diff --git gcc/gcc/c-family/c-opts.c gcc/gcc/c-family/c-opts.c
index 43a8b9d..b0cad20 100644
--- gcc/gcc/c-family/c-opts.c
+++ gcc/gcc/c-family/c-opts.c
@@ -1299,10 +1299,13 @@ sanitize_cpp_opts (void)
 
   /* Wlong-long is disabled by default. It is enabled by:
       [-Wpedantic | -Wtraditional] -std=[gnu|c]++98 ; or
-      [-Wpedantic | -Wtraditional] -std=non-c99 .
+      [-Wpedantic | -Wtraditional] -std=non-c99 ; or
+      -Wc90-c99-compat, if specified.
 
       Either -Wlong-long or -Wno-long-long override any other settings.  */
-  if (warn_long_long == -1)
+  if (warn_long_long == -1 && warn_c90_c99_compat != -1)
+    warn_long_long = warn_c90_c99_compat;
+  else if (warn_long_long == -1)
     warn_long_long = ((pedantic || warn_traditional)
 		      && (c_dialect_cxx () ? cxx_dialect == cxx98 : !flag_isoc99));
   cpp_opts->cpp_warn_long_long = warn_long_long;
diff --git gcc/gcc/c-family/c.opt gcc/gcc/c-family/c.opt
index 356a79f..087eabd 100644
--- gcc/gcc/c-family/c.opt
+++ gcc/gcc/c-family/c.opt
@@ -292,7 +292,7 @@ C ObjC C++ ObjC++ Warning
 Warn when a built-in preprocessor macro is undefined or redefined
 
 Wc90-c99-compat
-C ObjC Var(warn_c90_c99_compat) Warning
+C ObjC Var(warn_c90_c99_compat) Init(-1) Warning
 Warn about features not present in ISO C90, but present in ISO C99
 
 Wc++-compat
@@ -344,7 +344,7 @@ C++ ObjC++ Var(warn_ctor_dtor_privacy) Warning
 Warn when all constructors and destructors are private
 
 Wdeclaration-after-statement
-C ObjC Var(warn_declaration_after_statement) Warning
+C ObjC Var(warn_declaration_after_statement) Init(-1) Warning
 Warn when a declaration is found after a statement
 
 Wdelete-incomplete
diff --git gcc/gcc/c/c-decl.c gcc/gcc/c/c-decl.c
index 7ba35bf..138b014 100644
--- gcc/gcc/c/c-decl.c
+++ gcc/gcc/c/c-decl.c
@@ -4920,27 +4920,23 @@ check_bitfield_type_and_width (tree *type, tree *width, tree orig_name)
 static void
 warn_variable_length_array (tree name, tree size)
 {
-  int const_size = TREE_CONSTANT (size);
-  enum opt_code opt = (warn_vla == -1 && !warn_c90_c99_compat)
-		      ? OPT_Wpedantic : OPT_Wvla;
-
-  if (const_size)
+  if (TREE_CONSTANT (size))
     {
       if (name)
-	pedwarn_c90 (input_location, opt,
+	pedwarn_c90 (input_location, OPT_Wvla,
 		     "ISO C90 forbids array %qE whose size "
 		     "can%'t be evaluated", name);
       else
-	pedwarn_c90 (input_location, opt, "ISO C90 forbids array "
+	pedwarn_c90 (input_location, OPT_Wvla, "ISO C90 forbids array "
 		     "whose size can%'t be evaluated");
     }
   else
     {
       if (name)
-	pedwarn_c90 (input_location, opt,
+	pedwarn_c90 (input_location, OPT_Wvla,
 		     "ISO C90 forbids variable length array %qE", name);
       else
-	pedwarn_c90 (input_location, opt, "ISO C90 forbids variable "
+	pedwarn_c90 (input_location, OPT_Wvla, "ISO C90 forbids variable "
 		     "length array");
     }
 }
diff --git gcc/gcc/c/c-errors.c gcc/gcc/c/c-errors.c
index 5a95b88..89393b9 100644
--- gcc/gcc/c/c-errors.c
+++ gcc/gcc/c/c-errors.c
@@ -27,6 +27,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tm_p.h"
 #include "flags.h"
 #include "diagnostic.h"
+#include "opts.h"
 
