test/Transforms/InstCombine/strcall-no-nul.ll

; 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 i8* @strchr(i8*, i32)
declare i8* @strrchr(i8*, i32)
declare i32 @strcmp(i8*, i8*)
declare i32 @strncmp(i8*, i8*, i64)
declare i8* @strstr(i8*, i8*)

declare i8* @stpcpy(i8*, i8*)
declare i8* @strcpy(i8*, i8*)
declare i8* @stpncpy(i8*, i8*, i64)
declare i8* @strncpy(i8*, i8*, i64)

declare i64 @strlen(i8*)
declare i64 @strnlen(i8*, i64)

declare i8* @strpbrk(i8*, i8*)

declare i64 @strspn(i8*, i8*)
declare i64 @strcspn(i8*, i8*)

declare i32 @atoi(i8*)
declare i64 @atol(i8*)
declare i64 @atoll(i8*)
declare i64 @strtol(i8*, i8**, i32)
declare i64 @strtoll(i8*, i8**, i32)
declare i64 @strtoul(i8*, i8**, i32)
declare i64 @strtoull(i8*, i8**, i32)

declare i32 @sprintf(i8*, i8*, ...)
declare i32 @snprintf(i8*, i64, i8*, ...)


@a5 = constant [5 x i8] c"%s\0045";


; Fold strchr(a5 + 5, '\0') to null.

define i8* @fold_strchr_past_end() {
; CHECK-LABEL: @fold_strchr_past_end(
; CHECK-NEXT:    ret i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0)
;
  %p = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %q = call i8* @strchr(i8* %p, i32 0)
  ret i8* %q
}

; Fold strcmp(a5, a5 + 5) (and vice versa) to null.

define void @fold_strcmp_past_end(i32* %pcmp) {
; CHECK-LABEL: @fold_strcmp_past_end(
; CHECK-NEXT:    store i32 1, i32* [[PCMP:%.*]], align 4
; CHECK-NEXT:    [[PC50:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
; CHECK-NEXT:    store i32 -1, i32* [[PC50]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %c05 = call i32 @strcmp(i8* %p0, i8* %p5)
  %pc05 = getelementptr i32, i32* %pcmp, i32 0
  store i32 %c05, i32* %pc05

  %c50 = call i32 @strcmp(i8* %p5, i8* %p0)
  %pc50 = getelementptr i32, i32* %pcmp, i32 1
  store i32 %c50, i32* %pc50

  ret void
}


; Likewise, fold strncmp(a5, a5 + 5, 5) (and vice versa) to null.

define void @fold_strncmp_past_end(i32* %pcmp) {
; CHECK-LABEL: @fold_strncmp_past_end(
; CHECK-NEXT:    store i32 1, i32* [[PCMP:%.*]], align 4
; CHECK-NEXT:    [[PC50:%.*]] = getelementptr i32, i32* [[PCMP]], i64 1
; CHECK-NEXT:    store i32 -1, i32* [[PC50]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %c05 = call i32 @strncmp(i8* %p0, i8* %p5, i64 5)
  %pc05 = getelementptr i32, i32* %pcmp, i32 0
  store i32 %c05, i32* %pc05

  %c50 = call i32 @strncmp(i8* %p5, i8* %p0, i64 5)
  %pc50 = getelementptr i32, i32* %pcmp, i32 1
  store i32 %c50, i32* %pc50

  ret void
}


; Fold strrchr(a5 + 5, '\0') to poison (it's UB).

define i8* @fold_strrchr_past_end(i32 %c) {
; CHECK-LABEL: @fold_strrchr_past_end(
; CHECK-NEXT:    ret i8* poison
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %r = call i8* @strrchr(i8* %p5, i32 0)
  ret i8* %r
}


; Fold strstr(a5 + 5, a5) (and vice versa) to null.

define void @fold_strstr_past_end(i8** %psub) {
; CHECK-LABEL: @fold_strstr_past_end(
; CHECK-NEXT:    store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 0, i64 0), i8** [[PSUB:%.*]], align 8
; CHECK-NEXT:    [[PS50:%.*]] = getelementptr i8*, i8** [[PSUB]], i64 1
; CHECK-NEXT:    store i8* null, i8** [[PS50]], align 8
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %s05 = call i8* @strstr(i8* %p0, i8* %p5)
  %ps05 = getelementptr i8*, i8** %psub, i32 0
  store i8* %s05, i8** %ps05

  %s50 = call i8* @strstr(i8* %p5, i8* %p0)
  %ps50 = getelementptr i8*, i8** %psub, i32 1
  store i8* %s50, i8** %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], [5 x i8]* @a5, i32 0, i32 5
  %r = call i64 @strlen(i8* %p5)
  ret i64 %r
}


; TODO: Fold stpcpy(dst, a5 + 5) to (*dst = '\0', dst).

