Re: [RFA/mingw32] environment variables are case-insensitive on win32

Jerome Guitton
2012-12-07T09:22:11Z

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Eli Zaretskii (eliz@gnu.org):

> Configure-time test is not good enough, as the binary could then be
> run in a different environment.
>
> How about making it case-insensitive for Cygwin as well?

I ended up implementing Pedro's suggestion (a run-time test) but it
does not work in the case of Cygwin; getenv/setenv acts as if we add a
case-sensitive environment, but we use CreateProcess to create the
inferior, so we end up with a case-insensitive environment for the
inferior. So making it case-insensitive is indeed what makes sense.

Last versions of the patch in attachment, along with the testcase.
Fully tested on x86_64-linux; partially tested on Cygwin (e.g. without
gdb.threads) amd mingw32 (testenv.exp only).

Any comments?

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commit b67dcf26ae8f9ae0390c229518fe34456b4dfe20
Author: Jerome Guitton <guitton@adacore.com>
Date: Wed Dec 5 15:48:29 2012 +0100

Add test for case sensitivity in env vars

gdb/testsuite/ChangeLog:

* gdb.base/testenv.exp: Check consistent case sensitivity of
env variables.

diff --git a/gdb/testsuite/gdb.base/testenv.exp b/gdb/testsuite/gdb.base/testenv.exp
index 55e3088..4b681a5 100644
--- a/gdb/testsuite/gdb.base/testenv.exp
+++ b/gdb/testsuite/gdb.base/testenv.exp
@@ -123,3 +123,40 @@ gdb_exit
# Clear environment in case we're doing multiple runs
unset env(TEST_GDB_GLOBAL)

+# Check consistent case sensitivity of env variables
+# for GDB and the inferior
+
+clean_restart $binfile
+
+set upper_case_value "VAR1"
+set mixed_case_value "Var1"
+gdb_test_no_output "set env TEST_GDB_VAR1 $upper_case_value" \
+ "Set TEST_GDB_VAR1"
+
+gdb_test_no_output "set env TEST_GDB_Var1 $mixed_case_value" \
+ "Set TEST_GDB_Var1"
+
+set test "Case sensitivity for env vars in GDB"
+set var1_value $upper_case_value
+set nb_vars 2
+gdb_test_multiple "show env TEST_GDB_VAR1" $test {
+ -re ".*TEST_GDB_VAR1 = $upper_case_value.*$gdb_prompt $" {
+ set nb_vars 2
+ pass $test
+ }
+ -re ".*TEST_GDB_VAR1 = $mixed_case_value.*$gdb_prompt $" {
+ set nb_vars 1
+ pass $test
+ }
+}
+
+# make sure $pc is sane, in case we're talking to a board.
+if { ![runto_main] } {
+ gdb_suppress_tests;
+}
+
+gdb_breakpoint $bp_line
+gdb_test "continue" \
+ ".*Program found ${nb_vars} variables starting with TEST_GDB.*" \
+ "Case sensitivity for env vars in inferior"
+gdb_exit

commit df61bd719e348f530419215ce71f344198231d7f
Author: Jerome Guitton <guitton@adacore.com>
Date: Thu May 24 18:19:23 2012 +0200

environment variables are case-insensitive on win32

gdb/ChangeLog:

* environ.c (host_has_case_sensitive_env_vars)
(env_var_name_ncmp): New functions.
(get_in_environ, set_in_environ, unset_in_environ): Use
env_var_name_ncmp instead of strncmp.

diff --git a/gdb/environ.c b/gdb/environ.c
index 33426eb..e4cc30c 100644
--- a/gdb/environ.c
+++ b/gdb/environ.c
@@ -96,6 +96,57 @@ environ_vector (struct gdb_environ *e)
return e->vector;
}
\f
+
+/* Return 1 if the names of environ variables are case sensitive
+ on host. */
+
+static int
+host_has_case_sensitive_env_vars()
+{
+ static int result = -1;
+ char *value;
+
+ if (result != -1)
+ return result;
+
+ /* On Cygwin, setenv/getenv supports case-sensitive environment
+ variables; so the run-time check would return 1. However, GDB
+ uses the windows API to create the inferior, which is case
+ insensitive. So override the check. */
+
+#if defined (__CYGWIN__)
+ result = 0;
+ return result;
+
+#elif defined(_WIN32) && !defined(__CYGWIN__)
+ putenv ("__GDB_TEST_CASE_SENSITIVITY=set");
+
+#else
+ setenv ("__GDB_TEST_CASE_SENSITIVITY", "set", 1);
+#endif
+
+ value = getenv ("__GDB_test_CASE_Sensitivity");
+
+ if (value && (strcmp (value, "set") == 0))
+ result = 0;
+ else
+ result = 1;
+
+ return result;
+}
+
+/* Compare the first LENGTH characters of the names of two
+ environment variable A and B. */
+
+static int
+env_var_name_ncmp(const char *a, const char *b, int length)
+{
+ if (host_has_case_sensitive_env_vars())
+ return strncmp(a, b, length);
+ else
+ return strncasecmp (a, b, length);
+}
+
/* Return the value in environment E of variable VAR. */

char *
@@ -106,7 +157,7 @@ get_in_environ (const struct gdb_environ *e, const char *var)
char *s;

for (; (s = *vector) != NULL; vector++)
- if (strncmp (s, var, len) == 0 && s[len] == '=')
+ if (env_var_name_ncmp (s, var, len) == 0 && s[len] == '=')
return &s[len + 1];

return 0;
@@ -123,7 +174,7 @@ set_in_environ (struct gdb_environ *e, const char *var, const char *value)
char *s;

for (i = 0; (s = vector[i]) != NULL; i++)
- if (strncmp (s, var, len) == 0 && s[len] == '=')
+ if (env_var_name_ncmp (s, var, len) == 0 && s[len] == '=')
break;

if (s == 0)
@@ -170,7 +221,7 @@ unset_in_environ (struct gdb_environ *e, char *var)

for (; (s = *vector) != NULL; vector++)
{
- if (strncmp (s, var, len) == 0 && s[len] == '=')
+ if (env_var_name_ncmp (s, var, len) == 0 && s[len] == '=')
{
xfree (s);
/* Walk through the vector, shuffling args down by one, including