[analyzer] Report CFNumberGetValue API misuse

This patch contains 2 improvements to the CFNumber checker:
 - Checking of CFNumberGetValue misuse.
 - Treating all CFNumber API misuse errors as non-fatal. (Previously we treated errors that could cause uninitialized memory as syncs and the truncation errors as non-fatal.)

This implements a subset of functionality from https://reviews.llvm.org/D17954.

Differential Revision: https://reviews.llvm.org/D25876

llvm-svn: 285253

1 files changed, 19 insertions, 5 deletions

diff --git a/clang/test/Analysis/CFNumber.c b/clang/test/Analysis/CFNumber.c
index ebb3b1ac1ed..ec966ee4d6c 100644
--- a/clang/test/Analysis/CFNumber.c
+++ b/clang/test/Analysis/CFNumber.c
@@ -13,14 +13,16 @@ enum { kCFNumberSInt8Type = 1, kCFNumberSInt16Type = 2,
        kCFNumberMaxType = 16 };
 typedef CFIndex CFNumberType;
 typedef const struct __CFNumber * CFNumberRef;
+typedef unsigned char Boolean;
 extern CFNumberRef CFNumberCreate(CFAllocatorRef allocator, CFNumberType theType, const void *valuePtr);
+Boolean CFNumberGetValue(CFNumberRef number, CFNumberType theType, void *valuePtr);
 
-CFNumberRef f1(unsigned char x) {
-  return CFNumberCreate(0, kCFNumberSInt16Type, &x);  // expected-warning{{An 8 bit integer is used to initialize a CFNumber object that represents a 16 bit integer. 8 bits of the CFNumber value will be garbage}}
+__attribute__((cf_returns_retained)) CFNumberRef f1(unsigned char x) {
+  return CFNumberCreate(0, kCFNumberSInt16Type, &x);  // expected-warning{{An 8-bit integer is used to initialize a CFNumber object that represents a 16-bit integer; 8 bits of the CFNumber value will be garbage}}
 }
 
 __attribute__((cf_returns_retained)) CFNumberRef f2(unsigned short x) {
-  return CFNumberCreate(0, kCFNumberSInt8Type, &x); // expected-warning{{A 16 bit integer is used to initialize a CFNumber object that represents an 8 bit integer. 8 bits of the input integer will be lost}}
+  return CFNumberCreate(0, kCFNumberSInt8Type, &x); // expected-warning{{A 16-bit integer is used to initialize a CFNumber object that represents an 8-bit integer; 8 bits of the integer value will be lost}}
 }
 
 // test that the attribute overrides the naming convention.
@@ -28,6 +30,18 @@ __attribute__((cf_returns_not_retained)) CFNumberRef CreateNum(unsigned char x)
   return CFNumberCreate(0, kCFNumberSInt8Type, &x); // expected-warning{{leak}}
 }
 
-CFNumberRef f3(unsigned i) {
-  return CFNumberCreate(0, kCFNumberLongType, &i); // expected-warning{{A 32 bit integer is used to initialize a CFNumber object that represents a 64 bit integer}}
+__attribute__((cf_returns_retained)) CFNumberRef f3(unsigned i) {
+  return CFNumberCreate(0, kCFNumberLongType, &i); // expected-warning{{A 32-bit integer is used to initialize a CFNumber object that represents a 64-bit integer}}
+}
+
+unsigned char getValueTest1(CFNumberRef x) {
+  unsigned char scalar = 0;
+  CFNumberGetValue(x, kCFNumberSInt16Type, &scalar);  // expected-warning{{A CFNumber object that represents a 16-bit integer is used to initialize an 8-bit integer; 8 bits of the CFNumber value will overwrite adjacent storage}}
+  return scalar;
+}
+
+unsigned char getValueTest2(CFNumberRef x) {
+  unsigned short scalar = 0;
+  CFNumberGetValue(x, kCFNumberSInt8Type, &scalar);  // expected-warning{{A CFNumber object that represents an 8-bit integer is used to initialize a 16-bit integer; 8 bits of the integer value will be garbage}}
+  return scalar;
 }