[PATCH 3/4] c/c++, asm: Use nicer error for const and restrict

[Segher Boessenkool <segher at kernel dot crashing dot org>]

Not all qualifiers are asm qualifiers.  We can talk about that in a
nicer way than just giving a generic parser error.

This also adds two testcases for C++, that previously were for C only.


2018-12-10  Segher Boessenkool  <segher@kernel.crashing.org>

c/
	* c-parser.c (c_parser_asm_statement) <RID_CONST, RID_RESTRICT>: Give
	a more specific error message (instead of just falling through).

cp/
	* parser.c (cp_parser_asm_definition) <RID_CONST, RID_RESTRICT>: Give
	a more specific error message (instead of just falling through).

testsuite/
	* g++.dg/asm-qual-1.C: New testcase.
	* g++.dg/asm-qual-2.C: New testcase.
	* gcc.dg/asm-qual-1.c: Update.

---
 gcc/c/c-parser.c                  |  6 +++++
 gcc/cp/parser.c                   |  6 +++++
 gcc/testsuite/g++.dg/asm-qual-1.C | 13 +++++++++++
 gcc/testsuite/g++.dg/asm-qual-2.C | 46 +++++++++++++++++++++++++++++++++++++++
 gcc/testsuite/gcc.dg/asm-qual-1.c |  6 ++---
 5 files changed, 73 insertions(+), 4 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/asm-qual-1.C
 create mode 100644 gcc/testsuite/g++.dg/asm-qual-2.C

diff --git a/gcc/c/c-parser.c b/gcc/c/c-parser.c
index 652e53c..0def497 100644
--- a/gcc/c/c-parser.c
+++ b/gcc/c/c-parser.c
@@ -6411,6 +6411,12 @@ c_parser_asm_statement (c_parser *parser)
 	  c_parser_consume_token (parser);
 	  continue;
 
+	case RID_CONST:
+	case RID_RESTRICT:
+	  error_at (loc, "%qE is not an asm qualifier", token->value);
+	  c_parser_consume_token (parser);
+	  continue;
+
 	default:
 	  break;
 	}
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index 06a6bb0..4072afe 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -19693,6 +19693,12 @@ cp_parser_asm_definition (cp_parser* parser)
 	    cp_lexer_consume_token (parser->lexer);
 	    continue;
 
+	  case RID_CONST:
+	  case RID_RESTRICT:
+	    error_at (loc, "%qT is not an asm qualifier", token->u.value);
+	    cp_lexer_consume_token (parser->lexer);
+	    continue;
+
 	  default:
 	    break;
 	  }
diff --git a/gcc/testsuite/g++.dg/asm-qual-1.C b/gcc/testsuite/g++.dg/asm-qual-1.C
new file mode 100644
index 0000000..3fba592
--- /dev/null
+++ b/gcc/testsuite/g++.dg/asm-qual-1.C
@@ -0,0 +1,13 @@
+// Test that qualifiers other than volatile are disallowed on asm.
+// { dg-do compile }
+// { dg-options "-std=gnu++98" }
+
+void
+f ()
+{
+  asm volatile ("");
+
+  asm const (""); // { dg-error {'const' is not an asm qualifier} }
+
+  asm __restrict (""); // { dg-error {'__restrict' is not an asm qualifier} }
+}
diff --git a/gcc/testsuite/g++.dg/asm-qual-2.C b/gcc/testsuite/g++.dg/asm-qual-2.C
new file mode 100644
index 0000000..52968bd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/asm-qual-2.C
@@ -0,0 +1,46 @@
+// Test that qualifiers on asm are allowed in any order.
+// { dg-do compile }
+// { dg-options "-std=c++98" }
+
+void
+f ()
+{
+  asm volatile goto ("" :::: lab);
+  asm volatile inline ("" :::);
+  asm inline volatile ("" :::);
+  asm inline goto ("" :::: lab);
+  asm goto volatile ("" :::: lab);
+  asm goto inline ("" :::: lab);
+
+  asm volatile inline goto ("" :::: lab);
+  asm volatile goto inline ("" :::: lab);
+  asm inline volatile goto ("" :::: lab);
+  asm inline goto volatile ("" :::: lab);
+  asm goto volatile inline ("" :::: lab);
+  asm goto inline volatile ("" :::: lab);
+
+  /* Duplicates are not allowed.  */
+  asm goto volatile volatile ("" :::: lab);  /* { dg-error "" } */
+  asm volatile goto volatile ("" :::: lab);  /* { dg-error "" } */
+  asm volatile volatile goto ("" :::: lab);  /* { dg-error "" } */
+  asm goto goto volatile ("" :::: lab);  /* { dg-error "" } */
+  asm goto volatile goto ("" :::: lab);  /* { dg-error "" } */
+  asm volatile goto goto ("" :::: lab);  /* { dg-error "" } */
+
+  asm inline volatile volatile ("" :::);  /* { dg-error "" } */
+  asm volatile inline volatile ("" :::);  /* { dg-error "" } */
+  asm volatile volatile inline ("" :::);  /* { dg-error "" } */
+  asm inline inline volatile ("" :::);  /* { dg-error "" } */
+  asm inline volatile inline ("" :::);  /* { dg-error "" } */
+  asm volatile inline inline ("" :::);  /* { dg-error "" } */
+
+  asm goto inline inline ("" :::: lab);  /* { dg-error "" } */
+  asm inline goto inline ("" :::: lab);  /* { dg-error "" } */
+  asm inline inline goto ("" :::: lab);  /* { dg-error "" } */
+  asm goto goto inline ("" :::: lab);  /* { dg-error "" } */
+  asm goto inline goto ("" :::: lab);  /* { dg-error "" } */
+  asm inline goto goto ("" :::: lab);  /* { dg-error "" } */
+
+lab:
+  ;
+}
diff --git a/gcc/testsuite/gcc.dg/asm-qual-1.c b/gcc/testsuite/gcc.dg/asm-qual-1.c
index cb37283..eff6b45 100644
--- a/gcc/testsuite/gcc.dg/asm-qual-1.c
+++ b/gcc/testsuite/gcc.dg/asm-qual-1.c
@@ -8,9 +8,7 @@ f (void)
 {
   asm volatile ("");
 
-  asm const (""); /* { dg-error {expected '\(' before 'const'} } */
-  /* { dg-error {expected identifier} {} {target *-*-*} .-1 } */
+  asm const (""); /* { dg-error {'const' is not an asm qualifier} } */
 
-  asm restrict (""); /* { dg-error {expected '\(' before 'restrict'} } */
-  /* { dg-error {expected identifier} {} {target *-*-*} .-1 } */
+  asm restrict (""); /* { dg-error {'restrict' is not an asm qualifier} } */
 }
-- 
1.8.3.1