 /* Issue an ISO C99 pedantic warning MSGID.  */
 
@@ -56,26 +57,44 @@ pedwarn_c90 (location_t location, int opt, const char *gmsgid, ...)
 {
   diagnostic_info diagnostic;
   va_list ap;
-  bool warned = false;
 
   va_start (ap, gmsgid);
-  if (pedantic && !flag_isoc99)
+  /* Warnings such as -Wvla are the most specific ones.  */
+  if (opt != OPT_Wpedantic)
     {
-      diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_PEDWARN);
-      diagnostic.option_index = opt;
-      warned = report_diagnostic (&diagnostic);
+      int opt_var = *(int *) option_flag_var (opt, &global_options);
+      if (opt_var == 0)
+        goto out;
+      else if (opt_var > 0)
+	{
+	  diagnostic_set_info (&diagnostic, gmsgid, &ap, location,
+			       (pedantic && !flag_isoc99)
+			       ? DK_PEDWARN : DK_WARNING);
+	  diagnostic.option_index = opt;
+	  report_diagnostic (&diagnostic);
+	  goto out;
+	}
     }
-  else if (opt != OPT_Wpedantic)
+  /* Maybe we want to issue the C90/C99 compat warning, which is more
+     specific than -pedantic.  */
+  if (warn_c90_c99_compat > 0)
     {
-      diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
-      diagnostic.option_index = opt;
-      warned = report_diagnostic (&diagnostic);
+      diagnostic_set_info (&diagnostic, gmsgid, &ap, location,
+			   (pedantic && !flag_isoc99)
+			   ? DK_PEDWARN : DK_WARNING);
+      diagnostic.option_index = OPT_Wc90_c99_compat;
+      report_diagnostic (&diagnostic);
     }
-  if (warn_c90_c99_compat && !warned)
+  /* -Wno-c90-c99-compat suppresses the pedwarns.  */
+  else if (warn_c90_c99_compat == 0)
+    ;
+  /* For -pedantic outside C99, issue a pedwarn.  */
+  else if (pedantic && !flag_isoc99)
     {
-      diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_WARNING);
-      diagnostic.option_index = OPT_Wc90_c99_compat;
+      diagnostic_set_info (&diagnostic, gmsgid, &ap, location, DK_PEDWARN);
+      diagnostic.option_index = opt;
       report_diagnostic (&diagnostic);
     }
+out:
   va_end (ap);
 }
diff --git gcc/gcc/c/c-parser.c gcc/gcc/c/c-parser.c
index ca8577c..e1201f9 100644
--- gcc/gcc/c/c-parser.c
+++ gcc/gcc/c/c-parser.c
@@ -1073,7 +1073,10 @@ disable_extension_diagnostics (void)
 	     | (warn_long_long << 4)
 	     | (warn_cxx_compat << 5)
 	     | (warn_overlength_strings << 6)
-	     | (warn_c90_c99_compat << 7));
+	     /* warn_c90_c99_compat has three states: -1/0/1, so we must
+		play tricks to properly restore it.  */
+	     | ((warn_c90_c99_compat == 1) << 7)
+	     | ((warn_c90_c99_compat == -1) << 8));
   cpp_opts->cpp_pedantic = pedantic = 0;
   warn_pointer_arith = 0;
   cpp_opts->cpp_warn_traditional = warn_traditional = 0;
@@ -1098,7 +1101,8 @@ restore_extension_diagnostics (int flags)
   cpp_opts->cpp_warn_long_long = warn_long_long = (flags >> 4) & 1;
   warn_cxx_compat = (flags >> 5) & 1;
   warn_overlength_strings = (flags >> 6) & 1;
-  warn_c90_c99_compat = (flags >> 7) & 1;
+  /* See above for why is this needed.  */
+  warn_c90_c99_compat = (flags >> 7) & 1 ? 1 : ((flags >> 8) & 1 ? -1 : 0);
 }
 
