[PATCH v2 1/7] banned-die: create header for banning of functions

["Derrick Stolee via GitGitGadget" <gitgitgadget@gmail.com>]

From: Derrick Stolee <stolee@gmail.com>

We have universally-banned functions listed in banned.h since
c8af66ab8ad (automatically ban strcpy(), 2018-07-26), but some layers of
the code should be more strict than others.

One such example is the trace2 API which runs during atexit() and can
prove to cause die()-handler recursion problems if it calls die().

Create a new banned-die.h header file that will ban some Git methods
that call die(). Include that in all trace2 API implementation files.
This currently only bans die() itself, and that was already not used.

It would be reasonable to name this file trace2/tr2_banned.h to be
specific to the trace2 API, but it seems like such a restriction would
be valuable to put in some other areas of the code, so adding it at the
root of the tree seems like a good long-term approach.

Signed-off-by: Derrick Stolee <stolee@gmail.com>
---
 banned-die.h            | 14 ++++++++++++++
 trace2.c                |  1 +
 trace2/tr2_cfg.c        |  1 +
 trace2/tr2_cmd_name.c   |  1 +
 trace2/tr2_ctr.c        |  1 +
 trace2/tr2_dst.c        |  1 +
 trace2/tr2_sid.c        |  1 +
 trace2/tr2_sysenv.c     |  1 +
 trace2/tr2_tbuf.c       |  1 +
 trace2/tr2_tgt_event.c  |  1 +
 trace2/tr2_tgt_normal.c |  1 +
 trace2/tr2_tgt_perf.c   |  1 +
 trace2/tr2_tls.c        |  1 +
 trace2/tr2_tmr.c        |  1 +
 14 files changed, 27 insertions(+)
 create mode 100644 banned-die.h

diff --git a/banned-die.h b/banned-die.h
new file mode 100644
index 0000000000..5eff361e55
--- /dev/null
+++ b/banned-die.h
@@ -0,0 +1,14 @@
+#ifndef BANNED_DIE_H
+#define BANNED_DIE_H
+
+#include "banned.h"
+
+/*
+ * This header lists functions that must not be used by low-level APIs
+ * because they can cause Git to terminate.
+ */
+
+#undef die
+#define die banned(die)
+
+#endif /* BANNED_DIE_H */
diff --git a/trace2.c b/trace2.c
index c23c0a227b..1d0ed2db2b 100644
--- a/trace2.c
+++ b/trace2.c
@@ -17,6 +17,7 @@
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_tmr.h"
+#include "banned-die.h"
 
 static int trace2_enabled;
 static int trace2_redact = 1;
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index bbcfeda60a..06912a3ceb 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -7,6 +7,7 @@
 #include "trace2/tr2_cfg.h"
 #include "trace2/tr2_sysenv.h"
 #include "wildmatch.h"
+#include "banned-die.h"
 
 static struct string_list tr2_cfg_patterns = STRING_LIST_INIT_DUP;
 static int tr2_cfg_loaded;
diff --git a/trace2/tr2_cmd_name.c b/trace2/tr2_cmd_name.c
index b7b5a869b7..88f24e8781 100644
--- a/trace2/tr2_cmd_name.c
+++ b/trace2/tr2_cmd_name.c
@@ -1,6 +1,7 @@
 #include "git-compat-util.h"
 #include "strbuf.h"
 #include "trace2/tr2_cmd_name.h"
+#include "banned-die.h"
 
 #define TR2_ENVVAR_PARENT_NAME "GIT_TRACE2_PARENT_NAME"
 
diff --git a/trace2/tr2_ctr.c b/trace2/tr2_ctr.c
index ee17bfa86b..3067df4d18 100644
--- a/trace2/tr2_ctr.c
+++ b/trace2/tr2_ctr.c
@@ -2,6 +2,7 @@
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_ctr.h"
+#include "banned-die.h"
 
