Bug 393129 - Do not give "unused symbol" warning for file-scope variable

used in an asm block

Change-Id: I2088bed2dd26af1220069dbdf18fda17d32fdf21
Signed-off-by: Nathan Ridge <zeratul976@hotmail.com>
Reviewed-on: https://git.eclipse.org/r/14608
Reviewed-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>
IP-Clean: Sergey Prigogin <eclipse.sprigogin@gmail.com>
Tested-by: Sergey Prigogin <eclipse.sprigogin@gmail.com>

2 files changed, 41 insertions, 0 deletions

diff --git a/codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/UnusedSymbolInFileScopeChecker.java b/codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/UnusedSymbolInFileScopeChecker.java
index 9c34d78659a..37a94f82168 100644
--- a/codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/UnusedSymbolInFileScopeChecker.java
+++ b/codan/org.eclipse.cdt.codan.checkers/src/org/eclipse/cdt/codan/internal/checkers/UnusedSymbolInFileScopeChecker.java
@@ -25,6 +25,7 @@ import org.eclipse.cdt.codan.core.model.IProblem;
 import org.eclipse.cdt.codan.core.model.IProblemWorkingCopy;
 import org.eclipse.cdt.codan.core.param.ListProblemPreference;
 import org.eclipse.cdt.core.dom.ast.ASTVisitor;
+import org.eclipse.cdt.core.dom.ast.IASTASMDeclaration;
 import org.eclipse.cdt.core.dom.ast.IASTDeclSpecifier;
 import org.eclipse.cdt.core.dom.ast.IASTDeclaration;
 import org.eclipse.cdt.core.dom.ast.IASTDeclarator;
@@ -226,6 +227,7 @@ public class UnusedSymbolInFileScopeChecker extends AbstractIndexAstChecker {
 			ast.accept(new ASTVisitor() {
 				{
 					shouldVisitNames = true;
+					shouldVisitDeclarations = true;
 				}
 
 				@Override
@@ -266,7 +268,36 @@ public class UnusedSymbolInFileScopeChecker extends AbstractIndexAstChecker {
 
 					return PROCESS_CONTINUE;
 				}
+				
+				@Override
+				public int visit(IASTDeclaration declaration) {
+					// Bug 393129: A variable could be used inside assembly code.
+					if (declaration instanceof IASTASMDeclaration) {
+						String assembly = ((IASTASMDeclaration) declaration).getAssembly();
+						filterOutByAssembly(externFunctionDeclarations, assembly);
+						filterOutByAssembly(staticFunctionDeclarations, assembly);
+						filterOutByAssembly(staticFunctionDefinitions, assembly);
+						filterOutByAssembly(externVariableDeclarations, assembly);
+						filterOutByAssembly(staticVariableDeclarations, assembly);
+					}
+					
+					if (!isAnyCandidate())
+						return PROCESS_ABORT;
+					
+					return PROCESS_CONTINUE;
+				}
 
+				private void filterOutByAssembly(Map<IBinding, IASTDeclarator> declarators, String assembly) {
+					Iterator<Entry<IBinding, IASTDeclarator>> iter = declarators.entrySet().iterator();
+					while (iter.hasNext()) {
+						Entry<IBinding, IASTDeclarator> entry = iter.next();
+						IASTDeclarator decl = entry.getValue();
+						IASTName astName = getAstName(decl);
+						if (assembly.contains(astName.toString()))
+							iter.remove();
+					}
+				}
+				
 				private void filterOutByPlainName(Map<IBinding, IASTDeclarator> declarators, String id) {
 					Iterator<Entry<IBinding, IASTDeclarator>> iter = declarators.entrySet().iterator();
 					while (iter.hasNext()) {
diff --git a/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/UnusedSymbolInFileScopeCheckerTest.java b/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/UnusedSymbolInFileScopeCheckerTest.java
index 7bb967ed071..4849df42719 100644
--- a/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/UnusedSymbolInFileScopeCheckerTest.java
+++ b/codan/org.eclipse.cdt.codan.core.test/src/org/eclipse/cdt/codan/core/internal/checkers/UnusedSymbolInFileScopeCheckerTest.java
@@ -317,4 +317,14 @@ public class UnusedSymbolInFileScopeCheckerTest extends CheckerTestCase {
 		loadCodeAndRun(getAboveComment());
 		checkNoErrors();
 	}
+
+	//	extern int* pxCurrentTCB;
+	//
+	//	int main() {
+	//	    asm ("lds r26, pxCurrentTCB\n\t");
+	//	}
+	public void testUseInAsm_bug393129() throws IOException {
+		loadCodeAndRun(getAboveComment());
+		checkNoErrors();
+	}
 }