 /* Possibly kinds of declarator to parse.  */
@@ -4570,9 +4574,7 @@ c_parser_compound_statement_nostart (c_parser *parser)
 	  c_parser_declaration_or_fndef (parser, true, true, true, true,
 					 true, NULL, vNULL);
 	  if (last_stmt)
-	    pedwarn_c90 (loc, (pedantic && !flag_isoc99)
-			       ? OPT_Wpedantic
-			       : OPT_Wdeclaration_after_statement,
+	    pedwarn_c90 (loc, OPT_Wdeclaration_after_statement,
 			 "ISO C90 forbids mixed declarations and code");
 	  last_stmt = false;
 	}
@@ -4600,9 +4602,7 @@ c_parser_compound_statement_nostart (c_parser *parser)
 		 disable this diagnostic.  */
 	      restore_extension_diagnostics (ext);
 	      if (last_stmt)
-		pedwarn_c90 (loc, (pedantic && !flag_isoc99)
-				  ? OPT_Wpedantic
-				  : OPT_Wdeclaration_after_statement,
+		pedwarn_c90 (loc, OPT_Wdeclaration_after_statement,
 			     "ISO C90 forbids mixed declarations and code");
 	      last_stmt = false;
 	    }
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
index e8d2f03..97ee84c 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-4.c
@@ -1,48 +1,46 @@
 /* { dg-do compile } */
 /* { dg-options "-std=gnu90 -Wpedantic -Wno-c90-c99-compat" } */
 
-_Bool b; /* { dg-warning "ISO C90 does not support boolean types" } */
-_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-warning "ISO C90 does not support complex types" } */
-long long l; /* { dg-warning "ISO C90 does not support .long long." } */
-struct A { int i; char a[]; }; /* { dg-warning "ISO C90 does not support flexible array members" } */
-struct { long int b: 2; } s; /* { dg-warning "type of bit-field .b. is a GCC extension" } */
-const const int i; /* { dg-warning "duplicate .const." } */
-volatile volatile int v; /* { dg-warning "duplicate .volatile." } */
+_Bool b;
+_Complex double c = __builtin_complex (0.0, 0.0);
+long long l;
+struct A { int i; char a[]; };
+struct { long int b: 2; } s;
+const const int i;
+volatile volatile int v;
 
 struct S { int a[2]; };
 extern struct S foo (void);
 
-#define V(v, ...) (v, __VA_ARGS) /* { dg-warning "anonymous variadic macros were introduced in C99" } */
+enum { E, };
 
-enum { E, }; /* { dg-warning "comma at end of enumerator list" } */
-
-void fn1 (char [*]); /* { dg-warning "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+void fn1 (char [*]);
 
 void
-fn2 (char x[static 4]) /* { dg-warning "ISO C90 does not support .static. or type qualifiers" } */
+fn2 (char x[static 4])
 {
-  int i = (int) { 1 }; /* { dg-warning "ISO C90 forbids compound literals" } */
-  struct A a = { .i = 3 }; /* { dg-warning "ISO C90 forbids specifying subobject to initialize" } */
+  int i = (int) { 1 };
+  struct A a = { .i = 3 };
 }
 
 void
 fn3 (int n)
 {
   n = 3;
-  int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+  int i;
 }
 
 void
 fn4 (int n)
 {
   n = 3;
-  __extension__ int i; /* { dg-warning "ISO C90 forbids mixed declarations and code" } */
+  __extension__ int i;
 }
 
 void
 fn5 (void)
 {
-  (foo ()).a[0]; /* { dg-warning "ISO C90 forbids subscripting non-lvalue array" } */
+  (foo ()).a[0];
 }
 
 #define F(a) a
@@ -50,7 +48,7 @@ fn5 (void)
 void
 fn6 (void)
 {
-  F(); /* { dg-warning "invoking macro F argument" } */
+  F();
 }
 
-void fn7 (int n, int a[n]); /* { dg-warning "ISO C90 forbids variable length array .a." } */
+void fn7 (int n, int a[n]);
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
index 1344ae8..f41e960 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-5.c
@@ -1,48 +1,46 @@
 /* { dg-do compile } */
 /* { dg-options "-std=gnu90 -pedantic-errors -Wno-c90-c99-compat" } */
 
-_Bool b; /* { dg-error "ISO C90 does not support boolean types" } */
-_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-error "ISO C90 does not support complex types" } */
-long long l; /* { dg-error "ISO C90 does not support .long long." } */
-struct A { int i; char a[]; }; /* { dg-error "ISO C90 does not support flexible array members" } */
-struct { long int b: 2; } s; /* { dg-error "type of bit-field .b. is a GCC extension" } */
-const const int i; /* { dg-error "duplicate .const." } */
-volatile volatile int v; /* { dg-error "duplicate .volatile." } */
+_Bool b;
+_Complex double c = __builtin_complex (0.0, 0.0);
+long long l;
+struct A { int i; char a[]; };
+struct { long int b: 2; } s;
+const const int i;
+volatile volatile int v;
 
 struct S { int a[2]; };
 extern struct S foo (void);
 