define i8* @fold_stpcpy_past_end(i8* %dst) {
; CHECK-LABEL: @fold_stpcpy_past_end(
; CHECK-NEXT:    ret i8* [[DST:%.*]]
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %r = call i8* @strcpy(i8* %dst, i8* %p5)
  ret i8* %r
}


; TODO: Fold strcpy(dst, a5 + 5) to (*dst = '\0', dst).

define i8* @fold_strcpy_past_end(i8* %dst) {
; CHECK-LABEL: @fold_strcpy_past_end(
; CHECK-NEXT:    ret i8* [[DST:%.*]]
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %r = call i8* @strcpy(i8* %dst, i8* %p5)
  ret i8* %r
}


; TODO: Fold stpncpy(dst, a5 + 5, 5) to (memset(dst, 0, 5), dst + 5).

define i8* @fold_stpncpy_past_end(i8* %dst) {
; CHECK-LABEL: @fold_stpncpy_past_end(
; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
; CHECK-NEXT:    ret i8* [[DST]]
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %r = call i8* @strncpy(i8* %dst, i8* %p5, i64 5)
  ret i8* %r
}


; TODO: Fold strncpy(dst, a5 + 5, 5) to memset(dst, 0, 5).

define i8* @fold_strncpy_past_end(i8* %dst) {
; CHECK-LABEL: @fold_strncpy_past_end(
; CHECK-NEXT:    call void @llvm.memset.p0i8.i64(i8* noundef nonnull align 1 dereferenceable(5) [[DST:%.*]], i8 0, i64 5, i1 false)
; CHECK-NEXT:    ret i8* [[DST]]
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %r = call i8* @strncpy(i8* %dst, i8* %p5, i64 5)
  ret i8* %r
}


; Fold strpbrk(a5, a5 + 5) (and vice versa) to null.

define void @fold_strpbrk_past_end(i8** %psub) {
; CHECK-LABEL: @fold_strpbrk_past_end(
; CHECK-NEXT:    store i8* null, i8** [[PSUB:%.*]], align 8
; CHECK-NEXT:    [[PS50:%.*]] = getelementptr i8*, i8** [[PSUB]], i64 1
; CHECK-NEXT:    store i8* null, i8** [[PS50]], align 8
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %s05 = call i8* @strpbrk(i8* %p0, i8* %p5)
  %ps05 = getelementptr i8*, i8** %psub, i32 0
  store i8* %s05, i8** %ps05

  %s50 = call i8* @strpbrk(i8* %p5, i8* %p0)
  %ps50 = getelementptr i8*, i8** %psub, i32 1
  store i8* %s50, i8** %ps50

  ret void
}


; Fold strspn(a5, a5 + 5) (and vice versa) to null.

define void @fold_strspn_past_end(i64* %poff) {
; CHECK-LABEL: @fold_strspn_past_end(
; CHECK-NEXT:    store i64 0, i64* [[POFF:%.*]], align 4
; CHECK-NEXT:    [[PO50:%.*]] = getelementptr i64, i64* [[POFF]], i64 1
; CHECK-NEXT:    store i64 0, i64* [[PO50]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %o05 = call i64 @strspn(i8* %p0, i8* %p5)
  %po05 = getelementptr i64, i64* %poff, i32 0
  store i64 %o05, i64* %po05

  %o50 = call i64 @strspn(i8* %p5, i8* %p0)
  %po50 = getelementptr i64, i64* %poff, i32 1
  store i64 %o50, i64* %po50

  ret void
}


; Fold strcspn(a5, a5 + 5) (and vice versa) to null.

define void @fold_strcspn_past_end(i64* %poff) {
; CHECK-LABEL: @fold_strcspn_past_end(
; CHECK-NEXT:    store i64 2, i64* [[POFF:%.*]], align 4
; CHECK-NEXT:    [[PO50:%.*]] = getelementptr i64, i64* [[POFF]], i64 1
; CHECK-NEXT:    store i64 0, i64* [[PO50]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %o05 = call i64 @strcspn(i8* %p0, i8* %p5)
  %po05 = getelementptr i64, i64* %poff, i32 0
  store i64 %o05, i64* %po05

