98cf3e95ce
Submitted by:
Reviewed by:
The following code illustrates a bug in the semantic analysis for assignments:
int func() {
int *P;
char *x;
P = x; // type of this assignment expression should be "int *", NOT "char *".
}
While the type checking/diagnostics are correct, the type of the assignment
expression is incorrect (which shows up during code gen). With the fix,
the llvm code looks correct...
[dylan:~/llvm/tools/clang] admin% ../../Debug/bin/clang cast.c -emit-llvm
cast.c:4:5: warning: incompatible pointer types assigning 'char *' to 'int *'
P = x; // type of assignment expression is "int *", NOT "char *".
~ ^ ~
; ModuleID = 'foo'
define i32 @func() {
entry:
%P = alloca i32* ; <i32**> [#uses=1]
%x = alloca i8* ; <i8**> [#uses=1]
%allocapt = bitcast i32 undef to i32 ; <i32> [#uses=0]
%tmp = load i8** %x ; <i8*> [#uses=1]
%conv = bitcast i8* %tmp to i32* ; <i32*> [#uses=1]
store i32* %conv, i32** %P
ret i32 undef
}
Even though the fix was simple, I decided to rename/refactor the surrounding code
to make a clearer distinction between constraint checking and conversion.
- Renamed AssignmentConversionResult -> AssignmentCheckResult.
- Renamed UsualAssignmentConversions -> CheckAssignmentConstraints.
- Changed the return type of CheckAssignmentConstraints and CheckPointerTypesForAssignment
from QualType -> AssignmentCheckResult. These routines no longer take a reference to the result (obviously).
- Changed CheckAssignmentOperands to return the correct type (with spec annotations).
llvm-svn: 39601
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