-#define V(v, ...) (v, __VA_ARGS) /* { dg-error "anonymous variadic macros were introduced in C99" } */
+enum { E, };
 
-enum { E, }; /* { dg-error "comma at end of enumerator list" } */
-
-void fn1 (char [*]); /* { dg-error "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+void fn1 (char [*]);
 
 void
-fn2 (char x[static 4]) /* { dg-error "ISO C90 does not support .static. or type qualifiers" } */
+fn2 (char x[static 4])
 {
-  int i = (int) { 1 }; /* { dg-error "ISO C90 forbids compound literals" } */
-  struct A a = { .i = 3 }; /* { dg-error "ISO C90 forbids specifying subobject to initialize" } */
+  int i = (int) { 1 };
+  struct A a = { .i = 3 };
 }
 
 void
 fn3 (int n)
 {
   n = 3;
-  int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+  int i;
 }
 
 void
 fn4 (int n)
 {
   n = 3;
-  __extension__ int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+  __extension__ int i;
 }
 
 void
 fn5 (void)
 {
-  (foo ()).a[0]; /* { dg-error "ISO C90 forbids subscripting non-lvalue array" } */
+  (foo ()).a[0];
 }
 
 #define F(a) a
@@ -50,7 +48,7 @@ fn5 (void)
 void
 fn6 (void)
 {
-  F(); /* { dg-error "invoking macro F argument" } */
+  F();
 }
 
-void fn7 (int n, int a[n]); /* { dg-error "ISO C90 forbids variable length array .a." } */
+void fn7 (int n, int a[n]);
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-7.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-7.c
index e69de29..fbf0b0d 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-7.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-7.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -Wpedantic -Wc90-c99-compat -Wno-long-long -Wno-declaration-after-statement -Wno-vla" } */
+
+long long l;
+
+void
+fn3 (int n)
+{
+  n = 3;
+  int i;
+}
+
+void fn7 (int n, int a[n]);
diff --git gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-8.c gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-8.c
index e69de29..5e7a572 100644
--- gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-8.c
+++ gcc/gcc/testsuite/gcc.dg/Wc90-c99-compat-8.c
@@ -0,0 +1,56 @@
+/* { dg-do compile } */
+/* { dg-options "-std=gnu90 -pedantic-errors -Wc90-c99-compat" } */
+
+_Bool b; /* { dg-error "ISO C90 does not support boolean types" } */
+_Complex double c = __builtin_complex (0.0, 0.0); /* { dg-error "ISO C90 does not support complex types" } */
+long long l; /* { dg-error "ISO C90 does not support .long long." } */
+struct A { int i; char a[]; }; /* { dg-error "ISO C90 does not support flexible array members" } */
+struct { long int b: 2; } s; /* { dg-error "type of bit-field .b. is a GCC extension" } */
+const const int i; /* { dg-error "duplicate .const." } */
+volatile volatile v; /* { dg-error "duplicate .volatile." } */
+
+struct S { int a[2]; };
+extern struct S foo (void);
+
+#define V(v, ...) (v, __VA_ARGS) /* { dg-error "anonymous variadic macros were introduced in C99" } */
+
+enum { E, }; /* { dg-error "comma at end of enumerator list" } */
+
+void fn1 (char [*]); /* { dg-error "ISO C90 does not support .\\\[\\\*\\\]. array declarators" } */
+
+void
+fn2 (char x[static 4]) /* { dg-error "ISO C90 does not support .static. or type qualifiers" } */
+{
+  int i = (int) { 1 }; /* { dg-error "ISO C90 forbids compound literals" } */
+  struct A a = { .i = 3 }; /* { dg-error "ISO C90 forbids specifying subobject to initialize" } */
+}
+
+void
+fn3 (int n)
+{
+  n = 3;
+  int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn4 (int n)
+{
+  n = 3;
+  __extension__ int i; /* { dg-error "ISO C90 forbids mixed declarations and code" } */
+}
+
+void
+fn5 (void)
+{
+  (foo ()).a[0]; /* { dg-error "ISO C90 forbids subscripting non-lvalue array" } */
+}
+
+#define F(a) a
+
+void
+fn6 (void)
+{
+  F(); /* { dg-error "invoking macro F argument" } */
+}
+
+void fn7 (int n, int a[n]); /* { dg-error "ISO C90 forbids variable length array .a." } */
diff --git gcc/gcc/testsuite/gcc.dg/Wdeclaration-after-statement-4.c gcc/gcc/testsuite/gcc.dg/Wdeclaration-after-statement-4.c
index e69de29..c01d8bc 100644
--- gcc/gcc/testsuite/gcc.dg/Wdeclaration-after-statement-4.c
+++ gcc/gcc/testsuite/gcc.dg/Wdeclaration-after-statement-4.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-options "-std=c90 -pedantic -Wno-declaration-after-statement" } */
+
+extern void abort (void);
+extern void exit (int);
+
+int
+main (void)
+{
+  int i = 0;
+  if (i != 0)
+    abort ();
+  i++;
+  if (i != 1)
+    abort ();
+  int j = i;
+  if (j != 1)
+    abort ();
+  struct foo { int i0; } k = { 4 };
+  if (k.i0 != 4)
+    abort ();
+  exit (0);
+}
diff --git gcc/libcpp/charset.c gcc/libcpp/charset.c
index fa46f92..07a594d 100644
--- gcc/libcpp/charset.c
+++ gcc/libcpp/charset.c
@@ -995,7 +995,7 @@ _cpp_valid_ucn (cpp_reader *pfile, const uchar **pstr,
   if (!CPP_OPTION (pfile, cplusplus) && !CPP_OPTION (pfile, c99))
     cpp_error (pfile, CPP_DL_WARNING,
 	       "universal character names are only valid in C++ and C99");
-  else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+  else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat) > 0
 	   && !CPP_OPTION (pfile, cplusplus))
     cpp_error (pfile, CPP_DL_WARNING,
 	       "C99's universal character names are incompatible with C90");
diff --git gcc/libcpp/include/cpplib.h gcc/libcpp/include/cpplib.h
index 4cd66cd..b89ba20 100644
--- gcc/libcpp/include/cpplib.h
+++ gcc/libcpp/include/cpplib.h
@@ -467,7 +467,7 @@ struct cpp_options
   bool restore_pch_deps;
 
