macro-3.C
new file mode 100644
index 0000000000000000000000000000000000000000..32623fde58ec6c8c3a71a8530b0585fd02bad1db
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/macro-3.C
@@ -0,0 +1,25 @@
+// PR preprocessor/27746
+// { dg-do compile }
+// { dg-options "-fopenmp -fdump-tree-omplower" }
+
+#define omp		FOO
+#define p		parallel
+#define omp_parallel	_Pragma ("omp parallel")
+#define omp_p		_Pragma ("omp p")
+
+void bar (void);
+
+void
+foo (void)
+{
+  #pragma omp parallel
+    bar ();
+  #pragma omp p
+    bar ();
+  omp_parallel
+    bar ();
+  omp_p
+    bar ();
+}
+
+// { dg-final { scan-tree-dump-times "#pragma omp parallel" 4 "omplower" } }
diff --git a/gcc/testsuite/g++.dg/gomp/macro-4.C b/gcc/testsuite/g++.dg/gomp/macro-4.C
new file mode 100644
index 0000000000000000000000000000000000000000..9fc45b143d57323d3eeee250b861c2c8785fc1b4
--- /dev/null
+++ b/gcc/testsuite/g++.dg/gomp/macro-4.C
@@ -0,0 +1,29 @@
+// PR preprocessor/27746
+// { dg-do compile }
+// { dg-options "-fopenmp -Wunknown-pragmas" }
+
+#define p		_Pragma ("omp parallel")
+#define omp_p		_Pragma ("omp p")
+
+void bar (void);
+
+void
+foo (void)
+{
+#pragma omp p		// { dg-warning "ignoring #pragma omp _Pragma" }
+    bar ();
+  omp_p			// { dg-warning "ignoring #pragma omp _Pragma" }
+    bar ();
+}
+
+#define parallel	serial
+#define omp_parallel	_Pragma ("omp parallel")
+
+void
+baz (void)
+{
+#pragma omp parallel	// { dg-warning "ignoring #pragma omp serial" }
+    bar ();
+  omp_parallel		// { dg-warning "ignoring #pragma omp serial" }
+    bar ();
+}
diff --git a/gcc/testsuite/gcc.dg/cpp/_Pragma6.c b/gcc/testsuite/gcc.dg/cpp/_Pragma6.c
new file mode 100644
index 0000000000000000000000000000000000000000..369b334ae4427ba5dc7b5d6b2741e72a2335fceb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/cpp/_Pragma6.c
@@ -0,0 +1,10 @@
+/* PR c/27747 */
+/* This is supposed to succeed only if
+   the target doesn't define HANDLE_PRAGMA_PACK_WITH_EXPANSION.  */
+/* { dg-do compile { target { ! *-*-solaris2* } } } */
+
+#define push bar
+#define foo _Pragma ("pack(push)")
+foo
+int i;
+#pragma pack(pop)
diff --git a/gcc/testsuite/gcc.dg/gomp/macro-3.c b/gcc/testsuite/gcc.dg/gomp/macro-3.c
new file mode 100644
index 0000000000000000000000000000000000000000..dc4fe091b31d3118c8306c9a8f4e0be7c648ed12
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/macro-3.c
@@ -0,0 +1,25 @@
+/* PR preprocessor/27746 */
+/* { dg-do compile } */
+/* { dg-options "-fopenmp -fdump-tree-omplower" } */
+
+#define omp		FOO
+#define p		parallel
+#define omp_parallel	_Pragma ("omp parallel")
+#define omp_p		_Pragma ("omp p")
+
+void bar (void);
+
+void
+foo (void)
+{
+  #pragma omp parallel
+    bar ();
+  #pragma omp p
+    bar ();
+  omp_parallel
+    bar ();
+  omp_p
+    bar ();
+}
+
+/* { dg-final { scan-tree-dump-times "#pragma omp parallel" 4 "omplower" } } */
diff --git a/gcc/testsuite/gcc.dg/gomp/macro-4.c b/gcc/testsuite/gcc.dg/gomp/macro-4.c
new file mode 100644
index 0000000000000000000000000000000000000000..7d20f4cd68d19afcfe8631deab3daaabc2aab758
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gomp/macro-4.c
@@ -0,0 +1,29 @@
+/* PR preprocessor/27746 */
+/* { dg-do compile } */
+/* { dg-options "-fopenmp -Wunknown-pragmas" } */
+
+#define p		_Pragma ("omp parallel")
+#define omp_p		_Pragma ("omp p")
+
+void bar (void);
+
+void
+foo (void)
+{
+#pragma omp p		/* { dg-warning "ignoring #pragma omp _Pragma" } */
+    bar ();
+  omp_p			/* { dg-warning "ignoring #pragma omp _Pragma" } */
+    bar ();
+}
+
+#define parallel	serial
+#define omp_parallel	_Pragma ("omp parallel")
+
+void
+baz (void)
+{
+#pragma omp parallel	/* { dg-warning "ignoring #pragma omp serial" } */
+    bar ();
+  omp_parallel		/* { dg-warning "ignoring #pragma omp serial" } */
+    bar ();
+}
diff --git a/libcpp/ChangeLog b/libcpp/ChangeLog
index 80a1868d809821cfc23fd35510df26a6431f2ed0..865287b25455d1dbc21932698dfc7006bdad64d2 100644
--- a/libcpp/ChangeLog
+++ b/libcpp/ChangeLog
@@ -1,3 +1,18 @@
+2006-06-09  Jakub Jelinek  <jakub@redhat.com>
+
+	PR preprocessor/27746
+	* directives.c (do_pragma): Handle pragma with valid namespace
+	and invalid name coming from macro expansion.
+	* directives.c (destringize_and_run): Initialize next field in
+	context.
+
+	PR c/27747
+	PR c++/27748
+	* directives.c (destringize_and_run): Set NO_EXPAND on the
+	tokens.
+
+	* macro.c (_cpp_backup_tokens): Fix comment typo.
+
 2006-05-31  Daniel Jacobowitz  <dan@codesourcery.com>
 
