[commit] [patch] PR symtab/13277: Resolving opaque structures in ICC generated binaries.

[Jan Kratochvil <jan.kratochvil@redhat.com>]

On Thu, 24 May 2012 01:28:59 +0200, John Steele Scott wrote:
> Two tests in gdb.base/type-opaque effectively changed polarity: previously
> "opaque {struct,union} type resolving" failed, now those pass and "empty
> {struct,union} type resolving" fail. As previously discussed, this is the
> lesser of the two evils as far as I'm concerned.

This is a bug of ICC, GDB cannot do anything with it.  To be absolutely
correct the testfile should check the output is generated by ICC and XFAIL (X
= that it depends on environment = compiler) such testcase.  Personally I care
only about XFAILs/KFAILs for GCC.

main.c - where GDB searches from:
struct struct_libtype_empty {};    
lib.c:
struct struct_libtype_empty { int libfield_empty; };

 ptype pointer_struct_empty
 type = volatile struct struct_libtype_empty {
-    <no data fields>
+    int libfield_empty;
 } *
-(gdb) PASS: gdb.base/type-opaque.exp: empty struct type resolving
+(gdb) FAIL: gdb.base/type-opaque.exp: empty struct type resolving


> The patch at http://sourceware.org/ml/gdb-patches/2012-05/msg00739.html is
> still required to fix my non-trivial case, I hope that (or something like it)
> can be committed soon.

Going to commit it now.


> +static int
> +producer_is_gxx_lt_4_6 (struct dwarf2_cu *cu)
> +{
> +  if (!cu->checked_producer)
> +    check_producer(cu);

Missing space:
    check_producer (cu);

> +
> +  return cu->producer_is_gxx_lt_4_6;
>  }
[...]
> +static int
> +producer_is_icc (struct dwarf2_cu *cu)
> +{
> +  if (!cu->checked_producer)
> +    check_producer(cu);

Missing space:
    check_producer (cu);

> +
> +  return cu->producer_is_icc;
> +}


Checked in.


Thanks,
Jan


http://sourceware.org/ml/gdb-cvs/2012-05/msg00186.html
 - the code part:

--- src/gdb/ChangeLog	2012/05/24 17:03:20	1.14292
+++ src/gdb/ChangeLog	2012/05/24 22:09:18	1.14293
@@ -1,3 +1,14 @@
+2012-05-24  John Steele Scott  <toojays@toojays.net>
+
+	PR symtab/13277: Resolving opaque structures in ICC generated binaries.
+	* dwarf2read.c (struct dwarf2_cu) <producer_is_icc>: New field.
+	(producer_is_gxx_lt_4_6): Move the checking and caching to...
+	(check_producer): ... this new function, which also checks for ICC
+	and caches the result.
+	(producer_is_icc): New function.
+	(read_structure_type): Don't set TYPE_STUB_SUPPORTED if the
+	producer was ICC.
+
 2012-05-24  Pedro Alves  <palves@redhat.com>
 
 	PR gdb/7205
--- src/gdb/dwarf2read.c	2012/05/22 18:45:22	1.655
+++ src/gdb/dwarf2read.c	2012/05/24 22:09:20	1.656
@@ -429,12 +429,13 @@
      unoptimized code.  For a future better test see GCC PR other/32998.  */
   unsigned int has_loclist : 1;
 
-  /* These cache the results of producer_is_gxx_lt_4_6.
-     CHECKED_PRODUCER is set if PRODUCER_IS_GXX_LT_4_6 is valid.  This
-     information is cached because profiling CU expansion showed
-     excessive time spent in producer_is_gxx_lt_4_6.  */
+  /* These cache the results for producer_is_gxx_lt_4_6 and producer_is_icc.
+     CHECKED_PRODUCER is set if both PRODUCER_IS_GXX_LT_4_6 and PRODUCER_IS_ICC
+     are valid.  This information is cached because profiling CU expansion
+     showed excessive time spent in producer_is_gxx_lt_4_6.  */
   unsigned int checked_producer : 1;
   unsigned int producer_is_gxx_lt_4_6 : 1;
+  unsigned int producer_is_icc : 1;
 