 /*
  * A global counter block to aggregate values from the partial sums
diff --git a/trace2/tr2_dst.c b/trace2/tr2_dst.c
index 5be892cd5c..686a3e42fc 100644
--- a/trace2/tr2_dst.c
+++ b/trace2/tr2_dst.c
@@ -5,6 +5,7 @@
 #include "trace2/tr2_dst.h"
 #include "trace2/tr2_sid.h"
 #include "trace2/tr2_sysenv.h"
+#include "banned-die.h"
 
 /*
  * How many attempts we will make at creating an automatically-named trace file.
diff --git a/trace2/tr2_sid.c b/trace2/tr2_sid.c
index 1c1d27b0ee..358f61b301 100644
--- a/trace2/tr2_sid.c
+++ b/trace2/tr2_sid.c
@@ -3,6 +3,7 @@
 #include "strbuf.h"
 #include "trace2/tr2_tbuf.h"
 #include "trace2/tr2_sid.h"
+#include "banned-die.h"
 
 #define TR2_ENVVAR_PARENT_SID "GIT_TRACE2_PARENT_SID"
 
diff --git a/trace2/tr2_sysenv.c b/trace2/tr2_sysenv.c
index 4abc218514..deb3fabff4 100644
--- a/trace2/tr2_sysenv.c
+++ b/trace2/tr2_sysenv.c
@@ -4,6 +4,7 @@
 #include "config.h"
 #include "dir.h"
 #include "tr2_sysenv.h"
+#include "banned-die.h"
 
 /*
  * Each entry represents a trace2 setting.
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index c3b3822ed7..86725426f6 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -1,5 +1,6 @@
 #include "git-compat-util.h"
 #include "tr2_tbuf.h"
+#include "banned-die.h"
 
 void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 {
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 5a0381791f..a055e19bac 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -13,6 +13,7 @@
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_tmr.h"
+#include "banned-die.h"
 
 static struct tr2_dst tr2dst_event = {
 	.sysenv_var = TR2_SYSENV_EVENT,
diff --git a/trace2/tr2_tgt_normal.c b/trace2/tr2_tgt_normal.c
index 924736ab36..97d4c5d202 100644
--- a/trace2/tr2_tgt_normal.c
+++ b/trace2/tr2_tgt_normal.c
@@ -11,6 +11,7 @@
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_tmr.h"
+#include "banned-die.h"
 
 static struct tr2_dst tr2dst_normal = {
 	.sysenv_var = TR2_SYSENV_NORMAL,
diff --git a/trace2/tr2_tgt_perf.c b/trace2/tr2_tgt_perf.c
index 4eb9289f95..1f49d9f922 100644
--- a/trace2/tr2_tgt_perf.c
+++ b/trace2/tr2_tgt_perf.c
@@ -14,6 +14,7 @@
 #include "trace2/tr2_tgt.h"
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_tmr.h"
+#include "banned-die.h"
 
 static struct tr2_dst tr2dst_perf = {
 	.sysenv_var = TR2_SYSENV_PERF,
diff --git a/trace2/tr2_tls.c b/trace2/tr2_tls.c
index 7b023c1bfc..ae2d39d2f5 100644
--- a/trace2/tr2_tls.c
+++ b/trace2/tr2_tls.c
@@ -3,6 +3,7 @@
 #include "thread-utils.h"
 #include "trace.h"
 #include "trace2/tr2_tls.h"
+#include "banned-die.h"
 
 /*
  * Initialize size of the thread stack for nested regions.
diff --git a/trace2/tr2_tmr.c b/trace2/tr2_tmr.c
index 038181ad9b..a329c466b9 100644
--- a/trace2/tr2_tmr.c
+++ b/trace2/tr2_tmr.c
@@ -3,6 +3,7 @@
 #include "trace2/tr2_tls.h"
 #include "trace2/tr2_tmr.h"
 #include "trace.h"
+#include "banned-die.h"
 
 #define MY_MAX(a, b) ((a) > (b) ? (a) : (b))
 #define MY_MIN(a, b) ((a) < (b) ? (a) : (b))
-- 
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