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From: Andrew Burgess <andrew.burgess@embecosm.com>
To: Tom Tromey <tromey@adacore.com>
Cc: gdb-patches@sourceware.org
Subject: Re: [PATCH v2 4/8] Search global block from basic_lookup_symbol_nonlocal
Date: Tue, 27 Aug 2019 09:54:00 -0000	[thread overview]
Message-ID: <20190827095357.GO6076@embecosm.com> (raw)
In-Reply-To: <20190821103225.GF6076@embecosm.com>

* Andrew Burgess <andrew.burgess@embecosm.com> [2019-08-21 11:32:25 +0100]:

> * Tom Tromey <tromey@adacore.com> [2019-08-01 11:04:08 -0600]:
> 
> > This changes basic_lookup_symbol_nonlocal to look in the global block
> > of the passed-in block.  If no block was passed in, it reverts to the
> > previous behavior.
> > 
> > This change is needed to ensure that 'FILENAME'::NAME lookups work
> > properly.  As debugging Pedro's test case showed, this was not working
> > properly in the case where multiple identical names could be found
> > (the one situation where this feature is truly needed :-).
> > 
> > This also removes some old comments from basic_lookup_symbol_nonlocal
> > that no longer apply once this patch goes in.
> 
> So I guess the tests for this are going to be in the
> gdb.base/print-file-var.exp changes that are part of patch #8.  It
> would be great if the commit message could mention this - it just
> makes life easier later on.
> 
> I wonder if we need to update other *_lookup_symbol_nonlocal functions
> in a similar way?  For example can the C tests be compiled as C++,
> which should cause GDB to use cp_lookup_symbol_nonlocal.
> 
> Looking at both basic_lookup_symbol_nonlocal and
> cp_lookup_symbol_nonlocal, I wonder if your fix could be moved into
> lookup_global_symbol?  And just have 'block_global_block (block)'
> checked before the search of all global blocks?

The patch below applies on top of this series and extends
gdb.base/print-file-var.exp to compile as both C++ and C.  The C++
will fail initially.

The patch also includes a proposed fix to move the searching of the
"current" global block into lookup_global_symbol, after this both the
C++ and C versions of the test pass, and there are no other test
regressions.

This patch is going to clash with Christian Biesinger's patch to
refactor lookup_global_symbol, but hopefully merging these two
shouldn't be that hard.

I also tweaked the test to remove some duplicate test names.

What do you think?

Thanks,
Andrew

---

diff --git a/gdb/symtab.c b/gdb/symtab.c
index bd6fa35db6a..63a39e2996a 100644
--- a/gdb/symtab.c
+++ b/gdb/symtab.c
@@ -2426,22 +2426,6 @@ basic_lookup_symbol_nonlocal (const struct language_defn *langdef,
   if (result.symbol != NULL)
     return result;
 
-  /* If a block was passed in, we want to search the corresponding
-     global block now.  This yields "more expected" behavior, and is
-     needed to support 'FILENAME'::VARIABLE lookups.  */
-  const struct block *global_block = block_global_block (block);
-  if (global_block != nullptr)
-    {
-      result.symbol = lookup_symbol_in_block (name,
-					      symbol_name_match_type::FULL,
-					      global_block, domain);
-      if (result.symbol != nullptr)
-	{
-	  result.block = global_block;
-	  return result;
-	}
-    }
-
   /* If we didn't find a definition for a builtin type in the static block,
      search for it now.  This is actually the right thing to do and can be
      a massive performance win.  E.g., when debugging a program with lots of
@@ -2662,6 +2646,22 @@ lookup_global_symbol (const char *name,
   if (objfile != NULL)
     result = solib_global_lookup (objfile, name, domain);
 
+  /* If a block was passed in, we want to search the corresponding
+     global block first.  This yields "more expected" behavior, and is
+     needed to support 'FILENAME'::VARIABLE lookups.  */
+  const struct block *global_block = block_global_block (block);
+  if (global_block != nullptr)
+    {
+      result.symbol = lookup_symbol_in_block (name,
+					      symbol_name_match_type::FULL,
+					      global_block, domain);
+      if (result.symbol != nullptr)
+	{
+	  result.block = global_block;
+	  return result;
+	}
+    }
+
   /* If that didn't work go a global search (of global blocks, heh).  */
   if (result.symbol == NULL)
     {
diff --git a/gdb/testsuite/gdb.base/print-file-var-lib1.c b/gdb/testsuite/gdb.base/print-file-var-lib1.c
index aec04a9b02b..d172c15bc7d 100644
--- a/gdb/testsuite/gdb.base/print-file-var-lib1.c
+++ b/gdb/testsuite/gdb.base/print-file-var-lib1.c
@@ -19,6 +19,8 @@
 