 	* Makefile.in (CATALOGS): Add po/ prefix.
diff --git a/libcpp/directives.c b/libcpp/directives.c
index 0eea67d133c81d54c373f1268cb53af78cae5111..e08698d76b7c2c2669b3720c1e45f45f0d6b09e8 100644
--- a/libcpp/directives.c
+++ b/libcpp/directives.c
@@ -1265,11 +1265,13 @@ do_pragma (cpp_reader *pfile)
 {
   const struct pragma_entry *p = NULL;
   const cpp_token *token, *pragma_token = pfile->cur_token;
+  cpp_token ns_token;
   unsigned int count = 1;
 
   pfile->state.prevent_expansion++;
 
   token = cpp_get_token (pfile);
+  ns_token = *token;
   if (token->type == CPP_NAME)
     {
       p = lookup_pragma_entry (pfile->pragmas, token->val.node);
@@ -1318,7 +1320,22 @@ do_pragma (cpp_reader *pfile)
     }
   else if (pfile->cb.def_pragma)
     {
-      _cpp_backup_tokens (pfile, count);
+      if (count == 1 || pfile->context->prev == NULL)
+	_cpp_backup_tokens (pfile, count);
+      else
+	{
+	  /* Invalid name comes from macro expansion, _cpp_backup_tokens
+	     won't allow backing 2 tokens.  */
+	  /* ??? The token buffer is leaked.  Perhaps if def_pragma hook
+	     reads both tokens, we could perhaps free it, but if it doesn't,
+	     we don't know the exact lifespan.  */
+	  cpp_token *toks = XNEWVEC (cpp_token, 2);
+	  toks[0] = ns_token;
+	  toks[0].flags |= NO_EXPAND;
+	  toks[1] = *token;
+	  toks[1].flags |= NO_EXPAND;
+	  _cpp_push_token_context (pfile, NULL, toks, 2);
+	}
       pfile->cb.def_pragma (pfile, pfile->directive_line);
     }
 
@@ -1494,6 +1511,7 @@ destringize_and_run (cpp_reader *pfile, const cpp_string *in)
   pfile->context = XNEW (cpp_context);
   pfile->context->macro = 0;
   pfile->context->prev = 0;
+  pfile->context->next = 0;
 
   /* Inline run_directive, since we need to delay the _cpp_pop_buffer
      until we've read all of the tokens that we want.  */
@@ -1534,7 +1552,10 @@ destringize_and_run (cpp_reader *pfile, const cpp_string *in)
 	      maxcount = maxcount * 3 / 2;
 	      toks = XRESIZEVEC (cpp_token, toks, maxcount);
 	    }
-	  toks[count++] = *cpp_get_token (pfile);
+	  toks[count] = *cpp_get_token (pfile);
+	  /* Macros have been already expanded by cpp_get_token
+	     if the pragma allowed expansion.  */
+	  toks[count++].flags |= NO_EXPAND;
 	}
       while (toks[count-1].type != CPP_PRAGMA_EOL);
     }
diff --git a/libcpp/macro.c b/libcpp/macro.c
index 67e936ee31aec4e930e756e9d8bb105ef6cf2f28..b29f3a0c1fa7b6dc12ffbf4148f98832dd7ab866 100644
--- a/libcpp/macro.c
+++ b/libcpp/macro.c
@@ -1180,7 +1180,7 @@ cpp_scan_nooutput (cpp_reader *pfile)
   pfile->state.prevent_expansion--;
 }
 
-/* Step back one (or more) tokens.  Can only step mack more than 1 if
+/* Step back one (or more) tokens.  Can only step back more than 1 if
    they are from the lexer, and not from macro expansion.  */
 void
 _cpp_backup_tokens (cpp_reader *pfile, unsigned int count)