The note about duplicates attached to analyzer diagnostics feels like an
implementation detail; it's likely just noise from the perspective of an
end-user.
This patch disables it by default, introducing a flag to re-enable it.
Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu.
Pushed to master as 13b7691238f189c7a233aedec49306a7cb2b0a15.
gcc/analyzer/ChangeLog:
* analyzer.opt (fanalyzer-show-duplicate-count): New option.
* diagnostic-manager.cc
(diagnostic_manager::emit_saved_diagnostic): Use the above to
guard the printing of the duplicate count.
gcc/ChangeLog:
* doc/invoke.texi (-fanalyzer-show-duplicate-count): New.
gcc/testsuite/ChangeLog:
* gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c: Add
-fanalyzer-show-duplicate-count.
---
gcc/analyzer/analyzer.opt | 4 ++++
gcc/analyzer/diagnostic-manager.cc | 2 +-
gcc/doc/invoke.texi | 8 ++++++++
.../gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c | 2 ++
4 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/gcc/analyzer/analyzer.opt b/gcc/analyzer/analyzer.opt
index 4d122f3593a..22cf4b0ad3b 100644
--- a/gcc/analyzer/analyzer.opt
+++ b/gcc/analyzer/analyzer.opt
@@ -114,6 +114,10 @@ fanalyzer-fine-grained
Common Var(flag_analyzer_fine_grained) Init(0)
Avoid combining multiple statements into one exploded edge.
+fanalyzer-show-duplicate-count
+Common Var(flag_analyzer_show_duplicate_count) Init(0)
+Issue a note when diagnostics are deduplicated.
+
fanalyzer-state-purge
Common Var(flag_analyzer_state_purge) Init(1)
Purge unneeded state during analysis.
diff --git a/gcc/analyzer/diagnostic-manager.cc
b/gcc/analyzer/diagnostic-manager.cc
index b8e59334374..7435092e2d7 100644
--- a/gcc/analyzer/diagnostic-manager.cc
+++ b/gcc/analyzer/diagnostic-manager.cc
@@ -541,7 +541,7 @@ diagnostic_manager::emit_saved_diagnostic (const
exploded_graph &eg,
auto_cfun sentinel (sd.m_snode->m_fun);
if (sd.m_d->emit (&rich_loc))
{
- if (num_dupes > 0)
+ if (flag_analyzer_show_duplicate_count && num_dupes > 0)
inform_n (stmt->location, num_dupes,
"%i duplicate", "%i duplicates",
num_dupes);
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index dc7440db103..54375ebd679 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -8477,6 +8477,14 @@ By default, an edge in this graph can contain the
effects of a run
of multiple statements within a basic block. With
@option{-fanalyzer-fine-grained}, each statement gets its own edge.
+@item -fanalyzer-show-duplicate-count
+@opindex fanalyzer-show-duplicate-count
+@opindex fno-analyzer-show-duplicate-count
+This option is intended for analyzer developers: if multiple diagnostics
+have been detected as being duplicates of each other, it emits a note when
+reporting the best diagnostic, giving the number of additional diagnostics
+that were suppressed by the deduplication logic.
+
@item -fno-analyzer-state-merge
@opindex fanalyzer-state-merge
@opindex fno-analyzer-state-merge
diff --git a/gcc/testsuite/gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c
b/gcc/testsuite/gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c
index 53c046ed12f..b43148cb4a7 100644
--- a/gcc/testsuite/gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c
+++ b/gcc/testsuite/gcc.dg/analyzer/CVE-2005-1689-dedupe-issue.c
@@ -1,3 +1,5 @@
+/* { dg-additional-options "-fanalyzer-show-duplicate-count" } */
+
#include <stdlib.h>
typedef struct _krb5_data {
--
2.21.0
