Revert r135217, which wasn't the correct fix for PR10358. With this
patch, we actually move the state-machine for the value set backwards
one step. This can pretty easily lead to infinite loops where we
continually try to propagate a bit, succeed for one iteration, but then
back up because we find an uninitialized use.
A reduced test case from PR10379 is included.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@135359 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/UninitializedValues.cpp b/lib/Analysis/UninitializedValues.cpp
index 5e00eeb..1d6959d 100644
--- a/lib/Analysis/UninitializedValues.cpp
+++ b/lib/Analysis/UninitializedValues.cpp
@@ -495,11 +495,9 @@
ValueVector::reference val = vals[vd];
if (isUninitialized(val)) {
- if (bo->getOpcode() != BO_Assign) {
+ if (bo->getOpcode() != BO_Assign)
reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
- val = Unknown;
- } else
- val = Initialized;
+ val = Initialized;
}
return;
}
@@ -528,7 +526,7 @@
if (isUninitialized(val)) {
reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
// Don't cascade warnings.
- val = Unknown;
+ val = Initialized;
}
return;
}
@@ -560,7 +558,7 @@
if (isUninitialized(val)) {
reportUninit(res.getDeclRefExpr(), vd, isAlwaysUninit(val));
// Don't cascade warnings.
- vals[vd] = Unknown;
+ vals[vd] = Initialized;
}
}
return;
diff --git a/test/Sema/uninit-variables.c b/test/Sema/uninit-variables.c
index 06abc76..0caab3d 100644
--- a/test/Sema/uninit-variables.c
+++ b/test/Sema/uninit-variables.c
@@ -77,7 +77,7 @@
}
void test12(unsigned n) {
- for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' is uninitialized when used here}} expected-note{{variable 'i' is declared here}} expected-note{{add initialization to silence this warning}}
+ for (unsigned i ; n ; ++i) ; // expected-warning{{variable 'i' may be uninitialized when used here}} expected-note{{variable 'i' is declared here}} expected-note{{add initialization to silence this warning}}
}
int test13() {
@@ -237,7 +237,7 @@
void **pc; // expected-note{{variable 'pc' is declared here}} expected-note{{add initialization to silence this warning}}
void *dummy[] = { &&L1, &&L2 };
L1:
- goto *pc; // expected-warning{{variable 'pc' is uninitialized when used here}}
+ goto *pc; // expected-warning{{variable 'pc' may be uninitialized when used here}}
L2:
goto *pc;
}
@@ -289,7 +289,7 @@
void test43(int i) {
int x; // expected-note {{variable 'x' is declared here}} expected-note{{add initialization to silence this warning}}
for (i = 0 ; i < 10; i++)
- test43_aux(x++); // expected-warning {{variable 'x' is uninitialized when used here}}
+ test43_aux(x++); // expected-warning {{variable 'x' may be uninitialized when used here}}
}
void test44(int i) {
@@ -297,7 +297,7 @@
int y; // expected-note {{variable 'y' is declared here}} expected-note{{add initialization to silence this warning}}
for (i = 0; i < 10; i++ ) {
test43_aux(x++); // no-warning
- x += y; // expected-warning {{variable 'y' is uninitialized when used here}}
+ x += y; // expected-warning {{variable 'y' may be uninitialized when used here}}
}
}
@@ -352,3 +352,18 @@
}
return x; // expected-warning {{variable 'x' may be uninitialized when used here}}
}
+
+// This CFG caused the uninitialized values warning to inf-loop.
+extern int PR10379_g();
+void PR10379_f(int *len) {
+ int new_len; // expected-note {{variable 'new_len' is declared here}} expected-note{{add initialization to silence this warning}}
+ for (int i = 0; i < 42 && PR10379_g() == 0; i++) {
+ if (PR10379_g() == 1)
+ continue;
+ if (PR10379_g() == 2)
+ PR10379_f(&new_len);
+ else if (PR10379_g() == 3)
+ PR10379_f(&new_len);
+ *len += new_len; // expected-warning {{variable 'new_len' may be uninitialized when used here}}
+ }
+}