   /* True if warn about differences between C90 and C99.  */
-  bool cpp_warn_c90_c99_compat;
+  char cpp_warn_c90_c99_compat;
 
   /* Dependency generation.  */
   struct
diff --git gcc/libcpp/lex.c gcc/libcpp/lex.c
index 5cc2224..0713f65 100644
--- gcc/libcpp/lex.c
+++ gcc/libcpp/lex.c
@@ -2337,7 +2337,7 @@ _cpp_lex_direct (cpp_reader *pfile)
 	      buffer->warned_cplusplus_comments = 1;
 	    }
 	  /* Or if specifically desired via -Wc90-c99-compat.  */
-	  else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+	  else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat) > 0
 		   && ! buffer->warned_cplusplus_comments)
 	    {
 	      cpp_error (pfile, CPP_DL_WARNING,
diff --git gcc/libcpp/macro.c gcc/libcpp/macro.c
index ff6685c..a1ba137 100644
--- gcc/libcpp/macro.c
+++ gcc/libcpp/macro.c
@@ -1787,7 +1787,7 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
 		       " in ISO C++98",
 		       NODE_NAME (node),
 		       src->val.macro_arg.arg_no);
-	  else
+	  else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat))
 	    cpp_error (pfile, CPP_DL_PEDWARN,
 		       "invoking macro %s argument %d: "
 		       "empty macro arguments are undefined"
@@ -1795,7 +1795,7 @@ replace_args (cpp_reader *pfile, cpp_hashnode *node, cpp_macro *macro,
 		       NODE_NAME (node),
 		       src->val.macro_arg.arg_no);
 	}
-      else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+      else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat) > 0
 	       && ! macro->syshdr
 	       && ! cpp_in_system_header (pfile)
 	       && ! CPP_OPTION (pfile, cplusplus))
@@ -2858,7 +2858,7 @@ parse_params (cpp_reader *pfile, cpp_macro *macro)
 			(pfile, CPP_W_VARIADIC_MACROS,
 			"anonymous variadic macros were introduced in C99");
 		}
-	      else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat)
+	      else if (CPP_OPTION (pfile, cpp_warn_c90_c99_compat) > 0
 		       && ! CPP_OPTION (pfile, cplusplus))
 		cpp_error (pfile, CPP_DL_WARNING,
 			   "anonymous variadic macros were introduced in C99");
