commit 3692f251990ecb063bb9a3f8af1f820782be9973
author David Srbecky <dsrbecky@google.com> Thu Mar 08 16:57:19 2018 +0000
committer Christopher Ferris <cferris@google.com> Thu Mar 08 14:44:11 2018 -0800
tree 3c3df3a4f24d3bd2afb5a171de9953c13cccff44
parent 929112bcd19e92c9b9f647d8a227ba55c743239d

Don't implicitly dereference DW_CFA_def_cfa_expression.

The specification isn't entirely clear. Follow the gdb interpretation.

Bug: 73954823
Test: libunwindstack_test
Change-Id: If72717f54eed84e442f43af19e615143a9796b68

libunwindstack/tests/DwarfCfaTest.cpp

diff --git a/libunwindstack/tests/DwarfCfaTest.cpp b/libunwindstack/tests/DwarfCfaTest.cpp
index 68dc30c..7395b04 100644
--- a/libunwindstack/tests/DwarfCfaTest.cpp
+++ b/libunwindstack/tests/DwarfCfaTest.cpp
@@ -737,6 +737,8 @@
   ASSERT_TRUE(this->cfa_->GetLocationInfo(this->fde_.pc_start, 0x200, 0x284, &loc_regs));
   ASSERT_EQ(0x284U, this->dmem_->cur_offset());
   ASSERT_EQ(1U, loc_regs.size());
+  ASSERT_EQ(DWARF_LOCATION_VAL_EXPRESSION, loc_regs[CFA_REG].type);
+  ASSERT_EQ(0x81U, loc_regs[CFA_REG].values[0]);
 
   ASSERT_EQ("", GetFakeLogPrint());
   ASSERT_EQ("", GetFakeLogBuf());

libunwindstack/tests/DwarfSectionImplTest.cpp

diff --git a/libunwindstack/tests/DwarfSectionImplTest.cpp b/libunwindstack/tests/DwarfSectionImplTest.cpp
index 37305b2..99f4d87 100644
--- a/libunwindstack/tests/DwarfSectionImplTest.cpp
+++ b/libunwindstack/tests/DwarfSectionImplTest.cpp
@@ -99,7 +99,7 @@
   regs.set_sp(0x2000);
   regs[5] = 0x20;
   regs[9] = 0x3000;
-  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_EXPRESSION, {0x2, 0x5002}};
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_VAL_EXPRESSION, {0x2, 0x5002}};
   bool finished;
   ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
   EXPECT_EQ(DWARF_ERROR_MEMORY_INVALID, this->section_->LastErrorCode());
@@ -116,7 +116,7 @@
   regs[5] = 0x20;
   regs[9] = 0x3000;
   this->memory_.SetMemory(0x5000, std::vector<uint8_t>{0x96, 0x96, 0x96});
-  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_EXPRESSION, {0x2, 0x5002}};
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_VAL_EXPRESSION, {0x2, 0x5002}};
   bool finished;
   ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
   EXPECT_EQ(DWARF_ERROR_ILLEGAL_STATE, this->section_->LastErrorCode());
@@ -136,10 +136,8 @@
   this->memory_.SetMemory(0x80000000, &cfa_value, sizeof(cfa_value));
   loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_EXPRESSION, {0x4, 0x5004}};
   bool finished;
-  ASSERT_TRUE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
-  EXPECT_FALSE(finished);
-  EXPECT_EQ(0x12345U, regs.sp());
-  EXPECT_EQ(0x20U, regs.pc());
+  ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
+  EXPECT_EQ(DWARF_ERROR_ILLEGAL_VALUE, this->section_->LastErrorCode());
 }
 
 TYPED_TEST_P(DwarfSectionImplTest, Eval_cfa_val_expr) {
@@ -170,7 +168,7 @@
   regs[5] = 0x20;
   regs[9] = 0x3000;
   this->memory_.SetMemory(0x5000, std::vector<uint8_t>{0x50, 0x96, 0x96});
-  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_EXPRESSION, {0x2, 0x5002}};
+  loc_regs[CFA_REG] = DwarfLocation{DWARF_LOCATION_VAL_EXPRESSION, {0x2, 0x5002}};
   bool finished;
   ASSERT_FALSE(this->section_->Eval(&cie, &this->memory_, loc_regs, &regs, &finished));
   EXPECT_EQ(DWARF_ERROR_NOT_IMPLEMENTED, this->section_->LastErrorCode());