c: Fix location for _Pragma tokens [PR97498]

The handling of #pragma GCC diagnostic uses input_location, which is not always
as precise as needed; in particular the relative location of some tokens and a
_Pragma directive will crucially determine whether a given diagnostic is enabled
or suppressed in the desired way. PR97498 shows how the C frontend ends up with
input_location pointing to the beginning of the line containing a _Pragma()
directive, resulting in the wrong behavior if the diagnostic to be modified
pertains to some tokens found earlier on the same line. This patch fixes that by
addressing two issues:

    a) libcpp was not assigning a valid location to the CPP_PRAGMA token
    generated by the _Pragma directive.
    b) C frontend was not setting input_location to something reasonable.

With this change, the C frontend is able to change input_location to point to
the _Pragma token as needed.

This is just a two-line fix (one for each of a) and b)), the testsuite changes
were needed only because the location on the tested warnings has been somewhat
improved, so the tests need to look for the new locations.

gcc/c/ChangeLog:

	PR preprocessor/97498
	* c-parser.cc (c_parser_pragma): Set input_location to the
	location of the pragma, rather than the start of the line.

libcpp/ChangeLog:

	PR preprocessor/97498
	* directives.cc (destringize_and_run): Override the location of
	the CPP_PRAGMA token from a _Pragma directive to the location of
	the expansion point, as is done for the tokens lexed from it.

gcc/testsuite/ChangeLog:

	PR preprocessor/97498
	* c-c++-common/pr97498.c: New test.
	* c-c++-common/gomp/pragma-3.c: Adapt for improved warning locations.
	* c-c++-common/gomp/pragma-5.c: Likewise.
	* gcc.dg/pragma-message.c: Likewise.

libgomp/ChangeLog:

	* testsuite/libgomp.oacc-c-c++-common/reduction-5.c: Adapt for
	improved warning locations.
	* testsuite/libgomp.oacc-c-c++-common/vred2d-128.c: Likewise.

(cherry picked from commit 0587cef3d7962a8b0f44779589ba2920dd3d71e5)

diff --git a/gcc/c/c-parser.cc b/gcc/c/c-parser.cc
index 129dd727ef396257fc1ca28f2201c1c6f1a3819d..f679d53706a98bedace94a54176c0dde2c127f6b 100644 (file)
--- a/gcc/c/c-parser.cc
+++ b/gcc/c/c-parser.cc
@@ -12378,6 +12378,7 @@ c_parser_pragma (c_parser *parser, enum pragma_context context, bool *if_p)
   unsigned int id;
   const char *construct = NULL;
 
+  input_location = c_parser_peek_token (parser)->location;
   id = c_parser_peek_token (parser)->pragma_kind;
   gcc_assert (id != PRAGMA_NONE);
 

diff --git a/gcc/testsuite/c-c++-common/gomp/pragma-3.c b/gcc/testsuite/c-c++-common/gomp/pragma-3.c
index c1dee1bcc62c7d67119f9551d2da8bc42f8fe9cc..ae18e9b888613adde69fbb583f64f13abe29f7b6 100644 (file)
--- a/gcc/testsuite/c-c++-common/gomp/pragma-3.c
+++ b/gcc/testsuite/c-c++-common/gomp/pragma-3.c
@@ -1,13 +1,14 @@
 /* { dg-additional-options "-fdump-tree-original" }  */
 /* PR preprocessor/103165  */
 
-#define inner(...) #__VA_ARGS__ ; _Pragma("omp error severity(warning) message (\"Test\") at(compilation)")
+#define inner(...) #__VA_ARGS__ ; _Pragma("omp error severity(warning) message (\"Test\") at(compilation)") /* { dg-line inner_location } */
 #define outer(...) inner(__VA_ARGS__)
 
 void
 f (void)
 {
-  const char *str = outer(inner(1,2));  /* { dg-warning "'pragma omp error' encountered: Test" } */
+  const char *str = outer(inner(1,2));
+  /* { dg-warning "'pragma omp error' encountered: Test" "inner expansion" { target *-*-* } inner_location } */
 }
 
