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|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
;
; Verify that calls with arguments with pointers just past the end of
; a string to [a subset of] library functions that expect nul-terminated
; strings as arguments are folded to safe values. The rationale is that
; since they are undefined and even though folding them isn't important
; for efficiency and prevents sanitizers from detecting and reporting
; them, sanitizers usually don't run, and transforming such invalid
; calls to something valid is safer than letting the program run off
; the rails. See the Safe Optimizations for Sanitizers RFC for
; an in-depth discussion of the trade-offs:
; https://discourse.llvm.org/t/rfc-safe-optimizations-for-sanitizers
declare ptr @strchr(ptr, i32)
declare ptr @strrchr(ptr, i32)
declare i32 @strcmp(ptr, ptr)
declare i32 @strncmp(ptr, ptr, i64)
declare ptr @strstr(ptr, ptr)
declare ptr @stpcpy(ptr, ptr)
declare ptr @strcpy(ptr, ptr)
declare ptr @stpncpy(ptr, ptr, i64)
declare ptr @strncpy(ptr, ptr, i64)
declare i64 @strlen(ptr)
declare i64 @strnlen(ptr, i64)
declare ptr @strpbrk(ptr, ptr)
declare i64 @strspn(ptr, ptr)
declare i64 @strcspn(ptr, ptr)
declare i32 @atoi(ptr)
declare i64 @atol(ptr)
declare i64 @atoll(ptr)
declare i64 @strtol(ptr, ptr, i32)
declare i64 @strtoll(ptr, ptr, i32)
declare i64 @strtoul(ptr, ptr, i32)
declare i64 @strtoull(ptr, ptr, i32)
declare i32 @sprintf(ptr, ptr, ...)
declare i32 @snprintf(ptr, i64, ptr, ...)
@a5 = constant [5 x i8] c"%s\0045";
; Fold strchr(a5 + 5, '\0') to null.
define ptr @fold_strchr_past_end() {
; CHECK-LABEL: @fold_strchr_past_end(
; CHECK-NEXT: ret ptr getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0)
;
%p = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%q = call ptr @strchr(ptr %p, i32 0)
ret ptr %q
}
; Fold strcmp(a5, a5 + 5) (and vice versa) to null.
define void @fold_strcmp_past_end(ptr %pcmp) {
; CHECK-LABEL: @fold_strcmp_past_end(
; CHECK-NEXT: store i32 1, ptr [[PCMP:%.*]], align 4
; CHECK-NEXT: [[PC50:%.*]] = getelementptr i32, ptr [[PCMP]], i64 1
; CHECK-NEXT: store i32 -1, ptr [[PC50]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%c05 = call i32 @strcmp(ptr @a5, ptr %p5)
store i32 %c05, ptr %pcmp
%c50 = call i32 @strcmp(ptr %p5, ptr @a5)
%pc50 = getelementptr i32, ptr %pcmp, i32 1
store i32 %c50, ptr %pc50
ret void
}
; Likewise, fold strncmp(a5, a5 + 5, 5) (and vice versa) to null.
define void @fold_strncmp_past_end(ptr %pcmp) {
; CHECK-LABEL: @fold_strncmp_past_end(
; CHECK-NEXT: store i32 1, ptr [[PCMP:%.*]], align 4
; CHECK-NEXT: [[PC50:%.*]] = getelementptr i32, ptr [[PCMP]], i64 1
; CHECK-NEXT: store i32 -1, ptr [[PC50]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%c05 = call i32 @strncmp(ptr @a5, ptr %p5, i64 5)
store i32 %c05, ptr %pcmp
%c50 = call i32 @strncmp(ptr %p5, ptr @a5, i64 5)
%pc50 = getelementptr i32, ptr %pcmp, i32 1
store i32 %c50, ptr %pc50
ret void
}
; Fold strrchr(a5 + 5, '\0') to poison (it's UB).
define ptr @fold_strrchr_past_end(i32 %c) {
; CHECK-LABEL: @fold_strrchr_past_end(
; CHECK-NEXT: ret ptr poison
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call ptr @strrchr(ptr %p5, i32 0)
ret ptr %r
}
; Fold strstr(a5 + 5, a5) (and vice versa) to null.
define void @fold_strstr_past_end(ptr %psub) {
; CHECK-LABEL: @fold_strstr_past_end(
; CHECK-NEXT: store ptr @a5, ptr [[PSUB:%.*]], align 8
; CHECK-NEXT: [[PS50:%.*]] = getelementptr ptr, ptr [[PSUB]], i64 1
; CHECK-NEXT: store ptr null, ptr [[PS50]], align 8
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%s05 = call ptr @strstr(ptr @a5, ptr %p5)
store ptr %s05, ptr %psub
%s50 = call ptr @strstr(ptr %p5, ptr @a5)
%ps50 = getelementptr ptr, ptr %psub, i32 1
store ptr %s50, ptr %ps50
ret void
}
; Fold strlen(a5 + 5) to 0.
