forked from Imagelibrary/binutils-gdb
b6fc91c70a
Basic ambiguity detection assumes that when 2 fields with the same name
have the same byte offset, it must be an unambiguous request. This is not
always correct. Consider the following code:
class empty { };
class A {
public:
[[no_unique_address]] empty e;
};
class B {
public:
int e;
};
class C: public A, public B { };
if we tried to use c.e in code, the compiler would warn of an ambiguity,
however, since A::e does not demand an unique address, it gets the same
address (and thus byte offset) of the members, making A::e and B::e have the
same address. however, "print c.e" would fail to report the ambiguity,
and would instead print it as an empty class (first path found).
The new code solves this by checking for other found_fields that have
different m_struct_path.back() (final class that the member was found
in), despite having the same byte offset.
The testcase gdb.cp/ambiguous.exp was also changed to test for this
behavior.
gdb/ChangeLog:
PR gdb/28480
* valops.c (struct_field_searcher::update_result): Improve
ambiguous member detection.
gdb/testsuite/ChangeLog:
PR gdb/28480
Pushed by Joel Brobecker <brobecker@adacore.com>
* gdb.cp/ambiguous.cc: Add code to permit ambiguous member testing.
* gdb.cp/ambiguous.exp: Add ambiguous member test.
(cherry picked from commit a41ad3474c)
197 lines
2.2 KiB
C++
197 lines
2.2 KiB
C++
class empty { };
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class A1 {
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public:
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int x;
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int y;
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};
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class A2 {
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public:
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int x;
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int y;
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};
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class A3 {
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public:
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int x;
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int y;
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};
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#if !defined (__GNUC__) || __GNUC__ > 7
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# define NO_UNIQUE_ADDRESS [[no_unique_address]]
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#else
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# define NO_UNIQUE_ADDRESS
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#endif
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class A4 {
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public:
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NO_UNIQUE_ADDRESS empty x;
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};
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class X : public A1, public A2 {
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public:
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int z;
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};
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class L : public A1 {
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public:
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int z;
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};
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class LV : public virtual A1 {
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public:
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int z;
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};
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class M : public A2 {
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public:
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int w;
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};
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class N : public L, public M {
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public:
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int r;
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};
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class K : public A1 {
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public:
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int i;
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};
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class KV : public virtual A1 {
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public:
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int i;
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};
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class J : public K, public L {
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public:
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int j;
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};
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class JV : public KV, public LV {
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public:
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int jv;
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};
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class JVA1 : public KV, public LV, public A1 {
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public:
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int jva1;
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};
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class JVA2 : public KV, public LV, public A2 {
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public:
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int jva2;
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};
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class JVA1V : public KV, public LV, public virtual A1 {
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public:
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int jva1v;
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};
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class JE : public A1, public A4 {
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public:
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};
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int main()
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{
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A1 a1;
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A2 a2;
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A3 a3;
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X x;
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L l;
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M m;
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N n;
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K k;
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J j;
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JV jv;
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JVA1 jva1;
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JVA2 jva2;
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JVA1V jva1v;
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JE je;
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int i;
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i += k.i + m.w + a1.x + a2.x + a3.x + x.z + l.z + n.r + j.j;
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/* Initialize all the fields. Keep the order the same as in the
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.exp file. */
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a1.x = 1;
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a1.y = 2;
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a2.x = 1;
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a2.y = 2;
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a3.x = 1;
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a3.y = 2;
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x.A1::x = 1;
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x.A1::y = 2;
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x.A2::x = 3;
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x.A2::y = 4;
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x.z = 5;
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l.x = 1;
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l.y = 2;
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l.z = 3;
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m.x = 1;
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m.y = 2;
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m.w = 3;
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n.A1::x = 1;
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n.A1::y = 2;
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n.A2::x = 3;
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n.A2::y = 4;
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n.w = 5;
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n.r = 6;
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n.z = 7;
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k.x = 1;
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k.y = 2;
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k.i = 3;
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j.K::x = 1;
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j.K::y = 2;
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j.L::x = 3;
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j.L::y = 4;
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j.i = 5;
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j.z = 6;
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j.j = 7;
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jv.x = 1;
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jv.y = 2;
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jv.i = 3;
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jv.z = 4;
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jv.jv = 5;
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jva1.KV::x = 1;
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jva1.KV::y = 2;
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jva1.LV::x = 3;
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jva1.LV::y = 4;
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jva1.z = 5;
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jva1.i = 6;
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jva1.jva1 = 7;
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jva2.KV::x = 1;
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jva2.KV::y = 2;
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jva2.LV::x = 3;
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jva2.LV::y = 4;
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jva2.A2::x = 5;
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jva2.A2::y = 6;
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jva2.z = 7;
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jva2.i = 8;
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jva2.jva2 = 9;
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jva1v.x = 1;
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jva1v.y = 2;
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jva1v.z = 3;
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jva1v.i = 4;
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jva1v.jva1v = 5;
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je.A1::x = 1;
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return 0; /* set breakpoint here */
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}
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