 ATTRIBUTE_VISIBILITY int this_version_id = 104;
 
+START_EXTERN_C
+
 int
 get_version_1 (void)
 {
@@ -26,3 +28,5 @@ get_version_1 (void)
 
   return this_version_id;
 }
+
+END_EXTERN_C
diff --git a/gdb/testsuite/gdb.base/print-file-var-lib2.c b/gdb/testsuite/gdb.base/print-file-var-lib2.c
index 4dfdfa04c99..b392aff9f3d 100644
--- a/gdb/testsuite/gdb.base/print-file-var-lib2.c
+++ b/gdb/testsuite/gdb.base/print-file-var-lib2.c
@@ -19,9 +19,13 @@
 
 ATTRIBUTE_VISIBILITY int this_version_id = 203;
 
+START_EXTERN_C
+
 int
 get_version_2 (void)
 {
   printf ("get_version_2: &this_version_id=%p, this_version_id=%d\n", &this_version_id, this_version_id);
   return this_version_id;
 }
+
+END_EXTERN_C
diff --git a/gdb/testsuite/gdb.base/print-file-var-main.c b/gdb/testsuite/gdb.base/print-file-var-main.c
index 29d4fed22d1..1472bd44883 100644
--- a/gdb/testsuite/gdb.base/print-file-var-main.c
+++ b/gdb/testsuite/gdb.base/print-file-var-main.c
@@ -23,9 +23,13 @@
 
 #include "print-file-var.h"
 
+START_EXTERN_C
+
 extern int get_version_1 (void);
 extern int get_version_2 (void);
 
+END_EXTERN_C
+
 #if VERSION_ID_MAIN
 ATTRIBUTE_VISIBILITY int this_version_id = 55;
 #endif
diff --git a/gdb/testsuite/gdb.base/print-file-var.exp b/gdb/testsuite/gdb.base/print-file-var.exp
index a37cca70de6..1a065cf568b 100644
--- a/gdb/testsuite/gdb.base/print-file-var.exp
+++ b/gdb/testsuite/gdb.base/print-file-var.exp
@@ -17,7 +17,7 @@ if {[skip_shlib_tests]} {
     return -1
 }
 
-proc test {hidden dlopen version_id_main} {
+proc test {hidden dlopen version_id_main lang} {
     global srcdir subdir
 
     set main "print-file-var-main"
@@ -32,7 +32,7 @@ proc test {hidden dlopen version_id_main} {
     set libobj1 [standard_output_file ${lib1}$suffix.so]
     set libobj2 [standard_output_file ${lib2}$suffix.so]
 
-    set lib_opts { debug additional_flags=-fPIC }
+    set lib_opts { debug additional_flags=-fPIC $lang }
     lappend lib_opts "additional_flags=-DHIDDEN=$hidden"
 
     if { [gdb_compile_shlib ${srcdir}/${subdir}/${lib1}.c \
@@ -46,7 +46,7 @@ proc test {hidden dlopen version_id_main} {
 	return -1
     }
 
-    set main_opts [list debug shlib=${libobj1}]
+    set main_opts [list debug shlib=${libobj1} $lang]
 
     if {$dlopen} {
 	lappend main_opts "shlib_load" \
@@ -108,12 +108,14 @@ proc test {hidden dlopen version_id_main} {
 
