097ce76165
By default, clang assumes that all trailing array objects could be a FAM. So, an array of undefined size, size 0, size 1, or even size 42 is considered as FAMs for optimizations at least. One needs to override the default behavior by supplying the `-fstrict-flex-arrays=<N>` flag, with `N > 0` value to reduce the set of FAM candidates. Value `3` is the most restrictive and `0` is the most permissive on this scale. 0: all trailing arrays are FAMs 1: only incomplete, zero and one-element arrays are FAMs 2: only incomplete, zero-element arrays are FAMs 3: only incomplete arrays are FAMs If the user is happy with consdering single-element arrays as FAMs, they just need to remove the `consider-single-element-arrays-as-flexible-array-members` from the command line. Otherwise, if they don't want to recognize such cases as FAMs, they should specify `-fstrict-flex-arrays` anyway, which will be picked up by CSA. Any use of the deprecated analyzer-config value will trigger a warning explaining what to use instead. The `-analyzer-config-help` is updated accordingly. Depends on D138657 Reviewed By: xazax.hun Differential Revision: https://reviews.llvm.org/D138659
135 lines
5.1 KiB
C
135 lines
5.1 KiB
C
// -fstrict-flex-arrays=2 means that only undefined or zero element arrays are considered as FAMs.
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c90 \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c99 \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c11 \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c17 \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++98 -x c++ \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++03 -x c++ \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++11 -x c++ \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++14 -x c++ \
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// RUN: -fstrict-flex-arrays=2
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++17 -x c++ \
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// RUN: -fstrict-flex-arrays=2
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// By default, -fstrict-flex-arrays=0, which means that even single element arrays are considered as FAMs.
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c17 \
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// RUN: -DSINGLE_ELEMENT_FAMS
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// RUN: %clang_analyze_cc1 -triple x86_64-linux-gnu -analyzer-checker=core,unix,debug.ExprInspection %s -verify -std=c++17 -x c++ \
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// RUN: -DSINGLE_ELEMENT_FAMS
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typedef __typeof(sizeof(int)) size_t;
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size_t clang_analyzer_getExtent(void *);
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void clang_analyzer_dump(size_t);
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void *alloca(size_t size);
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void *malloc(size_t size);
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void free(void *ptr);
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void test_incomplete_array_fam(void) {
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typedef struct FAM {
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char c;
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int data[];
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} FAM;
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FAM fam;
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clang_analyzer_dump(clang_analyzer_getExtent(&fam));
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clang_analyzer_dump(clang_analyzer_getExtent(fam.data));
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// expected-warning@-2 {{4 S64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *p = (FAM *)alloca(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(p));
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clang_analyzer_dump(clang_analyzer_getExtent(p->data));
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// expected-warning@-2 {{4 U64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *q = (FAM *)malloc(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(q));
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clang_analyzer_dump(clang_analyzer_getExtent(q->data));
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// expected-warning@-2 {{4 U64b}}
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// expected-warning@-2 {{Unknown}}
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free(q);
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}
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void test_zero_length_array_fam(void) {
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typedef struct FAM {
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char c;
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int data[0];
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} FAM;
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FAM fam;
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clang_analyzer_dump(clang_analyzer_getExtent(&fam));
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clang_analyzer_dump(clang_analyzer_getExtent(fam.data));
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// expected-warning@-2 {{4 S64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *p = (FAM *)alloca(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(p));
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clang_analyzer_dump(clang_analyzer_getExtent(p->data));
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// expected-warning@-2 {{4 U64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *q = (FAM *)malloc(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(q));
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clang_analyzer_dump(clang_analyzer_getExtent(q->data));
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// expected-warning@-2 {{4 U64b}}
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// expected-warning@-2 {{Unknown}}
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free(q);
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}
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void test_single_element_array_possible_fam(void) {
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typedef struct FAM {
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char c;
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int data[1];
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} FAM;
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#ifdef SINGLE_ELEMENT_FAMS
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FAM likely_fam;
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clang_analyzer_dump(clang_analyzer_getExtent(&likely_fam));
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clang_analyzer_dump(clang_analyzer_getExtent(likely_fam.data));
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// expected-warning@-2 {{8 S64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *p = (FAM *)alloca(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(p));
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clang_analyzer_dump(clang_analyzer_getExtent(p->data));
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// expected-warning@-2 {{8 U64b}}
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// expected-warning@-2 {{Unknown}}
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FAM *q = (FAM *)malloc(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(q));
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clang_analyzer_dump(clang_analyzer_getExtent(q->data));
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// expected-warning@-2 {{8 U64b}}
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// expected-warning@-2 {{Unknown}}
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free(q);
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#else
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FAM likely_fam;
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clang_analyzer_dump(clang_analyzer_getExtent(&likely_fam));
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clang_analyzer_dump(clang_analyzer_getExtent(likely_fam.data));
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// expected-warning@-2 {{8 S64b}}
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// expected-warning@-2 {{4 S64b}}
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FAM *p = (FAM *)alloca(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(p));
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clang_analyzer_dump(clang_analyzer_getExtent(p->data));
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// expected-warning@-2 {{8 U64b}}
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// expected-warning@-2 {{4 S64b}}
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FAM *q = (FAM *)malloc(sizeof(FAM));
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clang_analyzer_dump(clang_analyzer_getExtent(q));
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clang_analyzer_dump(clang_analyzer_getExtent(q->data));
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// expected-warning@-2 {{8 U64b}}
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// expected-warning@-2 {{4 S64b}}
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free(q);
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#endif
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}
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