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Merged
emilio merged 3 commits into from
Mar 11, 2020
Merged

support large integer constants #490

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7101465
avoid gcc warning by appending ULL suffix to integer literals that ar…
devietti Mar 10, 2020
8638652
ran rustfmt
devietti Mar 10, 2020
6218281
updated constant_big test case with large negative numbers
devietti Mar 11, 2020
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6 changes: 5 additions & 1 deletion src/bindgen/ir/constant.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -163,7 +163,11 @@ impl Literal {
other_code => format!(r"L'\U{:08X}'", other_code),
})),
syn::Lit::Int(ref value) => {
Ok(Literal::Expr(value.base10_digits().to_string()))
if value.base10_parse::<i64>().is_err() {
Ok(Literal::Expr(format!("{}ULL", value.base10_digits())))
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@emilio emilio Mar 11, 2020

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Hmm, what if it is negative? Do we need just LL instead?

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@devietti devietti Mar 11, 2020

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Good question - per the C/C++ spec (https://en.cppreference.com/w/cpp/language/integer_literal, the Notes section):

There are no negative integer literals. Expressions such as -1 apply the unary minus operator to the value represented by the literal, which may involve implicit type conversions.

So to export a constant that has the value of i64::min_value(), the ULL suffix is needed because the magnitude of the value is too large to fit into a signed 64-bit representation. I added this to the constant_big.rs test case.

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@emilio emilio Mar 11, 2020

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Cool, that makes sense. Thanks for the extra test!

} else {
Ok(Literal::Expr(value.base10_digits().to_string()))
}
}
syn::Lit::Float(ref value) => {
Ok(Literal::Expr(value.base10_digits().to_string()))
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12 changes: 12 additions & 0 deletions tests/expectations/both/constant_big.c
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@@ -0,0 +1,12 @@
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
12 changes: 12 additions & 0 deletions tests/expectations/both/constant_big.compat.c
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@@ -0,0 +1,12 @@
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
12 changes: 12 additions & 0 deletions tests/expectations/constant_big.c
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@@ -0,0 +1,12 @@
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
12 changes: 12 additions & 0 deletions tests/expectations/constant_big.compat.c
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@@ -0,0 +1,12 @@
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
12 changes: 12 additions & 0 deletions tests/expectations/constant_big.cpp
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#include <cstdarg>
#include <cstdint>
#include <cstdlib>
#include <new>

static const int64_t SIGNED_DOESNT_NEED_ULL_SUFFIX = -9223372036854775807;

static const int64_t SIGNED_NEEDS_ULL_SUFFIX = -9223372036854775808ULL;

static const uint64_t UNSIGNED_DOESNT_NEED_ULL_SUFFIX = 8070450532247928832;

static const uint64_t UNSIGNED_NEEDS_ULL_SUFFIX = 9223372036854775808ULL;
12 changes: 12 additions & 0 deletions tests/expectations/tag/constant_big.c
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#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
12 changes: 12 additions & 0 deletions tests/expectations/tag/constant_big.compat.c
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@@ -0,0 +1,12 @@
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>

#define SIGNED_DOESNT_NEED_ULL_SUFFIX -9223372036854775807

#define SIGNED_NEEDS_ULL_SUFFIX -9223372036854775808ULL

#define UNSIGNED_DOESNT_NEED_ULL_SUFFIX 8070450532247928832

#define UNSIGNED_NEEDS_ULL_SUFFIX 9223372036854775808ULL
8 changes: 8 additions & 0 deletions tests/rust/constant_big.rs
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pub const UNSIGNED_NEEDS_ULL_SUFFIX: u64 = 0x8000_0000_0000_0000;
pub const UNSIGNED_DOESNT_NEED_ULL_SUFFIX: u64 = 0x7000_0000_0000_0000;

// i64::min_value()
pub const SIGNED_NEEDS_ULL_SUFFIX: i64 = -9223372036854775808;

// i64::min_value() + 1
pub const SIGNED_DOESNT_NEED_ULL_SUFFIX: i64 = -9223372036854775807;