  %o50 = call i64 @strcspn(i8* %p5, i8* %p0)
  %po50 = getelementptr i64, i64* %poff, i32 1
  store i64 %o50, i64* %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(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0))
; CHECK-NEXT:    ret i32 [[I]]
;
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5
  %i = call i32 @atoi(i8* %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(i64* %ps) {
; CHECK-LABEL: @fold_atol_strtol_past_end(
; CHECK-NEXT:    [[I0:%.*]] = call i64 @atol(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0))
; CHECK-NEXT:    store i64 [[I0]], i64* [[PS:%.*]], align 4
; CHECK-NEXT:    [[I1:%.*]] = call i64 @atoll(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0))
; CHECK-NEXT:    [[P1:%.*]] = getelementptr i64, i64* [[PS]], i64 1
; CHECK-NEXT:    store i64 [[I1]], i64* [[P1]], align 4
; CHECK-NEXT:    [[I2:%.*]] = call i64 @strtol(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0), i8** null, i32 0)
; CHECK-NEXT:    [[P2:%.*]] = getelementptr i64, i64* [[PS]], i64 2
; CHECK-NEXT:    store i64 [[I2]], i64* [[P2]], align 4
; CHECK-NEXT:    [[I3:%.*]] = call i64 @strtoul(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0), i8** null, i32 8)
; CHECK-NEXT:    [[P3:%.*]] = getelementptr i64, i64* [[PS]], i64 3
; CHECK-NEXT:    store i64 [[I3]], i64* [[P3]], align 4
; CHECK-NEXT:    [[I4:%.*]] = call i64 @strtoll(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0), i8** null, i32 10)
; CHECK-NEXT:    [[P4:%.*]] = getelementptr i64, i64* [[PS]], i64 4
; CHECK-NEXT:    store i64 [[I4]], i64* [[P4]], align 4
; CHECK-NEXT:    [[I5:%.*]] = call i64 @strtoul(i8* nocapture getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0), i8** null, i32 16)
; CHECK-NEXT:    [[P5:%.*]] = getelementptr i64, i64* [[PS]], i64 5
; CHECK-NEXT:    store i64 [[I5]], i64* [[P5]], align 4
; CHECK-NEXT:    ret void
;
  %pa5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %i0 = call i64 @atol(i8* %pa5)
  %p0 = getelementptr i64, i64* %ps, i32 0
  store i64 %i0, i64* %p0

  %i1 = call i64 @atoll(i8* %pa5)
  %p1 = getelementptr i64, i64* %ps, i32 1
  store i64 %i1, i64* %p1

  %i2 = call i64 @strtol(i8* %pa5, i8** null, i32 0)
  %p2 = getelementptr i64, i64* %ps, i32 2
  store i64 %i2, i64* %p2

  %i3 = call i64 @strtoul(i8* %pa5, i8** null, i32 8)
  %p3 = getelementptr i64, i64* %ps, i32 3
  store i64 %i3, i64* %p3

  %i4 = call i64 @strtoll(i8* %pa5, i8** null, i32 10)
  %p4 = getelementptr i64, i64* %ps, i32 4
  store i64 %i4, i64* %p4

  %i5 = call i64 @strtoul(i8* %pa5, i8** null, i32 16)
  %p5 = getelementptr i64, i64* %ps, i32 5
  store i64 %i5, i64* %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(i32* %pcnt, i8* %dst) {
; CHECK-LABEL: @fold_sprintf_past_end(
; CHECK-NEXT:    store i32 0, i32* [[PCNT:%.*]], align 4
; CHECK-NEXT:    [[PN05:%.*]] = getelementptr i32, i32* [[PCNT]], i64 1
; CHECK-NEXT:    store i32 0, i32* [[PN05]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %n5_ = call i32 (i8*, i8*, ...) @sprintf(i8* %dst, i8* %p5)
  %pn5_ = getelementptr i32, i32* %pcnt, i32 0
  store i32 %n5_, i32* %pn5_

  %n05 = call i32 (i8*, i8*, ...) @sprintf(i8* %dst, i8* %p0, i8* %p5)
  %pn05 = getelementptr i32, i32* %pcnt, i32 1
  store i32 %n05, i32* %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(i32* %pcnt, i8* %dst, i64 %n) {
; CHECK-LABEL: @fold_snprintf_past_end(
; CHECK-NEXT:    [[N5_:%.*]] = call i32 (i8*, i64, i8*, ...) @snprintf(i8* [[DST:%.*]], i64 [[N:%.*]], i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0))
; CHECK-NEXT:    store i32 [[N5_]], i32* [[PCNT:%.*]], align 4
; CHECK-NEXT:    [[N05:%.*]] = call i32 (i8*, i64, i8*, ...) @snprintf(i8* [[DST]], i64 [[N]], i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 0, i64 0), i8* getelementptr inbounds ([5 x i8], [5 x i8]* @a5, i64 1, i64 0))
; CHECK-NEXT:    [[PN05:%.*]] = getelementptr i32, i32* [[PCNT]], i64 1
; CHECK-NEXT:    store i32 [[N05]], i32* [[PN05]], align 4
; CHECK-NEXT:    ret void
;
  %p0 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 0
  %p5 = getelementptr [5 x i8], [5 x i8]* @a5, i32 0, i32 5

  %n5_ = call i32 (i8*, i64, i8*, ...) @snprintf(i8* %dst, i64 %n, i8* %p5)
  %pn5_ = getelementptr i32, i32* %pcnt, i32 0
  store i32 %n5_, i32* %pn5_

  %n05 = call i32 (i8*, i64, i8*, ...) @snprintf(i8* %dst, i64 %n, i8* %p0, i8* %p5)
  %pn05 = getelementptr i32, i32* %pcnt, i32 1
  store i32 %n05, i32* %pn05

  ret void
}