     # Compare the values of $sym1 and $sym2.
     proc compare {sym1 sym2} {
-	# Done this way instead of comparing the symbols with "print $sym1
-	# == sym2" in GDB directly so that the values of the symbols end
-	# up visible in the logs, for debug purposes.
-	set vsym1 [get_integer_valueof $sym1 -1]
-	set vsym2 [get_integer_valueof $sym2 -1]
-	gdb_assert {$vsym1 == $vsym2} "$sym1 == $sym2"
+	with_test_prefix "sym1=$sym1,sym2=$sym2" {
+	    # Done this way instead of comparing the symbols with "print $sym1
+	    # == sym2" in GDB directly so that the values of the symbols end
+	    # up visible in the logs, for debug purposes.
+	    set vsym1 [get_integer_valueof $sym1 -1]
+	    set vsym2 [get_integer_valueof $sym2 -1]
+	    gdb_assert {$vsym1 == $vsym2} "$sym1 == $sym2"
+	}
     }
 
     if $version_id_main {
@@ -123,13 +125,14 @@ proc test {hidden dlopen version_id_main} {
 
     compare "'print-file-var-lib1.c'::this_version_id" "v1"
     compare "'print-file-var-lib2.c'::this_version_id" "v2"
-
 }
 
-foreach_with_prefix hidden {0 1} {
-    foreach_with_prefix dlopen {0 1} {
-	foreach_with_prefix version_id_main {0 1} {
-	    test $hidden $dlopen $version_id_main
+foreach_with_prefix lang { c c++ } {
+    foreach_with_prefix hidden {0 1} {
+	foreach_with_prefix dlopen {0 1} {
+	    foreach_with_prefix version_id_main {0 1} {
+		test $hidden $dlopen $version_id_main $lang
+	    }
 	}
     }
 }
diff --git a/gdb/testsuite/gdb.base/print-file-var.h b/gdb/testsuite/gdb.base/print-file-var.h
index fe7a3460edb..c44e4848b4a 100644
--- a/gdb/testsuite/gdb.base/print-file-var.h
+++ b/gdb/testsuite/gdb.base/print-file-var.h
@@ -23,4 +23,12 @@
 # define ATTRIBUTE_VISIBILITY
 #endif
 
+#ifdef __cplusplus
+# define START_EXTERN_C extern "C" {
+# define END_EXTERN_C }
+#else
+# define START_EXTERN_C
+# define END_EXTERN_C
+#endif
+
 #endif /* PRINT_FILE_VAR_H */


  reply	other threads:[~2019-08-27  9:54 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-01 17:04 [PATCH v2 0/8] Handle copy relocations and add $_ada_exception Tom Tromey
2019-08-01 17:04 ` [PATCH v2 8/8] Make print-file-var.exp test attribute visibility hidden, dlopen, and main symbol Tom Tromey
2019-08-20 13:41   ` Andrew Burgess
2019-08-21 14:35     ` Andrew Burgess
2019-08-01 17:04 ` [PATCH v2 1/8] Change SYMBOL_VALUE_ADDRESS to be an rvalue Tom Tromey
2019-08-01 17:04 ` [PATCH v2 6/8] Make current_source_* per-program-space Tom Tromey
2019-08-20 15:57   ` Andrew Burgess
2019-08-21 19:05     ` Tom Tromey
2019-08-01 17:04 ` [PATCH v2 2/8] Handle copy relocations Tom Tromey
2019-08-21 15:35   ` Andrew Burgess
2019-08-21 19:11     ` Tom Tromey
2019-08-22  8:41       ` Andrew Burgess
2019-09-19 17:45         ` Tom Tromey
2019-09-19 18:28           ` Tom Tromey
2019-09-19 18:40             ` Andrew Burgess
2019-08-01 17:04 ` [PATCH v2 3/8] Back out earlier Ada exception change Tom Tromey
2019-08-01 17:04 ` [PATCH v2 7/8] Add $_ada_exception convenience variable Tom Tromey
2019-08-01 17:56   ` Eli Zaretskii
2019-09-20 19:16     ` Tom Tromey
2019-08-27  9:47   ` Andrew Burgess
2019-09-20 19:15     ` Tom Tromey
2019-08-01 17:12 ` [PATCH v2 5/8] Don't call decode_line_with_current_source from select_source_symtab Tom Tromey
2019-08-01 17:12 ` [PATCH v2 4/8] Search global block from basic_lookup_symbol_nonlocal Tom Tromey
2019-08-21 10:32   ` Andrew Burgess
2019-08-27  9:54     ` Andrew Burgess [this message]
2019-08-27 18:17       ` Christian Biesinger via gdb-patches
2019-08-28 12:34         ` Andrew Burgess

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