 #if 0

diff --git a/gcc/testsuite/c-c++-common/gomp/pragma-5.c b/gcc/testsuite/c-c++-common/gomp/pragma-5.c
index af54b682789ab2e7cdc872bc6b9b9b1c2683c168..8124f701502365d1416a02ed4e262ef428336d16 100644 (file)
--- a/gcc/testsuite/c-c++-common/gomp/pragma-5.c
+++ b/gcc/testsuite/c-c++-common/gomp/pragma-5.c
@@ -1,13 +1,14 @@
 /* { dg-additional-options "-fdump-tree-original" }  */
 /* PR preprocessor/103165  */
 
-#define inner(...) #__VA_ARGS__ ; _Pragma   (  "   omp         error severity   (warning)      message (\"Test\") at(compilation)" )
+#define inner(...) #__VA_ARGS__ ; _Pragma   (  "   omp         error severity   (warning)      message (\"Test\") at(compilation)" ) /* { dg-line inner_location } */
 #define outer(...) inner(__VA_ARGS__)
 
 void
 f (void)
 {
-  const char *str = outer(inner(1,2));  /* { dg-warning "'pragma omp error' encountered: Test" } */
+  const char *str = outer(inner(1,2));
+  /* { dg-warning "'pragma omp error' encountered: Test" "inner expansion" { target *-*-* } inner_location } */
 }
 
 #if 0

diff --git a/gcc/testsuite/c-c++-common/pr97498.c b/gcc/testsuite/c-c++-common/pr97498.c
new file mode 100644 (file)
index 0000000..f5fa420
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr97498.c
@@ -0,0 +1,4 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-Wunused-function" } */
+#pragma GCC diagnostic ignored "-Wunused-function"
+static void f() {} _Pragma("GCC diagnostic error \"-Wunused-function\"") /* { dg-bogus "-Wunused-function" } */

diff --git a/gcc/testsuite/gcc.dg/pragma-message.c b/gcc/testsuite/gcc.dg/pragma-message.c
index 2f44b617710434238edb58a9142b1197d3c82b5a..1b7cf09de0aac144a77e8c67a196cb25dda7c4d4 100644 (file)
--- a/gcc/testsuite/gcc.dg/pragma-message.c
+++ b/gcc/testsuite/gcc.dg/pragma-message.c
@@ -42,9 +42,11 @@
 #pragma message ("Okay " THREE)  /* { dg-message "Okay 3" } */
 
 /* Create a TODO() that prints a message on compilation.  */
-#define DO_PRAGMA(x) _Pragma (#x)
-#define TODO(x) DO_PRAGMA(message ("TODO - " #x))
-TODO(Okay 4)                     /* { dg-message "TODO - Okay 4" } */
+#define DO_PRAGMA(x) _Pragma (#x) /* { dg-line pragma_loc1 } */
+#define TODO(x) DO_PRAGMA(message ("TODO - " #x)) /* { dg-line pragma_loc2 } */
+TODO(Okay 4) /* { dg-message "in expansion of macro 'TODO'" } */
+/* { dg-message "TODO - Okay 4" "test4.1" { target *-*-* } pragma_loc1 } */
+/* { dg-message "in expansion of macro 'DO_PRAGMA'" "test4.2" { target *-*-* } pragma_loc2 } */
 
 #if 0
 #pragma message ("Not printed")

diff --git a/libcpp/directives.cc b/libcpp/directives.cc
index f804a441f394f1a5830d412b6e41a478a1bd69b5..4104d5166e2282805ab722b5758e39cdf73ceb21 100644 (file)
--- a/libcpp/directives.cc
+++ b/libcpp/directives.cc
@@ -1930,6 +1930,7 @@ destringize_and_run (cpp_reader *pfile, const cpp_string *in,
       maxcount = 50;
       toks = XNEWVEC (cpp_token, maxcount);
       toks[0] = pfile->directive_result;
+      toks[0].src_loc = expansion_loc;
 
       do
        {

diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/reduction-5.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/reduction-5.c
index bae1dee6ad2f815e2fb5eb180c44847858391ccd..16aa0dd4ac12fde9cde414cd6009bc47dd50c574 100644 (file)
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/reduction-5.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/reduction-5.c
@@ -12,7 +12,7 @@
 
 const int n = 100;
 
-#define DO_PRAGMA(x) _Pragma (#x)
+#define DO_PRAGMA(x) _Pragma (#x) /* { dg-line pragma_loc } */
 