define i64 @fold_strlen_past_end() {
; CHECK-LABEL: @fold_strlen_past_end(
; CHECK-NEXT: ret i64 0
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call i64 @strlen(ptr %p5)
ret i64 %r
}
; TODO: Fold stpcpy(dst, a5 + 5) to (*dst = '\0', dst).
define ptr @fold_stpcpy_past_end(ptr %dst) {
; CHECK-LABEL: @fold_stpcpy_past_end(
; CHECK-NEXT: ret ptr [[DST:%.*]]
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call ptr @strcpy(ptr %dst, ptr %p5)
ret ptr %r
}
; TODO: Fold strcpy(dst, a5 + 5) to (*dst = '\0', dst).
define ptr @fold_strcpy_past_end(ptr %dst) {
; CHECK-LABEL: @fold_strcpy_past_end(
; CHECK-NEXT: ret ptr [[DST:%.*]]
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call ptr @strcpy(ptr %dst, ptr %p5)
ret ptr %r
}
; TODO: Fold stpncpy(dst, a5 + 5, 5) to (memset(dst, 0, 5), dst + 5).
define ptr @fold_stpncpy_past_end(ptr %dst) {
; CHECK-LABEL: @fold_stpncpy_past_end(
; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
; CHECK-NEXT: ret ptr [[DST]]
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
ret ptr %r
}
; TODO: Fold strncpy(dst, a5 + 5, 5) to memset(dst, 0, 5).
define ptr @fold_strncpy_past_end(ptr %dst) {
; CHECK-LABEL: @fold_strncpy_past_end(
; CHECK-NEXT: call void @llvm.memset.p0.i64(ptr noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
; CHECK-NEXT: ret ptr [[DST]]
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%r = call ptr @strncpy(ptr %dst, ptr %p5, i64 5)
ret ptr %r
}
; Fold strpbrk(a5, a5 + 5) (and vice versa) to null.
define void @fold_strpbrk_past_end(ptr %psub) {
; CHECK-LABEL: @fold_strpbrk_past_end(
; CHECK-NEXT: store ptr null, ptr [[PSUB:%.*]], align 8
; CHECK-NEXT: [[PS50:%.*]] = getelementptr ptr, ptr [[PSUB]], i64 1
; CHECK-NEXT: store ptr null, ptr [[PS50]], align 8
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%s05 = call ptr @strpbrk(ptr @a5, ptr %p5)
store ptr %s05, ptr %psub
%s50 = call ptr @strpbrk(ptr %p5, ptr @a5)
%ps50 = getelementptr ptr, ptr %psub, i32 1
store ptr %s50, ptr %ps50
ret void
}
; Fold strspn(a5, a5 + 5) (and vice versa) to null.
define void @fold_strspn_past_end(ptr %poff) {
; CHECK-LABEL: @fold_strspn_past_end(
; CHECK-NEXT: store i64 0, ptr [[POFF:%.*]], align 4
; CHECK-NEXT: [[PO50:%.*]] = getelementptr i64, ptr [[POFF]], i64 1
; CHECK-NEXT: store i64 0, ptr [[PO50]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%o05 = call i64 @strspn(ptr @a5, ptr %p5)
store i64 %o05, ptr %poff
%o50 = call i64 @strspn(ptr %p5, ptr @a5)
%po50 = getelementptr i64, ptr %poff, i32 1
store i64 %o50, ptr %po50
ret void
}
; Fold strcspn(a5, a5 + 5) (and vice versa) to null.
define void @fold_strcspn_past_end(ptr %poff) {
; CHECK-LABEL: @fold_strcspn_past_end(
; CHECK-NEXT: store i64 2, ptr [[POFF:%.*]], align 4
; CHECK-NEXT: [[PO50:%.*]] = getelementptr i64, ptr [[POFF]], i64 1
; CHECK-NEXT: store i64 0, ptr [[PO50]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%o05 = call i64 @strcspn(ptr @a5, ptr %p5)
store i64 %o05, ptr %poff
%o50 = call i64 @strcspn(ptr %p5, ptr @a5)
%po50 = getelementptr i64, ptr %poff, i32 1
store i64 %o50, ptr %po50
ret void
}
; TODO: Fold the 32-bit atoi(a5 + 5) to zero.
; Verify that processing the invalid call doesn't run into trouble.
define i32 @fold_atoi_past_end() {
; CHECK-LABEL: @fold_atoi_past_end(
; CHECK-NEXT: [[I:%.*]] = call i32 @atoi(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
; CHECK-NEXT: ret i32 [[I]]
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%i = call i32 @atoi(ptr %p5)
ret i32 %i
}
; TODO: Likewise, fold the 64-bit atol(a5 + 5) to zero, and similarly
; for atoll and strtrol and similar.