   /* Non-zero if DW_AT_addr_base was found.
      Used when processing DWO files.  */
@@ -8271,16 +8272,14 @@
     }
 }
 
-/* Check for GCC PR debug/45124 fix which is not present in any G++ version up
-   to 4.5.any while it is present already in G++ 4.6.0 - the PR has been fixed
-   during 4.6.0 experimental.  */
+/* Check whether the producer field indicates either of GCC < 4.6, or the
+   Intel C/C++ compiler, and cache the result in CU.  */
 
-static int
-producer_is_gxx_lt_4_6 (struct dwarf2_cu *cu)
+static void
+check_producer (struct dwarf2_cu *cu)
 {
   const char *cs;
   int major, minor, release;
-  int result = 0;
 
   if (cu->producer == NULL)
     {
@@ -8292,22 +8291,11 @@
 	 for their space efficiency GDB cannot workaround gcc-4.5.x -gdwarf-4
 	 combination.  gcc-4.5.x -gdwarf-4 binaries have DW_AT_accessibility
 	 interpreted incorrectly by GDB now - GCC PR debug/48229.  */
-
-      return 0;
-    }
-
-  if (cu->checked_producer)
-    return cu->producer_is_gxx_lt_4_6;
-
-  /* Skip any identifier after "GNU " - such as "C++" or "Java".  */
-
-  if (strncmp (cu->producer, "GNU ", strlen ("GNU ")) != 0)
-    {
-      /* For non-GCC compilers expect their behavior is DWARF version
-	 compliant.  */
     }
-  else
+  else if (strncmp (cu->producer, "GNU ", strlen ("GNU ")) == 0)
     {
+      /* Skip any identifier after "GNU " - such as "C++" or "Java".  */
+
       cs = &cu->producer[strlen ("GNU ")];
       while (*cs && !isdigit (*cs))
 	cs++;
@@ -8316,13 +8304,30 @@
 	  /* Not recognized as GCC.  */
 	}
       else
-	result = major < 4 || (major == 4 && minor < 6);
+	cu->producer_is_gxx_lt_4_6 = major < 4 || (major == 4 && minor < 6);
+    }
+  else if (strncmp (cu->producer, "Intel(R) C", strlen ("Intel(R) C")) == 0)
+    cu->producer_is_icc = 1;
+  else
+    {
+      /* For other non-GCC compilers, expect their behavior is DWARF version
+	 compliant.  */
     }
 
   cu->checked_producer = 1;
-  cu->producer_is_gxx_lt_4_6 = result;
+}
 
-  return result;
+/* Check for GCC PR debug/45124 fix which is not present in any G++ version up
+   to 4.5.any while it is present already in G++ 4.6.0 - the PR has been fixed
+   during 4.6.0 experimental.  */
+
+static int
+producer_is_gxx_lt_4_6 (struct dwarf2_cu *cu)
+{
+  if (!cu->checked_producer)
+    check_producer (cu);
+
+  return cu->producer_is_gxx_lt_4_6;
 }
 
 /* Return the default accessibility type if it is not overriden by
@@ -9005,6 +9010,18 @@
   smash_to_methodptr_type (type, new_type);
 }
 
+/* Return non-zero if the CU's PRODUCER string matches the Intel C/C++ compiler
+   (icc).  */
+
+static int
+producer_is_icc (struct dwarf2_cu *cu)
+{
+  if (!cu->checked_producer)
+    check_producer (cu);
+
+  return cu->producer_is_icc;
+}
+
 /* Called when we find the DIE that starts a structure or union scope
    (definition) to create a type for the structure or union.  Fill in
    the type's name and general properties; the members will not be
@@ -9107,7 +9124,14 @@
       TYPE_LENGTH (type) = 0;
     }
 
-  TYPE_STUB_SUPPORTED (type) = 1;
+  if (producer_is_icc (cu))
+    {
+      /* ICC does not output the required DW_AT_declaration
+	 on incomplete types, but gives them a size of zero.  */
+    }
+  else
+    TYPE_STUB_SUPPORTED (type) = 1;
+
   if (die_is_declaration (die, cu))
     TYPE_STUB (type) = 1;
   else if (attr == NULL && die->child == NULL