From 01ef53a090c4ccdc5c1c68bf705c2a0e8f90bba0 Mon Sep 17 00:00:00 2001 From: Christoffer Lerno Date: Wed, 18 Jun 2025 10:13:48 +0200 Subject: [PATCH] Bug when offsetting pointers of large structs using ++ and --. --- releasenotes.md | 1 + src/compiler/llvm_codegen_expr.c | 2 +- test/test_suite/clang/2002-07.c3t | 20 ++++----- test/test_suite/expressions/big_incdec.c3t | 51 ++++++++++++++++++++++ test/test_suite/expressions/incdec.c3t | 4 +- 5 files changed, 65 insertions(+), 13 deletions(-) create mode 100644 test/test_suite/expressions/big_incdec.c3t diff --git a/releasenotes.md b/releasenotes.md index e0639529f..43ae2896f 100644 --- a/releasenotes.md +++ b/releasenotes.md @@ -48,6 +48,7 @@ - `$defined(#expr)` broken with binary. #2219 - Method ambiguity when importing parent module publicly in private submodule. #2208 - Linker errors when shadowing @local with public function #2198 +- Bug when offsetting pointers of large structs using ++ and --. ### Stdlib changes - Deprecate `String.is_zstr` and `String.quick_zstr` #2188. diff --git a/src/compiler/llvm_codegen_expr.c b/src/compiler/llvm_codegen_expr.c index bf01a5f7e..f9f4c679c 100644 --- a/src/compiler/llvm_codegen_expr.c +++ b/src/compiler/llvm_codegen_expr.c @@ -2015,7 +2015,7 @@ static inline LLVMValueRef llvm_emit_inc_dec_value(GenContext *c, SourceSpan spa case TYPE_POINTER: { // Use byte here, we don't need a big offset. - LLVMValueRef add = LLVMConstInt(diff < 0 ? llvm_get_type(c, type_ichar) : llvm_get_type(c, type_char), (unsigned long long)diff, diff < 0); + LLVMValueRef add = LLVMConstInt(diff < 0 ? llvm_get_type(c, type_isz) : llvm_get_type(c, type_usz), (unsigned long long)diff, diff < 0); return llvm_emit_pointer_gep_raw(c, llvm_get_pointee_type(c, type), original->value, add); } case ALL_FLOATS: diff --git a/test/test_suite/clang/2002-07.c3t b/test/test_suite/clang/2002-07.c3t index 81fa00d89..f643d032b 100644 --- a/test/test_suite/clang/2002-07.c3t +++ b/test/test_suite/clang/2002-07.c3t @@ -920,10 +920,10 @@ entry: loop.cond: ; preds = %loop.body, %entry %2 = load ptr, ptr %s1, align 8 - %ptradd_any = getelementptr i8, ptr %2, i8 1 + %ptradd_any = getelementptr i8, ptr %2, i64 1 store ptr %ptradd_any, ptr %s1, align 8 %3 = load ptr, ptr %s2, align 8 - %ptradd_any1 = getelementptr i8, ptr %3, i8 1 + %ptradd_any1 = getelementptr i8, ptr %3, i64 1 store ptr %ptradd_any1, ptr %s2, align 8 %4 = load i8, ptr %3, align 1 store i8 %4, ptr %2, align 1 @@ -948,7 +948,7 @@ entry: loop.cond: ; preds = %loop.body, %entry %2 = load ptr, ptr %s1, align 8 - %ptradd_any = getelementptr i8, ptr %2, i8 1 + %ptradd_any = getelementptr i8, ptr %2, i64 1 store ptr %ptradd_any, ptr %s1, align 8 %3 = load i8, ptr %2, align 1 %i2b = icmp ne i8 %3, 0 @@ -959,16 +959,16 @@ loop.body: ; preds = %loop.cond loop.exit: ; preds = %loop.cond %4 = load ptr, ptr %s1, align 8 - %ptradd_any1 = getelementptr i8, ptr %4, i8 -1 + %ptradd_any1 = getelementptr i8, ptr %4, i64 -1 store ptr %ptradd_any1, ptr %s1, align 8 br label %loop.cond2 loop.cond2: ; preds = %loop.body6, %loop.exit %5 = load ptr, ptr %s1, align 8 - %ptradd_any3 = getelementptr i8, ptr %5, i8 1 + %ptradd_any3 = getelementptr i8, ptr %5, i64 1 store ptr %ptradd_any3, ptr %s1, align 8 %6 = load ptr, ptr %s2, align 8 - %ptradd_any4 = getelementptr i8, ptr %6, i8 1 + %ptradd_any4 = getelementptr i8, ptr %6, i64 1 store ptr %ptradd_any4, ptr %s2, align 8 %7 = load i8, ptr %6, align 1 store i8 %7, ptr %5, align 1 @@ -993,11 +993,11 @@ entry: loop.cond: ; preds = %loop.body, %entry %2 = load ptr, ptr %s1, align 8 - %ptradd_any = getelementptr i8, ptr %2, i8 1 + %ptradd_any = getelementptr i8, ptr %2, i64 1 store ptr %ptradd_any, ptr %s1, align 8 %3 = load i8, ptr %2, align 1 %4 = load ptr, ptr %s2, align 8 - %ptradd_any1 = getelementptr i8, ptr %4, i8 1 + %ptradd_any1 = getelementptr i8, ptr %4, i64 1 store ptr %ptradd_any1, ptr %s2, align 8 %5 = load i8, ptr %4, align 1 %eq = icmp eq i8 %3, %5 @@ -1038,12 +1038,12 @@ if.then9: ; preds = %if.else6 if.else10: ; preds = %if.else6 %12 = load ptr, ptr %s1, align 8 - %ptradd_any11 = getelementptr i8, ptr %12, i8 -1 + %ptradd_any11 = getelementptr i8, ptr %12, i64 -1 store ptr %ptradd_any11, ptr %s1, align 8 %13 = load i8, ptr %ptradd_any11, align 1 %zext12 = zext i8 %13 to i32 %14 = load ptr, ptr %s2, align 8 - %ptradd_any13 = getelementptr i8, ptr %14, i8 -1 + %ptradd_any13 = getelementptr i8, ptr %14, i64 -1 store ptr %ptradd_any13, ptr %s2, align 8 %15 = load i8, ptr %ptradd_any13, align 1 %zext14 = zext i8 %15 to i32 diff --git a/test/test_suite/expressions/big_incdec.c3t b/test/test_suite/expressions/big_incdec.c3t new file mode 100644 index 000000000..b537d8d12 --- /dev/null +++ b/test/test_suite/expressions/big_incdec.c3t @@ -0,0 +1,51 @@ +// #target: macos-x64 +module test; +const FOO_SIZE = 500; + +alias Foo = char[FOO_SIZE]; + +fn int main(String[] args) +{ + const NUM = 10; + + Foo* x = calloc(Foo.sizeof * NUM); + for (int i = 0; i < 10; i++) + { + ++x; + } + return 0; +} + +/* #expect: test.ll + + +define i32 @test.main(ptr %0, i64 %1) #0 { +entry: + %args = alloca %"char[][]", align 8 + %x = alloca ptr, align 8 + %i = alloca i32, align 4 + store ptr %0, ptr %args, align 8 + %ptradd = getelementptr inbounds i8, ptr %args, i64 8 + store i64 %1, ptr %ptradd, align 8 + %2 = call ptr @std.core.mem.calloc(i64 5000) #3 + store ptr %2, ptr %x, align 8 + store i32 0, ptr %i, align 4 + br label %loop.cond + +loop.cond: ; preds = %loop.body, %entry + %3 = load i32, ptr %i, align 4 + %lt = icmp slt i32 %3, 10 + br i1 %lt, label %loop.body, label %loop.exit + +loop.body: ; preds = %loop.cond + %4 = load ptr, ptr %x, align 8 + %ptradd_any = getelementptr i8, ptr %4, i64 500 + store ptr %ptradd_any, ptr %x, align 8 + %5 = load i32, ptr %i, align 4 + %add = add i32 %5, 1 + store i32 %add, ptr %i, align 4 + br label %loop.cond + +loop.exit: ; preds = %loop.cond + ret i32 0 +} diff --git a/test/test_suite/expressions/incdec.c3t b/test/test_suite/expressions/incdec.c3t index 04fc6b6c9..9451081ab 100644 --- a/test/test_suite/expressions/incdec.c3t +++ b/test/test_suite/expressions/incdec.c3t @@ -20,10 +20,10 @@ fn void test(int* foo) %z = alloca float, align 4 store ptr %0, ptr %foo, align 8 %1 = load ptr, ptr %foo, align 8 - %ptradd_any = getelementptr i8, ptr %1, i8 4 + %ptradd_any = getelementptr i8, ptr %1, i64 4 store ptr %ptradd_any, ptr %foo, align 8 %2 = load ptr, ptr %foo, align 8 - %ptradd_any1 = getelementptr i8, ptr %2, i8 -4 + %ptradd_any1 = getelementptr i8, ptr %2, i64 -4 store ptr %ptradd_any1, ptr %foo, align 8 store i32 10, ptr %y, align 4 %3 = load i32, ptr %y, align 4