; Verify that processing the invalid call doesn't run into trouble.
define void @fold_atol_strtol_past_end(ptr %ps) {
; CHECK-LABEL: @fold_atol_strtol_past_end(
; CHECK-NEXT: [[I0:%.*]] = call i64 @atol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
; CHECK-NEXT: store i64 [[I0]], ptr [[PS:%.*]], align 4
; CHECK-NEXT: [[I1:%.*]] = call i64 @atoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
; CHECK-NEXT: [[P1:%.*]] = getelementptr i64, ptr [[PS]], i64 1
; CHECK-NEXT: store i64 [[I1]], ptr [[P1]], align 4
; CHECK-NEXT: [[I2:%.*]] = call i64 @strtol(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 0)
; CHECK-NEXT: [[P2:%.*]] = getelementptr i64, ptr [[PS]], i64 2
; CHECK-NEXT: store i64 [[I2]], ptr [[P2]], align 4
; CHECK-NEXT: [[I3:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 8)
; CHECK-NEXT: [[P3:%.*]] = getelementptr i64, ptr [[PS]], i64 3
; CHECK-NEXT: store i64 [[I3]], ptr [[P3]], align 4
; CHECK-NEXT: [[I4:%.*]] = call i64 @strtoll(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 10)
; CHECK-NEXT: [[P4:%.*]] = getelementptr i64, ptr [[PS]], i64 4
; CHECK-NEXT: store i64 [[I4]], ptr [[P4]], align 4
; CHECK-NEXT: [[I5:%.*]] = call i64 @strtoul(ptr nocapture nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0), ptr null, i32 16)
; CHECK-NEXT: [[P5:%.*]] = getelementptr i64, ptr [[PS]], i64 5
; CHECK-NEXT: store i64 [[I5]], ptr [[P5]], align 4
; CHECK-NEXT: ret void
;
%pa5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%i0 = call i64 @atol(ptr %pa5)
store i64 %i0, ptr %ps
%i1 = call i64 @atoll(ptr %pa5)
%p1 = getelementptr i64, ptr %ps, i32 1
store i64 %i1, ptr %p1
%i2 = call i64 @strtol(ptr %pa5, ptr null, i32 0)
%p2 = getelementptr i64, ptr %ps, i32 2
store i64 %i2, ptr %p2
%i3 = call i64 @strtoul(ptr %pa5, ptr null, i32 8)
%p3 = getelementptr i64, ptr %ps, i32 3
store i64 %i3, ptr %p3
%i4 = call i64 @strtoll(ptr %pa5, ptr null, i32 10)
%p4 = getelementptr i64, ptr %ps, i32 4
store i64 %i4, ptr %p4
%i5 = call i64 @strtoul(ptr %pa5, ptr null, i32 16)
%p5 = getelementptr i64, ptr %ps, i32 5
store i64 %i5, ptr %p5
ret void
}
; Fold sprintf(dst, a5 + 5) to zero, and also
; TODO: fold sprintf(dst, "%s", a5 + 5) to zero.
define void @fold_sprintf_past_end(ptr %pcnt, ptr %dst) {
; CHECK-LABEL: @fold_sprintf_past_end(
; CHECK-NEXT: store i32 0, ptr [[PCNT:%.*]], align 4
; CHECK-NEXT: [[PN05:%.*]] = getelementptr i32, ptr [[PCNT]], i64 1
; CHECK-NEXT: store i32 0, ptr [[PN05]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%n5_ = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr %p5)
store i32 %n5_, ptr %pcnt
%n05 = call i32 (ptr, ptr, ...) @sprintf(ptr %dst, ptr @a5, ptr %p5)
%pn05 = getelementptr i32, ptr %pcnt, i32 1
store i32 %n05, ptr %pn05
ret void
}
; Fold snprintf(dst, n, a5 + 5) to zero, and also
; TODO: fold snprintf(dst, n, "%s", a5 + 5) to zero.
define void @fold_snprintf_past_end(ptr %pcnt, ptr %dst, i64 %n) {
; CHECK-LABEL: @fold_snprintf_past_end(
; CHECK-NEXT: [[N5_:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST:%.*]], i64 [[N:%.*]], ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
; CHECK-NEXT: store i32 [[N5_]], ptr [[PCNT:%.*]], align 4
; CHECK-NEXT: [[N05:%.*]] = call i32 (ptr, i64, ptr, ...) @snprintf(ptr [[DST]], i64 [[N]], ptr nonnull @a5, ptr nonnull getelementptr inbounds ([5 x i8], ptr @a5, i64 1, i64 0))
; CHECK-NEXT: [[PN05:%.*]] = getelementptr i32, ptr [[PCNT]], i64 1
; CHECK-NEXT: store i32 [[N05]], ptr [[PN05]], align 4
; CHECK-NEXT: ret void
;
%p5 = getelementptr [5 x i8], ptr @a5, i32 0, i32 5
%n5_ = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr %p5)
store i32 %n5_, ptr %pcnt
%n05 = call i32 (ptr, i64, ptr, ...) @snprintf(ptr %dst, i64 %n, ptr @a5, ptr %p5)
%pn05 = getelementptr i32, ptr %pcnt, i32 1
store i32 %n05, ptr %pn05
ret void
}
|