 #define check_reduction(gwv_par, gwv_loop)             \
   {                                                    \
@@ -46,7 +46,7 @@ main (void)
   /* Nvptx targets require a vector_length or 32 in to allow spinlocks with
      gangs.  */
   check_reduction (num_workers (nw) vector_length (vl), worker);
-  /* { dg-warning "region is vector partitioned but does not contain vector partitioned code" "" { target *-*-* } .-1 } */
+  /* { dg-warning "region is vector partitioned but does not contain vector partitioned code" "test1" { target *-*-* } pragma_loc } */
   check_reduction (vector_length (vl), vector);
   check_reduction (num_gangs (ng) num_workers (nw) vector_length (vl), gang
                   worker vector);

diff --git a/libgomp/testsuite/libgomp.oacc-c-c++-common/vred2d-128.c b/libgomp/testsuite/libgomp.oacc-c-c++-common/vred2d-128.c
index 9c182d90a0d727e4c372d5a2339e3574a51c9d5a..84e6d51670bb051011cf5c9a5f073e0d197ab7ad 100644 (file)
--- a/libgomp/testsuite/libgomp.oacc-c-c++-common/vred2d-128.c
+++ b/libgomp/testsuite/libgomp.oacc-c-c++-common/vred2d-128.c
@@ -17,7 +17,7 @@ int a1[n], a2[n];
   void name ()                                 \
   {                                            \
   long i, j, t1, t2, t3; /* { dg-line vars } */        \
-  _Pragma(outer)                               \
+  _Pragma(outer) /* { dg-line outer } */       \
   for (i = 0; i < n; i++)                      \
     {                                          \
       t1 = 0;                                  \
@@ -40,44 +40,44 @@ int a1[n], a2[n];
 
 gentest (test1, "acc parallel loop gang vector_length (128) firstprivate (t1, t2)",
         "acc loop vector reduction(+:t1) reduction(-:t2)")
-/* { dg-warning {'t1' is used uninitialized} {} { target *-*-* } .-1 }
+/* { dg-warning {'t1' is used uninitialized} {} { target *-*-* } outer }
    { dg-note {'t1' was declared here} {} { target *-*-* } vars }
    { dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-4 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
-/* { dg-warning {'t2' is used uninitialized} {} { target *-*-* } .-5 }
+/* { dg-warning {'t2' is used uninitialized} {} { target *-*-* } outer }
    { dg-note {'t2' was declared here} {} { target *-*-* } vars }
    { DUP_dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-8 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
 
 gentest (test2, "acc parallel loop gang vector_length (128) firstprivate (t1, t2)",
         "acc loop worker vector reduction(+:t1) reduction(-:t2)")
-/* { dg-warning {'t1' is used uninitialized} {} { target *-*-* } .-1 }
+/* { DUPdg-warning {'t1' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t1' was declared here} {} { target *-*-* } vars }
    { dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-4 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
-/* { dg-warning {'t2' is used uninitialized} {} { target *-*-* } .-5 }
+/* { DUPdg-warning {'t2' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t2' was declared here} {} { target *-*-* } vars }
    { DUP_dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-8 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
 
 gentest (test3, "acc parallel loop gang worker vector_length (128) firstprivate (t1, t2)",
         "acc loop vector reduction(+:t1) reduction(-:t2)")
-/* { dg-warning {'t1' is used uninitialized} {} { target *-*-* } .-1 }
+/* { DUPdg-warning {'t1' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t1' was declared here} {} { target *-*-* } vars }
    { dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-4 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
-/* { dg-warning {'t2' is used uninitialized} {} { target *-*-* } .-5 }
+/* { DUPdg-warning {'t2' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t2' was declared here} {} { target *-*-* } vars }
    { DUP_dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-8 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
 
 gentest (test4, "acc parallel loop firstprivate (t1, t2)",
         "acc loop reduction(+:t1) reduction(-:t2)")
-/* { dg-warning {'t1' is used uninitialized} {} { target *-*-* } .-1 }
+/* { DUPdg-warning {'t1' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t1' was declared here} {} { target *-*-* } vars }
    { dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-4 }
      TODO See PR101551 for 'offloading_enabled' differences.  */
-/* { dg-warning {'t2' is used uninitialized} {} { target *-*-* } .-5 }
+/* { DUPdg-warning {'t2' is used uninitialized} {} { target *-*-* } outer }
    { DUP_dg-note {'t2' was declared here} {} { target *-*-* } vars }
    { DUP_dg-note {in expansion of macro 'gentest'} {} { target { ! offloading_enabled } } .-8 }
      TODO See PR101551 for 'offloading_enabled' differences.  */